US3367651A - Stacking machine for flexible workpieces - Google Patents

Description

Feb. 6, 'l968 D. L. ELLER ET Al. 3,367,651

STACKING MACHINE FOR FLEXIBLE WORKFIECES Filed April l2, 1966 5 Sheets-Sheet l HZ CONTROL \l Feb. 6, 1968 n.1.. ELLER ET AL STACKING MACHINE FOR FLEXIBLE WORKFIECES Fi'ed April 12, 196e 3 Sheets-Sheet 2 INVENTORS L erafv /aELEL En lll Feb. 6, 1968 D. ELLER ET AL 3,357,651

STACKING MACHINE FOR FLEXIBLE WORKPIECES Filed April 12, 196e s sheets-sheet s f 26 /za f 2 y 2/A M9, ,24 rx @2 INVENTOR 3 Bfwm @WMM ATTQRNEYS United States Patent Ollice 3,367,651 Patented Feb. 6, 1968 3,367,651 STACKING MACHINE FOR FLEXIBLE WORKPIECES Dale L. Eller, Lebanon, and Trigg R. Barton, Cleveland,

Va., assignors to Top Form-Yolande, Inc., Lebanon,

Va., a corporation of Virginia Filed Apr. 12, 1966, Ser. No. 542,008 9 Claims. (Cl. 271-70) The present invention relates to automatic stacking equipment and in particular to stacking equipment for automatically stacking llexible workpieces, such as garment components or the like, -as they issu-e from a sewing machine.

In the sewing and handling of garment components in the garment industry it is desirable that hand operations be kept at a minimum in order to maintain a high production rate. One area which has often included a hand operation is the picking up and stacking of components after a sewing machine operator has completed a number of pieces. For example, a sewing machine operator who receives a bundle of garment components will perform a stitching operation on each component following which she will transfer the components to another processing operation. It is often the practice for the operator to permit the stitched components to progress in sequence into a -bin or the like and to subsequently interrupt the sewing operation in order to gather up and stack the components before transferring them to the next operation.

It is recognized in the industry that these hand opera tions and interruptions of the sewing ope-ration are inelicient, and various automatic stacking equipment has been proposed. However, the proposed equipment has not proved entirely satisfactory because of its cost and complexity and the need for supervision to maintain it in p roper working order under different operating conditions. One problem which is particularly difficult to over come is the tendency of slick, highly llexible components, such as those made of silk or rayon, to slide olf the stacklng mechanism and otherwise avoid being properly handle-d. Another disadvantage of the prior sta-cking equipment is the common use of reciprocating elements which are not only complex in construction but also apt to mis handle the garment components operating at high speed.

According to the objects of the present invention these disadvantages of ineilicient operation at high speed and when handling slick fabrics are overcome by providing -a special stacking member of simple construction which rotates in only one direction in a manner to stack a garment component on top of another during each rotation. More specifically, the stacking member is mounted in a position such that during sequential rotation it engages a garment component from below, lifts that component upwardly out of its line of travel from the sewing machine and then carries it in an arc to the exposed end of a stack, the stacking member continuing to rotate in the same direction so as to return to and stop at a position for engaging another garment component. The stacking member is constructed generally as a pair of parellel spaced apart arms which rotate about a common axis normal thereto so as to pass on either side of a stationary stacking table or the like while at the same depositing and draping a garment component on top of the table.

Another feature of the present invention is the use of the above described stacking arms in conjunction with an 'endless conveyor arranged to maintain a slick, llexible garment component in a flat condition at the time of transfer. In this arrangement the stacking arms are mounted for lrotation in planes normal to the line of travel of the conveyor, and are spaced apart a distance slightly greater than the length of the conveyor. As a garment component of greater length than the conveyor moves along the conveyor there will occur a position in which the garment component extends beyond each end of the conveyor. When the component is in this position, the stacking arms are rotated so as to pass by the ends of the conveyor from the side opposite the garment component and to lift the component off the conveyo-r. In a prefer-red construction the conveyor is the center one of a group of three conveyors disposed in end-to-end relationship, and the arms of the stacking member pas-s through the spaces between adjacent conveyors.

