Paper set feeding apparatus

Abstract

A set feeding apparatus (10) separates an uppermost set of paper sheets from a staggered stack of sets (36) with a platform (34) that biases the stack toward a carriage (42) that is moveable with respect to the stack. The carriage includes a cam-activated pic and a knife head that combine to raise the uppermost set from the stack. A plow then engages the raised portion of the uppermost set to move the set off of the stack.

Description

FIELD OF THE INVENTION

[0001] The invention generally pertains to devices for handling sets of paper sheets. More specifically, the invention relates to a device that will separate and remove individual sets of sheets from a stack of sets arranged in a staggered, or offset, manner.

BACKGROUND OF THE INVENTION

[0002] Publishing, photocopying, and otherwise processing large quantities of printed materials such as books, loose-leaf collections, and other assemblages of individual sheets is often a multi-step process. Typically, printing or photocopying of individual copies, also known as sets, of the subject materials is followed by various other operations such as punching, binding, counting, sorting, and the like. Often, after each individual set comprising a copy of particular work passes through a process, it is stacked with other copies of the same work in preparation for feeding into subsequent process devices. Additional processing may occur “on-line” or “off-line.” In on-line processing, a single set of sheets is typically forwarded directly to the next process. In off-line processing arrangements, a stacked arrangement of identical, or differentiated, individual sets facilitates efficient bulk transfer of the sets between sequential processing stations that may or may not be located in physical proximity to each other. Thus, stacking individual sets of documents in a staggered or offset fashion eliminates the need for costly set separators and is the most efficient way to feed sets into processing equipment that only accepts sets fed one-by-one, rather than as an entire stack of sets.

[0003] Although a staggered arrangement of individual sets in a stack creates efficiencies in the selection and feeding of individual sets, feeding individual sets from a staggered stack can still be a time-consuming and labor-intensive undertaking. This is true of any paper-handling situation where individual sets are separately selected and removed from a stack. Each set must be carefully gathered, engaged, and handled without losing or separating individual sheets from a set, and without mixing sets. Further, many processing operations, even ordinary photocopying, require the individual page edges of a set to be in precise alignment. Sheets or edges, such as tabs, which extend beyond the general edge of the set may hamper reliably feeding large numbers of sets into processing equipment. Automated devices have been proposed to handle the task of separating and removing complete sets of sheets from a stack of identical or differentiated sets for feeding the individual sets into processing equipment.

[0004] A device for mechanically feeding a set of sheets for further processing is disclosed, for example, in U.S. Pat. Nos. 6,126,384, 5,820,334, and 5,556,254 to Darcy et al. In the set feeder disclosed in the Darcy patents, the sets are disposed in a hopper and fed from the lowermost end by a driven shutter mechanism. The force exerted by the stack of sets in such bottom-feeding apparatus, however, can effect the accuracy of the set feeding, particularly when the stack is relatively have or large.

OBJECTS AND BRIEF SUMMARY OF TEE INVENTION

[0005] It is a primary object of the invention to provide an automated device that reliably selects, gathers, and removes a set of sheets from a staggered stack of identical or differentiated sets. It is a related object of the invention to provide a set feeding apparatus which eliminates the effect of stack weight.

[0006] It is a further object of this invention to provide an automated means of feeding individual sets of sheets from a stack of substantially identical sets into processing equipment used in on-line applications or in off-line applications, including multi-stage printing or photocopying operations.

[0007] Another object of the invention is to provide a set feeding apparatus that can accommodate different sizes of sheets and protrusion from the edge of the set, such as tabs.

[0008] The present invention is directed to a set feeder apparatus for separating an uppermost set of paper sheets from a previously staggered stack of similar sets and individually feeding the uppermost set into a subsequent processing station. The invention provides a vertically movable platform which has a pliable, resilient upper surface or a foam pad or the like disposed along its upper surface. Thus, the stack of sheet sets resting on the platform can deflect downward when a pressure or force is applied to the upper sets.

