Abstract:
A multi-direction transfer conveyor for off-loading a stack of paper from a first work station or conveyor, rotating the stack 90 degrees left or right and aligning the stack with a second conveyor, for example. Guide components which may be ball casters are provided on a bottom surface of the transfer conveyor cart to move within U-shaped channels that together form an L-shaped or U-shaped track. Drive wheels actuate the transfer conveyor to move along and/or relative to the shaped track. By suitable motor control and/or suitably placed or actuated stops and guide structures, travel of the guide components down the shaped track is controlled to cause the cart to rotate and align with the respective conveyors.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
     When off-loading stacks of paper from a cutter or the like onto a conveyor, there are installations where the output conveyor must be 90-degrees left or right rather than in-line. To accomplish this, the invention provides a 90-degree transfer conveyor for being disposed between processing components such as between an off-loading stacker and a job conveyor. 
     More particularly, the invention relates to a multi-direction transfer conveyor for receiving a stack of paper from a first work station or conveyor, rotating the stack 90 degrees left or right and aligning the stack with a second conveyor, for example. Guide components which may be wheels or ball casters provided on a bottom surface of the transfer conveyor are engaged with and confined to move within U-shaped channels that together form an L-shaped or U-shaped track. Drive wheel(s) actuate the transfer conveyor to move along and/or relative to the shaped track. By suitable motor control and/or suitably placed or actuated stops, travel of the guide components down the shaped track is controlled to cause the cart to rotate and align with the respective stations or conveyors. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic top plan view of a transfer conveyor disposed on a support structure in accordance with the invention; 
     FIG. 2 is a schematic side elevational view of the transfer conveyor of FIG. 1; 
     FIG. 3 is a schematic side view of an exemplary support stand or table for supporting the transfer conveyor and shaped channels in accordance with the invention; 
     FIGS. 4A and 4B are schematic top plan views of the home and 90 degrees left positions, respectively, of a transfer conveyor adapted for 90 degrees left transfer according to an exemplary configuration of the invention; 
     FIGS. 5A and 5B are schematic top plan views of the home and 90 degrees right positions, respectively, of a transfer conveyor adapted for 90 degrees right transfer according to an alternate configuration of the invention; 
     FIGS. 6A-E are sequential schematic top plan views showing a sequence of operation of a 90 degree left transfer conveyor embodying the invention; 
     FIGS. 7A-C are schematic plan views showing a three way transfer unit embodying the invention; and 
     FIG. 8 is a schematic plan view of an alternate three way transfer unit in accordance with the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to FIGS. 1 and 3, an exemplary transfer conveyor  10  embodying the invention disposed on a suitable stand or table  12  is schematically illustrated. To guide and control movement of the transfer conveyor  10 , a plurality of U-channels  14 , 16 , 18  are provided about at least a portion of the periphery of the top surface of the stand to capture and guide one side  20  of the cart. For the transfer conveyor or cart (hereinafter referred to as a cart) to achieve a 90 degree turn operation, at least first and second U-channels are provided and intersect to define an L-shaped track that is generally U-shaped in vertical section to capture the cart guide components as discussed in greater detail below. For the stand to accommodate movement either 90 degrees right or 90 degrees left, U-channels are provided along three side edges  22 , 24 , 26  of the top surface  28  of the stand  12 . With suitably disposed sensors and control logic, as discussed in greater detail below, U-shaped channels could be provided on all four sides of the top surface of the stand to define in effect a continuous U-channel about the periphery of the stand top surface. 
     As illustrated in FIG. 3, the cart support stand  12  is preferably height adjustable. In the illustrated embodiment, the stand includes threaded height adjustment legs  30 , leveling pads  32 , a fix nut  34  and a lock nut  36  to allow the height of the top surface  28  of the stand  12  and thus the height of the cart  10  to be adjusted and then locked. As described in greater detail below, the stand may also include suitable electrical components  38  for cart control. 
