Plugging member for a drain port having a portion with decreased thickness and container using the same

P-0001[0001] This application is a continuation application of application Ser. No. 09/274,319, filed on Mar. 23, 1999.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a plugging member and a container, and more particularly to a plugging member which plugs a draining port for draining a material which is contained in a container, and the container. For example, the plugging member is used to plug a draining port of a photographic processing chemicals container which contains therein photographic processing chemicals.

[0004] 2. Description of the Related Art

[0005] As an example of a conventional plugging member, a plugging sheet <b>300</b> as a plugging element which plugs a bottle is shown in FIG. 19 (see Japanese Patent Application Laid-Open (JPA) No. 8-53147).

[0006] In this plugging sheet <b>300</b>, three fan portions <b>306</b> are formed from three radial portions <b>302</b> which comprise thin portions and three circumferential portions <b>304</b> which comprise thin portions. Each of the fan portions <b>306</b> is attached to a plugging element <b>310</b> by attaching portions <b>308</b>.

[0007] When this plugging sheet <b>300</b> is pressed and perforated by a protruding portion of a perforating means which is not shown, since splits are formed from the center of the plugging sheet <b>300</b> along the radial portions <b>302</b> and then, the splits extend along the circumferential portions <b>304</b>, respectively, the plugging sheet <b>300</b> is opened over the entire cross section of the opening of the bottle.

[0008] However, in this plugging sheet <b>300</b>, since the thin portions are curved at a small radius of curvature from the radial portions <b>302</b> to the circumferential portions <b>304</b>, there may be cases in which the force which has acted upon the radial portions <b>302</b> does not extend to the circumferential portions <b>304</b>. For this reason, when the amount of pressing force excited by the perforating means is small, the splits do not extend from the tip ends of the radial portions <b>302</b> to the circumferential portions <b>304</b>, and the fan portions <b>306</b> are bent at positions indicated by a dashed line C<b>6</b> in FIG. 19. Accordingly, it is impossible to open the plugging sheet <b>300</b> over the entire cross section of the opening of the bottle. As a result, the surface area of the opening is made narrower.

[0009] This plugging sheet <b>300</b> is formed from a high polymer material or a mixture of high polymer materials. Three fan portions <b>306</b> are formed by three radial portions <b>302</b> which have a thickness of between 0.1 and 0.3 mm and by three circumferential portions <b>304</b> which have a thickness of between 0.1 and 0.3 mm, similarly to the thickness of the three radial portions <b>302</b>. The fan portions <b>306</b> are each attached to a plugging element <b>310</b> by the attaching portions <b>308</b>.

[0010] When this plugging sheet <b>300</b> is pressed and perforated by the protruding portion of a perforating means which is not shown, since splits extend from the center of the plugging sheet <b>300</b> along the radial portions <b>302</b>, and then extend along the circumferential portions <b>304</b>, the plugging sheet <b>300</b> is opened over the entire cross section of the opening of the bottle.

[0011] However, in this plugging sheet <b>300</b>, if the thicknesses of the plugging sheet <b>300</b> in the areas adjacent to the radial portions <b>302</b> and the circumferential portions <b>304</b>, each of which has a thickness of between 0.1 mm and 0.3 mm, is close to the thicknesses of the radial portions <b>302</b> and the circumferential portions <b>304</b> (if, for example, the thickness of the radial portions <b>302</b> and the circumferential portions <b>304</b> of 0.3 mm and the thickness of the fan portions <b>306</b> is 0.4 mm), a portion of the tensional force which is supposed to act upon the radial portion <b>302</b> or the circumferential portions <b>304</b> due to the pressing force from the perforating means is dispersed and acts upon the fan portions <b>306</b>. Accordingly, the fan portions <b>306</b> are thereby stretched out together with the radial portions <b>302</b> or the circumferential portions <b>304</b>. As a result, in order to perforate the plugging sheet <b>300</b>, a large amount of pressing force is needed.

SUMMARY OF THE INVENTION

[0012] In view of the aforementioned facts, it is an object of the present invention to obtain a plugging member which can open a draining port wide with a low pressing force, and a container whose draining port is plugged by this plugging member.

[0013] The first aspect of the present invention is a plugging member which plugs a draining port for draining a material which is contained in a container, comprising: a plugging plate body which is mounted in the draining port and is able to plug the draining port; and a thin portion which is formed by decreasing the thickness of the plugging plate body in portions in the thickness direction thereof, using a concave portion which is formed linearly on one end surface of the plugging plate body in the thickness direction thereof and which is formed with a predetermined width or with a width which decreases from the one end surface to the other end surface of the plugging plate body in the thickness direction thereof, wherein the thinnest portion of the thin portion has the thickness T2 which ranges from not less than 0.05 mm to not more than 0.7 mm, the surfaces which face each other and form the concave portion are in parallel with each other, or the angle θ which is formed by the facing surfaces is more than 0° and equal to or less than 120°, and the ratio (L/T2) of the thickness L of the plugging plate body to the thickness T2 is equal to or more than 2.

[0014] In the state in which the plugging member is attached to the draining port, the draining port is plugged by the plugging plate body. In this state, when the substantially central portion of the plugging plate body is pressed by the pressing means such as a bar or the like, the tensional force acts upon portions of the plugging plate body at both sides of each of the thin portions in the direction in which the portions of the plugging plate body are made to separate from each other.

[0015] The ratio (L/T2) of the thickness L of the plugging plate body to the thickness T2 which is the thinest portion of the thin portion is equal to or more than 2. As compared to the thin portion, the portion of the plugging plate body on which a concave portion is not formed has a thickness which is equal to or more than a predetermined value. The opposite surfaces forming a concave portion are made to be in parallel with each other, or approach to each other so that the angle θ which is formed by the opposite surfaces is more than 0° and is equal to or less than 120°. The plugging plate body has a predetermined thickness at both side portions of the thin portion (on which the sloping surfaces are formed). For this reason, the tensional force generated from both side portions of the thin portion is concentrated at the thin portion. Since the thickness T2 of the thinest portion of the thin portion is equal to or less than 0.7 mm, the plugging plate body is broken along the thin portion by the tensional force which has concentrated at the thin portion.

[0016] The thickness T2 of the thinnest portion of the thin portion is equal to or more than 0.05 mm, and a predetermined strength is secured. Therefore, in the state in which the draining port is plugged by the plugging member, when the pressing force acts upon the plugging member due to an increase in the internal pressure of the container, the plugging plate body does not unexpectedly break.

[0017] Examples of the cross sectional configuration of the concave portion which is formed by decreasing the thickness of the plugging plate body in portions may include: a rectangular shape in which the surfaces facing each other and forming the concave portion are in parallel with each other; a substantially trapezoidal shape in which the opposite surfaces gradually approach to each other toward the other end surface of the plugging plate body; and a substantially V-shape in which the end portions of the opposite surfaces contact with each other.

[0018] The second aspect of the present invention is a plugging member according to the first aspect of the present invention, wherein a low strength portion is formed at the thin portion by decreasing the strength of the thin portion within a predetermined range from the center of the plugging plate body.

[0019] When the plugging plate body is pressed by the pressing means, firstly, the low strength portion is broken, and then, the broken portion extends to the portion of the plugging plate body other than the low strength portion (outside the predetermined range from the center of the plugging plate body). For this reason, over the entire body of the plugging plate body, the plugging plate body can be broken with an even smaller amount of pressing force as compared to the plugging plate body on which the low strength portion is not formed.

[0020] In the thin portion other than the low strength portion, since the thin portion has a strength which is higher than the low strength portion, for example, the plugging plate body is not broken unexpectedly due to the increase of the internal pressure of the container.

[0021] The third aspect of the present invention is a plugging member according to the first aspect of the present invention, wherein three or more of the thin portions are formed, and portions of these thin portions are low strength portions whose strength is made lower than the other thin portions.

[0022] When the plugging plate body is pressed by the pressing means, the low strength portions are broken, and then, the broken portion extends to the portions of the plugging plate body other than the low strength portions. For this reason, over the entire body of the plugging plate body, the plugging plate body can be broken with a much more smaller amount of pressing force as compared to the plugging plate body on which the low strength portions are not formed.

