US2652934A

US2652934A - Machine for separating and delivering metal sheets from a stack

Info

Publication number: US2652934A
Application number: US240488A
Authority: US
Inventors: Robert Van Schie
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-08-06
Filing date: 1951-08-06
Publication date: 1953-09-22
Anticipated expiration: 1970-09-22

Description

Sept. 22, 1953 R. VAN SCHIE MACHINE FOR SEPARATING AND DELIVERING METAL SHEETS FROM A STACK 4 Sheets-Sheet 1 Filed Aug. 6 1951 Sept. 22, 1953 R. VAN SCHIE 2,652,934

MACHINE FOR SEPARATING AND DELIVERING METAL SHEETS FROM A STACK 4 Sheets-Sheet 2 Filed A 6 I 951 ATTORNEY Sept. 22, 1953 R VAN sc E 2,652,934

MACHINE FOR SEPARATING AND DELIVERING METAL SHEETS FROM A STACK Filed Aug. 6, 1951 4 Sheets-Sheet 3 A TORNEY.

Sept. 22, 1953 R. VAN SCHIE 2,652,934

MACHINE FOR SEPARATING AND DELIVERING METAL SHEETS FROM A STACK Filed Aug. 6, 1951- 4 Sheets-Sheet 4 (Q/WWW v u 6 N? N vi m w \E m 1 llnlm. W n V wu v% w 1V0 Q I q EN w m R Q m wxw/fuw NN Q 1 5% m n b? b P o.mu & w %m imam? QQN x I R R Q m Q Q I Q Q .Qm l N 3 & MN w w m g NR kQN b m m i k RN QR Q N.

Patented Sept. 22, 1953 MACHINE FOR SEPARATING AND DELIVER- ING METAL SHEETS FROM A STACK Robert Van Schie, Grand Rapids, Mich.

Application'August 6, 1951, Serial No. 240,488

24 Claims. (01. 2214-85) This invention relates to improvements in a machine for separating and delivering metal sheets from a stack.

The principal objects of this invention are:

First, to provide a novel form of machine for vertically separating the top sheet from a stack of metal sheets and delivering the sheet in flat edgewise direction from the machine.

Second, to provide a sheet delivery machine which is economical to build and operate and which is easy to load with a stack of metal sheets.

Third, to provide a novel means for ejecting a single sheet from a machine after the machine has separated the single sheet from a stack of sheets.

Fourth, to provide a sheet separating and delivery machine with a device for breaking the sealing engagement between adjacent sheets of. a stack caused by oily coatings on the surfaces of i illustrate a highly practical form of my sheet separating and feeding machine.

Fig. 1 is a plan view of the machine with portions thereof broken away to better illustrate lower portions of the machine.

Fig. 2 is a side elevational View of the machine.

Fig. 3 is an end elevational view of the machine.

Fig. 4 is a transverse vertical cross sectional view through the machine in lowered sheet gripping position taken along the plane of line 5-4 in Fig. 1.

Fig. 5 is a fragmentary side elevational view of the seal breaking apparatus associated with the sheet separating and delivery mechanism, the seal breaking apparatus being illustrated in advanced operating position.

Fig. 6 is a fragmentary view illustrating the seal breaking apparatus in retracted position.

Fig. '7 is a fragmentary vertical cross sectional view taken along the plane of the line l--l in Fig. 5.

Fig. 8 is a fragmentary vertical cross sectional view through the sheet lifting head of the machine illustrating the mounting of a sheet fiexing pin thereon and taken along the plane of the line 8-8 in Fig. 1.

Fig. 9 is an enlarged elevational view of one of th sheet gripping levers and jaws.

Fig. 10 is a fragmentary elevational view of a modified form of seal breaking apparatus.

The basic purpose of my machine is to eliminate the necessity of manual handling of individual sheet metal sheets in separating the sheets from a bulk stack of sheets and delivering them to machines such as presses for operating on the sheets. The sheets may be in stacks of flat sheets or stacks of partially formed and bent sheets. Generally my machine includes a suitable base I adapted to receive and support a stack of several sheets 2. For the purposes of description the base may be considered as extending longitudinally in Figs. 1 and 2 with the front end of the machine from which the sheets are delivered located at the left of the figure. Upstanding guides 3 are transversely and longitudinally adjustably mounted on the base to receive and retain the stack of sheets 2. The example of the machine illustrated is for handling flat sheets but it should be understood that the surface of the base i and the positions of the guides 3 can be adjusted to accommodate a stack of nested, partially formed sheets having surface and outline configurations.

*Transversely and longitudinally spaced outwardly from the stack 2, the base is provided with supports at each corner that are longitudinally bored to receive pins or bolts 5. The bolts 5 serve to pivotally connect a box-like framework 6 to the base I. As is most clearly indicated in Fig. 3,

the framework 6 can be tilted laterally of the base by removing the bolts 5 on one side of the base and permitting the framework to swing about the bolts on the other side of the base.

The framework 5 includes corner uprights i that are connected by lower crosspieces 8 and upper crosspieces 9. Side rails H! are also provided near the bottom of the uprights. A pair of longitudinally extending top bars l i are supported in parallel spaced relationship by the top crossbars 9 and serve to support a centrally located vertically extending hydraulic cylinder 52. A piston reciprocal in the cylinder has its piston rod 53 projecting downwardly into the framework 5 and connected to a lifting head It.

The lifting head Id includes end bars [5 having shoes IE on each end that are slidably engaged with the corner uprights l to guid the lifting head in the framework 6. The end bars it are interconnected intermedial of their ends by the longitudinally extending rails H. The lifting head carries eight sheet gripping jaw assemblies generally indicated at l8, there being two jaw assemblies spaced along each side and each end of the lifting head. The jaw assemblies are designed, as will be more particularly described, to grip the top sheet 2 from the stack of sheets when the lifting head is lowered and elevate the single sheet when the lifting head is raised. Th jaw assemblies are further designed to release the individual sheet as the lifting head reaches the upper limit of its travel within the framework 6.

