Article carrying and discharge mechanisms

United States Patent

UH 3,589,501

<td> [72]</td><td> Inventor</td><td> John Harrison Lincolnwood, III.</td>

<td> [21]</td><td> Appl. No.</td><td> 816,493</td>

<td> [22]</td><td> Filed</td><td> Apr. 16, 1969</td>

<td> [45]</td><td> Patented</td><td> June 29,1971</td>

<td> [73]</td><td> Assignee</td><td> The Spra-Con Company</td>

<td></td><td></td><td> Chicago, III.</td>

3,386,563 6/1968 Harrison....................... 198/155

3,463,298 8/1969 Harrison........................ 198/155

Primary Examiner— Harvey C. Hornsby Assistant Examiner—Douglas D. Watts Attorney—McDougall, Hersh, Scott and Ladd

[ 54 ] ARTICLE CARRYING AND DISCHARGE

MECHANISMS

Claims, 14 Drawing Figs. (52] U.S. Cl........................................................ 198/155

[51] Int. Cl.........................................................B65g 15/00,

B65g 17/00, B65g 19/00

[50] Field of Search............................................198/155,38 (56] References Cited

UNITED STATES PATENTS

3,231,066 1/1966 Harrisonetal............... 198/155

ABSTRACT: An article delivery system comprising pivotally mounted trays or other article carrying means movable along a conveyor path and including a coding mechanism for selectively pivoting the article carrying means to achieve article discharge. The article carrying means are supported on a downwardly extending actuating member which is connected to a transversely movable element. Movable track sections are located at intervals along the conveyor path and the transversely movable element engages the movable track sections when discharge is to take place. The transverse movement is translated into pivoting movement of the article carrying means.

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ARTICLE CARRYING AND DISCHARGE MECHANISMS

This invention relates to conveyor constructions of the type including a plurality of article carrying means adapted to pivot in their course of movement along a conveyor path for discharging articles.

Article conveyors are advantageously employed for a variety of purposes. One specific application for such conveyors comprises a sortation system wherein articles having some distinguishing characteristics are loaded on the conveyor, A plurality of unloading stations are located along the path of the conveyor. Means are provided for selectively discharging the articles, depending upon which of the unloading stations is to receive articles of a specified character.

Post Office operations can readily employ systems of the type described. In such operations, a great deaf of sorting must be undertaken in order to direct articles to appropriate destinations. Conveyors are desirably employed, particularly conveyors which are capable of automatically discharging articles at a designated unloading station.

Pat. No. 3,231,066 provides an illustration of the type of conveyor system which can be employed. In this prior construction, the trays are supported for tilting movement to either side of the conveyor. The tilting operation is provided by cam means which can be selectively operated so that only designated trays will tilt at a particular station.

Constructions of this type are subject to a great deal of mechanical stress. Specifically, the camming action which characterizes these constructions necessarily involves an impact between stationary members located along the conveyor length and moving members associated with the trays. When the impact occurs, particularly in high-speed operations, high stress can result leading to mechanical failure.

Problems of the type described are also discussed in Harrison application Ser. No. 638,876, filed May 16, 1967, now patent No. 3,462,298. This application provides a system for overcoming these problems by pretilting trays prior to arrival at a discharge location. The pretilting can occur gradually so that impact is substantially reduced. Articles on the tilted trays are held in place by means of end gates, and discharge is accomplished by unlocking the end gates at an appropriate time. Impact then occurs between the end gate locking mechanism and the unlocking means interposed in the path of the locking . mechanism; however, the tray structure is generally free of direct and damaging impact forces.

The instant invention has for its general object the provision of an article delivery and discharge system which provides still further improvements from the standpoint of reliability of ; operation.

It is a more specific object of this invention to provide a system of the type described which includes highly reliable operating mechanisms whereby article discharge can be achieved in a highly efficient manner. ;

It is a still further object of this invention to provide a system of the type described which comprises a vary compact assembly so that maximum article distribution can be achieved in a minimum amount of space.

It is a further object of this invention to provide a system of 60 the type described which is characterized by operating devices of a highly versatile nature so that conveyor paths of different configurations can be selected, depending upon the nature of the facilities available.

