US 3039381 A
Description (OCR text may contain errors)
June 19, 1962 R. B. FITCH 3,039,381
AUTOMATIC MECHANISM FOR SELECTING BOXES ACCORDING TO LENGTH Filed Aug. 11, 1958 4 Sheets-Sheet 1 INVENTOR. Robert B. Fife/1 M, We.
R. B. FITCH June 19, 1962 AUTOMATIC MECHANISM FOR SELECTING BOXES ACCORDING TO LENGTH Filed Aug. 11, 1958 4 Sheets-Sheet 2 INVENTOR. Rober/ B. Fitch m, M YW\ ATTORNEYS.
June 19, 1962 R. B. FITCH 3,039,381
AUTOMATIC MECHANISM FOR SELECTING BOXES ACCORDING TO LENGTH Filed Aug. 11, 1958 4 Sheets-Sheet 3 I I M J IN VEN TOR.
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June 19, 1962 R. B. FITCH 3,039,381
AUTOMATIC MECHANISM FOR SELECTING BOXES ACCORDING TO LENGTH Filed Aug. 11, 1958 4 Sheets-Sheet 4 Zr/ 54 "L12 La? olp .fYY\4| I d aw i 3;
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United States Patent 3,039,381 AUTOMATIC MECHANISM FUR SELECTING BOXES ACCORDING TO LENGTH Robert B. Fitch, Lake Valhalla, Montville, N.J., assignor t stapling Machines C0., Rockaway, N..I., a corporation of Delaware Filed Aug. 11, 1958, Ser. No. 754,336 8 Claims. (Cl. 100-49) This invention relates to a mechanism for selecting containers according to length and type and more particularly for selecting wirebound boxes (including crates) of a predetermined length from among others of different lengths or type.
An object of this invention is to provide a simple, relatively inexpensive but efiicient arrangement which is able to operate quickly and automatically in selecting boxes according to length.
A more specific object is to provide a box-selecting mechanism which is not mechanically complicated and which is easily adjustable in its selecting operation.
Another object is to provide an arrangement of this kind which can easily be added to existing installations as well as being incorporated in new equipment.
These and other objects will in part be understood from and in part pointed out in the description given hereinafter.
In plants where different kinds of produce, such as fruits and vegetables, are processed and packed in boxes for shipment, different kinds and sizes of boxes, cartons and crates are used in accordance with industry standards for each item of produce. One widely used type of shipping container is a wirebound box which is trunklike in shape and has strong re-enforcing wires tied around it at points along-its length. Among the reasons for the popularity of this kind of box is the existence of high speed machinery which can take a fully packed but still open box, and close its topand fasten the binding wires to give a strong lightweight unit ready for shipment, this entire operation taken place automatically at great saving in labor cost. Box closing machines of this general kind are disclosed for example in US. Patents 2,517,710; 2,550,292 and 2,565,987. The present invention provides an automatic box-selecting arrangement for use in conjunction with such box handling or closing machines.
In accordance with the present invention there is provided an arrangement of electric switches and relays which function together to control the starting and stopping of box conveyors so as to deliver a selected box to a given location where it can be closed and fastened, for example. The box conveyorsare able to handle a variety of kinds and sizes of boxes and, the selecting mechanism will single out only desired ones of these boxes, the remaining ones being distributed to other work zones or shipping points. Thisbox selecting arrangement is relatively simple in structure and it is easily set up or programmed to choose a particular length of box from the others. To set this mechanism for choosing boxes of another length requires only therearrangement of several electric switches and is thus easily accomplished.
