Pack comprising a dispensing orifice created by overlapping portions of a laminated packaging material

Field of Invention

The invention relates to a pack of products that can be dispensed from the pack, such as a pack of paper handkerchiefs. The invention describes a pack that provides an optimum hygienic protection of the products in the pack while allowing for a easy, convenient dispensing of the products and optimizing the use of materials. The above advantages are in particular delivered by a closure means such as a flap or panel able to cover the dispensing opening and the surrounding material in an overlapping way.

Background of the Invention

Many products are sold in flexible packaging from which the products are dispensed. Such product can be paper handkerchiefs or wipes of all sorts. The packs act as protective barrier to prevent dust and dirt from coming in contact with the products during storage and use. The packs are also in many cases the preferred dispensing device from which the users can remove the product prior to use. In most cases, the dispensing is made through an orifice in the pack adapted to let the products (such as paper handkerchiefs) be removed from the pack while still confining the remaining products inside the pack and still allowing for good storage and protection of the unused products.

In the pending <patcit id="pcit0001" dnum="EP03007885A"><text>European application number 03 007 885, filed on the 7th April 2003, Goepfert et al</text></patcit> describes the advantages of having packs in which dispensing orifices include an overlapping portion: the overlap creates an efficient barrier to dust and dirt while allowing for a convenient use of the pack.

Pack made of flexible film materials are usually made by cutting and folding the film material in such a way that the end configuration correspond to the shape of the desired pack. In a conventional way, that overlapping portion (i.e. a flap) of the pack is added to the pack as a separate piece of material. Not only does this cause a significant complexity in the manufacturing process, but it also increase the total pack cost, as the presence of an overlap increases the consumption of material and increases the number of manufacturing steps.

Prior art

A useful example of the field of application of the present invention are the Tempo® paper handkerchiefs commercialized by The Procter &amp; Gamble company. The most usual packs are wrapped by a piece of plastic film shaped and sealed to from a substantially parallelepipedic pack having approximate dimensions of 110mm x 55mm x 20mm. Packs of smaller or larger dimensions exist or can be contemplated. The dispensing opening of these packs is located at one end of one of a front panel (or side), including one intermediate pack edge. A pre-perforated area can be broken to create an opening and a flap articulated over a hinge parallel to, or located on an intermediate pack edge. The opening is of a substantially half-circle shape. The piece of material covering initially the opening creates a flap that can alternatively close or open the dispensing orifice. The flap can be maintained in the closed position by a re-sealable tape bridging in a temporary way the flap and the front panel. The re-seal tape has one end not presenting any adhesive (so called "dry end") enabling for an easy gripping and operation of the tape and of the closure flap.

Two patent applications describe attempts to increase the convenience and hygienic properties of the above described conventional packs of paper handkerchiefs:

In <patcit id="pcit0002" dnum="EP01129421A"><text>European application EP 01129421</text></patcit>, Goepfert and Buschkiel describe a pack having a flap hingedly connected to a side panel. The shape and size of the non-overlapping flap are specifically designed to enhance the hygienic protection of the handkerchiefs while maximizing the convenience of dispensing.

In the pending <patcit id="pcit0003" dnum="EP03007885A"><text>European application number 03 007 885</text></patcit>, filed on the 7^th of April 2003 Goepfert et al. describe a pack having a dispensing orifice with an overlapping portion to further enhance the protection of the handkerchiefs.

Other documents describe packs with overlapping portions : In <patcit id="pcit0004" dnum="EP0475463B1"><text>EP 0475 463 B1</text></patcit>, H. Focke describes a pack for paper handkerchiefs with a re-seal tape partially or fully covering a closure flap.

In <patcit id="pcit0005" dnum="EP0961736A"><text>EP 0961 736, Muller et al.</text></patcit> describe a pack with a closure flap located on the side panel. The flap partly overlaps with the side panel of the pack. Slits are present in the film to delineate a dispensing orifice smaller than the side panel. A reseal tape is provided to reclose the flap over the dispensing orifice.

In a substantial similar way, Focke and Wach describe in <patcit id="pcit0006" dnum="EP0401621A"><text>EP 0401 621</text></patcit> a pack with a dispensing opening which is located on the side panel and delineated by severance cuts. The cuts can be extended to the front panel. It this embodiment, the dispensing orifice comprises portions of both front and side panels and the hinge of the flap located on the front panel.