[0023] Since the thin portions other than the low strength portions have a strength which is higher than the low strength portions, for example, the plugging plate body is not broken unexpectedly due to an increase of the internal pressure of the container or the like.

[0024] One low strength portion or a plurality of low strength portions can be provided. Further, low strength portions may be formed by applying different strengths to three or more of thin portions.

[0025] The fourth aspect of the present invention is a plugging member according to the third aspect of the present invention, wherein a high strength portion is formed on the thin portions by increasing the strength of the thin portions outside a predetermined range from the center of the plugging plate body.

[0026] Firstly, the low strength thin portions are broken by the pressing force of the pressing means. However, the breaking is obstructed by the high strength portions which are formed in the low strength thin portions. The tensional force acting upon the thin portions by the pressing force of the pressing means extends to the thin portions other than the aforementioned portions (the portions other than the low strength thin portions). Namely, the tensional force due to the pressing force of the pressing means is dispersed to and acts upon a plurality of thin portions (including the low strength thin portion) at different times so that all of the thin portions can be broken.

[0027] The fifth aspect of the present invention is a plugging member according to the first to fourth aspects of the present invention, wherein the plugging plate body is formed in a disc plate shape whose outer diameter R is not less than 0.5 cm and not more than 5 cm.

[0028] Accordingly, the plugging plate body has a predetermined strength, and the thin portion can be broken with a small amount of the pressing force.

[0029] The sixth aspect of the present invention is a plugging member which plugs a draining port for draining a material which is contained in a container, comprising: a plugging plate body which is mounted in the draining port and is able to plug the draining port; and a low strength portion which is formed on the plugging plate body where the strength of the plugging plate body is decreased by a plurality of radial portions which are formed radiating out from substantially the central portion of the plugging plate body toward the external edge thereof, a plurality of curved portions which are formed so as to be curved in an arcuate shape and continue from the tip end of each of the radial portions, and a plurality of circumferential portions which are formed so as to extend from the tip end of each of the curved portions in the direction along the edge of the opening of the draining port.

[0030] In the state in which the plugging member is mounted in the draining port, the plugging plate body plugs the draining port. In this state, when substantially the central portion of the plugging plate body is pressed by the pressing means such as a bar or the like, then at substantially the central portion of the plugging plate body, tensional force acts upon portions of the plugging plate body on both sides of each of the radial portions in the longitudinal direction thereof in the direction in which the portions of the plugging plate body are made to separate from each other, and substantially the central portion of the plugging plate body splits along the radial portions. This split extends to the outer edge of the plugging plate body along the radial portions, and further extends to the circumferential portions by way of the curved portions.

[0031] Since the circumferential portions are formed in the same direction as the edge of the opening of the draining port, the plugging plate body is broken along the edge of the opening of the draining port at portions where these circumferential portions are formed. For this reason, the plugging plate body is opened wide along the edge of the opening of the draining port.

[0032] Further, the radial portions and the circumferential portions are connected to each other, through the curved portions each of which is curved in an arcuate shape. Accordingly, the radial portions and the circumferential portions are not structured such that they deviate so as to connect to each other. For this reason, even if the pressing force by the pressing means is low, the tensional force, which has acted upon the respective radial portions, also acts upon the respective circumferential portions and the plugging plate body can thereby be broken along the circumferential portions.

[0033] The radial portions are not necessarily formed radiating from the center of the plugging plate body, and instead may be formed radiating from the substantially central portion (at a position slightly displaced from the center) of the plugging plate body provided that the plugging plate body is split along the radial portions by the pressing force from the pressing means.

[0034] The seventh aspect of the present invention is a plugging member according to the sixth aspect of the present invention, wherein the low strength portion is a groove which is formed by decreasing the thickness of the plugging plate body in portions.

[0035] By forming a groove on the plugging plate body, the cross sectional area of the plugging plate body in the groove portion decreases. Accordingly, the tensional force is concentrated in the groove portion, and the plugging plate body is broken along the groove. In this way, the low strength portion can be formed by a simple structure in which the groove is formed by decreasing the thickness of the plugging plate body in portions.

[0036] Other than the structure in which the thin portion is formed so as to be in continuous, the groove of the present invention may be formed by a structure in which the thin portion is formed intermittently at a predetermined distance so as to form as a whole a series of perforation.

[0037] The eighth aspect of the present invention is a container in which a draining port for draining a material contained therein is formed, and the draining port is plugged by the plugging member according to the first to seventh aspects of the present invention.

[0038] Because the draining port of the container is plugged by the plugging member, the material contained in the container does not leak from the container. Since air or the like does not flow into the container, changes in the characteristics or properties of the material contained therein can be prevented.

[0039] In the state in which the plugging member is attached to the draining port, namely, without detaching the plugging member from the draining port, the substantially central portion of the plugging plate body is pressed by the pressing means such as a bar or the like. The plugging plate body is opened wide along the edge of the opening of the draining port, and the material contained in the container can be emptied out.

[0040] The ninth aspect of the present invention is a container according to the eighth aspect of the present invention, wherein the container is used for the purpose of containing therein photographic processing chemicals.

[0041] The photographic processing chemicals do not leak from the container, and change in the characteristics or properties of the material contained in the container can be prevented.

[0042] In the state in which: the plugging member is attached to the draining port, the substantially central portion of the plugging plate body is pressed by a pressing means such as a bar or the like. The plugging plate body is opened wide along the edge of the opening of the draining port, and the photographic processing chemicals can be emptied out.

BRIEF DESCRIPTION OF THE DRAWINGS

P-0043[0043]FIG. 1 is an exploded perspective view illustrating a packing according to a first embodiment of the present invention, a cap in which this packing is mounted, and a container to which the cap is attached.

P-0044[0044]FIG. 2 is a cross sectional view illustrating a state in which the packing according to the first embodiment of the present invention is mounted-in the cap.

P-0045[0045]FIG. 3 is a perspective view illustrating the packing according to the first embodiment of the present invention.

P-0046[0046]FIG. 4A is a plan view illustrating the packing according to the first embodiment of the present invention.

P-0047[0047]FIG. 4B is a cross sectional view taken along the line IV-IV in FIG. 4A and illustrates the packing according to the first embodiment of the present invention.

P-0048[0048]FIG. 5 is a cross sectional view taken along the line V-V in FIG. 4A and illustrates the packing according to the first embodiment of the present invention.

P-0049[0049]FIG. 6 is a cross sectional view taken along the line VI-VI in FIG. 4A and illustrates the packing according to the first embodiment of the present invention.

P-0050[0050]FIG. 7A is a cross sectional view taken along the line VII-VII in FIG. 4A and illustrates the packing according to the first embodiment of the present invention.

P-0051[0051]FIG. 7B is a cross sectional view taken along the line VIII-VIII in FIG. 4A and illustrates the packing according to the first embodiment of the present invention.

P-0052[0052]FIG. 8 is a perspective view illustrating a schematic structure of photographic processing chemicals supplying device which supplies photographic processing chemicals from the container whose draining port is plugged by the packing according to the first embodiment of the present invention.

P-0053[0053]FIG. 9A is a plan view of the packing and illustrates the vicinity thereof in the state in which the container is set in the photographic processing chemicals supplying device which is shown in FIG. 8.

P-0054[0054]FIG. 9B is a cross sectional view of the packing and illustrates the vicinity thereof in the state in which the container is set in the photographic processing chemicals supplying device which is shown in FIG. 8.

P-0055[0055]FIG. 10A is a plan view of the packing and illustrates a state during the breaking of the packing by the photographic processing chemicals supplying device which is shown in FIG. 8.

P-0056[0056]FIG. 10B is a cross sectional view of the packing and illustrates a state during the breaking of the packing by the photographic processing chemicals supplying device which is shown in FIG. 8.

P-0057[0057]FIG. 11A is a plan view of the packing and illustrates a state during the breaking of the packing by the photographic processing chemicals supplying device which is shown in FIG. 8.