These and other objects of this invention will appear hereinafter and for purposes of illustration, but not of limitation, specific embodiments of the invention are shown in the accompanying drawings in which:

FIG. 1 is a vertical, sectional view of a conveyor construction illustrating a tray design characterized by the features Of this invention;

FIG. 2 is a horizontal, sectional view taken about the line 2-2 of FIG. 1;

FIG. 3 is a vertical, sectional view taken about the line 3-3 ofFIG. 1;

FIG. 4 is a vertical, sectional view taken about the line 4-4 ofFIG. 3;

FIG. 5 is a plan view illustrating the track construction including the means for achieving discharge;

FIG. 6 is a plan view of the construction shown in FIG. 5 in the discharge position;

FIG. 7 is an enlarged detail view illustrating the movable discharge track section;

FIG. 8 is an enlarged fragmentary view illustrating the movable track section and associated operating elements;

FIG. 9 is an enlarged, fragmentary sectional view illustrating a movable track employed for discharge purposes;

FIG. 10 is an enlarged fragmentary, sectional view taken about the line 10-10 of FIG. 5 and illustrating an alternative form of movable track;

FIG. 11 is a side view taken about the line 11-11 of FIG. 10;

FIG. 12 is an enlarged fragmentary side elevational view taken about the line 12-12 of FIG. 5;

FIG. 13 is an exploded perspective view illustrating operating components associated with the movable track section; and,

FIG. 14 is a schematic illustration of a conveyor system which can be adapted for use with the constructions of this invention.

The system of this invention generally comprises an article carrying means located on a conveyor for movement past at least one article loading station and past a plurality of article discharge stations. In accordance with conventional practice, 30 'he invention is most efficiently used in conjunction with a system having coding and memory devices so that a person placing an article on a conveyor can at the same time assign a code to the article, for example, by pushing buttons on a panel. Depending on the code assigned, the memory system will automatically operate discharge initiating means, for example, a solenoid, when the article carrying means supporting the article reaches the discharge location.

In accordance with this invention, the trays or other article carrying means are pivotally mounted so that they can be tilted for discharge purposes. The invention will be described relative to tilting immediately opposite a discharge location; however, it will be understood that the design of the means for tilting the article carrying means could be incorporated in a system of the type disclosed in Ser. No. 638,876 where an end gate is employed.

The article carrying means of the invention specifically include a downwardly extending actuating member which is pivotally connected at an intermediate point and which is tied to a transversely movable element. This transversely movable element is adapted to follow a track comprised of stationary and movable sections. When the movable sections are actuated to achieve tilting action, the resulting movement of the transversely movable element is translated into pivotal movement of the article carrying means. It has been found that the transverse movement can be carried out in a smooth fashion substantially free of significant impact forces. The tilting of a tray or other means is then accomplished without applying damaging forces to any of the associated components.

FIG. 14 illustrates in dotted lines a conveyor path 10 having an article loading station 12 adjacent thereto. In accordance with conventional practice, an individual shown at 14 operates a keyboard 16 to assign a code to each article at the loading station. The articles are transferred manually or automatically to article carrying means when the code is assigned.

A plurality of discharge stations 18 are located around the conveyor path. As illustrated, the discharge locations may be located in opposed relationship on both sides of the conveyor or in alternating relationship on both sides of the conveyor. In some instances, the stations may be situated on only one side whereby the trays or other article carrying means will only tilt in one direction.

FIGS. 1 through 4 illustrate a supporting frame 20 carrying opposed tracks 22, these tracks defining the conveyor path. Trucks 24 having wheels 26 are mounted for movement over the tracks. Each of the trucks includes downwardly extending

3,589,501 posts 28 supporting rollers 30 which ride between additional track forming members 32. A downwardly extending continuation 34, associated with one of the posts 38 on each truck, provides a means for connecting each truck to a drive chain 36.

Each truck carries an opposed pair of guide plates 38. Braces 40 extend upwardly from the guide plates for connection with the legs 42 of the U-shaped bar 44. Additional angularly extending braces 46 also extend between the rectangular frame of the truck and the legs 42.

Opposed openings are formed at the top of the legs 42 for pivotally supporting the shaft 48. An arm 50 is tied at the center of the shaft, and this arm extends upwardly for connection with the tray support 52. The tray support includes legs 54 which are tied to the shaft 48. The tray 56 will pivot about the axis defined by the shaft 48 in response to swinging movement of the arm 50.

The lower end of the arm 50 carries a pin 58 which supports rollers 60. A pair of bifurcated members are formed by the pieces 62 which are welded to the top surface of horizontally extending plate 64. The side edges 66 of the plate are received in grooves 68 defined by the opposed inner faces of the guide plates 38. This arrangement permits sliding movement of the plate 64 relative to the guide plates 38. In the course of this movement, the arm 50 will swing to impart pivotal movement to the tray 56. The bifurcated arrangement confining the end of the arm 50 permits this movement as best illustrated in FIGS. 1 and 4.

Extending downwardly from the plate 64 are a pair of rollers 70. These rollers engage stationary track sections 72 in the course of movement of a truck between discharge stations.

