Picking and transporting means for fabric sections and the like

Abstract

A method and apparatus for separating a single ply of limp material, such as fabric from a stack of such plies, and transporting the separated ply to a predetermined destination. The apparatus includes a rotatable ply gripping wheel, cooperating with a ply holding shoe. By rotating the wheel in contact with the ply, while restraining an adjacent area, the ply is buckled into a wave, nipped and then picked off of the stack. The gripping wheel and pressing shoe maintain a predetermined geometric relation, while being capable of independent yieldable contact with an uneven ply stack. The gripping wheel and holding shoe are operable in conjunction with an insertable flat plate, which is effective to progressively free the remainder of the ply. Thereafter, the flat plate is utilized to transport the freed ply to a desired destination, while the picking unit independently returns to the ply stack to commence its engagement with the next subsequent ply. Laterally movable sweep arms are provided as moving positioning abutments to secure the desired orientation of the ply at its destination.

I claim: 
     
       1. A picking apparatus for nipping and lifting a limp ply, which comprises a. ply gripping means including a movable ply gripping surface,   b. means for moving said ply gripping surface into controlled pressure contact with the top ply of a ply stack, whereby movement of said surface will effect displacement of the ply generally in the plane in which the ply initially rests,   c. a stationary ply retaining means positioned adjacent said movable gripping means,   d. means for moving said ply retaining means into contact with said top ply whereby upon movement of said gripping surface toward said retaining means, said ply is buckled into a wave between said surface and said retaining means, and   e. means for gripping and lifting said wave,   f. said ply gripping and said ply retaining means being mounted for individually controlled pressure contact with adjacent portions of the top ply of a ply stack,   g. said ply gripping means comprising a controllably rotatable ply gripping wheel having a ply gripping surface, and   h. said ply retaining means being mounted for pivoting movement about the axis of said wheel.   
     
     
       2. A picking apparatus according to claim 1, further characterized by a. support means for said ply gripping means,   b. first yieldable means associated with said support means and said gripping means for urging said ply gripping wheel against said ply stack with a predetermined adjustable force, and   c. second yieldable means independent of the first yieldable means and associated with said ply retaining means for urging said retaining means against said ply stack.   
     
     
       3. A picking apparatus according to claim 2, further characterized by said second yieldable means comprising spring means acting between said ply gripping means and said ply retaining means to urge said ply retaining means to move relative to said gripping means. 
     
     
       4. A picking apparatus for nipping and lifting a limp ply, which comprises a. ply gripping means including a movable ply gripping surface,   b. means for moving said ply gripping surface into controlled pressure contact with the top ply of a ply stack, whereby movement of said surface will effect displacement of the ply generally in the plane in which the ply initially rests,   c. a stationary ply retaining means positioned adjacent said movable gripping means,   d. means for moving said ply retaining means into contact with said top ply whereby upon movement of said gripping surface toward said retaining means, said ply is buckled into a wave between said surface and said retaining means,   e. means for gripping and lifting said wave,   f. said ply gripping and said ply retaining means being mounted for individually controlled pressure contact with adjacent portions of the top ply of a ply stack,   g. support means for said ply gripping means,   h. first yieldable means associated with said support means and said gripping means for urging said ply gripping surface against said ply stack with a predetermined adjustable force,   i. second yieldable means independent of the first yieldable means and associated with said ply retaining means for urging said retaining means against said ply stack,   j. said support means comprising a pivotally mounted lifting lever,   k. means for effectively substantially balancing said lever,   l. said first yieldable means comprising an actuator element operable through a predetermined stroke, and a spring interconnecting said lifting lever and said actuator, and   m. adjustable means interconnecting said spring and said actuator element for controlling the amount of displacement of said spring caused by the predetermined stroke of said actuator.   
     
     
       5. A picking apparatus for nipping and lifting a limp ply, which comprises a. a movable gripping member movable about an axis and having an arcuate ply gripping surface,   b. lifting means supporting said member for rotary movement of its gripping surface about said axis,   c. means forming a ply stripping element extending from a point outside the arcuate surface of the gripping member to a point within the projected configuration of the member and disposed at a relatively shallow angle with the gripping surface of the member at the point of intersection of said stripping element with said gripping surface,   d. ply retaining shoe means positioned to yieldably press upon the ply stack, adjacent said ply gripping member, whereby ply material displaced by movement of said member is caused to buckle into a wave in the region between said member and said shoe, and   e. said stripping element and said shoe means forming an accumulation cavity for receiving said wave.   
     