P-0058[0058]FIG. 11B is a cross sectional view of the packing and illustrates a state during the breaking of the packing by the photographic processing chemicals supplying device which is shown in FIG. 8.

P-0059[0059]FIG. 12A is a plan view of the packing and illustrates a state in which the packing is broken by the photographic processing chemicals supplying device which is shown in FIG. 8.

P-0060[0060]FIG. 12B is a cross sectional view of the packing and illustrates a state in which the packing is broken by the photographic processing chemicals supplying device which is shown in FIG. 8.

P-0061[0061]FIG. 13 is a perspective view illustrating a state in which the packing is broken by the photographic processing chemicals supplying device which is shown in FIG. 8.

P-0062[0062]FIG. 14A is a plan view which illustrates a packing according to a second embodiment of the present invention.

P-0063[0063]FIG. 14B is a cross sectional view taken along the line XIV-XIV in FIG. 14A and illustrates the packing according to the second embodiment of the present invention.

P-0064[0064]FIG. 15A is a graph illustrating the relationship between the moving distance and the pressing force of a perforating pipe in the case in which a plurality of thin portions of the packing have the same thickness.

P-0065[0065]FIG. 15B is a graph illustrating the relationship between the moving distance and the pressing force of a perforating pipe in the case of the packing according to the second embodiment of the present invention.

P-0066[0066]FIG. 16A is a plan view illustrating a packing according to a variant example of the second embodiment of the present invention.

P-0067[0067]FIG. 16B is a cross sectional view taken along the line XVI-XVI in FIG. 16A and illustrates the packing according to the variant example of the second embodiment of the present invention.

P-0068[0068]FIG. 17A is a plan view illustrating yet another packing according to the present invention.

P-0069[0069]FIG. 17B is a cross sectional view taken along the line XVII-XVII in FIG. 17A and illustrates yet another packing according to the present invention.

P-0070[0070]FIG. 18A is an enlarged cross sectional view illustrating grooves of the packing according to the present invention.

P-0071[0071]FIG. 18B is an enlarged cross sectional view illustrating grooves which are different from those shown in FIG. 18A.

P-0072[0072]FIG. 18C is an enlarged cross sectional view illustrating grooves which are different from those shown in FIGS. 18A and 18B.

P-0073[0073]FIG. 19 is a plan view illustrating a conventional plugging sheet.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

P-0074[0074] A packing <b>10</b>, a cap <b>12</b> in which the packing <b>10</b> is mounted, and a photographic processing chemicals container <b>14</b> (a container for containing a photographic processing chemicals) to which this cap <b>12</b> is attached, according to a first embodiment of the present invention are shown in FIG. 1. Further, the cross section of the cap <b>12</b> to which the packing <b>10</b> is mounted, and the packing <b>10</b> are shown in FIGS. 2 and 3, respectively. The photographic processing chemicals container <b>14</b> which is shown in FIG. 1 contains therein photographic processing chemicals, and is an example of a container whose draining port <b>18</b> is plugged by the cap <b>12</b>, in which the packing <b>10</b> is mounted, being attached thereto.

P-0075[0075] The entire body of this photographic processing chemicals container <b>14</b> is formed in a substantially rectangular cylindrical shape, and a cylindrically-shaped portion <b>16</b> is formed at one end of the container <b>14</b> in the axial direction thereof (at the upper end in FIG. 1). One end of the cylindrical portion <b>16</b> is used as a draining port <b>18</b>, and it is possible to drain the photographic processing chemicals which are contained in the photographic processing chemicals container <b>14</b> from this draining port <b>18</b>.

P-0076[0076] As shown in FIGS. 1 and 2, the cap <b>12</b> in which the packing <b>10</b> is mounted, comprises an attachment cylindrical portion <b>20</b> which is formed in a substantially cylindrical shape, and an anchoring cylindrical portion <b>22</b> which is formed integrally with one axial end of the attachment cylindrical portion <b>20</b> (at the upper end in FIG. 2) and whose diameter is smaller than the attachment cylindrical portion <b>20</b>.

P-0077[0077] As shown in FIG. 2, a female thread <b>24</b> is formed on the internal circumferential surface of the attachment cylindrical portion <b>20</b>. The female thread <b>24</b> is screwed onto a male thread <b>26</b> (see FIG. 1) which is formed on the external circumferential surface of the cylindrical portion <b>16</b> of the photographic processing chemicals container <b>14</b>. Accordingly, the cap <b>12</b> is screwed onto the cylindrical portion <b>16</b> and can be attached to the draining port <b>18</b>.

P-0078[0078] An annular ring <b>28</b> is formed integrally with the anchoring cylindrical portion <b>22</b> at one end in the axial direction thereof (the upper end in FIG. 2) so as to extend toward the inside of the anchoring cylindrical portion <b>22</b> in the radial direction. A packing mounting portion <b>32</b> in which the packing <b>10</b> is mounted is formed by the internal surface <b>22</b>B of the anchoring cylindrical portion <b>22</b> and the bottom surface <b>28</b>B of the ring <b>28</b>.

P-0079[0079] In the state in which the packing <b>10</b> is mounted in the packing mounting portion <b>32</b>, a clearance of a predetermined distance is formed between the external circumferential surface of an insertion cylindrical portion <b>36</b> and the internal circumferential surface of the attachment cylindrical portion <b>20</b>. When the cap <b>12</b> is screwed onto the cylindrical portion <b>16</b> of the photographic processing chemicals container <b>14</b>, and is attached to the draining port <b>18</b>, the upper portion of the cylindrical portion <b>16</b> enters into the aforementioned clearance. As a result, the insertion cylindrical portion <b>36</b> is inserted into the draining port <b>18</b> (at the inside of the cylindrical portion <b>16</b>) with no clearance. Accordingly, the external circumferential surface of the insertion cylindrical portion <b>36</b> and the internal circumferential surface of the cylindrical portion <b>16</b> contact with each other, and the position of the packing <b>10</b> in the radial direction of the photographic processing chemicals container <b>14</b> is fixed. Further, since the outer edge of a sealing disc portion <b>34</b> is nipped between the bottom surface <b>28</b>B of the ring <b>28</b> and the upper surface of the cylindrical portion <b>16</b>, the position of the packing <b>10</b> in the axial direction of the photographic processing chemicals container <b>14</b> is fixed. Moreover, in this state, when the cap <b>12</b> in which the packing <b>10</b> is mounted is attached to the draining port <b>18</b>, the draining port <b>18</b> is plugged by the packing <b>10</b>.

P-0080[0080] A protruding wall <b>30</b> is formed so as to protrude from the top surface <b>28</b>A of the ring <b>28</b> over the entire circumference of the ring <b>28</b>.

P-0081[0081] The cross section of the protruding wall <b>30</b> is formed in a substantially triangular shape having a guiding surface <b>30</b>A and a sloping surface <b>30</b>C. As seen from the cross section, the guiding surface <b>30</b>A is parallel with axis J<b>1</b>. The sloping surface <b>30</b>C extends from a protruding tip <b>30</b>B towards the radial external side of the ring <b>28</b> as it approaches the top surface <b>28</b>A of the ring <b>28</b>. By forming the protruding wall <b>30</b> having the configuration described above so as to protrude from the top surface <b>28</b>A, then in a state where the draining port <b>18</b> faces downward, and the photographic processing chemicals container <b>14</b> is held such that the axis J<b>1</b> corresponds to the vertical direction of the photographic processing chemicals container <b>14</b> (see FIGS. 8 and 9B), the sloping surface <b>30</b>C rises toward the radial external side. Accordingly, when a liquid material is contained in the photographic processing chemicals container <b>14</b>, then even if the draining port <b>18</b> faces downward and the material contained in the photographic processing chemicals container <b>14</b> flows out due to gravity, the material rises the sloping surface <b>30</b>C due to surface tension or the like as it empties out and, as a result, the material does not drain in the radial external direction of the photographic processing chemicals container <b>14</b>.