[0009] A frame supports a movable carriage, a stabilizing unit for stabilizing the stack of sets during an initial separation operation, and a plow assembly which pushes the uppermost set from the apparatus. The movable carriage supports the elements which provide an initial separation of one edge of the uppermost set from the remainder of the stack so that the plow can engage the uppermost set for removal. Thus, the movable carriage supports a pair of sensors for detecting the exact positions of the sets of the stack, a pic for providing an initial separation between the top two sets, and profiled knife for enhancing the separation between the top two sets for removal by the plow.

[0010] Once the platform is loaded, and the operator has input the paper dimensions, the platform raises the stack towards the moveable carriage. As the stack moves upward, the exposed edge portion of the set immediately below the uppermost set contacts one of the sensors disposed on the carriage, thus initializing the invention to begin the process of selecting and removing the uppermost set from the stack. The carriage sensors are disposed at opposite ends of the carriage to facilitate sensing at either end of the stack. Thus, each time the uppermost set is removed, the carriage can shift to detect the newly exposed edge portion at the opposite end of the stack.

[0011] The cam-activated pic on the movable carriage is configured to rotate to lift and separate an edge portion of the uppermost set from the stack. In operation, after the exposed edge portion of the set immediately below the uppermost set contacts the sensor, the pic moves into position at the exposed edge. The stabilizer unit is always preferably exerting a downward force on the stack during the operation of the pic and the knife. The eccentric, cam-driven rotation of the pic initially moves the pic downwardly, into contact with the exposed edge portion. After passing the lowest point of its travel, the pic rotates upwardly into contact with the bottom of the uppermost stack, lifting an edge portion thereof, and creating a gap between the two uppermost sets. A profiled knife, likewise disposed on the carriage, is advanced into the gap created by the pic between the two uppermost sets, so as to further lift and separate a portion of the uppermost set from the stack, while simultaneously exerting a downward force on the stack. When the pic is disposed at the end of the stack proximal to the plow, the knife is advanced into the gap immediately after the “pick” is performed. If the pic is operating at the end of the stack distal to the plow, the carriage moves the pic engaged between the top two sets to the end proximal the plow before the knife is advanced into the gap. Thus, the more significant separation due to the profiled knife is always ultimately disposed at the end proximal the plow.

[0012] Once an edge portion of the uppermost set of sheets is lifted above the remaining stack by the knife, the stabilizer unit releases the downward pressure on the stack, and a plow is deployed to engage the edge of the uppermost set raised by the knife. The plow travels in a horizontal path above the level of the unlifted stack, so that it only engages the uppermost set when the uppermost set is raised by the knife. Once the plow has engaged the uppermost set, the plow pushes this set off of the stack. The plow thus removes the uppermost set from the top of the stack without interfering with the rest of the stack. Significantly, neither the pic, the blade, nor the plow interfere with the use of tabs or the like which protrude from the front edge of the sets.

[0013] The knife and plow then return to their predetermined operating positions, the carriage positions itself to detect the next exposed edge portion, and the entire process will continue repeating itself, until all of the sets have been moved off of the platform.

[0014] The operation of the set feeding apparatus is thus an improvement over the prior art. These and other advantages of the present invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.

BRIEF DESCRIPTION OF THEE DRAWINGS

[0015] FIG. 1 is a perspective view of a preferred embodiment of paper set feeding apparatus constructed according to teaching of the present invention.

[0016] FIG. 2 is a front elevational view of the apparatus shown in FIG. 1.

[0017] FIG. 3 is a top plan view of the embodiment of the invention shown in FIG. 1.

[0018] FIG. 4 is a side elevational view of the embodiment of the invention shown in FIG. 1.

[0019] FIG. 5 is a perspective view of the stabilizer component of the present invention.

[0020] FIG. 6 is a perspective view of the carriage portion of the present invention.

[0021] FIG. 7 is an exploded perspective view of the carriage portion of the present invention shown in FIG. 6.