FIGS. 5 through 7 and 10 through 13 illustrate mechanisms utilized at a discharge location. The mechanisms include movable track sections 74 pivotally connected to the stationary track sections 72 at 76. The movable track sections each include an outer wall 78 providing an extension of the upstanding wall of the track 72. In addition, the movable track sections provide collapsible inner walls 80. If a tray is to pass by the discharge location shown in FIGS. 5 and 6 without discharging an article, then the rollers 70 will simply move from engagement with the track 72 into engagement with the wall 78 of the track 74 and then into engagement with the next stationary track section 72.

As best shown in FIGS. 8 and 12, a spring 82 is connected to a pin 84 extending downwardly from the movable track 74. This spring normally urges the track into the pivoted or switched position shown in FIG. 8. A lock for the track section 74 is illustrated in FIG. 9. This lock consists of a plate 86 defining a shoulder 88 for engagement with a second pin 90 extending downwardly from the track section 74. The shoulder normally extends upwardly through an opening 92 defined by a support plate 94. The plate is pivotally connected at 96 to a block 98 attached to the underside of the support plate, and a spring 100 normally forces the plate 86 into the solid line position shown in FIG. 9.

A solenoid 102 includes a core 104 which is connected at 106 to the plate 86. When the solenoid is pulled in, the plate 86 pivots to the dotted line position shown in opposition to the spring 100 thereby releasing the pin 90 and allowing the spring 82 to switch the movable track 74. A stop lug 108 is positioned on the top surface of the plate 94 to limit the movement of the track section 74 whereby the track section will be accurately aligned.

An additional track section 110 is provided as a continuation of the track section 74. This additional track section is employed to provide additional pivoting movement of the article carrying trays. Thus, a roller 70 will impart a certain amount of transverse movement to the plate 64 for achieving tilting of a tray in the course of movement of the roller along the track section 74. Additional tilting movement will be provided as the roller moves onto the track section 110; however, at this time, the track section 74 can be restored into alignment with the stationary track 72. This provides for improved operating capability since the speed of the conveyor is not limited by the necessity for achieving complete tray tilting and for moving the tray tilting element back to its starting position before the next tray arrives. An additional advantage is pro⁵ vided since the track section 74 may impart gradual tilting movement to reduce stress on the conveyor components, and this gradual tilting can then be continued by the track section 110 after the section 74 has been restored. Accordingly, gradual tilting does not place a limitation on the conveyor ‘° speed.

The restoring of the sections 74 is accomplished through engagement of a roller 70 with the extension 112 formed at the end of the lever 114. This extension is received in an elon₅ gated opening 116 defined by the wall 118 of the track section 110 and an opposed shorter opening 120 defined by the wall 122 of this track section. When a roller 70 enters the track section 110, the lever 114 is pivoted out of blocking position. This action moves the pin 124 carried by the arm 126 of the 2q lever into engagement with the arm 127 of a second lever 128.

The arm 127 includes a right angle extension 130, and a recess 132 is defined at the juncture of the extension and the arm. A pin 134 extending downwardly from the bottom of the movable track section 74 is received in this recess when the 25 movable track section is switched to the discharge position. A spring 136 is connected to the pin 138 carried by the arm 127 so that this arm is normally urged into engagement with the pin thereby locking the track section 74 in the switched position.

When the pin 124 on the arm 126 engages the arm 127, the latter arm is unlocked relative to the track section 74. The track section is restored due to the engagement of roller 140 with the track wall 142. The roller 140 is carried on the arm 144 which is mounted for pivotal movement about its end 146.

A pin 148 extending downwardly from the arm 150 of lever 128 is received in the openings 152 defined by the arm 144 whereby this arm will pivot into engagement with the track section 74 when the lever 128 is pivoted.

When the track section 74 has been restored into alignment ⁴θ with the track 72, the pin 134 is maintained in abutment with the outer edge 154 of the extension 130 on the lever 128. When the roller 70 has passed by the extension 112, this extension will move back into blocking position due to the action of spring 156 which extends between the pin 124 and the ⁵ stationary pin 158 which serves to hold the ends of both springs 136 and 156.

Where movable track sections 74 are located in opposed relationship on both sides of the conveyor construction, the 5θ interior walls of these track sections are formed in the manner shown in FIGS. 10 and 11. In this arrangement, each interior wall 160 is formed integrally with arms 162 which are pivotally connected at 164. The under sides of the arms are engaged by posts 166 which extend upwardly from a frame plate 168.