P-0082[0082] The packing <b>10</b> is formed from unfoamed resin. The resin contains 50% or more of low density polyethylene (LDPE) whose density range is determined to be between 0.910 and 0.929 (g/cm³) in JIS K 6748-1982, or similarly, 50% or more of high density polyethylene (HDPE) whose density range is determined to be equal to or more than 0.942 (g/cm³) in JIS K 6748-10.982. As shown in FIGS. 3, 4A and <b>4</b>B in more detail, the packing <b>10</b> is formed by the sealing disc portion <b>34</b> and the insertion cylindrical portion <b>36</b> which are formed integrally with each other. The sealing disc portion <b>34</b> is formed in a substantially disc shape having a constant thickness L. The insertion cylindrical portion <b>36</b> is formed in a flattened cylindrical shape and extends perpendicularly to the sealing disc portion <b>34</b> from a portion adjacent to the external circumference of the rear surface <b>34</b>B of the sealing disc portion <b>34</b>. The radial external side portion of the insertion cylindrical portion <b>36</b> functions as a flange <b>38</b>. The flange <b>38</b> has a constant thickness L, and imparts a predetermined strength to the sealing disc portion <b>34</b>. Further, the outer diameter R of the sealing disc portion <b>34</b> (see FIG. 4A) ranges from not less than 0.5 cm to not more than 5 cm, and the sealing disc portion <b>34</b> has a predetermined strength.

P-0083[0083] As shown in FIGS. 4A and 4B, by decreasing the thickness of the sealing disc portion <b>34</b> in portions (to a thickness T2, see FIG. 6), a plurality of arcuate thin portions <b>46</b> (four in the present embodiment), each of which is formed in a substantially arcuate shape as seen from a plan view, are formed on the surface <b>34</b>A of the sealing disc portion <b>34</b> at a predetermined distance from each other in the circumferential direction. Circular arc portions <b>46</b>A of the arcuate thin portions <b>46</b> correspond to the internal circumference of the flange <b>38</b>.

P-0084[0084] As shown in FIGS. 4A and 4B, grooves <b>50</b> are formed on the surface <b>34</b>A of the sealing disc portion <b>34</b>. The grooves <b>50</b> are formed by a plurality of radial grooves <b>52</b>, curved grooves <b>54</b>, and circumferential grooves <b>56</b>. The plurality of radial grooves <b>52</b> (four in the present embodiment) extend linearly from the center of the surface <b>34</b>A of the sealing disc portion <b>34</b> toward the external circumference of the sealing disc portion <b>34</b> (toward the center of each of the arcuate thin portions <b>46</b>). Each of the curved grooves <b>54</b> continues on from the extending end <b>52</b>A of each of the radial grooves <b>52</b> and curves in a smooth circular arc without deviation in the same direction and at a constant angle of curvature with the same central angle. Each of the circumferential grooves <b>56</b> extends without deviation from the tip end of each of the curved grooves <b>54</b> along the external circumference of the sealing disc portion <b>34</b> so as to form a smooth circular arc shape. A portion between the grooves <b>50</b> adjacent to each other is a fan portion <b>58</b> which is formed in a substantially fan shape having a thickness L which is the same as the flange <b>38</b>.

P-0085[0085] As shown in FIGS. <b>4</b>B, <b>7</b>A,, <b>7</b>B, and <b>18</b>A in more detail, each of the grooves <b>50</b> is cut diagonally from the surface <b>34</b>A to the rear surface <b>34</b>B of the sealing disc portion <b>34</b> so as to form a substantially V-shaped cross section having a pair of sloping surfaces <b>60</b>. The angle θ formed by the sloping surfaces <b>60</b> has a predetermined angle which is more than 0° and equal to or less than 120°. The distance between the sloping surfaces <b>60</b> gradually decreases from the surface <b>34</b>A to the rear surface <b>34</b>B, of the sealing disc portion <b>34</b>. By forming this groove <b>50</b>, a thin portion <b>62</b> having a predetermined thickness T3 is formed between a bottom end <b>50</b>A of the groove <b>50</b> and the rear surface <b>34</b>B of the sealing disc portion <b>34</b>.

P-0086[0086] The length L1 of each of the radial grooves <b>52</b> has a predetermined, length such that the tip end <b>52</b>A of the radial groove <b>52</b> does not extend to the arcuate thin portion <b>46</b> (i.e., the length of the radial groove portion <b>52</b> is smaller than the radius of the sealing disc portion <b>34</b>). More specifically if the internal circumference of the flange <b>38</b> (a circle which is formed by the circular arc portions <b>46</b>A of the arcuate thin portions <b>46</b>) is R1, then preferably,

0<i>≦L</i>1≦(4/5)×<i>R</i>1

P-0087[0087] from a standpoint of perforation performance (splittability of the groove <b>50</b>) which will be described later, and more preferably,

(1/5)×<i>R</i>1≦<i>L</i>1≦(2/3)×<i>R</i>1.

P-0088[0088] Moreover, in the case of L1=0, it means that there are no linear radial grooves <b>52</b>, and the curved grooves <b>54</b> are formed so as to extend directly from the center of the sealing disc portion <b>34</b>. Accordingly, these curved grooves <b>54</b> equate to both the radial portions and the curved portions of the present invention. In the packing <b>10</b> according to the present embodiment, R1=13 mm, and L1=5 mm.

P-0089[0089] As shown in FIGS. 4A, 4B, and <b>5</b>, a low strength portion <b>64</b> is formed on each of the radial grooves <b>52</b> within a predetermined range from the center of the sealing disc portion <b>34</b> (within the range indicated by a double-dashed line C<b>1</b> in FIG. 4A), by not changing the width W of the upper end of the radial groove <b>52</b> (see FIGS. 7A and 7B), but by deeply cutting the radial groove <b>52</b> (accordingly, the inclination angle θ formed by the sloping surfaces <b>60</b> is made smaller) thus further decreasing the thickness of the thin portion <b>62</b> (thickness T2).

P-0090[0090] The thickness T2 of the low strength portion <b>64</b> is set to range from not less than 0.05 mm to not more than 0.7 mm. Further, the thickness T2 is set such that the ratio of the plate thickness L of the sealing disc portion <b>34</b> to the thickness T2 of the low strength portion <b>64</b> (L/T2) is 2 or more.

P-0091[0091] As shown in FIG. 4A, the curved grooves <b>54</b> are curved in a circular arc shape, continuing on from the tip ends <b>52</b>A of the radial grooves <b>52</b> in the same direction (in the clockwise direction in FIG. 4A in the present embodiment), at a predetermined radius of curvature R2, and at a predetermined central angle. Each of the curved grooves <b>54</b> contacts with a chord portion <b>46</b>B (a straight line portion) of each of the arcuate thin portions <b>46</b>, and gradually extends toward the external circumference of the sealing disc portions <b>34</b>.

P-0092[0092] The radius of curvature R2 of the curved groove <b>54</b> is appropriately determined from a standpoint of perforation performance or the like which will be described later. However, preferably,

R1/5≦R2,

P-0093[0093] and more preferably,

R1/5≦R2≦R1/2.

P-0094[0094] In the packing <b>10</b> according to the present embodiment, R2=5 mm.

P-0095[0095] If the curved groove <b>54</b> is thought of as being divided into micro portions, in these micro portions, it is not necessary to maintain the radius of curvature R2 constant. The respective micro portions may have different radii of curvature R2 or a portion thereof may be formed by a straight line connecting internal portions of the arc provided that the smoothness of the curved groove <b>54</b> as a whole is not lost.

P-0096[0096] As shown in FIGS. 5, 6 and <b>7</b>B, the strength of the thin portion <b>62</b> of each of the curved grooves <b>54</b> is made to be much lower at a portion of the, sealing disc portion <b>34</b> outside a predetermined range from the center of the sealing disc portion <b>34</b> (outside the range indicated by the double-dashed line C<b>2</b> in FIG. 4A) without changing the width W of the upper end of the curved groove <b>54</b>, by deeply cutting the curved groove <b>54</b> and thereby decreasing the thickness of the thin portion <b>62</b> (thickness T2).