Focke and Mathews also substantially describe this latest embodiment in <patcit id="pcit0007" dnum="DE3920065A1"><text>DE 39 20 065 A1</text></patcit>.

<patcit id="pcit0008" dnum="DE3100286A1"><text>DE 31 00 286 A1</text></patcit>, describe a pack with a flap able to overlap fully the dispensing orifice. The dispensing orifice is located at one end of a front panel, close to an intermediate pack edge.

In <patcit id="pcit0009" dnum="DE3911779A1"><text>DE 39 11 779 A1</text></patcit>, Focke and Liedtke describe a pack with a reseal tape which overlaps the dispensing orifice in the front panel. The dispensing orifice of the front panel allows for the gripping of a handkerchief in the pack. The flexibility of the film enables the removal of the handkerchief in the opening created along an intermediate pack edge corresponding to the hinge of the flap.

In <patcit id="pcit0010" dnum="EP0553660B1"><text>EP 0 553 660 B1</text></patcit>, H. Focke describes a pack that has a dispensing orifice in the front panel. A flap overlaps the dispensing orifice. The overlapping part of the flap is created by a Z-fold in the one piece of film material constituting the pack, after appropriate cutting. The hinge of the flap is located along one intermediate pack edge. The defined size of the one piece of material limits the extent of the overlapping zone of flap around the dispensing orifice.

In <patcit id="pcit0011" dnum="WO9806369A"><text>WO 98/06369</text></patcit> and corresponding <patcit id="pcit0012" dnum="US6015045A"><text>US 6 015 045</text></patcit>, Joseph et al describe a pack for hygienic articles having a re-closable flap overlapping a dispensing orifice. An additional material is used to create the overlap of the flap around the dispensing opening. The hinge of the flap is located along the intermediate pack edge, opening in the front panel.

In <patcit id="pcit0013" dnum="DE3542999A1"><text>DE 35 42 999 A1</text></patcit>, filed on 5.12.1995 by Schickedanz, H. Pohl describes a pack which flap is constituted by an oversized reseal tape, covering a dispensing orifice as well the surrounding panel. A tissue edge appears through the dispensing hole. The reseal tape requires a complex adhesive distribution to insure the functionality of the break-out portion.

In <patcit id="pcit0014" dnum="EP1120356B1"><text>EP 1 120 356 B1</text></patcit>, Pierre Laurent et al. describe a pack having a flap which elements are formed in a single piece with the packaging.

In all of the packs described by the above documents the overlapping portion, when present, is constituted by 2 layers of a film material. Consequently an extra thickness is created by the 2 layers of material overlapping together. Also, in most cases the overlap is indeed an additional piece of film material that is cut and placed in such a way to overlap with the primary piece of film material forming the body of the pack.

There is a need to handkerchiefs packs having maximized orifice, fully enabling the convenience of dispensing of handkerchiefs.

There is need for a pack offering an enhanced level of tissue protection inside the pack, via an overlapping dispensing orifice, while being relatively simple to manufacture.

There is a need for a pack comprising flexible film materials having a overlapping portions with an optimized material utilization.

There a need for such a pack that is also designed and manufactured in a way that reduces production, capital and material cost.

There is a need for such a pack that is relatively easy to manufacture.

There is a need for such a pack that does not have a double layer of material in the overlapping area of the dispensing orifice.

Finally there is a need for such a pack that combines many or all of the above advantages.

Summary of the Invention

The present invention describes a pack usable for packing paper handkerchiefs. The pack comprises a flexible film material forming the pack, and the film material can comprise two layers of flexible film materials partially joined together. The film material has portions which overlap with other portions when the film is forming the pack. The film material has non-overlapping portions of film material outside the overlapping portions and the pack has a dispensing orifice.

The pack is as such that the overlapping portions of the film material overlap with other overlapping portions of film material. The non-overlapping portions of film material have a first thickness. The overlapping portions of the film material have a second and a third thickness.

The second and third thicknesses are less than the first thickness.The first layer of the flexible film material has a first slit. The second layer of the flexible film material has a second slit. Said overlapping portions of film material delineate said dispensing orifice. Said first and second layers are superimposed and joined in selected area such that no part of said first slit overlaps any part of said second slit and such that the area between said slits remains not joined.