     
       6. A picking apparatus according to claim 5, further characterized by a. means for actuating said gripping surface through a predetermined distance in one direction to effect a predetermined accumulation of ply material, and   b. said means for actuating being operative to drive said gripping surface through a greater distance in the opposite direction to effect cast off of the accumulated ply material.   
     
     
       7. A picking apparatus according to claim 6, further characterized by a. said ply gripping member comprising a wheel,   b. said means for actuating comprising a double-acting fluid actuator having a static position intermediate the limits of its strokes.   
     
     
       8. A picking apparatus according to claim 5, further characterized by a. said ply gripping member comprising a toothed wheel assembly,   means mounting said ply retaining shoe means for pivotal movement about the axis of said wheel, and   c. yieldable means urging said shoe means to pivot about said axis in the direction of the ply surface.   
     
     
       9. A picking apparatus according to claim 8, further characterized by a. said retaining shoe means including a supporting member mounted for pivoting movement about the wheel axis, and   b. said shoe means further including a pressing shoe pivotally mounted on said supporting member and engageable with the surface of the ply material.   
     
     
       10. A picking apparatus according to claim 9, further characterized by a. said pressing shoe having a gripping surface facing and spaced slightly from said wheel and accommodating the passage of a wave of buckled ply material, and   b. spring means normally urging said pressing shoe to pivot in a direction urging said gripping surface toward said wheel.   
     
     
       11. A picking apparatus according to claim 5, further characterized by a. first adjustable spring means urging said gripping surface into contact with said ply material, and   b. second adjustable spring means, independent of said first spring means, for urging said ply retaining shoe means into contact with said ply material.   
     
     
       12. An apparatus for picking and separating plies of limp material, one at a time, from a stack, which comprises a. gripping means for engaging the top ply and displacing it away from one edge of the ply stack,   b. said gripping means engaging the ply at a first predetermined distance from said one edge,   c. pressing means engaging the ply stack adjacent the gripping means and on the side thereof away from said edge, to restrain the upper ply against movement and thereby causing said fabric to be formed into a wave between said gripping and pressing means,   d. ply stack hold-down means engageable with the top of the stack in a region spaced from said edge,   e. said hold-down comprising a first portion extending above the stack in spaced relation and a second portion extending downward to engage the stack in a limited area spaced inward from said edge,   f. actuating means of limited effective stroke for actuating said gripping means through a movement of limited displacement to displace said top ply a second predetermined distance from said edge,   g. said second predetermined distance being less than said first predetermined distance, and   h. the second portion of said hold-down means engaging said stack in a region spaced from said edge a third predetermined distance, less than, but greater than half of, said second predetermined distance, whereby following displacement of a ply by said gripping means, said hold-down means engages said ply stack at a point removed from the topmost ply but over a lower ply secured edge-to-edge with said first ply.   
     
     
       13. An appparatus according to claim 12, further characterized by a. control means for lowering said hold-down means into engaged relation to said stack after actuation of said gripping means, to accommodate edge separation of successive plies, and   b. control means for raising said hold-down means following said edge separation to release folded-over lower plies previously attached to the trailing edge of the topmost ply.   
     
     
       14. An apparatus for picking and separating limp plies from a stack thereof, which comprises a. means for gripping the top ply and displacing it away from one edge of the stack,   b. stack hold-down means engageable with the stack in a region spaced between said edge and said gripping means,   c. means for lifting said gripping means and a top ply held thereby away from the stack while said hold-down means is engaged with the stack,   d. means for lifting the hold-down means substantially above the stack after said top ply has been removed by said lifting means,   e. said gripping means being engageable with said top ply in a region spaced inwardly from said one edge of the stack a first predetermined distance and being operative to displace said top ply, generally in the direction of its initial plane, away from said edge through a second predetermined distance which is less than the first predetermined distance, and   f. said hold-down means being positioned to engage said stack in a limited area located between said edge and said gripping means and spaced inward from said edge a distance less than the second predetermined distance but greater than one-half thereof.   
     