[0022] FIG. 8 is a perspective view of the plow portion of the present invention.

[0023] FIG. 9 is a side elevational view of the plow portion of the present invention.

[0024] FIG. 10 is a perspective view of the pic and associated cam of FIGS. 6 and 7.

DETAILED DESCRIPTION OF THE INVENTION

[0025] Turning now to the drawings, FIGS. 1-4 show a set feeder apparatus 10 constructed according to the present invention. The apparatus 10 has a rear 110 and a front 112. The apparatus 10 consists of a base 12 that carries a support surface or platform 34, which supports a stack of offset or staggered sheet sets 36, and a frame 11 which supports other powered elements of the set feeding apparatus 10. The frame 11 preferably includes upfront supports and horizontal elements connecting the upfront supports. In the preferred embodiment illustrated, front support 14 and a rear support 16, secured to the base 12, and extending generally upward therefrom. As best seen in FIGS. 1 and 2, the front support 14 is disposed and constructed such that it does not interfere with the movement of the individual sets of the stack of sheets 36 through the front end of the apparatus 10. In order to support mechanized components of the apparatus 10, the top 18 of the front support 14 is coupled to the top 20 of the rear support 16 by carriage rods 22, 24 and bracket 26 is coupled to support 14. It will be appreciated that the carriage rods 22, 24 also serve to further enhance the rigidity of the skeleton.

[0026] In accordance with the invention, the apparatus 10 includes powered elements which act on the stack of sets 36 supported on an upwardly biased platform 34 to separate the uppermost stack and advance it out of the front of the apparatus 10. The structure and each of these powered elements, as well as the platform 34, will be described in turn. In short, the apparatus 10 includes a movable support platform 34 which advances the stack of sets 36 upward until the uppermost set 37 is positioned adjacent a set picker assembly 69, which separates and slightly lifts the top set 37 from the second set 38, a stabilizer unit 49, which stabilizes the stack of sets 36 during the picking operation, and a plow assembly 88, which functions to push the uppermost set 37 from the stack of sets 36.

[0027] The platform 34 preferably includes not only a horizontal plate portion which supports the stack of sets 36, but at least one vertical element 34a against which an edge of the stack 36 may be disposed to ensure proper positioning. In the preferred embodiment illustrated, two such vertical elements 34a along the side and back of the apparatus 10 may be seen in FIGS. 2-4. Significantly, the vertical elements 34a are disposed such that they will not interfere with the operation of the powered elements of the apparatus 10.

[0028] To ensure that the sets always feed to the same position as they are fed out of the front 112 of the apparatus 10, the platform 34 is biased or powered to advance the stack of sets 36 upward to position the uppermost set 37 at the desired feed level, adjacent the set picker assembly 69 and plow assembly 88. In order to support the platform 34, platform rods 28, 30,32 are provided which extend upwardly from the base 12. Coupling brackets 35 slidably mounted on the platform rods 28, 30, 32 and secured to the platform 34 facilitate the vertical motion of the platform 34 along the platform rods 28, 30, 32 to vertically move a previously staggered stack 36 of sheet sets. The interface of the coupling bracket 35 with the platform rods 28, 30, 32 may consist of a reversible drive apparatus such as a motor which engages with one or more of the platform rods 28, 30, 32, via gears, frictionally, or via some other reversible means of facilitating vertical motion along the platform rods 28, 30, 32. Alternately, the platform 34 may be biased into the desired uppermost position by adjustable springs of the like. Thus, it will be appreciated by those of skill in the art that any appropriate mechanism may be utilized, so long as the uppermost set 37 is ultimately disposed at the desired location.