Pivotally supported along each side of the framework 6 is a supporting rail I9 which is arranged to swing underneath each successive sheet as the sheet is elevated by the lifting head to catch and support the sheet as it is dropped from the gripping jaw assemblies l8. The longitudinal rails ll of the lifting head also support a longitudinally extending cylinder 20 and a lazy tong structure 2! which are supported above the sheets being raised. The piston rod 22 of the cylinder 20 is connected to a rearward section of the lazy tongs as at 23 and the front links of the lazy tongs are provided with depending pusher fingers 2:3 which extend downwardly to the level of the individual sheets supported on the support rails 19. The piston rod 22 of the cylinder 20 can thus be retracted to extend the lazy tongs and push the individual sheet longitudinally forwardly along the support rails ill to ejept the individual sheet.

A. seal breaking structure indicated generally at 25 is mounted along the rear side of the base and operated in timed relationship with the lifting head to assist the jaw assemblies in separating the top sheet from the other sheets in the stack.

Sheet gripping y'aw structure The sheet gripping jaw assemblies it are all similar and a description of one of the assemblies mounted along the end of the lifting head will be sufficient to an understanding of their operation. A generally vertically disposed side plate 26 (see Fig. 2) is lapped along the side of the longitudinal rail ll of the lifting head and provided with a laterally extending shoe 26A engaged along the under side of the rail. A removable top plate 2'! is lapped over the top edge of the rail to slidably support the side plate on the rail. Setscrews 28 threaded into the top plate 2? adjustably clamp the side plate to the rail. Stub rails 29 for supporting the side jaw assemblies are secured to the longitudinal rails H as by bolts indicated at 36 (see Figs. 1 and 4). The side plate 26 of the jaw assembly carries a horizontally projecting pivot pin or screw 3! on which a lever 32 is pivotally supported. The inner end of the lever 32 is biased upwardly by a spring 33 connected to the top plate 2! and the outer end of the lever 32 projects below the shoe 25A and is notched on its under side as at 32 to leave a downwardly and inwardly projecting nose or jaw 36 that is pointed or sharpened to force its way into the crack between the top sheet and subadjacent sheet of the stack of sheets. The pointed jaw 3% is spaced vertically below the inner corner of the notch 32 by a distance approximately equal to the thickness of the sheets to be handled. Thus as the lifting head M is lowered the outer ends of the levers 32 strike the top sheet of the stack and slide outwardly over the edges of the stack with an upward swinging motion of the levers until the pointed jaws 3 1 snap over the edges of the sheet. Subsequent upward motion of the lifting head causes the jaws to grip inwardly between the sheets and tightly grip and lift the top sheet. The notch 32 in each lever serves to clear any burr or irregularity 4 on the upper edge of the sheet. Note that the length or width of successive sheets in the stack can vary considerably and still be gripped without readjustment of the gripper assemblies.

The top plates 27 of the jaw assemblies carry vertically extending pins 35 which engage the inner ends of the levers 32 in opposition to the springs 33. The pins 35 project upwardly above the lifting head and are arranged to strike abutment plates 36 secured to the top longitudinal bars H of the framework as the lifting head reaches its upper limit of travel. The pins 35 are thus forced downwardly and in turn force the inner ends of the levers 32 downwardly so that the gripping jaws 34 are swung upwardly and outwardly to automatically release the elevated top sheet.

Sheet support and discharge structure The previously mentioned support rails ii! are of upwardly and inwardly facing angle shape cross section and are provided at each end with a support bracket 37 that extends outwardly and upwardly from the support rails adjacent to the corner uprights l. The corner uprights l are provided with laterally extending plates 38 having a series of holes 39 therein arranged to selectively receive pivot pins 48 carried by the brackets 31. The outwardly offset character of the brackets 37 causes the rails is to swing downwardly below the pivots 48 as is best illustrated in Fig. 4. Springs ll connected to the top cross members 9 of the framework dampen the swinging motion of the support rails which thus normally swing to a retracted position in which they do not obstruct the upward lifting motion of the sheets 2.

The bracket 3'! at one end of each support rail is provided with an inwardly extending arm 52 (see Figs. 1 and 3) from which a pin 43 extends rearwardly to overlie and ride upon the rear crossrail I 5 of the lifting head. Thus as the lifting head is raised the pin 33 is raised to swing the support rails l9 inwardly of the framework to the position illustrated in Fig. 8 where they will catch and support the individual sheet as it is released from the jaws 3t. Adjustment of the pivot pins 48 in the holes 39 obviously permits adjustment of the support rails to function with sheets of different widths.

Sheet ejecting mechcmsim The previously mentioned lazy tongs 2! and the ejecting pins 24 carried thereby are supported longitudinally of the lifting head by longitudinally extending rails M which are spaced to act as guides for the connecting center pins d5 of the lazy tongs. The piston rod 22 of the cylinder 20 is connected to one of the center pins 25 to extend the lazy tongs in the manner indicated by the dotted lines at A36 in Fig. 1. Since the lazy tongs multiply longitudinal motion of the rear center pins d5, it is only necessary to retract the piston rod 22 a short distance in order to cause the pins 24 to move all the way to the forward end of the framework and completely eject the sheet supported on the support rails l9.

Seal breaking structure The seal breaking structure generally indicated at 25 and more particularly illustrated in Figs. 5, 6 and 7 consists of a support plate i? secured to a longitudinally extending portion of the base I. A pair of parallel

arm levers C

8 and 4?) are pivotally supported at their lower ends on the plate M as at 59 and have their upper ends connected by the separator bar 5|. The inner end of the separator bar 5| is provided with a pointed nose 52 Well adapted to penetrate and spread apart the crack between two adjacent sheets of metal. Once the seal, which may be created between two sheets of metal, thus broken at one point, atmospheric pressure enters between the sheets and separates them.