A better'understanding of the invention together with a fuller appreciation of its many advantages will best be gained from the following description given in connection with the accompanying drawings wherein:
FIGURE 1 is a plan view of the box conveyor portion of a box closing machine, this conveyor being fitted with a box-selecting mechanism according to the invention;
FIGURE 2 is a side view of the conveyor and mechanism;
FIGURE 3 is an enlarged right and center portion of FIGURE 1;
FIGURE 4 is a similarly enlarged section of FIGURE 1 taken as indicated by lines 44 therein;
FIGURE 5 is a section view taken as indicated by lines 55 in FIGURE 3;
FIGURES 6, 7 and 8 are similar to FIGURE 1 but show respectively a box too short to be selected, a box too long, and a box of proper length;
FIGURE 9 is an enlarged section view taken as indicated by lines 99 in FIGURE 2; and
FIGURE 10 is a circuit diagram showing the connection of electric switches and relays in the box-selecting mechanism.
As seen in FIGURES 1 and 2 boxes and crates of different kinds and lengths are adapted to be brought from the left single file from a filling Zone or Zones (not shown) upon a conveyor, generally indicated at 12, and delivered to a selecting mechanism generally indicated at 14. The latter includes an endless chain conveyor .16 which by way of illustration will be described as associated with a box closing machine (not shown) for wirebound boxes.
Conveyor 12 is driven by an electric motor 18 and chain 16 is driven by a similar motor 20. During feeding of the boxes, these motors are driven in unison but they are arranged to be stopped independently. As the various boxes travel along these conveyors, boxes which are longer or shorter than desired, or of different kind, are passed on to the right to a distribution zone (not shown). However, when a box of desired length and kind arrives at selecting mechanism 14, conveyor chain 16 will be stopped with the box in proper position upon it for subsequent automatic handling by the overhead box closing machine at this station. After the closing operation is completed conveyor chain 16 is restarted, the closed box is discharged to the right, and additional boxes are delivered from the left by conveyor 12. This continues until another box of proper length and kind is encountered, whereupon the above cycle of operation is automatically repeated, and so on.
The selecting of a box according to length and according to whether it is a wirebound box is illustrated in FIGURES 6, 7 and 8. As seen in FIGURE 6, a box 30* has just passed from conveyor 12 onto conveyor chain 16. This box is a wirebound type and has three reenforcing wires 31 around it, the box not yet being completely sealed and fastened by these wires. The forward end of this box extends almost but not quite to a treadle switch 32 positionedon the right of chain 16 (see FIG- URE 2) and extending slightly above the top level of the chain. Similarly, the right front edge of box 30 has not quite reached a forward side switch 34 which is adapted to be swung forward by the side of the box when it passes. A similar middle side switch 36 near the center of box 30 is already in contact with the box side and has been actuated. The left rear edge of the box also is still in position to actuate a rear side switch 38. Finally, the bottom rear edge of the box and the rear binding wire 3 1lie upon and bridge a pair of flexible contacts 49 of a detector switch 42 positioned just above the top level of chm'n 16.
Assuming that mechanism 14 including the switches just named have been set to select a box longer than box 30, conveyor chain 16 will continue to carry this box to the right and discharge it without stopping. If the next box to reach chain 16, as illustrated by box 44 in FIG- URE 7, happens to have a length greater than that of a box to be stopped, theconveyor chain will also keep running and discharge the box without stopping. However, when a box of proper length, as illustrated by box 46 in FIGURE 8, arrives the control switches will be operated in proper sequence to stop this box and to prevent further delivery of other boxes until the closing operation has been completed. The length of box 46 is such that the side switches 34, 36 and 38 and detector switch 42 can be simultaneously actuated by the box whereas treadle switch 32 would not yet be actuated. In the case of a longer box 44, treadle switch 32 would be actuated before rear switch 38 was released, while with a shorter box 30, switch 34 would not be actuated before switch 38 was released.
FIGURE 10 is a diagram of a circuit 5-0 for controlling the operation of the box selecting mechanism. This circuit incorporates the box actuated switches 32, 34, 36, 38 and 42 (all located near the lower part of the circuit) previously mentioned together with additional switches which function together to give the box selecting operation generally described above. All switches in FIG- URE are shown in their normal rest position.