[0029] According to an important feature of the invention, the platform 34 preferably incorporates a pliant, resilient pad (not pictured) or has a resilient upper surface. In this way, the stack 36 of sheets may locally deflect in response to downward pressure, the significance of which will be apparent upon an explanation of the set picking device below. This pad may be made of foam or other suitable material, which is sufficiently pliable to allow deflection, yet resilient enough to return to its original state when the downward force is removed. In the currently preferred embodiment, a urethane foam having a minimum thickness of apparently one inch (1″) or 25 mm is utilized. It has been determined that such a foam pad permits a deflection on the order of ⅜ inch. It will be appreciated that the required deflection will be dependent upon the dimensions of the set picker, as will be described below.

[0030] In order to properly position the stack of sets 36 so that the set picker assembly 69 and plow assembly 88 may separate and advance the uppermost set 37 from the stack 36, the apparatus 10 is preferably provided with one or more sensors 44, 46. The sensor(s) 44, 46 arranged so that they sense when the stack 36 is disposed with the uppermost and second sets 37, 38 in the desired position. In a stack of sets 36, the uppermost set 37 and the second set 38 are offset from one another such that a portion 39 of the second set 38 is exposed at one end of the uppermost set 37. In the preferred embodiment of the invention, two sensors 44, 46 are provided and are disposed to sense this exposed portion 39 at the front and the back, respectively, of the stack of sets 36. During operation, when the sensor 44,46 is just in from the edge of the stack of sets 36 (typically on the order of ¼″ to ¾″, depending upon the degree of offset in the staggering), the platform 34 will move upward until the sensor 44, 46 is activated or closed, at which time the platform 34 stops. In this way, the uppermost set 37 is appropriately positioned to be “picked,” and the set feeding sequence is initialized.

[0031] Due to the alternating staggered arrangement of the stack 36, each time the uppermost set is removed, the successive exposed portion 39 of the new second set 38 is located at an opposite end of the stack than was the previous exposed portion. Accordingly, the set picker assembly 69 as well as the sensors 44, 46 are preferably disposed on a movable carriage unit 42. The carriage unit 42 is attached to carriage rods 22, 24 by a carriage bracket 43. It will be appreciated that the interface of the carriage bracket 43 with the carriage rods 22, 24 may consist of any appropriate reversible drive apparatus such as a motor which engages with one or more of the carriage rods 22, 24 via gears, frictionally, or via some other reversible means of facilitating motion along the carriage rods 22, 24.

[0032] In use, as the platform 34 raises, the sensor 46 senses the exposed portion 39 of the second set 38 at the rear 110 of the stacked sets 36 (as may be seen in FIG. 4) to arrest the movement of the platform 34. The set picker assembly 69 is then moved into position to begin the picking operation, as will be explained in greater detail below. It will be appreciated that when the uppermost set 37, as shown in FIG. 4 is removed, the exposed portion 39a of the new second set will be disposed at the opposite or front end 112 of the stack of sets 36. When the exposed portion 39a is so disposed at the front end, the opposite sensor 44 is moved to a position at the front of the stack of sets 36 such that the platform 34 moves upward to raise the stack 36 to a position where the exposed surface 39a actuates or closes the sensor 44, at which point the platform 34 stops. The set picker assembly 69 is then moved into position to begin the picking operation at the front end of the stack 36. Thus, the positioning of the sensors 44, 46 to the front or rear of the set picking assembly 69 allows the sensors 44, 46 to perform the sensing function on opposite ends of the stack 36 as the uppermost set is removed, and the stack 36 continues to move upwardly toward the carriage 42. By utilizing two sensors 44, 46, to detect an exposed portion 39, 39a on either end of the stack 36, the range of motion of the carriage unit 42 can be minimized, thus reducing the overall size of the set feeding apparatus 10.

[0033] In order to stabilize the stack of sets 36 and prevent shifting of individual sheets or sets while the set picker assembly 69 lifts the uppermost set 37, a stabilizer unit 49 is provided. The stabilizer unit 49 is disposed such that it may be actuated to apply a downward force on the stack of sets 36 to sandwich the stack 36 between the stabilizer unit 49 and the platform 34. While the stabilizer unit 49 may be actuated before or after the set picker assembly 69 is moved into position, the stabilizer unit 49 is preferably actuated to apply a downward force immediately after the sensor 44, 46 is closed by exposed portion 39, 39a of the stack of sets 36.