When the movable track sections are in alignment with the stationary track sections 72, then the interior walls 160 are in the collapsible position shown in FIG. 10. Accordingly, the exterior walls 170 will be in alignment with the upstanding wall 60 of stationary track 72. When one of the adjustable tracks is switched under the influence of a spring 82, then the interior wall 160 of that track section will be cammed upwardly by the associated posts 166 to the dotted line position shown in FIG. 10. The opposite interior wall 160 remains in the collapsed 65 position so that the roller 70 on that side will clear this wall to permit the switching movement. When a wall 160 has been moved upwardly for switching purposes, then this wall will serve as the guiding surface for the roller 70 during tilting of a tray.

The arrangement shown in FIG. 9 is utilized where switching occurs on only one side of the conveyor at any given location. With this arrangement, both walls of the movable track section 74 are permanently attached. This arrangement may be used where the conveyor is designed to discharge from ⁷⁵ one side only or where discharge locations are located on both

3,589,501 sides but are in different positions along the length of the conveyor. FIG. 14 illustrates these three possible arrangements.

The lever 128 is provided with an outwardly extending bearing strip 174 which lies in the path of a roller 70 when the associated movable track section has been switched to the discharge position. This arrangement serves as a safety feature in the event that for some reason the movable track section is not restored to the aligned position after it has operated to tilt a tray. Referring to FIG. 6, it will be noted that the leading pair of rollers 70 is near completion of a tilting operation. The following pair of rollers 70 at the left in FIG. 6, has been acted on by a movable track section at a preceding discharge station and, accordingly, the lower roller 70 of this pair would engage the movable track section 74 if this track section remains in the switched position. This would result in jamming of the construction since the sliding plate 64 is at an extreme position.

This possibility is eliminated since the upper roller 70 of this trailing pair will engage the bearing strip 174 and pivot the lever 128 thereby releasing the pin 134 which is held in the recess 132. Continued movement of the lower roller 70 into the movable track section 74 will then force this track section into the aligned position where it will be held by the locking plate 86. ^s

The additional track section 110 may also be extended to the length shown to provide for adequate tray tilting. Since this will place the track section in the path of the upper roller 70 which has been moved to a discharge position at a preceding station, the track section 110 is pivotally connected at 176. A suitable spring is provided to normally hold the track section in the position illustrated, however, engagement by the roller 70 will force the track section inwardly in opposition to the spring until the roller has moved past the discharge station.

Various means may be employed for initiating tray discharge through operation of solenoids 102 which are located at the various discharge positions 18 around the conveyor. Other means, including manual operation could be employed for achieving the discharge action by operating the locking plate 86; however, the use of a pushbutton console for coding articles placed on the conveyor is definitely preferred. The code applied to an article at the end of loading can then be used to operate the solenoids, and control systems such as described in Speaker Pat. No. 3,034,665 could be utilized for this purpose. As explained in this patent, coding devices can be incorporated in this system which are capable of synchronization with the tray movement whereby an electrical signal will be generated when a tray reaches a location corresponding to a particular code. This signal can then be utilized for energizing the particular solenoid 102.

As indicated, the article conveying construction of this invention provides distinct advantages apart from the mechanism employed for achieving tilting at the particular discharge locations. Accordingly, the article carrying arrangements shown in FIGS. 1 through 4 could be employed in conjunction with other systems, for example, a system as described in the aforementioned Harrison application Serial No. 638,876. In this case, an end gate would be associated with each article carrying means and pretilting would be provided. The selective opening of end gates at discharge locations can then be accomplished by a coding system in the manner described.

Irrespective of the manner in which tilting is accomplished, the article carrying means may be restored to a horizontal position by the use of auxiliary tracks such as shown at 180 in FIG. 14. This track may simply comprise an inwardly directed surface for engaging rollers 70 which have been moved to outer discharge positions whereby these rollers will be forced back to a centrally located position with the associated article carrying means being restored to the horizontal.

The construction of this invention is readily convertible to a Ferris wheel type conveyor system instead of the carousal type illustrated. Although trays are shown as the article carrying means, other conveyor surfaces are clearly suitable, for exam25 pie a conveyor bed composed of slats with portions being tiltable relative to each other.

The design illustrated is quite compact and, therefore, requires a minimum amount of space and material for installation. All parts can be of welded construction, and the virtual elimination of castings provides a significant improvement in safety as well as cost. The system can be operated at very high speed because of the virtual elimination of high impact stresses. A minimum amount of energy is required for achieving tripping since the electrical signal need only operate the locking plate 86. In this connection, the trays are locked when in the horizontal position all along the conveyor path, including the discharge stations, to prevent accidental tipping.

It will be understood that various changes and modifications may be made in the above-described system which provide the characteristics of this invention without departing from the spirit thereof particularly as defined in the following claims.