US3194551A

US3194551A - Air operated work loading mechanism for sewing machines

Info

Publication number: US3194551A
Application number: US70497A
Authority: US
Inventors: John A Herr; Orland B Reid
Original assignee: Singer Co
Current assignee: Singer Co
Priority date: 1960-11-21
Filing date: 1960-11-21
Publication date: 1965-07-13
Anticipated expiration: 1982-07-13
Also published as: DE1485310B1; GB931046A

Description

J. A. HERR ETAL July 13, 1965 AIR OPERATED WORK LOADING MECHANISM FOR SEWING MACHINES Filed NOV. 21, 1960 3 Sheets-Sheet 1 INVENTORS Orland B. Reid and John A. Herr Z iro/WE) 3 Sheets-Sheet 2 J. A. HERR ETAL AIR OPERATED WORK iOADING MECHANISM FOR SEWING MACHINES INVENTORS? OflandBReidzand Ja'hn A. Hemv July 13, 1965 Filed Nov. 21, 1960 J. A. HERR ETAL 3,194,551

July 13, 1965 I AIR OPERATED WORK LOADING MECHANISM FOR SEWING MACHINES Filed Nov. 21. 1960 3 Sheets-Sheet 3 INVENTORS Orland 8. Reid and Jphn A l le rr i E E AYf'ORND- United States Patent 3,194,551 AIR OPERATED WORK LOADING MECHANKSM FOR SEWING MACHINES John A. Herr, Garwood, and rland B. Reid, Kenilworth,

N.J., assignors to The Singer Company, a corporation of New Jersey Filed Nov. 21, 1960, Ser. No. 70,497 13 Claims. (Cl. 271-14) The present invention relates to and has for an object to provide means for automatically removing individually from a stack work pieces which are subsequently loaded into a sewing machine.

Further objects of this invention are to provide such means which is economical and in operation is quick, eificient, dependable and durable so as to operate reliably over long periods of time and thus be suitable for indus trial applications.

Having in mind the above and other objects that will be evident from an understanding of this disclosure, the

invention comprises the devices, combinations and arrangements of parts as illustrated in the presently preferred embodiment of the invention which is hereinafter set forth in such detail as to enable thoseskilled in the art readily to understand the function, operation, constructionand advantages of it when read in conjunction with the accompanying drawings in which:

FIG. 1 is a fragmentary plan view of a machine embodying the present invention,

FIG. 2 is a fragmentary vertical sectional view substantially on the line 22 of FIG. 1,

FIG. 3 is a fragmentary plan view of a portion of the device of FIG. 1 with parts broken away to illustrate the underlying mechanism,

FIG. 4 is a horizontal sectional view taken substantially on the line 44 of FIG. 2,

FIG. 5 is a fragmentary vertical sectional view taken substantially on the line 55 of FIG. 1,

FIG. 6 is a fragmentary vertical sectional view taken substantially on the line 66 of FIG. 5,

FIG. 7 is a horizontal sectional view taken substantially on the line 77 of FIG. 2,

FIG. 8 is a fragmentary sectional View taken substantially on the line 88 of FIG. 2,

FIG. 9 is a fragmentary vertical sectional view similar to a portion of FIG. 2 and on an enlarged scale and illustrating one step in the operation of the device,

FIG. 10 is a view similar to FIG. 9 and illustrating a subsequent step in the operation of the device.

The device in accordance with this invention was designed to feed work pieces individually from a stack and to present them automatically for a subsequent sewing operation. The invention as herein illustrated is designed to feed one layer of a shirt cuff and while the device could be made to feed the material directly to the sewing machine, it is herein illustrated as feeding the same to a loading mechanism, such as disclosed in the copending application of Herr and Reid, Serial No. 74,820, now Patent No. 3,089,441, filed December 9, 1960, where a further layer of material is combined with it, and the cuff assembly is automatically fed to the sewing machine. The loading mechanism is herein disclosed only insofar as is believed to be necessary for an understanding of this invention and reference may be had to the application of Herr and Reid for a more detailed disclosure of the same.