     With reference to FIGS. 1 and 2, the transfer conveyor cart is for example a belt type conveyor assembly provided with continuous belt  40 , in the illustrated embodiment supported at one end by a drive roller  42  and at the other end by a free-rolling guide roller  44 . A belt drive gear motor  46  is provided for driving the driven roller  42  in a conventional manner. In the illustrated embodiment, the belt is a 18″×18″ continuous belt, although a series of belts having lesser widths, for example, may be disposed on the cart to define the conveyor surface thereof. Also, a conveying system other than a belt conveyor can be provided. 
     Guide components  47 ,  48 , such as ball casters, are provided along one side edge  20  of the cart for being captured by the U-shaped channels  14 , 16 , 18  of the guide track to guide and determine the position of the cart  10  with respect to the top surface  28  of the support stand  12 . In the presently preferred embodiment, the guide components  47 ,  48  are ball transfer rollers, e.g. ball casters, that ride inside U-shaped channels on the top of the stand. 
     The end of the cart opposite side  20  advantageously includes at least one drive wheel for driving the cart to rotate relative to the support stand. In the illustrated embodiment, a pair of drive wheels  50  are mounted inboard of the peripheral edge of the cart, so as to avoid undesired engagement with the U-channels, and are suitably driven by a cart drive gear motor  52  via a drive belt or chain  54 , or the like. In the alternative to a pair of commonly driven drive wheels, as shown, the gear motor  52  may directly drive a single drive wheel to effect movement of the cart relative to the stand top surface. In that event, the illustrated drive wheels may instead be rollers or casters similar to those disposed in the U-channels. 
     In the presently preferred embodiment, a plurality of stop pins are disposed in the U-channels for engaging an edge of the cart and/or one of the ball casters to force the transfer conveyor cart to rotate rather than move linearly in the U-channel direction, as described in greater detail below, and to set the stop point at the end of rotation. Accordingly, stop pin locations SPL are defined for the 90 degrees left operation of the transfer conveyor and stop pin locations SPR are provided for the 90 degrees right operation of the transfer conveyor cart. Also provided in the presently preferred illustrated embodiment are an “IN” sensor  56  for detecting incoming work product, e.g. so that the belt  40  can be actuated and receive and properly position the work product, and an “OUT” sensor  58  for actuating a next adjacent, e.g., job, conveyor  60  (FIG. 6) to receive off-loaded work product and/or for detecting the completion of the off-load of work product. Also provided in the presently preferred embodiment are a plurality of proximity sensors/switches mounted to the top surface of the stand. In the illustrated embodiment, three proximity sensors/switches are disposed e.g., at  62 ,  64  and  66  for 90 degrees left operation and two further proximity sensor/switch locations at  68  and  70  (FIGS. 5A and 5B) are provided for use together with a proximity sensor/switch mounted at  66  for 90 degrees right operation and described in greater detail below. Vanes V 1  and V 2  or the like are provided on the bottom of the cart, adjacent side  20  of the cart  10 , spaced apart in correspondence with the spacing of the proximity sensors/switches on the support  12 . Thus, when the vanes V 1  and V 2  are disposed in correspondence with proximity sensors  62  and  64 , the cart home position (FIG. 4A) is designated. When the vanes are disposed in positions corresponding to  64  and  66 , the cart is designated at 90 degrees left. Similarly, the location of the vanes V 1 , V 2  at positions corresponding to proximity sensors  68  and  70  designates a home position for a 90 degrees right operation and disposition of vanes V 1  and V 2  respectively at positions  66  and  68  designates a 90 degrees right position of the cart. 
     With reference to FIGS. 4A and 4B, an exemplary 90 degrees left configuration is shown with the cart drive motor omitted for clarity. In this configuration, stop pins  82 ,  84  are disposed at positions SPL and the first and second vanes V 1 , V 2  disposed on the bottom of the cart are aligned with position sensors (proximity sensors)  62  and  64 . 