     
       15. Apparatus for separating and transporting limp plies one at a time from a stack thereof, which comprises a. means for gripping and lifting one edge portion of a top ply of the stack,   b. hold-down means for engaging the stack below the top ply in the region of said one edge,   c. a plate-like shutter means movable into interposition below said top ply and above the remainder of the stack, to fully separate said top ply from said stack, and   d. means guiding said plate-like shutter for progressive interposing, longitudinal movement, entering adjacent said one edge and progressing toward and beyond the opposite edge,   e. said plate-like shutter being of greater width than the plies of said stack, whereby progressive longitudinal interposing movement of the plate is operative to effect positive separation of the side edges of said top ply from lower plies,   f. said means for gripping and lifting being engageable with limited areas only of said top ply,   g. said plate-like shutter having a tapered leading edge portion adapted to be received initially between said top ply and said stack in the limited region in which said top ply is gripped and lifted, and   h. said tapered leading edge portion progressively forcing outward and separating any edges of said top ply which are attached to said stack.   
     
     
       16. Apparatus for separating and transporting limp plies one at a time from a stack thereof, which comprises a. means for gripping and lifting one edge portion of a top ply of the stack,   b. hold-down means for engaging the stack below the top ply in the region of said one edge,   c. a plate-like shutter means movable into interposition below said top ply and above the remainder of the stack, to fully separate said top ply from said stack,   d. means guiding said plate-like shutter for progressive interposing, longitudinal movement, entering adjacent said one edge and progessing toward and beyond the opposite edge,   e. means for reciprocating said plate-like shutter between an interposed position, between said stack and top ply, and a predetermined destination position, and   f. means independent of said gripping and lifting means effective to retain said top ply on said shutter during movement of the shutter and the ply to said destination position.   
     
     
       17. Apparatus for separating and transporting limp plies one at a time from a stack thereof, which comprises a. means for lifting one edge of a top ply of the stack,   b. plate-like transport shutter means,   c. means for guiding and actuating said plate-like shutter means in a plane above the top of the ply stack but below a lifted edge of the top ply, whereby a lifted top ply may be engaged and supported for transport by said shutter means, and   d. means for actuating said shutter means to move with a ply to a predetermined destination position,   e. said shutter means being movable between said top ply and said stack progressively from one end edge of the ply to the other,   f. ply engaging means carried by said shutter means adjacent its leading edge and engageable with said other end edge of the top ply for positive engagement with said ply during movement of the shutter means toward said destination position, and   g. means for effecting removal of a ply from said shutter means at said destination position,   h. said means for effecting removal comprising means for retaining said ply and means for effecting return movement of said shutter means.   
     
     
       18. The apparatus of claim 17, furthr characterized by a. ply positioning means independent of said shutter means being mounted adjacent said destination position and engageable with said one end edge of the ply when said shutter means is in said destination position. .[.   
     
     
       19.  An apparatus for separating and transporting limp plies one at a time from a ply stack, which comprises a. means to pick plies one at a time from a ply stack,   b. a flat shutter plate for receiving plies one at a time from the picking means,   c. means for actuating said shutter plate between ply receiving and ply delivering positions, and   d. means for orienting said plies on said plate comprising a pair of sweep elements engageable with one end edge of a ply supported by said plate, near the center of said edge, and movable symmetrically away from said center while maintaining engagement between said edge and at least one of said sweep elements..]. .[.20. The apparatus of claim 19, further characterized by   a. said sweep elements comprising a pair of pivotally mounted sweep arms having portions closely overlying said shutter plate and having edge engaging lugs engaging the surface of the plate,   b. first control means for raising and lowering said sweep arms, and   c. second control means for swinging said sweep arms outwardly to cause said edge engaging lugs to displace and reorient a misaligned ply..]. .[.21. The apparatus of claim 20, further characterized by   a. third control means for effecting movement of said shutter plate in a direction to urge a ply supported thereon toward said edge engaging lugs during outward sweeping movements of said arms..]. .[.22. The apparatus of claim 21, further characterized by   a. plies of material being discharged from said plate of said destination   
     
     
        by movement of said plate while said sweep arms are lowered..]. 23. The method of picking and removing limp plies one at a time from a stack, which comprises a. displacing a first limited area of the top ply through a predetermined limited distance generally in the plane of the ply and away from a predetermined edge of the ply,   b. simultaneously restraining against displacement a second limited area portion of the top ply closely adjacent the first area and on the side thereof opposite said predetermined edge, whereby said ply is buckled into a wave,   c. gripping said ply in the region of said wave,   d. subsequent to displacement of said top ply, engaging and restraining the remainder of the stack of plies in a limited region located between said predetermined edge and said first limited area and spaced from said predetermined edge a distance greater than one-half of said predetermined distance, and   
     