With reference to the drawings, there is provided a support 1 having a slot 2 extending longitudinally of the same, which slot 2 is rabbetted, as at 3, to form a track for supporting a work carrying element 4 for sliding endwise of the slot with the upper or work supporting sur- 3 ,134,551 Patented July 13, 1965 See face thereof in the plane of the upper surface of the support 1. The element 4 has means for clamping work thereon comprising a pair of work clamping fingers 5 carried by a bar 6 pivotally mounted on the element and biased by torsion springs 7 to hold the fingers 5 in work clamping relation. The bar is releasably held with the fingers out of work clamping relation by a latch lever 8 having a detent 9 at one end cooperating with the bar 6. The element 4 is moved endwise of the slot 2 by a drive mechanism including a cord 10 secured at its ends to the element4 entrained about a pulley 11 mounted on the bottom of the support 1, and adapted to be driven in opposite directions by a reversible electric motor (not shown).

In the loading position, the work carrying element 4 is in engagement with the end 12 of the slot 2 and the work clamping fingers 5 are held in the open position by the latch lever 8. At the loading position of the element 4 there is provided on the support 1 a plate 13 (FIGS. 1 and 5) having an edge 14 and an angle piece or guide 15 having an upstanding flange 16 for positioning the forward and rearward edges of the bottom ply of the cuff material. The guide 15 is adjustably secured by a rearwardly extending arm 17 to a plate 19 that is secured to the support 1. The guide 15 also has a horizontal flange 20 that supports the rear edge of the material and is extended lengthwise of the slot 2 to support and guide the rear edge of the material and is extended lengthwise of the slot 2 to support and guide the rear edge of the material as it is moved by the element 4. A guide 21, a fragrnentary portion of which is shown in FIG. -1, guides and folds the forward edge of the material as it is moved by the element 4.

A thin sheet metal plate 22 is mounted on the plate 13 in vertically spaced relation relatively to the upper surface of the support 1 and the element 4-. The plate 22 has a receiving end 23 that is flared relatively to the support 1 to facilitate the introduction of work. An angle piece 24 has a vertical flange 25 secured to the flange 16 of the piece 15 and a horizontal flange 26 disposed in vertically spaced relation to the flange 20 of the piece 15. The flange 26 also has a receiving end 27 flared upwardly relatively to the support 1. The plate 22 has an upturned flange 28 at the forward edge which, together with the flange 25 serves to position the upper ply of cuff material which is loaded on top of the plate 22 and flange 26. The plate 22 is cutaway as at 29 (FIG. 1) in the area between the work clamping fingers 5 and the element 4 so that the fingers 5 will act through the cut away 29 to secure both the upper ply and the lower ply of the cuff material to the element 4.

The plies of cuff material are both positioned endwise at the loading position by a retractible stop arm 30 extending upwardy through an aperture 31 in the support 1. The stop arm 30 is secured to the upper portion of a vertical arm 32 of a I-shaped lever 33 which is pivoted at its free end by a pivot screw 34 to a bracket 35 secured to the bottom of the support 1. The lever 33 is biased by a tension spring 36 in a direction to lift the stop arm 30 to its operative position. A pull chain 37 is connected at its upper end to the lever 33 and at its lower end to an operator actuated element, for example a foot treadle (not shown) so that when the pull chain 37 is tensioned, the lever 33 is depressed to retract the stop arm 36 below the level of the upper surface of the support 1, thus permitting the plies of cup material to pass freely over the same.

39 that pass through slots 40 in the plate. The plate 38 is biased endwise into latching position by a leaf spring 41 secured at one end to a bracket 42 secured to the underside of the support 1 and at its free end engaging a lug 43 depending from the plate 38. The lug 43 is adapted to overlie a wearplate 44 secured to the stop arm 39 to hold the same depressed. The stop arm 30 is held depressed by the latch plate 33 until the work carrying element 4 is returned to the loading position, at which time a depending lug (not shown) on the element 4 engages the cam shaped rear end 45 of the latch plate 38 to force the same forwardly against the action of the spring 41 to move the lug 43 out of cooperation with the plate 44 thereby releasing the same and permitting the spring 36 to move the lever 33 and stop arm 30 to, the normal loading or rest position.