Three-phase power is applied to control circuit 50 at its upper end through three conductors L-1, L2, and L-3, respectively. To begin operation of conveyors 12 and 16, a START switch 32 is momentarily closed and this connects the coil of a relay 54 through the normally closed STOP switch 56 to lines L-1 and L2. Relay 54 has associated with it four separate pairs of contacts, namely, contacts 54a connected in parallel with START switch 52, contacts 54b connected between line L1 and a lead 60, contacts 540 connected between line L-2 and a lead 62, and contacts 54d connected between line L-3 and a lead 64. As soon as relay 54 is energized, its contacts 54a close and hold the relay energized independently of START switch 52 until STOP switch 56 is thereafter opened. So long as relay 54 is energized power line voltage is applied to leads 60, 62 and 64.
The voltage between leads 60 and 62 is connected through switches 33 in position 1 and switch 34 in series with it to a control relay 66. The latter while energized closes and holds closed three additional pairs of contacts, contacts 66a in parallel with front side switch 34, contacts 66b, and contacts 660. Relay 66 necessarily remains energized until rear side switch 38 is moved from position 1 to position 2 by a box in passing, and until a pair of relay contacts 68a, in parallel with position 1 of switch 38 is opened. Contacts 68a are controlled by detector switch 42 and are opened when contacts 40 of the switch are shorted by a box binding wire 31, this in turn energizing a relay 68 (associated with contacts 68 a) from lines 60 and 62 through a step-down transformer 70.
Contacts 660 are connected in series with a relay 72 which in turn controls the operation of motor and conveyor chain 16. To this end, relay 72 has associated with it three pairs of contacts 72a, 72b and 720 which connect motor 20 to leads 60, 62 and 64. Motor 20, and with it conveyor chain 16, will be driven whenever relay 66 is energized or whenever rear switch 3 8 is held in position 2 by a box. When rear switch 38 is released by a box to position 1 and relay 66 is at that instant not energized, then motor 20 will be stopped. This occurs only when a wirebound box of desired length is encountered. Thus, as seen in FIGURE 8, box 46 is holding switch 38 in position 2 and is holding switch 34 open, contacts 68a open, and switch 336 closed, but treadle switch 32 has not yet been reached and closed by the front end of the box. Accordingly, as seen in FIGURE 10, relay 66 will not at this instant be energized. Therefore, when the rear end of the box releases switch 38 to position 1, switch 34 and contacts 66a will be open, and accordingly relay 72 will be de-energized to stop motor 20 and chain 16. Relay 66 will remain de-energized and with it relay 72, until the box closing machine now completes its cycle of operation.
A box such as box 30 in FIGURE 6, which is shorter than the desired length, will release rear switch 38 to position 1 before front side switch 3-4 is opened and, as a consequence, as soon as switch 38 returns to position 1, relay 66 will be energized. This in turn keeps relay 72 energized through contacts 666 and therefore conveyor chain 16 carries this box without stopping on to the right out of the machine.
Conversely, a box such as box 44 in FIGURE 7, longer than desired, will have closed both side switch 36 and treadle switch 32 before releasing rear side switch 38 to position 1. Consequently, before switch 38 is released, relay 66 will be energized through switches 38 in position 2, and switches 36 and 32. After switch 38 is released to position 1, relay 66, and relay 72, will remain energized without interruption through contacts 660 and .switches 36 and 32. Therefore, this longer box will also be conveyed through the machine without stopping.
When a box of proper length and type is encountered, relay 72 is de-energized to stop motor 20 and conveyor chain 16. Contacts 72d associated with this relay are thereupon opened. This in turn de-energizes a solenoid 74 which as seen in FIGURES 4 and 5 controls the raising and lowering of a bumper arm 76. This arm is pivoted at 78 to a swing link 79 and as seen in FIGURES 3 and 5, it has a sideward projection 77 which is contacted by an arm 80a of lever 80. This lever is connected to armature 82 of solenoid 74. When solenoid 74 is energized, armature 82 is drawn to the right causing lever 80 and bumper arm 76 to rotate in counterclockwise direction until bumper arm is in solid line position of FIG- URE 4. In this retracted position it lies below the top level of chain 16 and boxes can freely pass over it. When solenoid 74 is de-energized, bumper 76 is released and is drawn upward to the dotted line position shown by a tension spring 84. In this raised position, a box moving to the right along conveyor chain 16 will be stopped by the bumper which in the encounter will, along with swing link 7 9, be deflected somewhat to the right. This slight rightward movement of the bumper results in the momentary closing of a switch 86 positioned just beneath the bumper. Bumper 76 is raised only when a wirebound box of proper length is encountered.