[0034] As shown in FIGS. 1-3, channel 54 of the stabilizer unit 49 is secured to bracket 26 by bolts or the like. The detail of the stabilizer unit 49 itself is best depicted in FIG. 5, a perspective view. The stabilizer unit 49 includes a stabilizer pad 50 to which rods 58, 60,62 are mounted. The rods 58, 60,62 are slidably mounted to the channel 54 with bearings or the like such that sliding the rods 58, 60, 62 relative to the channel 54 moves the pad 50 downward or upward to move the pad 50 into or out of contact with the stack of sets 36. The stabilizer unit 49 further includes stabilizer motor or actuator 52 which provides such vertical movement to the pad 50 and rods 58, 60, 62. The actuator 52 is preferably coupled to the pad 50 by a rack and pinion gear arrangement 56, 57. The shaft of the pinion gear 57 extends through the bracket 54 and meshes with the rack 56 disposed along one of the rods 60. In this way, as the actuator 52 imparts a rotating motion to the pinion gear 57, the pad 50 is moved upward or downward with the rod 60. In operation, the stabilizer pad 50 contacts the uppermost set 37 and applies a downward force thereto in order to hold the uppermost set 37 of sheets in place and together as a group while an edge is lifted from the remaining stack 36.

[0035] Once the stabilizer unit 49 has applied a downward force to the uppermost set 37, the uppermost set 37 is ready for lifting for eventual separation from the remaining stack 36. As previously mentioned, the carriage 42 may be shifted so that the set picker assembly 69 is appropriately positioned to lift the uppermost set 37 either before or after the stabilizer unit 49 has established the stabilizing downward force on the stack 36, so long as the set picker assembly 69 is not actuated until after the force has been applied.

[0036] Turning to FIGS. 6 and 7, the set picker assembly preferably includes a protrusion or pic 70, which provides an initial lifting of the uppermost set 37 from the stack 36, and a separation enhancer or knife 76, which is subsequently advanced to a position between the uppermost and second sets 37, 38 to enhance the separation for the final removal of the uppermost set 37 from the stack 36. The pic 70 itself has an elongated structure and is preferably formed of a relatively low friction material so that it does not shift the papers of the second set during the “pick” operation. In order to actually lift the corner edge of the uppermost set 37 from the second set 38, the pic 70 is mounted on an eccentric, rotatable cam arrangement 71 to the pic actuator 72 (shown in more detail in FIG. 10). Significantly, the pic 70 may be rotated in either a clockwise or counterclockwise direction, the significance of which will become apparent upon further explanation.

[0037] When the carriage 42 shifts to position the set picker assembly 69, the pic 70 is positioned above the exposed portion 39, 39a of the second set 38. Specifically, the carriage 42 will shift such that the pic 70 is located at substantially the same position relative to the stack 30 that the sensor 44, 46 was previously located. Once the carriage 42 has shifted (and the stack 36 is stabilized by the downward pressure of the stabilizer pad 50), pic actuator 72 eccentrically rotates the pic 70 downward and toward the centerline of the stack 36 from a predetermined position above the lowest point of the rotational path of pic 70. As the eccentric motion of the actuator 72 rotates the pic 70, initially in a downward arc, the pic 70 depresses the exposed portion 39 of the second set 38. Inasmuch as the platform 34 includes a pliant, resilient pad along its upper surface, the stack 36 below the pic 70 deflects downward as the pic 70 continues to rotate downward. As the pic 70 passes the lowest point of its rotation, the continuing eccentric motion of the pic actuator 72 will cause the pic 70 to move in an upward circular motion. The upward circular motion of the pic 70 will thus bring the pic 70 into contact with the bottom of the uppermost set 37. The continued upward motion of the pic 70 raises the uppermost set 37 to a predetermined level, creating a space between the uppermost set 37 and the second set 38. Upon reaching a predetermined, uppermost position, the rotation of the pic 70 ceases, thus maintaining the space between the sets.