These and other objects and a-dvantages will become apparent from the following detailed description in conjunction with the drawings in which:

FIGURE 1 is a side elevational view of a stacking machine embodying the principles of the present invention;

FIGURE 2 is a top plan view of the machine of FIG- URVE 1;

FIGURE 3 is an end elevational view looking from the left of FIGURE 1 along the line 3 3;

FIGURE 4 is a simplified fragmentary view, on an enlarged scale, of part of FIGURE l;

FIGURE 5 is a schematic simplied block diagram illustrat-ing the principles of a control system for the stacking machine of FIGURES 1 4; and

FIGURE 6 is a schematic side elevational view of a modified form of stacking machine.

Referring to FIGURES l, 2 and 3 there is shown a garment component stacking machine 1l) in combination with a sewing machine table 12. The latter includes a horizontal generally rectangular plate 14 having a cutout 16 for receiving the base (not shown) of a conventional commercial sewing machine 18. During use of the equipment a sewing machine operator sits at the front, or righthand end of the table 12 facing the rear, or left-hand end of the equipment as viewed in FIGURES 1 and 2. In conducting sewing operations on a garment component, the operator moves the component under 'the operating head of the sewing machine 18 in a direction toward the rear of the table 12. Once the component becomes free of the sewing machine 18 it is automatically conveyed away, as Aillustrated at 19, and stacked on top of the next previous component at a location to one side ofthe equipment.

The stacking apparatus 10 includes three horizontal endless conveyor belts 20, 22 and 24 mounted in end-toend relationship behind the sewing machine 18 with their upper runs substantially in the plane of the upper surface of the table 12. The belts are driven in a direction to convey the garment components away from the sewing machine 18 toward the rear or left end of the equipment. As a component 19 traverses the center belt 22 a rotatable stacking mechanism 26 lifts the component 19 olf the belt 22 and deposits it on a stacking table 28 in a position 21, on one side of the line of travel of the belts. The for- Wardmost belt 20 is disposed in a cutout 29 in the sewing machine table 14 in a location rearwardly of the cutout 16 so as to receive components 19 from the sewing machine 18. The center belt 22 is disposed with, its forward end slightly spaced from the rear end of the forwardmost belt 20. Just rearwardly of the center belt 22 is the third or rear belt 24, whose forward end is slightly spaced from the rear end of the center belt 22.

Each of the belts 20, 22, 24 is looped over a pair of spaced apart rollers which are supported in fixed positions in any suitable manner. As shown, the forwardmost belt 20 is looped over rollers 30 and 32, whose shafts are journalled in suitable front end brackets 34 and 36 secured to the sewing table 14. The center and rear belts are looped over rollers 38,' 40 and 42, 44, respectively, whose shafts are journalled in intermediate and rear end brackets 46 and 48, respectively. The table 14 and brackets 46 and 48 are mounted in any suitable manner on a main frame 50 which rests on the floor 52. The conveyor belts are synchronously driven at constant speed by a motor drive unit 54 and a chain drive linkage mounted on one side of the equipment. As best shown in FIGURE 2 the motor unit 54 is mounted on the rear edge of the sewing machine table 14 and is provided with an output shaft 56 which is directly coupled at 58 to the shaft of the rear roller 32 of the front conveyor 20. The center conveyor 22 is driven from the roller 32 through a sprocket 60 thereon, a chain 62 and a sprocket 64 on the roller 40. A second sprocket 66 on the roller 40l carries a second chain 68 which drives the rear conveyor 24 through a sprocket 70 on the roller 44.

According to the principles of the present invention the stacking mechanism 26 includes a rotatable flip shaft 72 disposed out of the line of travel of a garment comp@ nent 19 and provided with a plurality of stacking arms which in operation lift a garment component from its line of travel and flip it on to a suitable support, such as the stacking table 28. In the embodiment of FIGURES 1 4 the axis of the flip shaft 72 is disposed parallel to the lineof travel of the garment components or established by the conveyors 20, 22 and 24. As seen in FIGURES l and 2 the shaft 72 is disposed in the same plane as the conveyors and is journalled in brackets 74 which are secured to the frame member 48 on the opposite side of the machine from the chain drive for the conveyors. The right-hand end portion of the shaft 72 as viewed in the drawings carries two pairs of radially projecting stacker arms 76, 78 and 80, 82. The pairs are disposed at an angle of 180 to each other, and the members of each pair lie in a common plane and are spaced apart along the axis of the shaft 72 a distance such that they can straddle either the ends of the center conveyor 22 or the sides of the stacking table 28, Thus, during clockwise rotation of the shaft 72 as viewed in FIGURE 3 the outer portions of a pair of arms will pass simultaneously upwardly through the two spaces at the ends of the center conveyor 22 and then downwardly past the table 28. Rotation of the shaft 72 is effected by an endless timing belt 73 which is looped over a pulley 75 carried at the rear end of the shaft 72.