As soon as a selected box is brought to a stop by bumper 76 and switch 86 closed, a box closing machine (not shown) positioned above and alongside conveyor chain 16 engages the box and closes its top. The box closing machine is powered by an electric motor 88 (seen only in FIGURE 10) which as will be explained is controlled by switch 36 among others. This motor when set in operation also drives a shaft 90 (see FIGURES 2 and 9) which makes a single revolution for each full cycle of the box closing machine. Fixed to this shaft are two separate cams 92 and 94 which engage, respectively, cam followers 96 and 98. These in turn control the switches 100 and 102 respectively.
As seen in FIGURE 10, motor 88 which operates the box closing machine is ultimately controlled by switch 86 which is in series with a relay 104. The latter has associated with it three contacts 104a, 104b and 104a which when the relay is energized connect motor 88 to leads 60, 62 and 64. A normally closed safety switch 106 is in series with switch 86 and when open prevents the starting of the box closing machine. Switch 106 is physically positioned as shown in FIGURE 2 beneath the right end of conveyor chain 16. It is controlled by a pivoted arm 10 7 which extends above the level of the conveyor chain. When this arm is depressed by the weight of a box upon it, switch 106 will be opened. Thus a finished box which has not moved off of conveyor chain 16 will prevent the box closing machine from closing the next one.
As seen in FIGURE 10, when switch 86 is momentarily energized (by the impact of a box against bumper 76) 0 relay 104 will be energized. Thereupon motor 88 starts and shaft begins to rotate immediately closing switch 102. This establishes a second path for energizing this relay, namely through switch 102 and through a pair of contacts 104d associated with the relay and closed when it is energized. Relay 104 will now remain energized until switch 102 is again opened upon the completion of a revolution of shaft 90 at the end of the machine closing cycle.
As shaft 90 completes a revolution it momentarily closes switch 100 and in so doing energizes control relay 66. The latter in turn closes contacts 660 to start motor 20 and conveyor chain 16 and also closes contacts 66b. These contacts are in series with a relay 108 having associated with it three contacts 108a, and 1080. When closed, these contacts connect motor 18 to leads 60, 62 and 64 and start conveyor 12, which in turn delivers boxes to selector mechanism 14.
Conveyor 12 is able to run independently of the box selecting mechanism by virtue of a normally closed switch 110 in series with relay 108 and paralleling contacts 66b. As seen in FIGURE 1, for example, switch 110 is physically located at one side of conveyor 12 and is adapted to be actuated by any box passing it. Thus, even while the box closing mechanism is operating and relay 66 de-energized, motor 18 and with it conveyor 12 will continue to run until a box arrives and opens switch 110. Thereupon this conveyor will also stop and remain so until the box closing mechanism completes its cycle and relay 66 is again energized. The box that was just closed is discharged to the right from conveyor chain 16 and the box (if any) standing at switch 110 on conveyor 12 is advanced onto the conveyor chain. Thereafter, box selecting mechanism 14 operates again in the way described previously, and so on for each succeeding box.
The above description of the invention is intended in illustration and not in limitation thereof. Various changes may occur to those skilled in the art and these may be made without departing from the spirit or scope of the invention as set forth.