In order to force the nose 52 between the top sheet being lifted and a sub-adjacent sheet which may stick to the top sheet, the parallel arms 38 and is are constantly urged inwardly by a spring 53. The arms are moved outwardly and the spring 53 is tensioned each time the lifting head descends by engagement of a cam bar 54 on the lifting head (see Figs. 1, 2 and 3) with a pin 55 projecting from the outer arm 48. The arms and separator bar are held in cocked retracted position by a latch 56 that is pivotally connected at 5'! to the outer arm 48. The inner end of the latch 56 rides along the top surface of the plate t1 and engages a lock notch 58 therein. A trip bar 59 pivotally supported on the plate 4'! at 66 is provided with an inwardly projecting actuating nose 5i that projects into the path of the upwardly moving top sheet. Elevation of each successive sheet thus lifts the nose 6! and trip bar 59 to engage the pin 52 on the latch and lifts the latch from the notch 58. By properly positioning the elevation of the nose 6! with respect to the rate of movement of the elevated top sheet 2, the separator structure may be timed to press the sharpened nose 52 between the elevated sheet and any sub-adjacent sheet.

Directly cooperating with the separator bar 5i in breaking the seal between two adjacent sheets is a tensioning pin 52A vertically slidably mounted in a plate 63 secured to one of the main rails ll of the lifting head. The tensioning pin is biased downwardly, as is best illustrated in Fig. 8, by a coil spring 6t compressed between the plate 63 and a crosspin 65. The pin 62A extends downwardly below the level of the gripping jaws 34 and is thus pressed upwardly compressing the spring 6 5- by engagement with the top surface of the top sheet when the lifting head is lowered to engage the top sheet. As the lifting head rises carrying with it the top sheet of the stack, the compression in the spring (it acts to how the top sheet downwardly. Any sub-adjacent sealing action of an oil film between the sheets will similarly be bowed downwardly. Actually, of course, it is the atmospheric pressure acting on the opposite surfaces of two adjacent sheets which. holds the sheets together. The combined action of the tensioning pin 62A and the separator bar 5! serves to form an initial opening be' Modified seal breaking structure Figure 10 illustrates a modified form of seal breaking structure in which a separator bar 66 is pivotally connected to the depending lower end sheets Y which may adhere to the top sheet due to the 6 of a generally vertical lever arm 61. The lever arm 6'! is pivotally connected at 68 to one of the longitudinal rails ll of the lifting head. A pair of springs 69 maintain the lever arm 67 in gen- 1 erally upright position, while a spring constantly urges the inner end of the separator bar downwardly about its pivot ll. A stop 12 on the separator bar limits the downward swinging motion of the inner end of the separator bar.

The inner end of the separator bar 66 has an inwardly projecting rounded nose '83 which is positioned to bear against and slide along the top surface of the top sheet 2 of the stack as the lifting head is lowered to engage the gripping jaws with the top sheet. Below the nose it the separator bar is provided with a downwardly and inwardly opening rounded notch M terminating at its lower edge in a sharpened nose 75 that is inclined slightly upwardly. The sharpened nose i5 is spaced outwardly substantially from the rounded nose i3 and is spaced therebelow by a distance approximately equal to the thickness of the sheets 2. The upper end of the lever arm. 6'! is provided with an inwardly facing cam portion to that is arranged to cammingly engage a pin or other abutment ll carried by a depending bracket 78 on one of the main longitudinal rails i l of the machine framework. Thus the lever arm 67 and sharpened nose '55 of the separator bar will be reciprocable vertically with the lifting head, and the nose 15 will be positioned adjacent to the lower edge of the top sheet 2 carried by the gripping jaw assemblies I8 as the head is elevated. After the head has moved upwardly away from the stack the pin 77 will engage the cam 76 to move the sharpened nose i5 sharply inwardly against the lower edge of the top sheet, and should a subadjacent sheet adhere to the top sheet, the nose 15 will form an initial separation between the two sheets. It should be understood that the separator bar 65 operates in conjunction with a sheet flexing pin 52 in the same manner as the first form of seal breaking structure, so that the subadjacent sheet will fall away from the top sheet.

Detail of gripping jaws Fig. 9 illustrates on an enlarged scale some of the important details of the construction of the gripping jaw levers 32 and the jaws 34. The lower edge of the lever 32 is downwardly and outwardly curved as at 79 to the notch 32 so that the lever will ride smoothly and rock on the top sheet of the stack regardless of irregularities in the width of the sheets being handled. Desir- 1 ably a sharpened jaw 34 is formed on the bottom of a hardened insert 80 retained in the notch 32* by a screw 8!. The lower edge of the jaw 34 is outwardly and upwardly curved as at 82 to slide smoothly over the surface of the top sheet on the stack until the jaw 36 snaps over the edge of the sheet. As was pointed out, the notch 32 extends upwardly above the lower curved edge '59 of the lever to clear any burr on the edge of the sheet, and the sharpened nose 3 is positioned sufficiently below the lower edge of the lever to just receive the edge of the top sheet of the stack.

I have not attempted to illustrate other possible modifications of my structure as it is believed that the foregoing description will indicate to those skilled in the art how my invention may be employed and adapted to various sheet handling and delivering problems. The disclosure is therefore intended'as an example only and not as a definition of the limits of my invention as set forth in the following claims.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