     
       e. thereafter removing said top ply. 24.  The method of claim 23, further characterized by a. the step of removing said ply being effected by the progressive interposition of an element between the partly displaced top ply and the remainder of the stack to separate and support said top ply, and   b. thereafter bodily removing the element and the top ply to another   
     
     
        location. 25. The method of claim 23, further characterized by a. said first limited area being displaced a predetermined distance to effect formation of said wave, and   b. said first limited area being urged for displacement through a greater   
     
     
        distance in an opposite direction for effecting castoff. 26. The method of picking and removing limp plies, one at a time, from a stack which comprises a. controllably, yieldably engaging a first limited area of the top ply adjacent one edge of the ply and displacing it in a direction away from said one edge through a predetermined limited distance,   b. thereafter pressing downward on the ply stack in a second limited area between said one edge and said first limited area and spaced from said one edge a distance less than, but greater than one-half of, the distance of displacement, whereby to engage all plies below the top, including any plies whose edges are connected to said one edge,   c. said second limited area being sufficiently removed from said one edge to substantially avoid creasing of the folded-over margin of a connected lower ply, and   
     
     
       d. thereafter lifting said top ply. 27. The method of claim 26, further characterized by a. said top ply being lifted a limited distance in said limited area,   b. thereafter said top ply being fully separated from said stack by progressive interposition between said stack and said top ply of a flat element,   c. after said full separation, said limited area of said top ply being released,   d. the separated top ply being supported on substantially its entire bottom surface and transported laterally from said stack, and   e. the transported ply being aligned and oriented while so supported, and   
     
     
        then discharged. 28. The method of picking and removing limp plies, one at a time, from a stack, which comprises a. controllably, yieldably engaging a first limited area of the top ply adjacent one edge of the ply and displacing it in a direction away from said one edge through a predetermined limited distance,   b. thereafter pressing downward on the ply stack in a second limited area between said one edge and said first limited area and spaced from said one edge a distance less than, but greater than one-half of, the distance of displacement, whereby to engage all plies below the top, including any plies whose edges are connected to said one edge,   c. thereafter lifting said top ply,   d. controllably, yieldably engaging said top ply in a second limited area, immediately adjacent said first area and on the side thereof opposite said one edge,   e. restraining said second area while displacing the first to form a wave in the ply,   f. nipping the ply near the base of the wave and lifting the nipped area,   g. while continuing to nip the ply, interposing a member progressively between the ply and the stack to fully disengage and separate said ply from said stack, and   h. after disengaging and separating said ply, transporting said ply to a predetermined destination while simultaneously commencing to engage a next successive ply in the sequence set forth in subparagraphs (a), (b) and (c) hereof. .[.29. The method of orienting a limp ply after transportation thereof, on a flat plate to a destination, which comprises   a. while the ply remains on the plate, interposing a pair of spaced edge engaging elements adjacent one end edge of the ply and spaced well inward from its side edges,   b. thereafter moving said plate in a direction to move said end edges toward said edge engaging elements, and   c. during engagement of said end edge with at least one of said elements and while continuing to move said plate in said direction, moving said edge engaging elements symmetrically outward from the center of the ply..]. .[.30. The method of claim 29, further characterized by   a. continuing to move said plate in said direction while maintaining said edge in engagement with at least one of said elements, until said plate is fully removed from under said ply..]. .Iadd. 31. An apparatus for picking and separating plies of limp material, one at a time, from a stack, which comprises   (a) gripping means for engaging a first limited area of the top ply and displacing it away from one edge of the ply stack through a predetermined limited distance,   (b) ply stack hold-down means engageable with the top of the stack in a second limited area spaced from said one edge a distance less than, but greater than half the distance of displacement, whereby to engage all plies below the top ply, including any plies whose edges are connected to said top ply,   (c) control means for lowering said hold-down means into engaged relation to said stack after actuation of said gripping means, and   (d) means for lifting said top ply. .Iaddend..Iadd. 32. The method of picking and removing limp plies, one at a time, from a stack, which comprises   (a) engaging a first limited area of the top ply,   (b) displacing said first limited area away from one edge of the ply stack through a predetermined limited distance,   (c) subsequent to displacement of said top ply, engaging the top of the ply stack in a second limited area spaced from said one edge a distance less than, but greater than half of the distance of displacement, whereby to engage all plies below the top ply, including any plies whose edges are connected to said top ply, and   (d) thereafter removing said top ply. .Iaddend.