As previously indicated the stacker arms 76, 78, 80 and 82 are moved through an arc of 180 each time a garment component 19 arrives in a position in which it straddles the center conveyor 22. A drive mechanism 83 for accomplishing this is illustrated in FIGURES l, 3 and 4 and schematically in FIGURE 5. As shown, the mechanism 83 includes a constant speed motor drive unit 84 supported by the main frame 50 and a chain drive for transmitting power to the ip shaft 72. The motor drive unit 84 has an output shaft 86 drivingly connected by means of a worm drive 88 to a continuously driven main shaft 90 which is suitably journalled at its ends in the main frame 50. An electric clutch 92 and a spur gear 94 are mounted concentrically with the main shaft 90 in a manner such that the clutch 92 will effect a driving connection between the shaft 90 and the gear 94 when engaged. When the clutch 92 is disengaged, the shaft 90 rotates freely within the gear 94. A secondary shaft 96 is mounted within the frame 50 below and parallel to the main shaft 90 and is provided with a timing pulley 98 at its outer end. The timing belt 73 is looped over the pulley 98, over an idler pulley 102 supported by the main frame 50, and over the pulley 75 on the flip shaft 72.

A spur gear 104 fixed on the secondary shaft 96 intermediate its ends meshes with the spur gear 94 on the main shaft 90. An electric brake 106, supported by the main frame 50, is mounted concentrically with the secondary shaft 96 for intermittently locking the latter against rotation. A cam 108 on the shaft 96 between the brake 106 and the gear 104 actuates a fixed niicroswitch 110 at each one-half revolution of the shaft 96 to thereby lock the brake 106 and disengage the clutch 92. This stops rotation of the shafts 72 and 96 until a sensing device 112 senses the arrival of the next garment component at the center conveyor 22 and simultaneously releases the brake 106 and engages the clutch 92. The clutch 92 and brake 106 are conventional devices and are controlled through a conventional control box 114.

The stacking machine 10 also includes a keeper arm 116 employed to rest on top of any stack of garment components which has been built up on top of the stacking table 28. As best shown in FIGURES 2 and 3 the table 28 is constructed as an elongated wooden bar, or the like, which projects laterally from the main frame 50 and which has an exposed upper surface. If desired, the upper surface of the block may carry a fixed bracket 117 as an aid in retaining garments thereon.

The keeper arm 116 is constructed in the general shape of an inverted U and is pivoted at one end to the outer end of the table 28 for rotation in a vertical plane about a horizontal pivot pin 118. The free end of the arm 116 is provided with a horizontal extension 120 constructed of rubber or the like which is shown as engaging a garment component 19 draped over the top of the stacking table 2.8. The arm 116 is pivotable clockwise from the position shown in FIGURE 3 by means of a solenoid-operated rod 120 and linkage arrangement 122. The latter includes a generally L-shaped link 124 pivotally connected at one end to the arm 11.6 and at its other end to an end of the rod 120. The heel of the link 124 is pivotally connected to one end of a short, straight link 126 whose other end is pivoted to the end of the table 28. The end of the rod 120 opposite the linkage arrangement 122 is bent at a right angle to the remainder of the rod and is secured to a drive rod 128 whose ends are connected to the plungers of a pair of spaced apart solenoids 130 and 132. Energization of the up solenoid 130 pulls on the lower end of the rod 120 and causes the arm 116 to rise, while energization of the down solenoid 132 pushes the rod 120 and causes the arm 116 to return to its FIGURE 3 position. The solenodis are mounted in any suitable manner, as on a triangular bracket 134 which also supports the table y28.

The rod 120 is formed in two pieces 120a and 12011, joined together by a set collar 136 so that the effective length of the rod 120 can be varied to adjust the pivotal position of the arm 116.