P-0097[0097] Either one of the pair of sloping surfaces <b>60</b> which are shown in FIGS. 7A and 7B is not formed at a portion at which the curved groove <b>54</b> is formed along the chord portion <b>46</b>B of the arcuate thin portion <b>46</b>. However, in this portion also, the thickness of the arcuate thin portion <b>46</b> is T2 so that, essentially, the curved groove <b>54</b> is formed.

P-0098[0098] As shown in FIG. 6, the circumferential grooves <b>56</b> extend from the respective tip ends of the curved grooves <b>54</b> along the external circumference of the sealing disc portion <b>34</b>. The circumferential grooves <b>56</b> are different from the radial grooves <b>52</b> and the curved grooves <b>54</b> in that each of the circumferential grooves <b>56</b> is formed by a single sloping surface <b>60</b> extending from the surface <b>34</b>A to the rear surface <b>34</b>B of the sealing disc portion <b>34</b>, and by a vertical surface portion <b>46</b>C which forms the circular arcuate portion <b>46</b>A of the arcuate thin portion <b>46</b>. The thin portions <b>62</b> having the same thickness T2 as the arcuate thin portions <b>46</b> are formed by the circumferential grooves <b>56</b>. Accordingly, as can be seen from an overall view of the grooves <b>50</b> in FIGS. 4A, 4B, and <b>5</b>, the low strength portion <b>64</b> in which the thickness of the thin portion <b>62</b> is decreases even further (thickness T2) is formed within the range from the center of the sealing disc portion <b>34</b> to the double-dashed line C<b>1</b>. Within the range between the double-dashed line C<b>1</b> and the double-dashed line C<b>2</b>, the thickness of the thin portion <b>62</b> is not decreased any more (thickness T3) so that a constant strength can be maintained. Outside the range indicated by the double-dashed line C<b>2</b>, the thickness of the thin portion <b>62</b> is decreased once more (thickness T2).

P-0099[0099] Next, a description of a direction in which photographic processing chemicals are drained from the photographic processing chemicals container <b>14</b> whose draining port <b>18</b> is plugged by the packing <b>10</b> according to the present embodiment, and an operation of the packing <b>10</b> will be given.

P-0100[0100] A photographic processing chemicals supplying device <b>70</b> in the automatic developer is schematically shown in FIG. 8. When the photographic processing chemicals container <b>14</b> is set in the photographic processing chemicals supplying device <b>70</b>, the photographic processing chemicals are supplied from the container <b>14</b>.

P-0101[0101] In order to supply the photographic processing chemicals from the photographic processing chemicals container <b>14</b> into the automatic developer, as shown in FIG. 8, firstly, the photographic processing chemicals container <b>14</b> is inserted into a holding hole <b>74</b> of a holding plate <b>72</b> and set upside down. The photographic processing chemicals container <b>14</b> is held above a replenishing tank (not shown) in a state where the draining port <b>18</b> (see FIG. 1) faces downward. At this time, because the draining port <b>18</b> of the photographic processing chemicals container <b>14</b> is plugged by the packing <b>10</b>, the photographic processing chemicals does not flow out inadvertently from the photographic processing chemicals container <b>14</b>. Further, as shown in FIG. 9B, the upper end of a perforating pipe <b>76</b> which is provided in the photographic processing chemicals supplying device <b>70</b> is positioned beneath the packing <b>10</b> plugging the draining port <b>18</b>.

P-0102[0102] Next, an unillustrated controller rotates a pinion inside a driving portion <b>78</b> and raises an elevating portion <b>80</b>. The perforating pipe <b>76</b> extending from the elevating portion <b>80</b> is thereby raised, and the tip end of the perforating pipe <b>76</b> pushes up the central portion of the packing <b>10</b> which plugs the draining port <b>18</b>.

P-0103[0103] As shown in FIGS. 10A and 10B, when the center of the packing <b>10</b> is pressed up by the tip end of the perforating pipe <b>76</b>, in the vicinity of the center of the sealing disc portion <b>34</b>, the tensional force acts upon the fan portions <b>58</b>, which are provided on both side portions of each of the radial grooves <b>52</b> (see FIG. 4) which form the grooves <b>50</b>, in the direction in which the fan portions <b>58</b> are separated from each other.

P-0104[0104] Generally, when a member with a fixed thickness is pressed in the direction of that thickness and is broken, the maximum amount of pressing force (perforation force) is needed at the initial stage of the pressing, i.e., immediately before and after perforation starts. In the packing <b>10</b> according to the present embodiment, among the thin portions <b>62</b>, low strength portions <b>64</b> are formed at portions of the thin portions <b>62</b> within the range indicated by the double-dashed line C<b>1</b> in FIG. 4, and the strength thereof is weakened. Accordingly, even if the force for elevating the perforating pipe <b>76</b> is small, in other words, even if the rotational torque of the pinion of the driving portion <b>78</b> is small, the sealing disc portion <b>34</b> can be broken along the radial grooves <b>52</b>. Namely, the thin portions <b>62</b> in the vicinity of the central portion of the sealing disc portion <b>34</b> can be split with a small amount of pressing force. Accordingly, the sealing disc portion <b>34</b> can be broken along the thin portions <b>62</b>.

P-0105[0105] As shown in FIGS. 11A and 11B, when the perforating pipe <b>76</b> is further raised, the splits extend to the external side of the sealing disc portion <b>34</b> in the radial direction thereof, and further extend to the thin portions <b>62</b> which are formed by the curved grooves <b>54</b> (see FIG. 4A). During this splitting process, the splits extend from the low strength portion <b>64</b> to a portion of the thin portion <b>62</b> at which the low strength portion <b>64</b> is not formed (within the range between the double-dashed line C<b>1</b> and the double-dashed line C<b>2</b> in FIG. 4A). However, at this time, since splits have already been formed on the sealing disc portion <b>34</b>, these splits can be expanded with a small amount of pressing force.

P-0106[0106] As can be seen from FIG. 4A, since the curved grooves <b>54</b> continue on from the radial curved grooves <b>52</b> without deviation, and are curved at a constant radius of the curvature, the tensional force acts upon the fan portions <b>58</b> which are provided on both sides of each of the curved grooves <b>54</b> in the direction where the fan portions <b>58</b> are forced to separate from each other. As a result, the splits extend smoothly toward the external side portion of the sealing disc portion <b>34</b> in the radial direction thereof along the curved grooves <b>54</b>.

P-0107[0107] Among the thin portions <b>62</b> which are formed by the curved grooves <b>54</b>, the thickness of a portion of each of the thin portions <b>62</b> outside the range indicated by the double-dashed line C<b>2</b> in FIG. 4A is decreased again (thickness T2), and the strength thereof is made low. For this reason, when the splits extend to these low strength portions, the sealing disc portion <b>34</b> is broken with a smaller amount of pressing force. Especially when the splits extend to the chord portions <b>46</b>B of the arcuate thin portions <b>46</b>, only the fan portion <b>58</b> on one side of each of the thin portions <b>62</b> is pulled away from the arcuate thin portion <b>46</b>. However, even in this case, the splits expand along the low strength portions of the thin portions <b>62</b> which are formed by the curved grooves <b>54</b>, and extend to the thin portions <b>62</b> which are formed by the circumferential grooves <b>56</b>.

P-0108[0108] When splits further expand along the thin portions <b>62</b>, and the sealing disc portion <b>34</b> is broken, because the thin portions <b>62</b> (the circumferential grooves <b>56</b>) are formed along the external circumference of the sealing disc portion <b>34</b>, as shown in FIGS. 12A and 12B, each of the fan portions <b>58</b> is thereby bent at the chord portion <b>46</b>B of the arcuate thin portion <b>46</b>. Namely, as is also shown in FIG. 13, the sealing disc portion <b>34</b> is opened and the area of the opening is made wider (in contrast to this, for example, when the circumferential groove <b>56</b> is not formed on the sealing disc portion <b>34</b>, since the fan portion <b>58</b> is bent along the line indicated by the double-dashed line C<b>3</b> which is shown in FIG. 4A, the area of the opening of the sealing disc portion <b>34</b> is made narrower).