At an intermediate portion of the lever 33 there is provided a trip arm 46 which, together with a switch actuating arm 47 and a pair of cross pieces 48 encirclethe lever 33 and are held against endwise movement thereon by a pair of cross pins 49. The trip arm 46 extends upwardly through an aperture in the support 1 and at its upper end is formed with a laterally extending lug t) overlying the rearwardly extending arm of the lever 8. The switch actuating arm 47 has a laterally extending lug 51 overlying a pair of switches 52 which are carried by a bracket 53 that is secured to the bracket 35. Thus,

when the lever 33 is depressed, simultaneously with retraction of the stop arm 39, the latch lever S is pivoted to release the work clamping fingers 5 and the switches 52 are actuated. One of the switches 52 is adapted to close and initiates actuation of the Work carrying element 4 which transports the work to and initiates actuation of the sewing machine and then returns to the loading position. The other one of the'switches 52 controls the operation of the work loading mechanism hereinafter described. This switch is opened by the arm 47 and, upon return of the element 4' to the loading position, which releases the lever 33 and thus raises the arm 47, closes to initiate cycling of the work loading mechanism. The upper end of the vertical arm 32 of the lever 33 is bent laterally to form a lug 54 that cooperates with a bracket 55 secured to the underside of the support 1 to limit downward movement of the lever 33 under tension placed on the pull chain 37.

The work loading mechanism comprises a mounting plate 56 depending from the support 1. A series of five solenoid operated

valves

57, 58, 59, 6t) and 61 are carried by the mounting plate 56 and are connected by a manifold 62 and a conduit 63 to a source of compressed air (not shown), a cover 64 is secured to the mounting plate 56 to shield the electrical wiring (not shown) and other elements on the front face of the mounting plate.

, The valve 59 is connected through a pressure reducer 65 to a conduit e6 which is connected to the lower end of a vertically arranged air cylinder 67 carried by the mounting plate 56. A piston rod 68 is disposed in the cylinder 67 and has a piston 69 at the lower end thereof. On the upper end of the piston rod 68 there is a fitting 70 on which is mounted a platform 71. A stack 72 of work pieces is mounted upon the platform 71 and is positioned thereon endwise by upstanding arms 73 carried by a bracket 74 secured to the mounting plate 56 and sidewise by the mounting plate 56 and upstanding arms 75 carried by the mounting plate 56. The piston 69 together with the piston rod 68 and platform 71 are raised upon the application of pressure to the cylinder 67 by the valve 59 until the stack 72 is in engagement with an abutment member which in this caseis a light leaf spring 725 secured to the underside of the support 1 as illustrated in FIG. 9 and the full line position in FIG. 10. The pressure reducer 65 is adjusted to provide a relatively light pressure which is adequate to lift the platform together with the associated elements and the work pieces thereon and to clamp the uppermost work piece W lightly.

The purpose of the movable platform 71 is to position the uppermost work piece W uniformly upon each cycle and also to provide a releasable clamping'means for holding the work piece W at a point spaced from the edge 5 thereof to define a free edge E which is adapted to be lifted and thus separated from the stack and which can be operated upon to remove the work piece W from the stack. By the use of the air cylinder 67, the uppermost work piece will be uniformly positioned and clamped upon each cycle regardless of the number of work pieces in the stack. The platform 71 falls by gravity from the operative position as shown in FIG. 9 to the inoperative position as shown in FIG. 2 and in dotted lines in FIG. 10 when the valve 59 is actuated to terminate the application of pressure to and to exhaust the air cylinder 67.

The mounting plate 56 is positioned so that the platform 71 and the stack 72 thereon is in line with the work c-arryingelement 4 and theuppermost work piece W can be moved endwise directly from the stack onto the work carrying element 4; In the area above the free edge E of the work piece W, the support 1 is cut away to provide an opening 79 through which the work piece moves.

. To lift the free edge E of the work piece W from the stack '72 there is provided a thin sheet metal plate 8%, herein termed an air foil, which is disposed directly over the work piece and includesa first edge 80a adjacent to the work piece W near the point where. his clamped by the spring 78 and a free edge 3% disposed substantially over and in spaced relation to thefree edge E of the work piece W. The air foil 8%) diverges relatively to the work piece W from the edge 89a toward the edge 8%, or more particularly, is cylindrically shaped with the edge fatla dis= V posed adjacent to the work piece W andis curved upwardly therefrom toward the free edge 8%.. 7

The air foil 8%) is carried by a pair of transversely spaced nozzles 81 that are in turn carried by a supporting plate 82 secured to the underside of thesupport '1. The

V nozzles Mare designed to direct a stream of 'air across the air foil from the edge 30a towardthe free edge 89b, that is, they are disposed with the outlet thereof adjacent to the edge 86a and are formed to discharge a stream of air substantially tangentially to the air foil 80. The nozzles 81 are connected by a manifold 83 and conduit 84 with the valve 58.