[0038] It will be appreciated by those of skill in the art that the pic 70 always moves down and inward toward the stack 36 during the “pick” operation. Thus, when exposed portion 39 is disposed at the rear 110 of the apparatus 10 (i.e., to the left as shown in FIG. 4), the pic 70 is moved in a counterclockwise direction. Conversely, when the exposed portion 39 is disposed at the front 112 of the apparatus 10 (i.e., to the right as shown in FIG. 4), the pic 70 moves in a clockwise direction.

[0039] In order to provide a more significant separation between the uppermost and second sets 37, 38, the set picker assembly 42 further includes a separation enhancer, in this case a profiled knife 76. The knife 76 is rotatably coupled to a knife rod 80 which is further coupled to a powered knife actuator 74. The extending and retracting motion of the knife 76 is facilitated by a knife cam 78 driven by the knife actuator 74. The eccentric motion of the knife cam 78 imparts a longitudinal reciprocating motion to the knife rod, between the horizontal extreme portions of the knife cam 78 rotational path. To provide the knife 76 some vertical and lateral flexibility so that the knife 76 can engage the stack 36 over a wide positional tolerance range, a knife spring 82 disposed adjacent the knife 76. Although the knife 76 is biased to the illustrated position, the knife spring 82 permits some rotational movement of the knife 76 about the axis of the knife rod 80.

[0040] In operation at the rear end 110 of the apparatus 10, after the pic 70 has stopped, the knife actuator 74 fires, pushing the profiled knife 76 into the space created between the uppermost set 37 and the next set 38 by the pic 70. Significantly, the knife 76 is advanced into the stack 36 at a point further from the edge of the uppermost set 37 than where the pic 70 is engaged. In this way, the knife 76 increases the spacing between the uppermost set 37 and the second set 38 not only as a result of its higher profile, but also as a result of its more distal disposal. The knife 76 then remains in this position, maintaining the space between the uppermost set 37 and the second set 38, in preparation for the uppermost set 37 removal operation. Thus, when the carriage sensor 44 detects the exposed edge surface 39 at the rear end 110 of the stack 36, the entire lifting and separating operation will occur at the rear end 110 of the stack.

[0041] When the carriage sensor 44 detects the stack 36 and initializes the lifting operation from the front end 112 of the stack, however, the pic 70 will engage and lift the uppermost set from the front end 112. In order to position the knife 76 for firing, the carriage unit 42 then moves toward the rear end 110 of the stack 36 with the pic 70 still engaged in the stack 36, stopping before the pic 70 clears the end of the uppermost set 38. It will be appreciated that the pic 70 and knife 76 are now disposed in the same position at the rear 110 of the apparatus 10 as if the pic 70 had originally performed the separation operation entirely at the rear 110, as explained above. With the pic 70 still engaged with the uppermost set 38, now at the rear end 110 of the stack 36, the profiled knife 76 is advanced into the pic-created opening in the stack 36, increasing the separation between the uppermost sets.

[0042] Thus, the set picker assembly 69 presents a gap between the uppermost and second set 37, 38 at the rear 110 of the stack 36, whether initial separation by the pic 70 occurred at the front 112 or rear 110 of the stack 36. Once the knife 70 is advanced to so separate the sets 37, 38, the stabilizer unit 49 is actuated to retract the stabilizer pad 50 and discontinue the downward stabilizing force on the stack 36.