l. A machine for separating and delivering individual metal sheets from a stack of sheets comprising, a base adapted to support said stack. guides laterally adjustably mounted on said base for retaining the sides of said stack, a framework supported from the edges of said base and extending thereabove and thereover, one side of said framework being pivotally connected to said base whereby said framework may be tilted away from said base for loading a stack on said base, a lifting head vertically reciprocably mounted in said framework and guided in its motion by engagement with the upright corners thereof, means including a fluid actuated piston mounted on top of said framework and connected to reciprocate said head, a plurality of gripping jaws spaced along all sides of said head and inwardly and outwardly adjustably connected to said head, said jaws having inwardly extending lever arms pivotally connected intermediate of their ends to said head whereby lowering motion of said head will present said gripping jaws to the top sheet of said stack and slide the jaws outwardly into gripping engagement with the edges of the top sheet of the stack, said jaws opening inwardly and downwardly of said head and projecting below their lever arms by a distance approximately equal to the thickness of said sheets, vertically reciprocable release pins carried by said head and engageable with said levers inwardly of their pivots, springs urging the inner ends of said levers upwardly, stopplates on the top of said framework engageable with the upper ends of said pins at the upper limit of travel of said head to move said jaws outwardly to sheet releasing position, parallel supporting rails pivotally mounted along opposite sides of said framework and having inwardly directed sheet supporting projections on their lower ends weight-biased to swing outwardly from the sides of said stack, means connected to said rails including inwardly projecting arms rigidly extending from said rails above their pivots and engageable with said head for pivoting said rails inwardly under each elevated sheet as said head is elevated, a longitudinally extensive lazy tong structure slidably supported on said head and connected to the rear end thereof above the level of said jaws, depending discharge pins secured to the forward end of said lazy tong structure and engageable with the rear edge of a sheet supported on said sup-port rails, means including a fluid operated piston carried by said head and connected to a rearward portion of said lazy tong structure to extend said structure forwardly, a horizontally extending and reciprocable separator bar mounted on said base outwardly from said stack and having a pointed inner edge spaced above the lower limit of travel of said jaws, spring means biasing said separator bar inwardly toward said stack, a retracting finger carried by said head and cammingly engageable with said separator bar to retract said separator bar on downward movement of said head and said finger, a latch operable to hold said bar retracted, a latch release lever projecting over said stack and engageablc with each elevated sheet to release said latch in timed relationship with the upward movement of said head and a sheet carried thereby whereby said separator bar penetrates between the top sheet and any sub-adjacent sheet adhering thereto, and a sheet tensioning pin vertically and yieldably mounted on said head within the outline of said gripping jaws and projecting downwardly below the level of said jaws to apply downward flexing stress to plates supported in said jaws.

2. A machine for separating and delivering individual metal sheets from a stack of sheets comprising, a base adapted to support said stack, guides laterally adjustably mounted on said base for retaining the sides of said stack, a framework supported from the edges of said base and extending thereabove and thereover, one side of said framework being pivotally connected to said base whereby said framework may be tilted away from said base for loading a stack on said base. a lifting head vertically reciprocably mounted in said framework and guided in its motion by engagement with the upright corners thereof, means including a fluid actuated piston mounted on top of said framework and connected to reciprocate said head, a plurality of gripping jaws spaced along opposite sides of said head and inwardly and outwardly adjustably connected to said head, said jaws having inwardly extending lever arms pivotally connected intermediate of their ends to said head whereby lowering motion of said head will present said gripping jaws to the top sheet of said stack and slide the jaws outwardly into gripping engagement with the edges of the top sheet of the stack, said jaws opening inwardly and downwardly of said head, vertically reciprocable release pins carried by said head and engageable with said levers inwardly of their pivots, stop plates on the top of said framework engageable with the upper ends of said pins at the upper limit of travel of said head to move said jaws outwardly to sheet releasing position, supporting rails pivotally mounted along opposite sides of said framework and having inwardly directed sheet supporting projections on their lower ends weight-biased to swing outwardly from the sides of said stack, means connected to said rails and engageable with said head for pivoting said rails inwardly under each elevated sheet as said head is elevated, a longitudinally extensible lazy tong structure slidably supported on said head and connected to the rear end thereof above the level of said jaws, depending discharge pins secured to the forward end of said lazy tong structure and engageable with the rear edge of a sheet supported on said support rails, means including a fluid operated piston carried by said head and connected to a rearward portion of said lazy tong structure to extend said structure forwardly, a horizontally extending and reciprocable separator bar mounted on said base outwardly from said stack and having a pointed inner edge spaced above the lower limit of travel of said jaws, spring means biasing said separator bar inwardly toward said stack, a retracting finger carried by said head and cammingly engageable with said separator bar to retract said separator bar on downward movement of said head and said finger, a latch operable to hold said bar retracted, a latch release lever projecting over said stack and engageable with each elevated sheet to release said latch in timed relationship with the upward movement of said head and. a sheet carried thereby whereby said separator bar penetrates between the top sheet and. any subadjacent sheet adhering thereto, and a sheet tensioning pin Vertically and yieldably mounted on said head Within the outline of said gripping jaws and projecting downwardly below the level of said jaws to apply downward flexing stress to plates supported in said jaws.

3. A machine for separating and delivering individual metal sheets from a stack of sheets comprising, a base adapted to support said stack, a framework supported from the edges of said base and extending thereabove and thereover, one side of the framework being pivotally connected to said base whereby said framework may be tilted away from said base for loading a stack on said base, a lifting head vertically reciprocably mounted in said framework and guided in its motion by engagement therewith, means including a fluid actuated piston for reciprocating said head, a plurality of gripping jaws spaced along opposite sides of said head and inwardly and outwardly adjustably connected to said head, said jaws having inwardly extending lever arms pivotally connected intermediate of their ends to said head whereby lowering motion of said head will present said gripping jaws to the top sheet of said stack and slide the jaws outwardly into gripping engagement with the edges of the top sheet of the stack, vertically reciprocable release pins carried by said head and engageable with said levers inwardly of their pivots, stop plates on the top of said framework engageable with the upper ends of said pins at the upper limit of travel of said head to move said jaws to sheet releasing position, supporting rails pivotally mounted along opposite sides of said framework and having inwardly directed sheet supporting projections on their lower ends biased to swing outwardly from the sides of said stack, means connected to said rails and engageable with said head for pivoting said rails inwardly under each elevated sheet as said head is elevated, a longitudinally extensible lazy tong structure slidably supported on said head and connected to the rear end thereof above the level of said jaws, depending discharge pins secured to the forward end of said lazy tong structure and engageable with the rear edge of a sheet supported on said support rails, means including a fluid operated piston carried by said head and connected to a rearward portion of said lazy tong structure to extend said structure forwardly, a horizontally extending and reciprocable separator bar mounted on said base outwardly from said stack and having a pointed inner edge spaced above the lower limit of travel of said jaws, means for moving said separator bar inwardly toward said stack, a retracting finger carried by said head and cammingly engageable with said separator bar to retract said separator bar on downward movement of said head and said finger, a latch operable to hold said bar retracted, means operative to release said latch in timed relationship with the upward movement of said head and a sheet carried thereby whereby said separator bar penetrates between the top sheet and any sub-adjacent sheet adhering thereto, and a sheet tensioning means vertically movably and yieldably mounted on said head within the outline of said gripping jaws and projecting downwardly below the level of said jaws to apply flexing stress to plates supported in said jaws.