A movable guide 85 is mounted on a slide 86 seated in a recess 87 in the top of the support 1, the recess and slide being formed to provide for sliding movement of the slide 86 in a direction longitudinally of the work piece. The guide 85 has a bottom plate 88 that in the one extreme position as illustrated in FIG. 9 only slightly overhangs the free edge E of the workpiece W and in the other extreme position as illustrated in FIG. 10 is extended substantially over the edge E of the work piece W or in other words, between the stack 72 and the upturned free edge E so that the edge E will be deposited thereon. The slide 86 'is secured to-a slide block 89 having a tongue 9% received within a slot' 91 'in the support 1. The slide block 89 is connected to one end of a piston rod 92 that extends into an air cylinder 93 and has secured thereto within the cylinder a piston 94. The opposite ends of the air cylinder are connected by

conduits

95 and 96 with the valves 61 and 60 respectively.

The valve 57 has a T-coupling 97 at the discharge there- One of the outlets of the coupling 97 is: connected by a conduit 98 and a tube 99 with a nozzle 1% carried by a bracket 101 secured to the top of the support 1 and having the discharge thereof disposed generally adjacent to the center of the free end of the air foil 84B and directed at an acute angle toward the leading edgev of the bottom plate -88 of the guide 85 when the guide 85 is in the one extreme position, as illustrated in FIG. 10. The other outlet of the coupling 97 is connected by-a conduit 102 and tube ltiiwith a nozzle 104 mounted on the receiving end 23 of the plate 22 and directsa stream of air at an acute angle onto the work carrying element 4. The

tube 103 is supported by a bracket 105 mounted on the top of the support 1. The air emerging from the

nozzles

100 and 104 moves generally in the direction in which the work piece travels from the stack 72 onto the work carrying element 4.

The valves 57-61 may be controlled by a timer mechanism 106 which periodically and in accordance with a prescribed sequence as hereinafter noted actuates switches which in turn control the valves. To facilitate the electrical connection of the switches of the timer mechanism 106 there are provided a pair of terminals 107 carried by the mounting plate 56. Cycling of the mechanism may be effected automatically by a switch 52 that is actuated by the work carrying element 4 upon return to the loading position or manually by a switch 108 carried by the mounting plate 56 and having a push button 109.

The normal rest position of the mechanism is illustrated in FIG. 1. Upon initiation of a cycle of operation, as by closing either the switch 52 or the switch 109, the timing mechanism 106 is started. Initially, the valve 59 is opened to move the stack 72 to the raised position and the valve 61 is opened to move the guide 85 to the right, as seen in FIG. 9. The valve 53 is then opened to discharge air through the nozzles 81. This flow of air relative to the air foil 80 causes the free edge E of the uppermost work piece W on the stack 72 to rise as shown in FIG. 9. The spring 78 prevents the work piece W from being removed from the stack 72 at this time. The valve 61 is then closed and the valve 60 is opened to move the guide 85 to the left in which position the bottom plate 88 thereof moves between the free edge E of the work piece W and the remainder of the stack is in position to be impinged upon by the stream of air issuing from the nozzle 100. The valve 59 is closed which disconnects the air cylinder 67 from the source of pressure and exhausts the same to permit the platform 71 and stack 72 to fall by gravity to its inoperative position as shown in the dotted line position in FIG. thereby releasing the clamping action on the work piece W. The valve 58 is closed to stop the air stream at the nozzles 81, which causes the end of the work piece W to fall from the dotted line to the full line position in FIG. 10 and thus depositing it on the bottom plate 88 of the guide 85. The valve 57 is then opened whereupon, the streams of air issuing from the

nozzles

100 and 104 act in series upon the separated work piece W to slide it from the stack 72, through the guide 85 and beneath the plate 22 on the work carrying element 4 and into contact with the stop arm 30. Finally, the

valves

57 and 60 are closed. Thereupon, having completed one cycle of actuation, the timer mechanism is automatically brought to a stop.

Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of my invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.