     With reference to FIG. 6A in a typical operation, incoming work product is printed at a printer  74 , continuously fed as a paper web  76  to a cutter  78  whereupon the cut sheets are received by a stacker  80  to define a stack  72 . In the illustrated embodiment, a 90 degree left conveyor cart  10  is disposed on the stand at the output of the stacker, to the left of FIG. 6A for disposing the stack on a job conveyor  60 . As the stack  72  approaches the 90 degree conveyor cart  10  as shown in FIG. 6A, the stacker module  80  of the cutter system indicates an off-load of a stack of cut sheets. When the leading edge of the stack is detected by the IN sensor  56 , the belt motor  46  is switched on. The belt  40  speed is desirably adjustable to match the speed of the stacker off-load belts, either manually or automatically. When the trailing edge of the stack is detected by the IN sensor  56 , the belt motor is switched off so that the cut sheets are disposed as shown in FIG.  4 A. 
     The cart motor  52  is then switched on in the forward direction so that the drive wheels  50  rotate in a clockwise direction as shown in the configuration of FIG.  2 . Thus, the cart tries to move to the left as shown in FIG.  4 A. Because stop pin  82  precludes movement of the one side  20  of the cart, the bottom edge in the orientation shown in FIG. 6A, the cart will begin to rotate in a counterclockwise manner so that caster  47  moves in direction A in U-shaped channel  14  and caster  48  moves in direction B in U-shaped channel  16 . Thus, the cart continues to rotate in a counterclockwise manner in plan view until the cart is disposed in the position shown in FIG.  4 B. At this point, pin  84  precludes further movement of the cart  10  in the counterclockwise direction. and the stack  72  of cut sheets is aligned with the job conveyor  60  as shown in FIG.  6 C. When this rotation has been completed and both cart vane V 1  and vane V 2  are detected by proximity sensors  64  and  66 , showing that the 90 degree position has been reached, the cart motor  52  is switched off. The belt motor  46  is then switched on to transfer the stack  72  to the job conveyor  60 . Advantageously, a relay contact closure provides a signal to the job conveyor  60  to enable the drive belts of the job conveyor. This relay contact closure may be linked to detection of the leading edge of the stack  72  by the OUT sensor  58 . When the OUT sensor detects the trailing edge of the stack  72 , the belt motor  46  is switched off and after a short time delay, the relay contact is opened to stop the job conveyor  60 . Such a time delay is also advantageously provided with respect to the IN sensor  56  so that the stack  72  is appropriately located on the transfer cart  10  when it is received from the stacker  80 . 
     Once the stack  72  has been off-loaded, the cart motor  52  is switched on in the reverse direction so as to rotate the drive wheels in a counterclockwise direction as shown in FIG.  2 . Because pin  84  precludes movement of the cart in direction B, as shown in FIG. 4B, the cart will begin to rotate in a clockwise direction so that ball caster  47  is received in channel  14  and ball caster  48  will begin to travel in U-shaped channel  16  towards the U-shaped channel intersection. When both cart vane V 1  and cart vane V 2  are detected by proximity sensors  62  and  64 , the home position has been reached and the cart motor  52  is switched off. At this point, also, pin  82  precludes further movement of the cart in a clockwise rotation. The cart will thus be disposed as shown in FIG. 6E, ready to receive a subsequent stack of printed and cut sheets or other work product, as also shown in FIG.  6 A. 
     As presently proposed, the transfer conveyor cart is adapted for use with the 8850 Cutter System in which product flows from right to left as shown in FIG.  6 A. Thus, the most likely and presently preferred orientation for a 90-degree job conveyor is to the left as described hereinabove. Desirably, therefore, the default configuration of the 90 degree conveyor is 90 degrees left. The illustrated structure can, however, readily be converted from 90 degrees left operation to a 90 degrees right configuration. 
     The conversion from 90 degrees left to 90 degrees right can be best understood with reference to FIG. 1, FIG. 4A, and FIG.  5 A. In an exemplary embodiment, to convert from 90 degrees left to 90 degrees right configurations, the stop pins are moved from positions SPL to positions SPR. To do this, the cart  10  may be lifted out of the U-channels  14 , 16 , 18 . The cart may then be placed elsewhere on the work surface  28  of the support table  12  and moved as needed to access the components which must be moved or adjusted for 90 degree right configuration. Thus, in the illustrated configuration, the two stop pins  82 , 84  are moved from positions SPL to positions SPR as noted above. For a 90 degree right operation, the proximity sensors provided at  62  and  64  in FIG. 4A are moved from the locations shown therein to the locations  68  and  70  shown in FIG.  5 A. 