4. A machine for separating and delivering metal sheets from a stack of sheets comprising, a base adapted to support said stack, a framework supported from the edges of said base and extending thereabove and thereo-ver, alifting head vertically reciprocably mounted in said framework, means for reciprocating said head, a plurality of gripping jaws spaced along opposite sides of said head, said aws having inwardly extending lever arms pivotally connected intermediate of their ends to said head whereby lowering motion of said head will present said gripping jaws to the top sheet of said stack and slide the jaws outwardly into gripping engagement with the edges of the top sheet of the stack, vertically movable means carried by said head and engageable with said levers, means on the top of said framework engageable with said vertically movable means at the upper limit of travel of said head to actuate said movable means to move said jaws to sheet releasing position, supporting rails pivotally mounted along opposite sides of said framework and having inwardly directed sheet supporting projections on their lower ends biased to swing outwardly from the sides of said stack, means connected to said rails and engageable with said head for pivoting said rails inwardly under each elevated sheet as said head is elevated, a longitudinally extensible lazy tong structure slidably supported on said head and connected to the rear end thereof above the level of said jaws, depending discharge pins secured to the forward end of said lazy tong structure and engageable with the rear edge of a sheet supported on said support rails, means carried by said head and connected to a rearward portion of said lazy tong structure to extend said structure forwardly, a horizontally extending and reciprocable separator bar mounted on said base outwardly from said stack and having a pointed inner edge spaced above the lower limit of travel of said jaws, means for moving said separator bar inwardly toward said stack, a retracting finger carried by said head and cammingly engageable with said separator bar to retract said separator bar on downward movement of said head and said finger, a latch operable to hold said bar retracted, means operative to release said latch in timed relationship with the upward movement of said head and a sheet carried thereby whereby said separator bar penetrates between the top sheet and any sub-adjacent sheet adhering thereto, and a sheet tensioning means vertically movable mounted on said head within the outline of said gripping jaws and projecting downwardly below the level of said jaws to apply flexing stress to plates supported in said jaws.

5. A machine for separating and delivering individual metal sheets from a stack of sheets comprising, a framework adapted to be positioned over said stack to extend thereabove and thereover, a lifting head vertically reciprocably mounted in said framework, means for reciprocating said head, a plurality of gripping jaws spaced along opposite sides of said head and inwardly and outwardly adjustably connected to said head, said jaws having inwardly extending lever arms pivotally connected intermediate of their ends to said head whereby lowering motion of said head will present said gripping jaws to the top sheet of said stack and slide the jaws outward- 1y into gripping engagement with the edges of the top sheet of the stack, means carried by said head and engageable with said levers inwardly of their pivots to move said levers and jaws to sheet releasing position, abutments on the top of said framework engageable with said last means at the upper limit of travel of said head to actuate said means and move said jaws to sheet releasing position, supporting elements laterally movably mounted on opposite sides of said framework and having inwardly directed sheet supporting projections on their inner ends biased to swing outwardly from the sides of said stack, means connecting said elements with said head for moving said projections inwardly under each elevated sheet as said head is elevated, a longitudinally extensible lazy tong structure slidably supported on said head and connected to the rear end thereof above the level of said jaws, depending discharge pins secured to the forward end of said lazy tong structure and. engageable with the rear edge of a sheet supported on said projection, means including a fluid operated piston carried by said head and connected to a rearward portion of said lazy tong structure to extend said structure, a horizontally extending and translatable separator bar mounted on said framework outwardly from said stack and having a pointed inner edge, spring means biasing said separator bar inwardly toward said stack, a retracting finger carried by said head and cammingly engageable with said separator bar to retract said separator bar on downward movement of said head and said finger, a latch operable to hold said bar retracted, a latch release means actuatable in timed relationship with the upward movement of said head and a sheet carried thereby whereby said separator bar is released and penetrates between the top sheet and any sub-adjacent sheet adhering thereto, and a sheet tension means vertically yieldably mounted on said head within the outline of said gripping jaws and projecting downwardly below the level of said jaws to apply flexing stress to plates supported in said jaws.

6. A machine for separating and delivering individual metal sheets from a stack of sheets comprising, a framework adapted to be positioned over said stack to extend thereabove and thereover, a lifting head vertically reciprocably mounted in said framework, means for reciprocating said head, a plurality of gripping jaws spaced along opposite sides of said head, said jaws having inwardly extending lever arms pivotally connected intermediate of their ends to said head whereby lowering motion of said head will present said gripping jaws to the top sheet of said stack and slide the jaws outwardly into gripping engagement with the edges of the top sheet of the stack, means providing thrust engagement between said framework and the inner ends of said levers at the top of the travel of said head to move said levers and jaws to sheet releasing position, supporting elements laterally movably mounted on opposite sides of said framework and having inwardly directed sheet supporting projections on their inner ends, means connecting said elements with said head for moving said projections inwardly under each elevated sheet as said head is elevated, a longitudinally extensible lazy tong structure slidably supported on said head and connected to the rear end thereof above the level of said jaws, depending discharge pins secured to the forward end of said lazy tong structure and engageable with the rear edge of a sheet supported on said projections, means including a fluid operated piston carried by said head and connected to a rearward portion of said lazy tong structure to extend said structure, a horizontally extending and translatable separator bar mounted on said framework outwardly from said stack and having a pointed inner edge, means biasing said separator bar inwardly toward said stack, a retracting means operative in timed relationship with said head and engageable with said separator bar to retract said separator bar on downward movement of said head, a latch operable to hold said bar retracted, a latch release means actuatable in timed relationship with the upward movement of said head and a sheet carried thereby whereby said separator bar is released and penetrates b8? tween the top sheet and any sub-adjacent sheet adhering thereto, and a sheet tensioning means vertically yieldably mounted on said head within the outline of said gripping jaws and projecting downwardly below the level of said jaws to apply flexing stress to plates supported in said aws.