Having thus set forth the nature of the invention, what is claimed herein is:

1. A work loading mechanism for sewing machines for removing work pieces individually from a stack and presenting the same to said sewing machine, comprising a platform adapted to receive a stack of work pieces, releasable clamping means adapted to clamp the uppermost work piece on the stack and to define a free edge that is adapted to be raised from said stack, an air foil disposed over the stack and having a first end adjacent to that portion of the stack held by said releasable clamping means and a second end disposed in spaced relation and substantially over the free edge of the work piece, said air foil diverging relatively to the stack from said first end to said second end, a nozzle for directing a stream of air along said air foil from said first end toward said second end, means for providing a supply of air to said nozzle, a plate, means for moving said plate between a first position in which the free edge of the uppermost work piece in the stack is adapted to be raised from the stack by the action of the air foil and a second position in which the edge of said plate is adapted to be disposed over the edge of the stack and on which the free edge of the uppermost work piece is adapted to be deposited upon termination of the action of the air foil, means adapted to act upon that portion of the work piece on said plate for moving the uppermost work piece from the stack, and sequential actuating means for actuating in sequence said releasable clamping means, the supply of air to said nozzle, said means for moving said plate, and said means for moving said work piece from said stack.

2. A work loading mechanism for sewing machines in accordance with claim 1 in which said air foil is cylindrically shaped and said nozzle directs a stream of air onto said air foil substantially tangentially to said air foil.

3. A work loading mechanism for sewing machines in accordance with claim 1 in which said releasable clamping means comprises an abutment member and means for moving said platform from an inoperative position to an operative position in which said platform is adapted to hold the uppermost work piece on the stack under pressure against said abutment member and thereby to hold the uppermost work piece in a predetermined operative relation relatively to said air foil.

4. A work loading mechanism for sewing machines in accordance with claim 3 in which said means for moving said platform comprises an air cylinder, piston means disposed within said air cylinder, means for providing a supply of air to said cylinder for moving said piston endwise of said cylinder and means for connecting said platform to said piston.

5. A work loading mechanism for sewing machines in accordance with claim 1 in which said sequential actuating means includes a time-controlled mechanism.

6. A work loading mechanism for sewing machines in accordance with claim 1 in which the means for moving the uppermost work piece from the stack comprises a nozzle for directing a stream of air generally in the direction in which the work piece is to move, and means providing a supply of air to said nozzle after the release of said releasable clamping means.

7. A work loading mechanism for sewing machines in accordance with claim 1 including a work carrying element having a loading position and adapted to carry a work piece from the loading position and to present the same to a sewing machine, and in which said means for moving the uppermost work piece from the stack is adapted to move the same onto said work carrying element at the loading position and comprises a plurality of nozzles for directing a stream of air generally in the direction in which the work piece is to move, and means providing a supply of air to said nozzles after the release of said releasable clamping means.

8. A work loading mechanism for sewing machines in accordance with claim 7 including means responsive to the movement of said work carrying element into the loading position for automatically initiating actuation of said sequential actuating means.

9. A method of initiating the separation of the uppermost textile work piece individually from a stack preparatory to performing a sewing operation thereon comprising the steps of providing a stack of substantially identical work pieces that had been cut simultaneously from a plurality of layers of textile material, juxtaposing the stack of work pieces and an air foil with the air foil extending from adjacent the uppermost Work piece in the stack at a point remote from a free edge thereof and diverging relatively to the work piece toward a free edge disposed substantially over and in spaced relation to the free edge of the uppermost work piece of the stack, directing a stream stack, and acting upon said raised free edge for removing the work piece from the stack.

10. A method of initiating the seperation of the uppermost textile work piece individually from a stack preparatory to performing a sewing operation thereon comprising the steps of providing a stack of substantially identical work pieces that had been cut simultaneously from a plurality of layers of textile material, juxtaposing the stack of work pieces and an air foil with the air foil extending from adjacent the uppermost work piece in the stack at a point remote from a free edge thereof and diverging relatively to the work piece toward a free edge disposed substantially over and in spaced relation to the free edge of the uppermost work piece of the stack, clamping the uppermost work piece relatively to said stack, directing a stream of air along the air foil toward the free edge thereof to raise the free edge of the uppermost work piece from the stack, and releasing the uppermost work piece and acting upon said raised free edge thereof for removing the work piece from the stack.