     As can be seen from a comparison of FIG.  4 A and FIG. 5A, the cart is then rotated 180 degrees with respect to its 90 degrees left home position and located with the guide components or ball casters  47 , 48  in the U-channel  18 . Finally, inside the electrical enclosure  38  (FIG. 3) an orientation select jumper (not shown) is changed from left to right. This will automatically reverse the cart motor  52  direction and the IN/OUT sensors  56 , 58  for proper operation in the 90 degree right configuration. The operation of the transfer conveyor cart in the 90 degrees right configuration is analogous to the operation in the 90 degrees left configuration, as would be apparent from an examination of FIG.  5 A and FIG.  5 B. As noted above, the stops are provided to force the transfer conveyor cart to rotate rather than move linearly in the U-channel direction and set the stop point at the end of rotation. In the exemplary embodiment described above, the stops are in the form of stop pins  82 , 84  that are selectively placed at points SPL and points SPR to define the 90 degree left and 90 degree right configurations. As an alternative to interchangeable pins, however, engagement/actuation of the stops can be controlled, e.g., with solenoids. Similarly, the proximity sensors can be actuated/deactuated as needed rather than moved as aforesaid. 
     As shown in FIGS. 7A,  7 B and  7 C, by replacing wheels  50  with a direct drive wheel  150  and two guide rollers  86 , 88 , by providing selectively actuatable cart guides  90 ,  92 , and by controlling engagement of the stops  182 ,  184  with guides  147 ,  148  using solenoids, a unit can be configured for selective three-way transfer. More specifically, with reference to FIG. 7A, a first guide  90  is provided to selectively force a linear rather than rotary transfer of the transfer conveyor cart  110 . For a straight out transfer, stop  182  is disengaged, guide  90  is engaged and the drive wheel  150  is enabled in the clockwise direction to move the transfer cart out in direction C in FIG.  7 A and in the counterclockwise direction to return to the home state. 
     Transfer 90 degrees left is accomplished as described hereinabove if stop  182  and stop  184  are engaged and guide  90  is disengaged, as shown in FIG.  7 B. For 90 degree right operation, first the transfer conveyor cart can be rotated 90 degrees left as shown in FIG.  7 C and then stop  184  is disengaged and guide  92  is engaged to control the direction of travel of the transfer conveyor cart. The drive wheel(s) are then rotated in a counterclockwise direction to move the conveyor cart to the right, as shown by arrow D in FIG.  7 C. Suitable stops (not shown) can be provided to limit movement of the transfer conveyor cart  110  in direction D. As is apparent from FIGS. 7A-C, an L-shaped U-channel  114 ,  116  is sufficient to accommodate this three-way transfer. As a further alternative, however, a full U-shaped U-channel may be provided with suitable stops and guides to effect similar motion as shown in FIG. 7A-C in the right corner of the track. As yet a further alternative, again with suitable guides and stops, U-channels can be provided about the entire periphery of the support stand for universal transfer. 
     FIG. 8 shows another way in which a 3-way transfer may be accomplished, without stops or guides, by adding a second gear motor  352  and drive wheel  350 . To drive the cart  210  straight out, motor  252  is operated to rotate the drive wheels  250  in a clockwise direction while motor  352  is operated in a counterclockwise direction. Conversely, to return the cart  210  to the home position, motor  252  is operated in a counterclockwise direction while motor  352  is operated in a clockwise direction. To rotate the transfer cart 90 degrees left, both motors  252 ,  353  are rotated in a clockwise manner. Conversely to return to the home position, both motors are rotated in a counterclockwise direction. To move the transfer cart  210  straight to the right from the 90 degrees left orientation. Motor  252  is operated in a counterclockwise manner and motor  352  is operated clockwise. Conversely to return the transfer cart  210  straight left, motor  252  is operated in a clockwise manner while motor  352  is operated in a counterclockwise manner. In the embodiment illustrated in FIG. 8, the second motor  352  is provided with a single drive gear or wheel  350  as the wheels  250  associated with the first motor  252  and the ball casters  247 ,  248  maintain the transfer conveyor cart in a horizontal disposition. 
     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.