The sensing device which is employed for recognizing the arrival of a garment component at the center Conveyor 22, and for providing a signal for activating the stacking drive 83 upon this occurrence may be of any suitable type. The device illustrated at 112 is a conventional photoelectric cell unit of the kind which produces a beam of light, projects the beam against a remote surface which reliects the beam to the unit and senses any interruption ofthe beam. As seen in FIGURES l, 2 and 3 the unit 112 is mounted above and intermediate the ends ofthe rear conveyor 24. A beam of light 138 (FIG- URES 3 and 5) is projected downwardly from a light generating portion 140 of the unit 112 toward the surface of the upper run of the conveyor 24 at such an angle.- that the beam 138 which is reflected by the conveyor 24'- returns to a photocell portion 142 of the unit 112. Upon interruption of the beam by the leading edge of a garment component 19 the unit 112 together with a suitable elecf tric control circuit 144 (FIGURE 5) produces an elec-- tric signal for initiating upward movement of the keeper arm 116 and a one-half revolution of the iip shaft 72' and consequent stacking of the garment component 19 on the stacking table 28. In FIGURES 2 and 3 the component which is on the conveyors 20, 22 and 24 is shown in a position immediately prior to its interruption of the light beam 138.

The position of the sensing unit 112 along the length of the rear conveyor 24 is selected so that the midpoint of a garment component 19 is approximately at the midpoint of the center conveyor 22 when the leading edge of the component interrupts the light beam 138. By this arrangement the stacker arms 76, i8 or 80, 82 will engage the component 19 near its middle so that the component 19 will drape evenly over the arms with no tendency to slip off. The sensing unit 112 may be mounted so as to be adjustable along the length of the rear conveyor 24 to thereby accommodate the machine 1t) to processing garment components of different lengths. In the embodiment illustrated the unit 112 is supported by a nut 146 which is fixed against rotation and which is carried on a threaded rod 148 extending parallel to and to one side of the rear conveyor 24. The rod 148 is journalled at its ends in brackets 150 carried by the rear frame member 48 and is coupled to the output shaft of a reversible motor 152 which is also supported from the frame member 48. The motor 152 is manually controlled to rotate the rod 148 in either direction thereby moving the nut 146 and the sensing unit 112 to any desired position along the conveyor 24.

It will be understood that other sensing devices and drive mechanisms may be employed for effecting intermittent rotation of the stacker arms 76, 78 and 80, 82 upon arrival of a garment Component at the center conveyor 22.

FIGURE 6 illustrates in simplified form a modified stacking machine 10' suitable for stacking garment components 19 of firmer, less slick fabric than the components processed by the machine 10` of FIGURES 1-5. In the FIGURE 6 construction the natural stiffness of the components 19 is relied on to maintain them in a sufllciently flat condition to be delivered to and flipped by the stacker arms, two of which are :shown at 78 and 82. As shown, the sewing machine table 14 is horizontally and vertically spaced from the stacking machine 10', and the components 19' are allowed to slide by gravity down a stationary inclined extension 154 at the rear of the table 14. The flip shaft 72 is disposed rearwardly of and below the lower end of the extension 154 and is braked in a position such that one of its pairs of arms will receive the component as it slides oil" the extension 154. A stationary photocell sensing unit 112 is positioned so as to be straddled by the arms during rotation and so as to sense the leading edge of the component 19'. In this arrangement the sensing unit 112 is constructed to produce an activating signal for the drive 83 when light from its beam producing element 158 is rellected from the component 19 into its photocell element 160.

Operation The stacking machine 10 is placed in a condition to receive and stack garment components 19 automatically by first energizing the motors 54 and 84, thereby placing the conveyors 20, 22 and 24 and the main drive shaft 98 (FIGURE 4) in continuons operation. As described previously, the motor 54 drives the conveyors at constant speed through the sprocket and chain arrangement shown in FIGURE 2. An operator, sitting at the forward end of the sewing machine table 14, then performs a stitching operation on a garment component by manually guiding the component under the sewing head of the sewing machine 18. As the leading edge of a component 19 is discharged rearwardly by the sewing machine 18 it is engaged by the upper run of the forward conveyor and pulled rearwardly thereby maintaining the fabric in a flattened condition. When the trailing edge of the component 19 is released by the sewing machine 18 the entire component is conveyed rearwardly in a flat condition. The conveyor 20 operates at a high linear speed so that each garment component Will become spaced from the following one. As is conventional in this type of stitching operation each garment component will be connected by a thread chain to the subsequent component, and it will be assumed that the thread chain is cut either man- 6 ually or automatically as each component leaves the sewing machine 18.