11. An apparatus for initiating the removal of the uppermost work piece individually from a stack of substantially identical work pieces that had been cut simultaneously from a plurality of layers of textile material comprising a platform for receiving a stack of work pieces, an air foil disposed over the platform and in'coogieration with the uppermost work piece of the stack on the platform, said air foil having a first portion adjacent the uppermost work piece at a point remote from a free edge thereof and diverging relatively to the work piece toward a second portion disposed substantially over and in spaced relation to the free edge of the work piece, means for directing a stream of air along the air foil from said first portion toward said second portion, means for providing a supply of air to said directing means while said air foil is in cooperation with the uppermost work piece of a stack for raising the free edge of the work piece from the stack, and means for effecting relative movement between the platform and the air foil for moving the air foil out of cooperation with the uppermost work piece of the stack to permit removal of'the uppermost work piece from the stack. 7 V a p 12. An apparatus in accordance with claim 11 in which the means for'eliecting relative movement of the platform and the airfoil comprises an air cylinder. Y

113. apparatusfor'rernoving the uppermost work piece individually from a stack of substantially identical work pieces that had-been cut simultaneously from a plurality of layers of textile material comprising a platform for receivin" a stack of Work pieces, an air foil disposed over the platform and in cooperation with the uppermost work piece of the stack on the platform, said air foil having a first portion adjacent the uppermost workpiece at a point remote from a free edge thereof and diverging relatively to the work piece toward asecono' portion disposed substantially over and in spaced relation to the free edge of the Work piece, means for directing a stream of air 7 along the air foil from said first portion towardsaidrseo piece from the stack;

ond portion for raising the free edge of the workpiece, means for providing a supply of air to said directing means while said air foil is in cooperation with tl e upper most work piece of a stack forraising the free edge of the Work piece from thestack, means for effecting relative movement between the platform and the air foil for moving the air foil out of cooperation with the uppermost Work piece of the stack to permit removal of the uppermost work piece from the stack, and means for operating upon the work piece after the free edge thereof has been raised by the air foil and the platform has been moved out of cooperation with said air foil for moving the Work References @itedhylthe Examiner V UNITED sTATEs PATENTS 672,148

ROBERT e. REEVES, Acting Primary Examiner. ROBERT A. LEronEY, RAPHAEL M. LUPO,

' a V Examiners.

Claims

1. A WORK LOADING MECHANISM FOR SEWING MACHINES FOR REMOVING WORK PIECES INDIVIDUALLY FROM A STACK AND PRESENTING THE SAME TO SAID SEWING MACHINE, COMPRISING A PLATFORM ADAPTED TO RECEIVE A STACK OF WORK PIECES, RELEASABLE CLAMPING MEANS ADAPTED TO CLAMP THE UPPERMOST WORK PIECE ON THE STACK AND TO DEFINE A FREE EDGE THAT IS ADAPTED TO BE RAISED FROM SAID STACK, AN AIR FOIL DISPOSED OVER THE STACK AND HAVING A FIRST END ADJACENT TO THAT PORTION OF THE STACK HELD BY SAID RELEASABLE CLAMPING MEANS AND A SECOND END DISPOSED IN SPACED RELATION AND SUBSTANTIALLY OVER THE FREE EDGE OF THE WORK PIECE, SAID AIR FOIL DIVERGING RELATIVELY TO THE STACK FROM SAID FIRST END TO SAID SECOND END, A NOZZLE FOR DIRECTING A STREAM OF AIR ALONG SAID AIR FOIL FROM SAID FIRST END TOWARD SAID SECOND END, MEANS FOR PROVIDING A SUPPLY OF AIR TO SAID NOZZLE A PLATE, MEANS FOR MOVING SAID PLATE BETWEEN A FIRST POSITION IN WHICH THE FREE EDGE OF THE UPPERMOST WORK PIECE IN THE STACK IS ADAPTED TO BE RAISED FROM THE STACK BY THE ACTION OF THE AIR FOIL AND A SECOND POSITION IN WHICH THE EDGE OF SAID PLATE IS ADAPTED TO BE DISPOSED OVER THE EDGE OF THE STACK AND ON WHICH THE FREE EDGE OF THE UPPERMOST WORK PIECE IS ADAPTED TO BE DEPOSITED UPON TERMINATION OF THE ACTION OF THE AIR FOIL, MEANS ADAPTED TO ACT UPON THAT PORTION OF THE WORK PIECE ON SAID PLATE FOR MOVING THE UPPERMOST WORK PIECE FROM THE STACK, AND SEQUENTIAL ACTUATING MEANS FOR ACTUATING IN SEQUENCE SAID RELEASABLE CLAMPING MEANS, THE SUPPLY OF AIR TO SAID NOZZLE, SAID MEANS FOR MOVING SAID PLATE, AND SAID MEANS FOR MOVING SAID WORK PIECE FROM SAID STACK.