P-0109[0109] In this way, in the packing <b>10</b> according to the present embodiment, curved grooves <b>54</b>, which continue on smoothly without deviation from the radial grooves <b>52</b>, and circumferential grooves <b>56</b>, which continue on smoothly without deviation from the curved grooves <b>54</b> along the external circumference of the sealing disc portion <b>34</b>, are formed on the sealing disc portion <b>34</b> for plugging the draining port <b>18</b> of the photographic processing chemicals container <b>14</b>. As a result, the sealing disc portion <b>34</b> can be opened wide with a small amount of pressing force.

P-0110[0110] In the packing <b>10</b> according to the present embodiment, since the low strength portions <b>64</b> are formed at portions within a predetermined range from the center thereof (within the range indicated by the double-dashed line C<b>1</b> which is shown in FIG. 4A) of the thin portions <b>62</b> which are formed on the sealing disc portion <b>34</b> as compared to the packing in which the strength of these portions is not reduced, the sealing disc plate <b>34</b> is broken with a smaller amount of pressing force, and the draining port <b>18</b> of the photographic processing chemicals container <b>14</b> can thereby be opened.

P-0111[0111] Further, because the strength at portions of the thin portions <b>62</b> within the range between the double-dashed line C<b>1</b> and the double-dashed line C<b>2</b> is not reduced, the sealing disc portion <b>34</b> maintains a constant strength. Accordingly, due to, for example, a change or the like of the internal pressure of the photographic processing chemicals container <b>14</b>, even if the sealing disc portion <b>34</b> is pressed outwardly or inwardly of the photographic processing chemicals container <b>14</b>, the sealing disc portion <b>34</b> is not broken unexpectedly. Especially when the photographic processing chemicals container <b>14</b> is dropped, the internal pressure of the container <b>14</b> may increase temporarily, however, even in this case, the sealing disc portion <b>34</b> is not broken.

P-0112[0112] In the packing <b>10</b> according to the present embodiment, since the outer diameter of the sealing disc portion <b>34</b> is between not less than 0.5 cm and not more than 5 cm, the sealing disc portion <b>34</b> stretches appropriately due to pressing force from the pressing means (however, it does not stretch excessively), the sealing disc portion <b>34</b> can be broken with a small amount of pressing force.

P-0113[0113] As described above, in the packing <b>10</b> according-to the present embodiment, opposing properties can be realized, namely, that a predetermined amount of strength is maintained in the sealing disc portion <b>34</b>, and the pressing force which is needed by the pressing means to perforate this sealing disc portion <b>34</b> (i.e., the perforating force of the perforating pipe <b>76</b>) can be minimized.

P-0114[0114] A packing <b>110</b> according to the second embodiment of the present invention is shown in FIG. 14. In this packing <b>110</b>, only the configuration of grooves in the second embodiment of the present invention is different as compared to the packing <b>10</b> according to the first embodiment of the present invention. Structural parts and members identical to those of the packing <b>10</b> according to the first embodiment are denoted by the same reference numerals, and a description thereof will be omitted.

P-0115[0115] In this packing <b>110</b>, as shown in FIG. 14A, among four thin portions <b>114</b>A, <b>114</b>B, <b>114</b>C, and <b>114</b>D which are formed by grooves <b>112</b>, as a whole, the thickness of each of the two thin portions <b>114</b>A and <b>114</b>B is smaller than that of each of the other two thin portions <b>114</b>C and <b>114</b>D. Namely, the thin portions <b>114</b>A and <b>114</b>B are low strength thin portions having a strength which is lower than the other thin portions <b>114</b>C and <b>114</b>D.

P-0116[0116] Generally, the relationship which is shown in FIG. 15A exists between the length of a split which is formed by the sealing disc portion <b>116</b> being pressed by the pressing means (the perforating pipe <b>76</b>), and the pressing force which is generated by the pressing means and is needed to expand the split. The relationship between the distance moved (on the basis of the distance moved from the tip end of the perforating pipe <b>76</b> at the point the tip end contacts with the sealing disc portion) and the pressing force of the perforating pipe <b>76</b> is shown in the graph in FIG. 15A. As can be seen from this graph, if the four thin portions have the same thickness, at a stage in which the distance moved by the perforating pipe <b>76</b> is small, the pressing force amounts to its maximum value F1 (which is referred to as maximum pressing force, hereinafter). At this point, splits are formed at the thin portions. Once splits are formed on the sealing disc portion <b>34</b>, only a small amount of pressing force is needed in order to expand the splits. Accordingly, after the pressing force has exceeded the maximum pressing force F1, the pressing force decreases invariably.

P-0117[0117] Conversely, the relationship between the distance moved and the pressing force of the perforating pipe <b>76</b> when a sealing disc portion <b>116</b> of the packing <b>110</b> is pressed and broken by the perforating pipe <b>76</b> is shown in FIG. 15B. In the packing <b>110</b>, since the strength at the thin portions <b>114</b>A and <b>114</b>B is made lower than the other thin portions <b>114</b>C and <b>114</b>D, the maximum pressing force F2, which is needed to form splits at the thin portions <b>114</b>A and <b>114</b>B, is less than the maximum pressing force F1 which is shown in FIG. 15A. Moreover, in the graph of FIG. 15B, as it can be seen from the fact that there are a plurality of maximum values of pressing force, the pressing force acts upon and is dispersed at the four thin portions <b>114</b>A, <b>114</b>B, <b>114</b>C and <b>114</b>D at different times.

P-0118[0118] Accordingly, when the center of the sealing disc portion <b>116</b> of the packing <b>110</b> is pressed by the perforating pipe <b>76</b>, splits are formed at the thin portions <b>114</b>A and <b>114</b>B (the low strength thin portions) and the sealing disc portion <b>116</b> is thereby broken. When the splits extend to the portions near the external circumference of the sealing disc portion <b>116</b>, since the amount of pressing force which is needed to form splits at the thin portions <b>114</b>A and <b>114</b>B (see FIG. 15B) is small, splits extend to the other thin portions <b>114</b>C and <b>114</b>D as well. The sealing disc portion <b>116</b> is thus entirely broken, and the draining port <b>18</b> (see FIG. 1) is opened.

P-0119[0119] Among the four thin portions <b>114</b>A, <b>114</b>B, <b>114</b>C and <b>114</b>D, by making the two thin portions <b>114</b>A and <b>114</b>B low strength portions whose strength is lower than the other thin portions <b>114</b>C and <b>114</b>D, the tensional force which acts upon the fan portions <b>58</b> adjacent to each other by the pressing force of the pressing means can be dispersed at different times. Accordingly, the sealing disc portion <b>116</b> can be broken with a small amount of pressing force. Further, splits can be first induced at the thin portions <b>114</b>A and <b>114</b>B by making the thin portions <b>114</b>A and <b>114</b>B low strength portions. Accordingly, since the thickness of the other thin portions <b>114</b>C and <b>114</b>D can be made relatively larger, it is possible to make the thickness of all four thin portions <b>114</b>A, <b>114</b>B, <b>114</b>C and <b>114</b>D larger. For this reason, the strength of the sealing disc portion <b>116</b> can be kept constant and even when the sealing disc portion <b>116</b> is pressed inwardly or outwardly of the photographic processing chemicals container <b>14</b>, the sealing disc portion <b>116</b> does not unexpectedly break.

P-0120[0120] In order to disperse the tensional force acting upon the fan portions <b>58</b> adjacent to each other, it is not necessary to reduce the strength of two of the plurality of thin portions and instead, the strength of one thin portion or three or more of the thin portions may be made to be lower than the other thin portions. Further, when the number of thin portions is equal to or more than three (accordingly, the number of the fan portions <b>58</b> is equal to or more than three), the above-described effect which is obtained by forming low strength thin portions (the tensional force acting upon the fan portions <b>58</b> is dispersed at different times) can be accomplished.