'7. A machine for separating and delivering metal sheets from a stack of sheets comprising, a base adapted to support said stack, guides laterally adjustably mounted on said base for retaining said stack, a framework supported from the edges of said base and extending thereabove and thereover, one side of said framework being pivotally connected to said base whereby said framework may be tilted away from said base for loading a stack on said base, a lifting head vertically reciprocably mounted in said framework and guided in its motion by engagement therewith, means including a fluid actuated piston for reciprocating said head, a plurality of gripping jaws spaced along opposite sides of said head and inwardly and outwardly adj ustably connected to said head, said jaws having inwardly extending lever arms pivotally connected to said head whereby lowering motion of said head will present said gripping jaws to the top sheet of said stack and slide the jaws outwardly into gripping engagement with the edges of the top sheet of the stack, vertically reciprocable release pins carried by said head and engageable with said levers inwardly of their pivots, abutments on the top of said framework engageable with the upper ends of said pins at the upper limit of travel of said head to move said jaws to sheet releasing position, parallel supporting rails pivotal- 1y mounted along opposite sides of said framework and having inwardly directed sheet supporting projections on their lower ends weightbiased to swing outwardly from the sides of said stack, means connected to said rails including inwardly projecting arms engageable with said head for pivoting said rails inwardly under each elevated sheet as said head is elevated, a longitudinally extensible lazy tong structure slidably supported on said head and connected to the rear end thereof above the level of said jaws, depending discharge pins secured to the forward end of said lazy tong structure and engageable with the rear edge of a sheet supported on said support rails, and means including a fluid operated piston carried by said head and connected to a rearward portion of said lazy tong structure to extend said structure.

8. A machine for separating and delivering metal sheets from a stack of sheets comprising, a base adapted to support said stack, guides laterally adjustably mounted on said base for retaining said stack, a framework supported from the edges of said base and extending thereabove and thereover, one side of said framework being pivotally connected to said base whereby said framework may be tilted away from said base for loading a stack on said base, a lifting head vertically reciprocably mounted in said framework, means for reciprocating said head, a plurality of gripping jaws spaced along opposite sides of said head and inwardly and outwardly adjustably connected to said head, said jaws having inwardly extending lever arms pivotally connected to said head whereby lowering motion of said head will present said gripping jaws to the top sheet of said stack and slide the jaws outwardly into gripping engagement with the edges of the top sheet of the stack, means forming a thrust engagement between said framework and the inner ends of said levers at the upper limit of travel of said head to move said jaws to sheet releasing position, supporting rails pivotally mounted along opposite sides of said framework and having inwardly directed sheet supporting projections on their lower ends biased to swing outwardly from the sides of said stack, means connected to said rails engageable with said head for pivoting said rails inwardly under each elevated sheet as said head is elevated, a longitudinally extensible lazy tong structure slidably supported on said head and connected to the rear end thereof above the level of said jaws, a depending discharge element secured to the forward end of said lazy tong structure and engageable with the rear edge of a sheet supported on said support rails, and means carried by said head and connected to a rearward portion of said lazy tong structure to extend said structure.

9. A machine for separating and delivering metal sheets from a stack of sheets comprising, a base, a framework supported from the edges of said base and extending thereabove and thereover, one side of said framework being pivotally connected to said base whereby said framework may be tilted away from said base for loading a stack under said framework, a lifting head vertically reciprocably mounted in said framework, means for reciprocating said head, a plurality of gripping jaws spaced along opposite sides of said head, said jaws having inwardly extending lever arms pivotally connected to said head whereby lowering motion of said head will present said gripping jaws to the top sheet of said stack and slide the jaws outwardly into gripping engagement with the edges of the top sheet of the stack, means forming a thrust engagement between said framework and the inner ends of said levers at the upper limit of travel of said head to move said jaws to sheet releasing position, supporting elements laterally movable mounted along opposite sides of said framework and having inwardly directed sheet supporting projections on their lower ends, said elements being biased outwardly from the sides of said stack, means connected to said elements including inwardly projecting arms engageable with said head for moving said elements inwardly under each elevated sheet as said head is elevated, ejecting mechanism supported on said head and extensible therealong above the level of said jaws, a depending discharge element secured to said mechanism and engageable with the rear edge of a sheet supported on said support rails, and means operative to extend said mechanism.

10. A machine for separating and delivering metal sheets from a stack of sheets comprising, a base, a framework supported from the edges of said base and extending thereabove and thereover, one side of said framework being pivotally connected to said base whereby said framework may be tilted away from said base for loading a stack under said framework, a lifting head vertically reciprocably mounted in said framework, means for reciprocating said head, a plurality of gripping jaws spaced along opposite sides of said head, said jaws having inwardly extending lever arms pivotally connected to said head whereby lowering motion of said head will present said gripping jaws to the top sheet of said stack and slide the jaws outwardly into gripping engagement with the edges of the top sheet of the stack, means carried by said head and engageable with said levers at the upper limit of travel of said head to move said jaws to sheet releasing position, supporting elements laterally movable mounted along opposite sides of said framework and having inwardly directed sheet supporting projections on their lower ends, said elements being biased outwardly from the sides of said stack, means connected to said elements for moving said elements inwardly under each elevated sheet as said head is elevated, ejecting mechanism supported on said head and extensible therealong above the level of said jaws, a depending discharge element secured to said mechanism and engageable with the rear edge of a sheet supported on said support rails, and means operative to extend said mechanism.