[0043] In order to remove the spaced, uppermost set 37 from the remaining stack 36, a set removal device, here, a plow assembly 88 is provided, as shown in detail in FIGS. 8 and 9. It will be appreciated by those of skill in the art, however, that an alternate removal device, such as a grasping device, may be provided. The plow assembly 88 includes a plow blade 90, which is mounted for linear movement to engage the separated, uppermost set 37, and push it from the stack 36, and an actuator or motor 108 for driving the blade 90. The motor 108 is coupled to the rear bracket 16 by a cradle 100. As best seen in FIG. 8, plow guide rods 92, 94, 104, in this case, three such guide rods, are secured to the plow blade 90 at one end and slidably mounted in bores 96, 98 in the cradle 100. Axial motion is imparted to the plow guide rods 92, 94, 104 from the motor 108 by a rack and pinion system. More specifically, a rotatably driven gear 106 is mounted to engage a rack 105 disposed along one of the guide rods 104. Thus, as the motor 108 rotates the gear 106, the rack 105 moves the guide rod 104 in an axial direction to drive the plow blade 90 either forward to push the set 37 from the apparatus 10, or rearward to retract the plow blade 90.

[0044] Thus, during operation while the edge of the uppermost set 37 is lifted off of the stack 36 by the knife 76, a plow blade 90 moves forward and engages the uppermost set 37. The plow blade 90 continues forward to a predetermined point, at which the uppermost stack 37 has been completely removed from the stack 36. As shown in FIGS. 8 and 9, the plow blade 90 includes a protruding lower edge 91 which prevents the uppermost set 37 from falling back onto the stack 36 during this step.

[0045] After this final operation, the plow blade 90 and the knife 76 retract to their predetermined starting positions. The carriage unit 42 is then shifted to the opposite staggered side of the stack 36, and the entire lift, separate, and push sequence is repeated to remove a newly uncovered set from the stack 36.

[0046] It will be appreciated by those of skill in the art that the motors or actuators 52, 72, 74, 108 may be of any appropriate type or design. Further, the motors or actuators 5, 72, 74, 108 may be coupled together by any appropriate means so that signals may be conveyed between them as necessary to initiate operation.

[0047] While this invention has been described with an emphasis upon preferred embodiments, variations of the preferred embodiments can be used, and it is intended that the invention can be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications encompassed within the spirit and scope of the invention as defined by the following claims.

[0048] All of the references cited herein, including patents, patent applications, and publications, are hereby incorporated in their entireties by reference.

Claims

1. A sheet set feeding apparatus for separating and feeding successive sheet sets from a stack of sheet sets, said successive sheet sets being offset relative to adjacent sheet sets in said stack, said sheet set feeding apparatus comprising: a set picker, said set picker exerting a temporary downward force on said stack of sheet sets during operation; and; a support surface adapted to support said stack of sheet sets, said support surface having an upper surface with a rest position, said upper surface being pliant and resilient such that the upper surface deflects from the rest position in response to said downward force exerted on the supported stack of sheet sets and said upper surface returns to substantially its rest position upon removal of the downward force.

2. The sheet set feeding apparatus of claim 1 wherein the support surface includes a pad.

3. The sheet set feeding apparatus of claim 2 wherein said pad comprises foam.

4. The sheet set feeding apparatus of claim 1 further comprising a platform disposed subjacent said support surface.

5. The sheet set feeding apparatus of claim 2 wherein the pad is at least ½ inch thick.

6. The sheet set feeding apparatus of claim 5 wherein the pad is at least 1 inch think.

7. The sheet set feeding apparatus of claim 1 wherein the support surface deflects no more than ½ inch during operation of the set picker.

8. A sheet set feeding apparatus for separating and feeding successive sheet sets from a stack of sheet sets, said stack of sheet sets including at least an uppermost set having a lower surface, and a penultimate set disposed subjacent said lower surface and having an upper surface, said penultimate set being offset from said uppermost set to present an upper exposed portion, said penultimate set being disposed offset from the sheet sets of said stack of sheet sets disposed subjacent said penultimate set such that the stack of sheet sets presents staggered sheet set edges at opposed ends of the stack of sheet sets, said sheet set feeding apparatus comprising: a support surface adapted to support said stack of sheet sets; a set picker assembly, said set picker assembly including a pic adapted to create a separation between the uppermost set and the penultimate set, said pic comprising a rotatable camming arrangement including a protrusion disposed to engage said staggered sheet set edges and moveable through an arc to exert a downward force on the exposed portion of the penultimate set, continued rotation exerting a separation force on the lower surface of the uppermost set to cause said separation between the lower surface of the uppermost set and the upper surface of the penultimate set, and a set removal device disposed to engage the separated uppermost set and remove the uppermost set from the stack of sheet sets.