1. In an automatic machine for selecting boxes according to length, an electric control circuit comprising a first motor for driving a box conveyor, a second motor for driving a box closing machine and the like, a control relay, a front box-actuated switch in series with said control relay, a rear box-actuated switch having two positions, one in series with said control relay and said front box actuated switch, a first motor relay for operating said first motor, said motor relay being in series with the second position of said rear box-actuated switch, a first switch and a second switch controlled by said control relay, said first switch being in parallel with said front box-actuated switch, said second switch being in parallel with the second position of said rear box-actuated switch, and a long-box switch in series with said control relay and the second position of said rear box-actuated switch, whereby when said rear box-actuated switch is released to position one when said front box-actuated switch is open and before said long-box switch is closed, said motor relay is de-energized and remains so until restarted.
2. The circuit as in claim 1 in further combination with an electromagnet for raising and lowering a bumper to stop boxes of desired length, said electromagnet being controlled by said motor relay to raise said bumper when said relay is tie-energized.
3. The circuit as in claim 1 in further combination with a third switch actuated by said second motor, said third switch being in series with said control relay to momentarily energize it upon the completion of a cycle of operation of said second 'motor.
4. The circuit as in claim 1 in further combination with a wirebound-box-actuated switch in parallel with position one of said rear box-actuated switch, said switch being opened upon contact with a binding wire of a box.
5 The circuit as in claim 2 in further combination with a switch actuated by a box striking said bumper, said switch when actuated energizing said second motor.
6. A box selecting and handling mechanism comprising a first conveyor and motor for advancing boxes along a path, a second conveyor and motor for advancing boxes to said first conveyor, a third motor for driving a box closing machine and the like positioned adjacent said first conveyor, a front box-actuated switch adjacent said path, a rear box-actuated switch adjacent said path and having two positions, a long-box switch adjacent said path and in front of said front switch, a control relay, a first relay for operating said first motor, said control relay being in series with said front switch and position one of said rear switch, said first relay being in series with position two of said rear switch, a first switch, a second and a third switch controlled by said control relay, said first switch being in parallel with said front switch, said second switch being in parallel with position two of said rear switch, said third switch being connected to actuate said second motor, a fourth switch controlled by said first relay, an electromagnetically controlled bumper positioned adjacent the box conveying path of said first conveyor and adapted to be moved athwart the path of boxes moving thereon when said fourth switch is actuated, a fifth switch associated with said bumper and connected to actuate said third motor when a box runs against said bumper, a sixth switch controlled by said third motor and in series with said control relay for momentarily energizing it when said third motor completes a cycle of operation, and a seventh switch in parallel with said first switch for independently actuating said second motor, said seventh switch being positioned adjacent said second conveyor for actuation by boxes thereon.
7. A mechanism as in claim 6 in further combination with a detector switch actuated by binding wires of a box and positioned adjacent said first conveyor near said rear switch said detector switch being in parallel with position one of said rear switch, whereby only a box having a selected iength and of wirebound construction will be stopped by said bumper.
8. A box selecting and handling mechanism comprising a first conveyor and motor for advancing boxes along a path, a second motor for driving a box closing machine and the like positioned adjacent said first conveyor, a front box-actuated switch adjacent said path, a rear box-actuated switch adjacent said path and having two positions, control means, first means for operating said first motor, said control means being in series with said front box-actuated switch and position one of said rear box-actuated switch, said first means being in series with position two of said rear box-actuated switch, an electromagnetically controlled bumper positioned adjacent the box conveying path of said first conveyor and adapted to be moved athwart the path of boxes moving thereon said bumper being controlled by said first means and moved into the path of said boxes when said first motor is stopped, an auxiliary switch associated with said bumper and connected to actuate said second motor when a box runs against said bumper.
References Cited in the file of this patent UNITED STATES PATENTS 2,033,645 Parkhil-l Mar. 10, 1936 2,132,516 Paxton Oct. 11, 1938 2,517,710 Platt Aug. 8, 1950 2,542,083 Holstebroe Feb. 20, 1951 2,565,987 Platt Aug. 28, 1951 2,608,038 Knowlton Aug. 26, 1952 2,630,043 Kolisch Mar. 3, 1953 2,835,385 Eckart May 20, 1958