11. In a sheet separating and delivering machine having a framework supported over and around a stack of sheets to be separated, a sheet lifting head vertically reciprocably mounted in said framework and comprising, two longitudinally extending main rails, laterally projecting z subrails extending outwardly from opposite sides of said main rails and positioned toward each end thereof, a gripping jaw assembly horizontally adjustably mounted on the ends or each of said rails, each assembly including a plate lapped along the side of the rail with a shoe slidably engaged with the under side of the rail, a top flange on the side plate overlapping the top of the rail, a setscrew in said top flange engageable with the rail, a lever pivotally supported intermediate of its ends on the plate with its lower end projecting downwardly and outwardly below said shoe, a downwardly and inwardly facing jaw on the lower end of said lever, the vertical opening of the jaw below the adjacent inner portion of the lever being substantially equal to the thickness of the sheets to be gripped, a release pin vertically reciprocably carried by said top flange and engageable at its lower end with the inner end of said lever, and fixed abutments carried by said framework engageable with the upper ends of the pins of said assemblies at the upper limit of travel of said head to move said gripping jaws to sheet releasing position.

12. In a sheet separating and delivering machine having a framework supported over and around a stack of sheets to be separa ed, a sheet lifting head vertically reciprocably mounted in said framework and comprising, two longitudinally extending main rails, laterally projecting subrails extending outwardly from opposite sides of said main rails and positioned toward each end thereof, a gripping jaw assembly horizontally adjustably mounted on the ends of each of said rails, each assembly including a plate lapped along the side of the rail with a shoe slidably engaged with the under side of the rail, a top flange on the side plate overlapping the top of the rail, a setscrew in said assembly engageable with the rail, a lever pivotally supported intermediate of its ends on the plate with its lower end projecting downwardly and outwardly below said shoe, a downwardly and inwardly facing jaw on the lower end of said lever, a release pin vertically reciprocably carried by said top flange and engageable at its lower end with the inner end of said lever, and fixed abutments carried by said framework engageable with the upper ends of the pins of said assemblies at the upper limit of '15 travel of said .head to move said gripping jaws to sheet releasing position.

13. In a sheet separating and delivering machine having a framework supported .over astack of sheets .to be separated, a sheet lifting head vertically reciprocably mounted in said framework and comprising, longitudinally extending main rails, laterally projecting subrails extending outwardly from opposite sides of 'saidsmain rails and spaced therealong, a gripping jaw assembly horizontally adjustably mounted on the ends of each of said rails, each assembly including a plate lapped along the side of the rail with a shoe slidably engaged with the under side of the rail, a lever pivotally supported intermediate of its ends on the plate with its lower end projecting downwardly and outwardly below said shoe, a downwardly and inwardly facing jaw on the lower end-of said lever, a release pin vertically reciprocably carried by said plate and engageable at its lower end with the inner end of said lever, and fixed abutments carried by said framework engageable with the upper ends of the pins of said assemblies at the upper limit of travel of said head to move said gripping jaws to sheet releasing position.

14. In a sheet separating and delivering machine having a framework supported over and around a stack of sheets to be separated, a sheet lifting head vertically reciprocably mounted in said framework and comprising, longitudinally and laterally projecting rails, a gripping j w assembly horizontally adjustably mounted on the outer ends of said rails, each assembly including a plate slidably engaged with the rail, a lever pivotally supported intermediate of its ends on the plate with its lower end projecting downwardly and outwardly below said head, a downwardly and inwardly facing jaw on the extreme lower end of said lever, the vertical opening of the jaw below the adjacent inner portion of the lever being substantially equal to the thickness of the sheets to be gripped and the lower end of the jaw being inclined upwardly and outwardly whereby no substantial portion of the lever projects below the jaw, and means carried by said head engageable with said levers and operative at the upper imit of travel of said head to move said gripping jaws to sheet releasingposition.

15. In a sheet separating and delivering machine having a framework supported over and around a stack of sheets to be separated, a sheet lifting head vertically reciprocably mounted in said framework and comprising, longitudinally and laterally projecting rails, a gripping jaw assembly horizontally adjustably mounted on the outer ends of said rails, each'assembly including a plate slidably engaged "with the rail, a lever pivotally supported on therplate with its lower end projecting downwardly and outwardly below said head, a downwardly and inwardly facing jaw on the extreme lower end of said lever, the lower end of the jaw being inclined'upwardly and outwardly whereby no substantial portion of the lever projects below the jaw, andmeans carried by said head engageable with said levers/and operative at the upper limit of travel ofsaid head to move said gripping jaws to sheet-releasing position.

16. A sheet separating and delivering machine comprising, a hollow framework adapted to be positioned over a stack of sheets, a lifting head vertically reciprocably mounted within said framework, gripping jaws pivotally supported on said head andprojecting therebelow and. adapted to engage the edges of the top sheet of said stack when said head is lowered, means for moving said jaws to sheet releasing position in an elevated position of said head, a horizontally translatable penetrating element mounted along one side of said framework and having a pointed end directed inwardly toward the path of travel of said head and a .sheet carried thereby, means actuated in timed relationship with reciprocation of said -head to move said element inwardly into engagement with an upper edge of a sub-adjacent sheet supported by said jaws, and a depending sheet flexing element carried by said head and yieldably urged downwardly into flexing engagement with the top surface of a sheet supported by said jaws and inwardly of the periphery of the sheet.

1'7. A sheet separating delivering machine comprising, a hollow framework adapted to be positioned over a stack of sheets, a lifting head vertically reciprocably mounted within said framework, gripping jaw levers pivotally supported on said head and projecting downwardly and outwardly of said head from their pivots on opposite sides of said head, inwardly facing pointed gripping jaws on the lower sides of the outer ends of said levers and spaced below the loweredges of the levers :by a distance approximately equal to the thickness of the sheets to be separated, means for moving said jaws and lovers to sheet releasing position in an elevated position of said head, a horizontally translatable penetrating element supported from said framework and to one side of said stack of sheets, said element having an inwardly facing sharpened nose, means actuated in response to vertical movement of said head to advance said element and said nose inwardly in penetrating fashion along the lower-edge of a sheet suspended'by said jaws, and a depending sheet flexing element carried by said head and yieldably urged downwardly into flexing engagement with the top surface of a sheet supported by said jaws and inwardly of the periphery of the sheet.