In another aspect, the present invention relates to the process of manufacturing such a pack.

For example, the present invention can apply to a pack for paper handkerchiefs having a dispensing orifice covered by a panel (or a flap) that overlaps one or two of the walls of the pack.. In one of the embodiments, the overlapping portion (for example the flap) can cover the dispensing orifice and overlap with another overlapping portion when the pack is in his final folded configuration.

In one embodiment, the present invention combines of at least two relatively thin layers of material that are cut and joined together in such a way that the overlapping portions of material are thinner than the non overlapping portions: the two layers of film material are laminated in most of their surface except in the portions that will form the overlaps on the pack. In those areas, only one layer of material is present. Slits and cuts are provided on the film material to define the dispensing orifice when the pack is folded.

One of the advantages of the pack of the invention is that the utilization of the film material is enhanced and that the pack is relatively simple to manufacture.

Brief Description of the Drawings

<ul id="ul0001" list-style="none"><li>Figure 1 is an isometric view of one example of the pack of the present invention (a pack of paper handkerchiefs).</li><li>Figure 2 shows a first layer of film material used to construct the pack.</li><li>Figure 3 shows a second layer of film material used to construct the pack.</li><li>Figure 4 shows the pack material resulting from the lamination of the first and second layers of film material.</li><li>Figure 5 represent a isometric view of a pack, showing the arrangement of the laminated 2 layers of film material.</li></ul>

Detailed Description of the Invention

<u style="single">Definitions:</u>

Figure 1 shows and defines, for the purpose of this document: <ul id="ul0002" list-style="bullet" compact="compact"><li>The front panels (1) are defined as the panel of largest area. The pack (10) exemplified in Figure 1 has 2 front panels. For simplicity in this document, the reference to "the" front panel of the pack indicates the one panel comprising the dispensing orifice or part of it.</li><li>The side panels are labeled (2), the top panel (3) and bottom panel (4).</li><li>The dispensing orifice (9) is the aperture though which the products (the tissue in the case of a pack of paper handkerchiefs) can be grabbed and possibly removed from the pack during the dispensing operation.</li><li>The flap or closure means (5) is a piece of material movable between a close and an open position, and able to cover at least partially the dispensing orifice. The flap may articulates around a hinge (6) that is connected to a pack panel or pack edge. The periphery of the closure means (5) then has a "connected portion" (7) (articulating around a hinge (6) and an "unconnected portion"(8). The unconnected peripheral portion (8) is not permanently connected to the pack. In the present invention, the flap not only covers the dispensing orifice but its overlapping area (20) overlaps a portion of material forming one panel, preferably the front panel.</li><li>The reseal tape, or reseal piece (11) is a piece of material able to lock the flap in the closed position and generally allows the pack to be re-open at the users need to enable the dispensing operation.</li></ul>

For the purpose of the present invention, the following terms and wording are defined and used interchangeably, and with the same meaning: <ul id="ul0003" list-style="dash" compact="compact"><li>Products or articles such as handkerchiefs, paper handkerchiefs, towels or tissues.</li><li>Film, flexible film, wrapping material, packing material to describe the flexible material constituting the majority of the pack. The flexible film used in the present invention can be any type of film suitable for the making of packs and combining a flexibility and resistance. In certain embodiments, the film may be a heat sealable film comprising polyethylene or polypropylene or mixture thereof.</li><li>Pack or container is a receptacle for products, usually intended to protect and keep the products together during storage and use. Preferably, the pack has at least one panel that is a substantially flat surface.</li><li>Dispensing orifice, orifice or dispensing aperture: orifice through which the individual product (for examples paper handkerchiefs) are usually removed from the pack.</li><li>Dispensing flap, or flap or closure means describe the piece of material covering at least partially the dispensing orifice. Also describe a part of the packing material intended to cover part of another portion of packaging material in the final configuration of the pack.</li><li>Overlap or overhang or Overlapping portion of film material: for the purpose of the present invention, an overlapping portion is defined as a portion of film material that, in the intended final configuration of the pack and in normal usage conditions, can overlap another portion of film material of the pack (for reciprocity reason, that other portion of material being overlapped is also defined as being an overlapping portion, as both portions mutually overlap each other). In one embodiment of the present invention, one overlapping portion is located on the flap covering the dispensing orifice: Upon closure of the flap against the front panel, the overlap can cover a part of the front panel (to insure high protection of the products inside the pack).</li><li>Non-overlapping portion of film material is defined as a portion of film material of the pack that, in the intended final configuration of the pack and under normal usage conditions, is not intended to overlap with another portion of material. It is however understood that the film material of the invention is typically a flexible film. Therefore any portion of the pack could be considered as able to overlap another portion, when the pack is crushed, flattened, folded or squeezed. The above definitions specifically exclude those cases as they are not "normal usage conditions" and that a pack crushed, squeezed, flattened or folded pack is not in its "intended final configuration".</li><li>Thickness of film material or caliper of film material is measured according to the method provided hereafter. It is understood that the thickness of a layer is the average thickness of that material measured in areas where the material is homogeneous and of substantially constant thickness (it is assumed that common film materials, as those used for the purpose of this invention, are usually provided as raw materials of substantially constant thickness).</li></ul>