The garment component then rapidly passes from the forward conveyor 20 to this center conveyor 22 and then to the rear conveyor 24 without any wrinkling or buckling. If desired, the rear conveyor 24 may be run at a higher speed than the center conveyor 22 and the latter at a higher speed than the forward conveyor 20, by appropriate selection of the size of the sprockets 64, 66 and 70, in order to increase the flattening effect on the garment component during its travel. During this period the sensing unit 112 Will be ineffective, because the beam of light 138 will be continuously reflected from the surface of the conveyor 24 to the photocell portion 142 of the unit 112. When the leading edge of a component 19 moves slightly rearwardly from the position illustrated in FIGURE 1 to the position illustrated in FIGURE 5 the light beam 138 will be interrupted] and the flip shaft 72 will be rotated through 180 through the agency of the sensing unit 112, the control circuit 144 and the drive mechanism 83. The position of the sensing unit 112 along the length of the rear conveyor 24 will have previously been adjusted by rotation of the threaded rod 148 so that approximately one-half of the garment component 19 will have traversed the center conveyor 22 at the time of interrupting the light beam 138. The midpoint of the garment component 19 will therefore be about midway between the stacker arms 76 and 78 when the latter are rotated.

-Upon interruption of the light beam 138 by the garment component 19 the sensing unit 1.12 creates a signal which is employed to initiate rotation of the flip shaft 72 and simultaneously to raise the keeper arm 116 away from the stacking table 28. More specifically, these operations are effected by a suitable control circuit, illustrated at 144 in FIGURE 5, which upon receiving the signal from the sensing unit 112 engages the electric clutch 92, releases the brake 186 and energizes the up solenoid 130. Energization of the latter rotates the keeper arm 116 clockwise as viewed in FIGURE 3. Engagement of the clutch 92 causes the normally stationary gear 94 to rotate with the continuously rotating shaft 92 and to transmit driving force to the shaft 96 through the gear 104. Since the brake 106 is released simultaneously, the Shaft 96 rotates and drives the flip shaft 72 through the agency of the pulleys 98, 102 and 72 and the belt 100.

The cam 108 on the shaft 96 is designed to actuate the microswitch 110 after 180 of rotation. When actuated, the microswitch together with the control circuit disengages the clutch 92 and applies the brake 106 thereby bringing the shaft 92 and the flip shaft 72 to an abrupt halt. At the same time the up solenoid is de-energized and the down solenoid 132 is energized to rotate the keeper arm 116 counterclockwise as viewed in FIG- URE 3. The flip shaft 72 and the keeper arm 116 are then in position to be reactuated upon the next interruption of the light beam 138.

Referring again to FIGURES 1-3 it will be seen that of rotation of the flip shaft 72 from the position shown in these figures will move the stacker arms 76 and 78 through an arc upwardly through the spaces at the ends of the center conveyor 22 and then downwardly past the upper surface of the table, thereby defining onehalf of a cylinder of rotation. Since the pairs of arms 76, 78 and 80, 82 are angularly spaced apart 180, each pair will come to rest in the position previously occupied by the other paid.

As previously described the garment component 19, at the moment of rotation of the flip shaft 72, is straddling the center conveyor 22 and will therefore be engaged intermediate its ends by the arms 76 and 78. Upon upward movement of the arms 76 and 78 the component 19 will be lifted off the conveyors with the leading end of the component draping over the arm 76 and the trailing end draping over the arm 78. The component 19 must, of course, be of sufficient length that the Weight of the draped portions will prevent the entire component from collapsing into the space between the arms 76 and 78. In addition, the movement of the arms 76 and 78 must be sufficiently rapid to deposit the component 19 on top of the table 23 before it can slip off the arms.

By the time the arms 76 and 78 have moved into proximity with the table 28 the keeper arm 116v will have pivoted out of the line of travel of the arms so that the component, now illustrated at 21, Will be deposited in an inverted position on top of the table 28. The keeper arm 1116 will then descend and clamp the component 21 and all previously stacked components between the table top and the extension 120. The keeper arm .116 is sufficiently fiexible that it will bend to accommodate a stack of components 21 of considerable height. Ultimately, of course, the stack is manually removed from the table 28 by the operator and transferred to another station.