18. A sheet separating delivering machine comprising, a hollow framework adapted 'to'be positioned over a stack of sheets, a lifting head vertically reciprocably mounted within said framework, gripping jaw levers pivotally supported on said head and projecting downwardly and outwardly of said head from their pivots on opposite sides of said head, inwardly facing gripping jaws on the lower sides of the outer ends of said levers, means for movingsaid jaws and levers to sheet releasing position in an elevated position of said head, a horizontally translatable penetrating element supported from said framework and to one side of said stack of sheets, said element having an inwardly facing sharpened nose, and means actuated in response to vertical movement of said head to advance said element and said nose inwardly in penetrating fashion along thelower edge of a sheet suspended by said jaws.

1.9. A sheet separating and delivering machine comprising, a hollow framework adapted to be positioned over astack of sheets, a lifting head vertically reciprocably mounted within said framework, inwardly facing gripping jaws pivotally supported on opposite sides of said head and projecting therebelow and adapted to engage the edges of the top sheet of said stack, means for moving said jaws to sheet releasing position in an elevated position of said head, an upright lever arm pivot ally supported on said head'outwardly from :said :gripping jaws, a separator :bar

pivotally carried on the lower end or said lever arm and yieldably supported in an inwardly di rooted generally horizontal position, a supporting nose on the inner end of said separator bar adapted to be supportingly engaged by a sheet supported by said gripping jaws, a pointed penetrating nose on said separator bar positioned substantially outwardly from the inner end of said supporting nose and spaced downwardly from said supporting nose by a distance approximately equal to the thickness of one of said sheets and separated from said supporting nose by a rounded notch adapted to clear the edge of said top sheet, and an abutment carried by said framework and cammingly engageable with the upper end of said lever arm to move said separator bar and the sharpened nose thereon inwardly in response to upward motion of said head and into penetrating engagement with the lower edge of the top sheet supported by said gripping jaws.

20. A sheet separating and delivering machine comprising a hollow framework adapted to be positioned over a stack of sheets, a lifting head vertically reciprocably mounted within said framework, inwardly facing gripping jaws pivotally supported on opposite sides of said head and projecting therebelow and adapted to engage the edges of the top sheet of said stack, means for moving said jaws to sheet releasing position in an elevated position or" said head, an upright lever arm pivotally supported on said head outwardly from said gripping jaws, a separator bar pivotally carried on the lower end of said lever arm and yieldably supported in an inwardly directed generally horizontal position, a supporting nose on the inner end of said separator bar adapted to be supportingly engaged by a sheet supported by said gripping jaws, a pointed penetrating nose on said separator bar positioned substantially outwardly from the inner end of said supporting nose and spaced downwardly from said supporting nose and separated from said supporting nose by a notch adapted to clear the edge of said top sheet, and, an abutment carried by said framework and cammingly engageable with said lever arm to move said separator bar and the sharpened nose thereon inwardly in response to upward motion of said head and into penetrating engagement with the lower edge of the top sheet supported by said gripping jaws.

21. A sheet separating and delivering machine comprising, a hollow framework adapted to be positioned over a stack of sheets, a lifting head vertically reciprocably mounted within said framework, gripping jaws supported on opposite sides of said head and projecting therebelow and adapted to engage the edges of a sheet of said stack, means for moving said jaws to sheet releasing position in an elevated position of said head, a separator bar connected to said head and yieldably supported in an inwardly directed generally horizontal position, a supporting nose on the inner end of said separator bar adapted to be supportingly engaged by a sheet supported by said gripping jaws, a pointed penetrating nose on said separator bar positioned substantially outwardly from the inner end of said supporting nose and spaced downwardly from said supporting nose and separated from said supporting nose by a notch adapted to clear the edge of said top sheet, an abutment carried by said framework, and means cammingly engageable with said abutment before said head reaches its fully elevated position and located to engage said separator bar to move said separator bar and the sharpened nose thereon inwardly in response to upward motion of said head and into penetrating engagement with the lower edge of a sheet supported by said gripping jaws.

22, A sheet lifting apparatus comprising, a vertically reciprocable head, lever arms pivotally supported on opposite sides of said head and extending transversely thereof, said lever arms having downwardly and outwardly curved lower edges on their outer ends adapted to slidably engage the top sheet of the stack, the outer ends of said lever arms having downwardly opening recesses therein, and hardened jaw plates removably secured in said recesses and having inwardly facing sharpened gripping jaws on their lower edges spaced outwardly from the lower inside corners of said recesses, said jaws being spaced below the lower edges of said lever arms by a distance approximately equal to the thickness of said sheets.

23. A sheet lifting apparatus comprising, a verti ally reciprocable head, lever arms pivotally supported on opposite sides of said head and extending transversely thereof, said lever arms having downwardly and outwardly curved lower edges on their outer ends adapted to slidably engage the top sheet of the stack, the outer ends of said lever arms having downwardly opening recesses therein, and hardened jaw plates removably secured in said recesses and having inwardly facin sharpened gripping jaws on their lower edges spaced downwardly and outwardly from the lower inside corners of said recesses.

24. A sheet lifting apparatus comprising, a vertically reciprocable head, lever arms pivotally supported on opposite sides of said head and extending transversely thereof, said lever arms having downwardly and outwardly curved lower edges on their outer ends adapted to slidably engage the top sheet of the stack, the outer ends of said lever arms having downwardly opening recesses therein, and inwardly facing sharpened gripping jaws on said lever arms spaced downwardly and outwardly from the lower inside corners of said recesses.

ROBERT VAN SCHIE.

References Cited in the file of this patent UNITED STATES PATENTS Number