Detailed description of the invention:

In the context of packs of product such as paper handkerchiefs, one can understand easily that a large flap covering all the dispensing orifice and extending over it to create an overlap on one of the panel, is extremely beneficial for the protection of the products inside the pack. However such a large overlap may require additional and significant material cost. It may also presents the technical difficulty of requiring a particular process and-or a secondary material providing for the flap or overlap. <patcit id="pcit0015" dnum="WO9806369A"><text>Patent application WO98/06369</text></patcit> uses for that purpose an additional piece of material, whereas <patcit id="pcit0016" dnum="EP0553660A"><text>EP 0553 660</text></patcit> creates a Z-fold in the material to create the overlap. <patcit id="pcit0017" dnum="DE3542999A1"><text>DE 35 42 999A1</text></patcit> uses an over-dimensioned re-seal tape for that purpose.

In any case in the conventional packs, the simple fact of having an overlapping portion of film material diminishes the optimum utilization of the film as the overlap represents a zone having double amount of film material. Furthermore the thickness of that extra material can cause some issues in certain types of packaging.

In the present invention, the pack includes of 2 (or 3 or more) layers of material that are generally joined together in a face-to-face relationship to substantially constitute the body of the pack. In the areas of overlap, however, the 2 (or 3 or more) layers of material are not joined together, but only juxtaposed.

The slits and cuts defining the dispensing orifice of the pack are severed on the film material. They are positioned on each layer in such a way that they do not overlap when the layers are juxtaposed and joined together.

The portions of film material located between the slits are not joined together, thus enabled to separate the flap from the panel when the pack in its final folded configuration. This construction creates an overlapping zone surrounding the dispensing orifice(s) insuring good protection of the packed products.

Figure 1 exhibits a particular example of the pack of the present invention. The pack (10) comprises panels (1, 2, 3, 4, 21, i.e. front panel, side panels, bottom panel and back panel) and a dispensing orifice (9). The pack is made of a flexible film material. The body of the pack is made of at least 2 layers of film material joined together (to note, the joined layers of flexible film material, considered as a whole, represent as well a flexible film packing material). A flap (5), hingily connected to the body of the pack, covers the dispensing orifice (9) and overlaps a portion of the film material forming the front panel (1) (thus insuring an increased protection of the products).

It is to be noted that each single layer of flexible film material usable as per the present invention can be comparatively of lower caliper (or/and lower basis weigh) in comparison to conventional packs: As a (at least) double layer of material is used to form the body of the pack, the film material protecting the products is altogether as thick and as resistant as in conventional packs.

In Figure 2 a first piece of relatively thin packaging film material is shown (12). It constitutes the first layer of film material in the construction of the pack. The film material (12) is cut in a substantially rectangular shape. That shape corresponds to the material necessary to form the substantially parallelipedic pack (10) of Figure 1. The material is severed by a slit (13) in the material corresponding to the general shape of the flap (5) shown in figure 1. The slit (13) will delineate the edge of the dispensing orifice in the formed pack.

Similarly, in Fig 3 is shown a second piece of relatively thin packaging material (14). It will constitute the second layer of film material in the construction of the pack (10). As for the first layer, a slit (15) is severed in the second piece of film material. The slit (15) on the second piece of film material (14) has preferably a shape substantially similar to the shape of the slit (13) on the first piece of film material (12). In other embodiments however, the slits can have substantially different shapes. To note, however, is that the position of the slits (13, 15) (relative to the pieces of material) is different in the first (12) and second (14) pieces of film material.