P-0121[0121] As shown in FIG. 14B, high strength portions <b>118</b> where the thickness of the thin portions <b>114</b>A, <b>114</b>B, <b>114</b>C, and <b>114</b>D has been increased can be formed outside a predetermined range from the center of the sealing disc portion <b>116</b> (outside the range indicated by the double-dashed line C<b>4</b> in FIG. 14A) by increasing the angle θ (refer to FIGS. 7A and 7B) which is formed by the sloping surfaces <b>60</b>. By forming these high strength portions <b>118</b>, splits which are formed at the thin portions <b>114</b>A and <b>114</b>B are prevented from extending any more, and thereafter, the thin portions <b>114</b>C and <b>114</b>D) which are not formed as low strength portions begin to split. When the splits of the thin portions <b>114</b>C and <b>114</b>D reach the high strength portions <b>118</b>, the four thin portions <b>114</b>A, <b>114</b>B, <b>114</b>C, and <b>114</b>D are caused to split at the same time, and the sealing disc portion <b>116</b> is thereby broken.

P-0122[0122] By forming the high strength portions <b>118</b> at the four thin portions <b>114</b>A, <b>114</b>B, <b>114</b>C, and <b>114</b>D, it is thereby possible to prevent splits from being formed only at the thin portions <b>114</b>A and <b>114</b>B having low strength. Splits can reliably be formed at the four thin portions <b>114</b>A, <b>114</b>B, <b>114</b>C, and <b>114</b>D so that the sealing disc portion <b>116</b> can be broken.

P-0123[0123] Instead of the high strength portions <b>118</b> which are shown in FIG. 14B, as shown in FIGS. 16A and 16B, within the local areas P, each of which is spaced apart from the center of the sealing disc portion <b>116</b>, the thickness of the thin portions <b>114</b>A and <b>114</b>B is made larger (thickness T4) by increasing the angle θ which is formed by the sloping surfaces <b>60</b> (see FIGS. 7A and 7B). Within the predetermined area P only, the strength of each of the thin portions <b>114</b>A, <b>114</b>B, <b>114</b>C, and <b>114</b>D is increased so that high strength portions <b>120</b> can be formed. In this way, by forming the high strength portions <b>120</b> locally, as compared to the packing <b>110</b> having the cross section which is shown in FIG. 14B, after the tip ends of splits have exceeded the high strength portions <b>120</b>, the splits can extend with a small amount of pressing force, and the sealing disc portion <b>116</b> can be broken.

P-0124[0124] A packing <b>130</b> as an another example is shown in FIGS. 17A and 17B. In this packing <b>130</b>, within a predetermined range from the center of a sealing disc portion <b>132</b> (within the range indicated by the double-dashed line C<b>5</b>), the thickness of each of thin portions <b>136</b> which are formed by grooves <b>134</b> is made larger in portions by increasing the angle θ which is formed by the sloping surfaces -<b>60</b> (see FIGS. 7A and 7B), and the strength thereof thereby increases. For this reason, as compared, for example, to the packing <b>10</b> according to the first embodiment of the present invention, at the initial stage of perforating the sealing disc portion <b>132</b>, it is necessary to press the sealing disc portion <b>132</b> with a larger amount of pressing force. However, once splits are formed at each of the thin portions <b>136</b>, and the tip ends of the splits extend to the range of the sealing disc portion <b>132</b> outside the range indicated by the double-dashed line C<b>5</b>, the splits extend to the outside of the sealing disc portion <b>132</b> in the radial direction thereof with an extremely small amount of pressing force, and the sealing disc portion <b>132</b> can be opened.

P-0125[0125] In the above description, as is also shown in FIG. 18A, an example in which the sloping surfaces <b>60</b> which form the grooves <b>50</b>, <b>112</b>, and <b>134</b> contact with each other at their bottom ends, and the cross sectional view of each of the grooves <b>50</b>, <b>112</b>, and <b>134</b> is formed in a substantially V-shape has been described. However, the configurations of the grooves <b>50</b>, <b>112</b>, and <b>134</b> are not limited to this. For example, as shown in FIG. 18B, they can be formed in a substantially trapezoidal configuration in which the bottom ends <b>60</b>A of the sloping-surfaces <b>60</b> do not contact with each other and are separated from each other. A flat portion <b>66</b> which is parallel with the rear surface <b>34</b>B of the sealing disc portion <b>34</b> is formed between the bottom ends <b>60</b>A of the sloping surfaces <b>60</b>. Further, a curved portion may be formed which is curved so as to form a concave shape protruding towards the rear surface <b>34</b>B, between the bottom ends <b>60</b>A of the sloping surfaces <b>60</b>. Moreover, as shown in FIG. 18C, the sloping surfaces <b>60</b> may be formed perpendicular to the top surface <b>34</b>A and the rear surface <b>34</b>B, of the sealing disc portion <b>34</b> (therefore, in actual fact, the sloping surfaces <b>60</b> do not slope) in a rectangular shape having a flat portion <b>66</b> between the bottom ends of the sloping surfaces <b>60</b>.

P-0126[0126] As to the structure in which the thin portions <b>62</b>, <b>114</b>, and <b>136</b> have low strength or high strength partially or locally, an example of the structure in which the thicknesses of the thin portions <b>62</b>, <b>114</b>, and <b>136</b> are increased or decreased by changing the angle θ which is formed by the sloping surfaces <b>60</b> has been explained. However, the structure in which each of the thin portions <b>62</b>, <b>114</b>, and <b>136</b> has low strength or high strength partially or locally is not limited to this. For example, as described above, in the case where the bottom ends <b>60</b>A of the sloping surfaces <b>60</b> are separated from each other by a predetermined distance and each of the thin portions <b>62</b>, <b>114</b> and <b>136</b> has the flat portion <b>66</b> having a predetermined width, it is possible for each of the thin portions <b>62</b>, <b>114</b> and <b>136</b> to have low strength or high strength partially or locally by also changing the width of the flat portion <b>66</b>. Namely, if the width of the flat portion <b>66</b> of each of the thin portions <b>62</b>, <b>114</b> and <b>136</b> is made narrower (including the sloping surfaces <b>60</b> without a flat portion <b>66</b> therebetween, as is shown in FIG. 18A), the tensional force is concentrated within this narrow range. Accordingly, the elongation of the thin portions <b>62</b> as a whole in the tensional direction decreases, and the thin portions <b>62</b> split easily. However, if the width of the flat portion <b>66</b> is made wider, since the tensional force is dispersed within this wider range, the elongation of the thin portions <b>62</b> as a whole in the tensional direction increases, and the thin portions <b>62</b> do not split easily.

P-0127[0127] The thin portions <b>62</b>, <b>114</b>, and <b>136</b> do not necessarily have low strength or high strength partially or locally and instead may have constant strength (thickness T2 or T4) from the center of the sealing disc portion <b>34</b> to the outer circumference thereof. Namely, even in this case, provided that the curved grooves <b>54</b> which continue in a smooth without deviation from the extending ends <b>52</b>A of the radial grooves <b>52</b> are formed and, provided that the circumferential grooves <b>56</b> which continue in a smooth arcuate shape without deviation from the curved grooves <b>54</b> along the outer circumference of the sealing disc portion <b>34</b> are formed, the sealing disc portion <b>34</b> can be opened wide with a small amount of pressing force.

P-0128[0128] The thin portions <b>62</b>, <b>114</b> and <b>136</b> may have a constant strength (constant thickness T4). Namely, even in this case, in the same manner that the ratio (L/T2) of the thickness L of the sealing disc portion <b>34</b> to the thickness T2 of the low strength portion <b>64</b> is set to be equal to or more than 2, (L/T4) is set to be equal to or more than 2, and the sealing disc portion <b>34</b> can thereby be opened wide with a small amount of pressing force.