9. The sheet set feeding apparatus of claim 8 wherein the camming arrangement includes an eccentric, said protrusion extending toward said sheet set stack from said eccentric, rotation of said eccentric resulting in rotation of said protrusion through said arc.

10. The sheet set feeding apparatus of claim 8 wherein said pic is moveably mounted to be disposed at the opposed ends of the stack of sheet sets, and said protrusion is rotatable in either direction dependent upon the location of the pic at either of the opposed ends of the stack of sheet sets.

11. The sheet set feeding apparatus of claim 10 wherein the set removal device is disposed at a first end of the opposed ends of the stack of sheet sets, and the pic is moveably mounted to cause said separation at the opposed end opposite the first end, said pic mounted to continue to exert the separation force on the lower surface of the uppermost set while traversing the stack of sheet sets to dispose said separation along said first end.

12. The sheet set feeding apparatus of claim 11 wherein the pic does not traverse the stack of sheet sets when causing said separation at the first end of the opposed ends of the stack of sheet sets.

13. The sheet set feeding apparatus of claim 11 further comprising a separation enhancer, said separation enhancer being disposed at the first end of the opposed ends of the stack of sheet sets to enter the separation between the uppermost and penultimate sets to enhance the separation.

14. The sheet set feeding apparatus of claim 8 further comprising a separation enhancer, said separation enhancer being disposed to enter the separation between the uppermost and penultimate sets to enhance the separation,

15. The sheet set feeding apparatus of claim 8 wherein the set removal device is a plow which exerts a pushing force on the uppermost set.

16. The sheet set feeding apparatus of claim 8 wherein the set removal device is a grasping device which grasps and exerts a pulling force on the uppermost set.

17. The sheet set feeding apparatus of claim 8 further comprising a stabilizer disposed to selectively exert a downward force on stack of sheet sets.

18. The sheet set feeding apparatus of claim 11 further comprising a stabilizer disposed to exert a downward force on the stack of sheet sets during at least traversing of the pic.

19. The sheet set feeding apparatus of claim 8 wherein the support surface has an upper surface with a rest position, said upper surface being pliant and resilient such that said upper surface deflects fro said rest position in response to said downward force and said upper surface substantially returns to its rest position upon removal of the downward force.

20. A sheet set feeding apparatus for separating and feeding successive sheet sets from a stack of sheet sets, said stack of sheet sets including at least an uppermost set having a lower surface, and a penultimate set disposed subjacent said lower surface and having an upper surface, said penultimate set being offset from said uppermost set to present an upper exposed portion, said penultimate set being disposed offset from the sheet sets of said stack of sheet sets disposed subjacent said penultimate set such that the stack of sheet sets presents staggered sheet set edges at opposed ends of the stack of sheet sets, said sheet set feeding apparatus comprising: a support surface adapted to support said stack of sheet sets; a set picker assembly, said set picker assembly including a pic adapted to create a separation between the uppermost set and the penultimate set, said pic being mounted to be substantially linearly moveable to traverse the stack of sheet sets, said pic being operable to create said separation at either of the opposed ends of the stack depending upon the location of the exposed portion of the penultimate set, said pic further being adapted to maintain said separation while traversing the stack of sheet sets, a separation enhancer disposed at a first end of said opposed ends of the stack of sheet sets, and a set removal device disposed to engage the separated uppermost set and remove the uppermost set from the stack of sheet sets.

21. The sheet set feeding apparatus of claim 20 further comprising a stabilizer disposed to exert a downward force on the stack of sheet sets during at least traversing of the pic.