The material of the first and second pieces (12, 14) of flexible film material can be identical material or their composition can differ. Preferably, their composition, thickness and characteristics are adapted to deliver the intended characteristics (resistance, color, softness, etc) to the body of the pack.

An advantage of the present invention is that the film material can be substantially thinner (and/or of lower basis weight) than the film material used in conventional pack making. This is enabled by the use of a double layer of material to constitute the final pack walls (i.e. the first and second pieces of film material joined together). In one embodiment, the film material used in the present invention has a basis weight of less than 30 g/sqm, more preferably less than 25 g/sqm most preferably less than 20 g/sqm.

The film material (12, 14) may be printed with decorative or other visual indicia, such as logos, pictures or text in relation with the product.

Figure 4 shows the pieces of film material (12, 14) of Figure 3 and 4 superimposed for form the total material that make the body of the pack (10). That film (constituted of the first (12) and second (14) pieces of film material superimposed) will be folded, further severed, and joined to adopt the 3 dimensional configuration of the pack (10). The slits (13, 15) of the first and second layers of material preferably do not superimpose nor cross over each other. The pieces of film material (12, 14) are joined together on most of their surface, except in the area between the slits (13, 15). Reference (16) indicates the area in which the 2 layers are joined together. Reference (17) indicates the area in which the 2 layers are not joined together but only superimposed. This area (17) becomes the overlapping area (20) in the folded pack (10). The 2 layers can be joined together by any mean insuring the attachment of the layers, for example gluing, thermal bonding, lamination under high pressure or any combination therefrom.

Figure 5 represent a cross section on the pack (10) (indicated A-A' on fig 1). In the illustration, in order to enhance the understanding, the 2 layers (12, 14) of film material are shown as separate entities, whereas the layers (12, 14) are preferably joined in such a way that they substantially constitute a single piece of film material once joined together, and they do not separate in use.

The edges of the dispensing orifice (9) and of the overlapping flap (5) comprises the edge (23) of the first layer (made from the slit (13) in the first layer of film material (12)), and the edge (22) of the second layer (14) (made from the slit (15) in the second layer (14)).

The overlap is defined by the portion of material of the first (12) and second layers (14) that are located between the slits (13,15). The overlapping portion (25) of the first layer of material (12) overlaps with the second overlapping portion (24) of the second layer of material (14).

The thickness of the non-overlapping portions of material (26) is called first thickness. In one embodiment, said first thickness is the general thickness of the walls or panels of the pack (except in the overlapping portions).

In one embodiment, the total thickness of the pack panels is substantially the thickness of the two layers (12, 14) of material joined together.

In one embodiment of the invention, the overlapping portions of material (24, 25 in the zone (20) ) are constituted by one of the layers only. The thickness of the overlapping portions is substantially the thickness of their corresponding single layer of film material.

They constitute the so-called second and third thickness. Of note the second and third thicknesses can be equal (for example when the same film material is used for the first (12) and second layers (14) ), or can be different. Preferably the second and third thicknesses are equal.

In certain embodiments of this invention, one or more layers of film material used in the construction of the pack can be made of the same material (i.e. be identical). In other embodiments, the first layer (12) or second (14) layer can be different and/or have same or different thicknesses in comparison to the second or third thickness.

A method to measure to measure the thickness of the film packaging material is provided herein. Any industry standard method is however adequate, provided that the measurements of the overlapping portions and non-overlapping portions of material are made according to the same method.

By construction, the thickness of each overlapping portion of material (24, 25) (so-called second and third thickness) is less than the thickness of the portion of non-overlapping film, so-called first thickness (shown as reference (26) on fig 5). In the embodiment illustrated in a simplified way in Fig 5, the thickness of the overlapping portion of film is about half the thickness of non-overlapping portions of film: the overlapping portion (24, 25) includes of only 1 layers of film whereas the non-overlapping portion (26) includes 2 layers of film.

Preferably, the total thickness of the overlapping portions the film material together (sum of the second and third thickness) is less than 1.8 time the thickness of the non overlapping portion (first thickness), but may be less than 1.5 times, or more preferably less than 1.2 times.