P-0129[0129] The number of each of the grooves <b>50</b>, <b>112</b> and <b>134</b> is not limited to the above-described number of four. However, even if the pressing force is weak, in order to open the sealing disc portion <b>34</b>, <b>116</b> and <b>132</b> widely, the number of grooves is preferably three to five, and more preferably four. Conversely, if the number of the grooves <b>50</b>, <b>112</b>, and <b>134</b> is six or more, after the opening, the fan portions <b>58</b> (see FIG. 4A) of each of the sealing disc portions <b>34</b>, <b>116</b> and <b>132</b> contact closely with the pressing means (the perforating pipe <b>76</b>), and a clearance which is formed between each of the fan portions <b>58</b> and the pressing means decreases. On the other hand, if the number of the grooves <b>50</b>, <b>112</b>, and <b>134</b> is two or less, it becomes difficult to substantially open the sealing disc portions <b>34</b>, <b>116</b>, and <b>132</b>. However, even if the number of grooves is two or less, the grooves can be structured as if the number of the grooves <b>50</b>, <b>112</b> and <b>134</b>, respectively, were three to five, by curving the grooves so as to be formed in a suitable configuration. If three to five grooves are formed, they don't need to be formed radiating from the center of each of the sealing disc portions <b>34</b>, <b>116</b>, and <b>132</b> at a fixed central angle.

P-0130[0130] The grooves <b>50</b>, <b>112</b>, and <b>134</b> do not need to be formed in a continuous linear shape and, for example, may be formed intermittently at predetermined distances in the longitudinal direction thereof so as to form, as a whole, a series of perforations.

P-0131[0131] The low strength portions according to the present invention are not limited to the grooves <b>50</b>, <b>112</b>, and <b>134</b> or grooves which are formed in a perforated shape. For example, a portion, which may be split by the pressing force of the pressing means, can be formed by changing the physical properties of the sealing portions <b>34</b>, <b>116</b>, and <b>132</b>. An example of this is the weld line. A weld line is formed during injection molding of a resin molded product when resin which has flowed out of the gate and diffused around the gate rebonds inside the die. Namely, at portions where a weld line is formed, in many cases, the strength of the resin is deteriorated. Accordingly, molding conditions, the position of the gate, or the like should be set appropriately so that weld lines are formed in the same shape as the thin portions when seen in a plan view.

P-0132[0132] As described above, the sealing disc portion can be broken along a weld line simply by forming the weld line, however, by further forming the grooves <b>50</b>, <b>112</b>, and <b>134</b> at the portions where weld lines are formed, it is possible to form a packing which can open with a smaller amount of pressing force.

P-0133[0133] In the above description, an example in which each of the packings <b>10</b>, <b>110</b>, and <b>130</b> is formed separately from the cap <b>12</b> has been explained. However, the respective packings <b>10</b>, <b>110</b>, and <b>130</b> may be integrated with and the cap <b>12</b>. In this way, when each of the packings <b>10</b>, <b>110</b>, and <b>130</b> are integrated with the cap <b>12</b> and, each of the packings <b>10</b>, <b>110</b>, and <b>130</b> does not fall from the cap <b>12</b>.

P-0134[0134] In the above description, an example of the photographic processing chemicals container <b>14</b> in which the photographic chemicals are contained has been explained. However, the present invention is not limited to this and instead, any type of container can be used.

P-0135[0135] As photographic processing chemicals contained in the photographic processing chemicals container <b>14</b>, for example, a color developing solution, a black &amp; white developing solution, a bleaching solution, a fixing solution, or the like can be listed. These photographic processing chemicals are used to treat a halogen silver photosensitive material, are commercially available, and are known.

P-0136[0136] In the above description, as a material which forms the packings <b>10</b>, <b>110</b>, and <b>130</b>, unfoamed resin which contains 50% or more of low density polyethylene (LDPE) or 50% or more of high density polyethylene (HDPE) has been listed. However, of course, the present invention is not limited to this and instead, materials are appropriately determined by taking chemical resistance, physical strength, or the like of the materials to be contained in the container into consideration. As described above, when the photographic processing chemicals container <b>14</b> in which the photographic processing chemicals are contained is used, from a standpoint of chemical resistance or physical strength, polyethylene is listed as one of the preferable materials.

P-0137[0137] Especially, in the case in which the packing is formed from a resin material which contains a large amount of low density polyethylene (LDPE), as compared to when the packing is formed from a resin material which contains high density polyethylene (HDPE), because the resin itself is soft, the packing is apt to elongate. Accordingly, the central portion of each of the sealing disc portions <b>34</b>, <b>116</b>, and <b>132</b> can be broken with a low pressing force. Further, due to the softness of the resin itself, when the distance moved by the perforating pipe <b>76</b> is short, it is possible that the central portions of the sealing disc portions <b>34</b>, <b>116</b>, and <b>132</b> are in an elongated state but are not broken. Even in this case, by providing a sufficient moving distance for the perforating pipe <b>76</b>, splits which have been formed on the sealing disc portions <b>34</b>, <b>116</b>, and <b>132</b> are extended to the outside of each of the sealing disc portions <b>34</b>, <b>116</b>, and <b>132</b> in the radial direction thereof and the sealing disc portions <b>34</b>, <b>116</b>, and <b>132</b> can be opened wide. Moreover, due to the softness of resin itself, because the sealing disc portions <b>34</b>, <b>116</b>, and <b>132</b> are apt to elongate, for example, if the photographic processing chemicals container <b>14</b> is dropped, even if the internal pressure of the container <b>14</b> changes, this change of the internal pressure can be absorbed by the sealing disc portions <b>34</b>, <b>116</b>, and <b>132</b> being elongated, and packings <b>10</b>, <b>110</b>, and <b>130</b> which are not broken unexpectedly can be formed.

P-0138[0138] On the other hand, if the packings <b>10</b>, <b>110</b>, and <b>130</b> are formed from a resin material which contains a large amount of high density polyethylene (HDPE), as compared to when the packings <b>10</b>, <b>110</b>, and <b>130</b> are formed from a resin material which contains a large amount of low density polyethylene (LDPE), the resin itself is hard. Accordingly, at the initial stage of breaking the sealing disc portions <b>34</b>, <b>116</b>, and <b>132</b>, a larger amount of pressing force is needed. However, once splits are formed on the sealing disc portions <b>34</b>, <b>116</b>, and <b>132</b> (the sealing disc portions <b>34</b>, <b>116</b>, and <b>132</b> are broken), the entire body of each of the sealing disc portions <b>34</b>, <b>116</b>, and <b>132</b> deforms, and perforating force (tensional force) acts upon the thin portions <b>62</b> which are structured by the grooves <b>50</b>. Accordingly, even if the distance moved by the perforating pipe <b>76</b> is small, it is possible to open the sealing disc portions <b>34</b>, <b>116</b>, and <b>132</b> wide. Further, because the resiliency of the resin material itself is lower than a resin material which contains a large amount of low density polyethylene (LDPE), when each of the sealing disc portions <b>34</b>, <b>116</b>, and <b>132</b> are opened, due to the resiliency, it becomes difficult for the fan portions <b>58</b> to return to the original position they were in before the sealing disc portions were opened so that each of the sealing disc portions <b>34</b>, <b>116</b>, and <b>132</b> is held in an open shape. For this reason, a clearance which is formed between the fan portions <b>58</b> and the perforating pipe <b>76</b> due to liquid pressure or the like, when the material contained in the container (photographic processing chemicals or the like) is drained does not decrease, and the draining of the contents can be ensured.

P-0139[0139] The above-described conditions may be realized by using a resin which contains a large amount of middle density polyethylene (MDPE) having a density range of between 0.930 and 0.941 (g/cm³) in JIS K 6748-1982.

P-0140[0140] As described above, a method of opening the packing <b>10</b>, <b>110</b>, and <b>130</b> is not limited to the case in which the photographic processing chemicals container <b>14</b> is set in the photographic processing chemicals supplying device <b>70</b> (see FIG. 8) in an automatic developer, and the packing <b>10</b> is pressed by the perforating pipe <b>76</b>. For example, the packings <b>10</b>, <b>110</b>, and <b>130</b> can be pressed by a bar or the like and thereby opened.