The operation of the modified machine 10 of FIGURE 6 is similar to that of the machine i0. Garment components 19', assuming that any thread chain between adjacent components becomes cut after leaving the sewing machine 18', slide by gravity down the fixed inclined extension 154 and into a draped position on a pair of spaced arms one of which is shown at 82. The leading edge of the garment component 19 then reflects a beam of light from the element 158 to the element 160 of the sensing unit 112' whereupon the flip shaft '72 is rotated 180 counterclockwise. The garment component 19 is thereby moved through an arc and draped over the top of the ta'ble 28', the other pair of arms simultaneously moving into a position to receive another garment component 19. This arrangement requires that the components 19' have considerable stiffness, Ibecause if too flexible they would tend to bunch while sliding into position and would thereby fail to drape properly over the arms.

It will be understood that modifications of the embodiments disclosed herein may be made without departing from the scope of the invention which is defined by the appended claims. It will be understood, for example, that a single set of stacker arms or more than two sets of arms may be employed provided that the drive system is constructed to rotate the sets through arcs of such length that only one set sweeps the line of travel of the Workpiece during each arcuate movement.

What is claimed is:

1. An automatic stacking machine for stacking liexible workpieces such as garment components and the like comprising: movable stacking means for engaging one face of a workpiece and for subsequently depositing the workpiece on the exposed end of a stack of previously handled workpieces with the other face in contact with said exposed end, said stacking means including a pair of generally parallel coextensive arms mounted in spaced apart relationship for simultaneous rotation about a common axis through one end of said arms; a stationary workpiece receiving stand having a receiving surface at least partially Within the cylinder of revolution defined by rotation of said arms, said receiving surface having a dimension in the direction of said axis of rotation which is less than the minimum distance between said arms whereby during rotation said arms can sweep past said surface without engaging the same; and drive means -for intermittently rotating said arms through a predetermined arc past said receiving surface remote therefrom whereby said arms may engage one surface of a workpiece at said remote position and cause the workpiece to drape over said arms and whereby the workpiece Will be deposited with its other face in contact with said receiving surface or with the exposed end of a stack of workpieces on said receiving surface during sweeping of said arms past said receiving surface 2. An automatic stacking machine for handling and stacking each of a plurality of flexible workpieces such as garment components and the like moving in longitudinally spaced apart relationship along a line of travel, said machine comprising: a pair of generally parallel coextensive arms each having an inner end mounted for simul-A taneous rotation and an outer end 4portion remote from the axis of rotation, said arms being disposed adjacent the line of travel of the workpieces in a position such that said outer end portions of the arms can sweep transversely through the line of travel when said arms are rotated; means defining a stationary workpiece-receiving surface having a dimension less than the minimum distance between said outer end portions, said receiving surface being disposed in a position in which it lies between said outer end portions during part of one revolution of said arms; and motor drive and control means for said arms including means responsive to the arrival of a workpiece at a predetermined position along the line of travel lfor rotating said arms through a predetermined arc in a direction such that said outer end portions of said arms sweep into the line of travel from below and for subsequently stopping said arms after said outer end portions have swept past said workpiece-receiving surface whereby the workpiece is lifted out of the line of travel by engagement of said outer end portions with the lower face of the workpiece and is subsequently deposited on said receiving surface or on the exposed end of a stack of workpieces on said surface with the upper face of the workpiece in engagement with said surface or with the exposed end.

3. Apparatus as in claim 2 wherein said drive and control means includes a continuously running motor, edgeresponsive means for detecting the arrival of the leading edge of the workpiece at the predetermined position and for effecting a driving connection between said motor and said arms upon detection of the workpiece edge, said drive and control means further including means for disconnecting said driving connection when said arms have rotated through a predetermined arc past said receiving surface.

4. Apparatus as in claim 2 wherein said arms are mounted radially on a common shaft, said shaft being disposed parallel to the line of travel of the workpieces.

5. Apparatus as in claim 2 wherein there are a plurality of pairs of arms extending radially from a common axis of rotation and wherein said drive and control means upon arrival of a workpiece at the predetermined position rotates all of said arms simultaneously through an arc of such length that only `one pair of arms sweeps the line of travel and said receiving surface during each movement of said arms.