As the total thickness of the overlapping portions of material (in the area of the flap) is less than the first thickness (general thickness of the walls or panels of the pack), is it easily understood that the material utilization can be optimized: In the flap area, generally, no portion of film has a thickness more than the general thickness of the panels of the pack. This helps to reduce the cost of material per pack. Additionally better closure, handling and functionality of the flap are contemplated.

Process of making the pack of the presenting invention:

The present invention also relates to the process of making the pack of the invention. As illustrated in the description of the figures, the process of the present invention includes the steps of severing pieces of film packing material, by cutting slits and joining the pieces of material in a face to face relationship such a way that the slits of each piece of material do not superimposed each other: There is no part of any slit superimposing to any part of the any other slit. The combined layers of material is then folded, further severed and join together to form the intended final configuration of the pack. The slits are made in such a way that they defined and delineate the dispensing orifice of the pack when the pack is formed.

One of the process steps joins of the layers of film material together. It can be done by any mean insuring an adequate attachment of the layers together (for example gluing, thermal bonding, lamination under pressure, application of binders, etc...). However the area between the slits is not subjected to any attachment (beside the presence of the re-seal tape). That area thus forms the overlapping portions of the pack.

The area of non attachment is substantially the area located between the slits when the 2 layers of film material are superimposed. The area of non-attachment is delimited by virtual lines extending from the end points of one slit to the corresponding end points of the other slit. However, one can foresee that the area not attached may be adapted to match the intended design and additional functionalities. This can allow designing flap with a specific form and shape of the overlapping area: For example, non attached areas extending around the slits (and not only between the slits) can create more flexibility in the pack and allow for optimum dispensing.

The area of non-attachment can be created by a discontinuity in the attachment process, a selection of the attachment area, a masking of the area during the attachment process to prevent them to be affected by the attachment process or by any other adequate mean.

In one embodiment of the present invention, the slits are substantially parallel: the slits are a substantially identical shape and the distance between them (when the layers are superimposed) is substantially a constant (the distance along a tangential direction of one slit). For the purpose of the present invention, it is understood that the term "substantially parallel" includes but is not limited to the parallelism of each portion of the slits, e.g. portion of curved line or portion of straight line. The approximated parallelism of the general directions of the slits and the correspondence of their shape is also included.

In other preferred embodiments the slits are curved and do not comprise any straight portions.

In yet other embodiments the slits on the first and second layers are non parallel but their shape if adapted to form a functional aperture in the 3 dimensional configuration of the formed pack.

It is easily understood that one of the advantage of process of the present invention is to avoid cutting out pieces of materials that need to be removed from the manufacturing lines (i.e. only slits are provided in the layers). This increases both the efficiency of the manufacturing process and reduces the material cost.

Example of Tempo ® paper handkerchiefs packs:

It has been found that a pack of paper handkerchiefs can be made according to this invention. The film material is available from Bischof + Klein GmbH, (Bischof + Klein GmbH &amp; Co. Rahestraße 47 49525 Lengerich - Germany), is made of 100% polyethylene and has a thickness of 18 micrometers. Two pieces of film material (previously printed to the desired graphical design) are cut into the desired shape to provide each one layer of film for making the pack. The pieces of film material are joined together by applying (via conventional glue printing) a thin layer of glue (for example glue type 2k-LF570/Härter 130 available from Herberts GmbH, 42271 Wuppertal Germany) on the first and the second pieces of material and immediately laminating the two pieces together under sufficient pressure to insure a quasi-permanent bonding of the layers. The glue printing leaves on each layer one area free of glue (the glue-free area will form the overlapping portion of the pack material). Once laminated together the layers are submitted to a standard process for forming a flexible pack from a flexible film : the material is folded, sealed, further cut following the procedures known in the art. Similarly additional pieces of material (such as a reseal tape) are added.

Methods:

<i>Thickness of film (Caliper of film):</i> The calipers (or thickness) of the films of the present invention are measured (unless otherwise indicated) according to the International standard method ISO-4593 (second edition 1993-11-15) titled "Plastics- films and sheeting- determination of thickness by mechanical scanning".

<i>Film basis weight:</i> The basis weights (g/sqm) of the films of the present invention are measured (unless otherwise indicated) according to the International norm DIN - ISO 536, issue 1976-06-15.

While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the scope of the invention.