6. Apparatus as in claim 2 including an endless conveyor having an upper run determining the line of travel of the workpieces, said upper run being of lesser length than the minimum distance between said outer end portions of said arms and being disposed in a plane parallel to the axis of rotation of said arms whereby during rotation of said arms said outer end portions sweep past both ends of said upper run and lift off a workpiece which straddles said run.

7. Apparatus as in claim 2 including three endless conveyors having upper runs disposed in end-to-end relationship and determining the line of travel of the workpieces, the end conveyors being slightly spaced from the center conveyor in the plane of said conveyors so as to permit said outer end portions of said pair of arms to pass between each of the end conveyors and the center conveyor, the upper run of the center conveyor being of lesser length than the minimum distance between said outer end portions of said arms and being disposed in a plane parallel to the axis of rotation of said arms whereby during rotation of said arms said outer end portions sweep past both ends of the upper run of said Center conveyor and lift off a workpiece straddling said run.

S. An automatic stacking machine for sequentially receiving flexible workpieces, particularly slick garment components, from a sewing machine and for automatically stacking the workpieces one on top of another, said machine comprising: three continuously driven endless conveyors disposed in longitudinally spaced apart end-to-end relationship and having upper runs which carry the workpieces along a line of travel while maintaining them in a flat condition, the upper run of the center conveyor being of lesser length than a workpiece whereby a workpiece during a portion of its movement along the line of travel will overlie the whole of the upper run of the center conveyor and Will overlap the ends of the upper runs of the other two conveyors; a rotatable shaft disposed to one side of said conveyors and extending parallel to the upper run of said center conveyor; a pair of arms extending radially from said shaft and spaced apart along the shaft in an axial direction, the length and spacing of said arms being such they pass through the spaces between the center conveyor and the other two conveyors upon rotation of said shaft; a stacking table disposed on the other side of said shaft from said conveyors in a position opposite said center conveyor, the dimension of said table in the direction of the axis of said shaft being less than the distance between said arms, said table being disposed so as to lie between said arms during a portion of a complete revolution of said shaft whereby intermittent rotation of said shaft in a direction to raise said arms past the ends of said center conveyor lifts a workpiece from said conveyors, drapes it over said arms, carries it through an arc and drapes it over the top of said table or over the top of a workpiece which has been previously deposited.

9. Apparatus as in clairn 8 including a plurality of pairs of arms carried by said shaft at the same axial position and at equal angular intervals and further including intermittent drive means for said shaft for intermittently rotating said shaft through equal arcs 4during each of which only one pair of arms is raised past said center conveyor and past said table. g

References Cited UNITED STATES PATENTS 1,027,283 5/1912 Scott 271-66 EDWARD A. SROKA, Primary Examiner.

Claims (1)

1. AN AUTOMATIC STACKING MACHINE FOR STACKING FLEXIBLE WORKPIECES SUCH AS GARMENT COMPONENTS AND THE LIKE COMPRISING: MOVABLE STACKING MEANS FOR ENGAGING ONE FACE OF A WORKPIECE AND FOR SUBSEQUENTLY DEPOSITING THE WORKPIECE ON THE EXPOSED END OF A STACK OF PREVIOUSLY HANDLED WORKPIECES WITH THE OTHER FACE IN CONTACT WITH SAID EXPOSED END, SAID STACKING MEANS INCLUDING A PAIR OF GENERALLY PARALLEL COEXTENSIVE ARMS MOUNTED IN SPACED APART RELATIONSHIP FOR SIMULTANEOUS ROTATION ABOUT A COMMON AXIS THROUGH ONE END OF SAID ARMS; A STATIONARY WORKPIECE RECEIVING STAND HAVING A RECEIVING SURFACE AT LEAST PARTIALLY WITHIN THE CYLINDER OF REVOLUTION DEFINED BY ROTATION OF SAID ARMS, SAID RECEIVING SURFACE HAVING A DIMENSION IN THE DIRECTION OF SAID AXIS OF ROTATION WHICH IS LESS THAN THE MINIMUM DISTANCE BETWEEN SAID ARMS WHEREBY DURING ROTATION SAID ARMS CAN SWEEP PAST SAID SURFACE WITHOUT ENGAGING THE SAME; AND DRIVE MEANS FOR

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