US2247466A

US2247466A - Sheet feeding apparatus

Info

Publication number: US2247466A
Application number: US345744A
Authority: US
Inventors: Baker Leonard; Leo C Williams
Original assignee: Dexter Folder Co
Current assignee: Dexter Folder Co
Priority date: 1940-07-16
Filing date: 1940-07-16
Publication date: 1941-07-01
Anticipated expiration: 1958-07-01

Description

July 1, 1941.

| BAKER ETAL SHEET FEEDING APPARATUS 1i Sheets-Sheet 1 Filed July 16, 1940 mg. I!

INVEB'ITORS LEONARD BAKER LEO c WILLIAMS ATTOR Y July 1, 1941. L BAKER EIAL .SHEET FEEDING APPARATUS 11 Shets -Sheet 2 Filed July 16, 1940 Fig). 2

INVENTORS LEONARD BAKER LEO c. WILLIAMS ATTORNE July I, 1941.

L. BAKER ETAL SHEET FEEDING APPARATUS Filed July-l6, 1940 ll Sheets-Sheet 4 W 0m v h EML U R in V m M M H mm mm.. 4

July 1,1941. L. BAKER ETAL SHEET FEEDING APPARATUS 11 Sheets- Sheet 5 Filed July 16, 1940 INVENTO RS LEONARD BAKER LEO C WILLIAMS ATTOR Y n lNm w f II 03 n 4 m A \w m mm Em mwm mmw y 1941. L BAKER ET AL 2,247,466

SHEET FEEDING APPARATUS Filed July 16, 1940 11 Sheets-Sheet 6 ll [1 328 1* w w 339 .f 38 INVENTOR 556 i i ifiiwgs 355 LEO C.WILLIAMS 337 357 .\\\\\\\\\w m 34s 347 34a 52a --a34 342 July 1, 1941. L. BAKER ETAL 2,247,466

SHEET FEEDING APPARATUS 1 1 Sheets-Sheet 7 OHM Y n R I- July 1, 1941.

L. BAKER ETAL SHEET FEEDING APPARATUS Filed July 16, 1940 ll Sheets-Sheet 8 mvsmons RD BAKER ATTORN July 1,1941.

1.. BAKER ET AL SHEET FEEDING-APPARATUS Filed July 16, 1940 ll Sheets-Sheet 9 mvsufons LEONARD BAKER LEO C. WILLIAMS Juiy 1, 1941. L BAKER EFAL FEEDING APPARATUS Filed July 16, 1940 11 sh ets-sheath- INVENTORS LEONARD BAKER Y LEO C. WILLIAMS B ATTORN Patented July 1, 1941 Leonard Baker, Hillsdale, N. J., and Leo C. Williams, Pearl River, N. Y., assignors to Dexter Folder Company, Pearl River, N. Y., a corporation of New York Application July 16, 1940, Serial No. 345,744

27 Claims.

is disclosed a sheet feeder having a hydraulically actuated pile elevator. This hydraulically actuated pile elevator includes a vertically disposed ram directly connected with the pile support, which is objectionable by reason of the requirement for a well or cylinder for the ram which well or cylinder obviously must be arranged in the foundation of the building or structure wherein the sheet feeder is installed, thus limiting the installation of the sheet feeder to a certain definite location only. This type of hydraulically actuated pile elevator is further objectionable for the reason that the pile of sheets must be positioned in the center of the pile support, because any shifting of the pile out of said position would cause binding of the vertically disposed ram in the well or cylinder with resulting faulty operation of the feeder.

It is accordingly one object of the present invention to provide a sheet feeder having a pile elevator which is actuated by improved hydraulic mechanism that does not require a vertically disposed ram directly connected with the pile support and thus overcomes the above mentioned objections.

Another object of the present invention is to provide a sheet feeder having a pile elevator which is actuated by improved hydraulic mechanlsm so arranged and constructed that said mechanism is disposed wholly within the sheet feeder.

Another object of the present invention is to provide a sheet feeder having a pile elevator which is intermittently raised by improved hydraulic mechanism and controlled pneumatically through .movement of the pile and removal of sheets therefrom.

Another object of the present invention is to provide improved hydraulic mechanism for actuating a pile elevator of the type that is suspended at four corners by cables, chains or other flexible elements.

Another object of the present invention is to provide a sheet feeder having improved hydraulic mechanism for intermittently raising the pile elevator and for rapidly lowering and raising the pile elevator,

These and other objects of the present invention will appear as the following description thereof proceeds and in order to more clearly understand said invention reference may be had to the accompanying drawings which illustrate two embodiments of said invention.

In said drawings:

Fig. 1 is a side elevation of a sheet feeder constituting one embodiment of the present invention;

Fig. 2 is a front elevation of said feeder, showing hydraulic pile elevator actuating means;

Fig. 3 is a top plan view of the feeder shown in Figs. 1 and 2;

' Fig. 4 is a horizontal sectional view on the line 4-4 of Fig. 1;

*Figs.' 5 and 6 are enlarged side elevations of brackets forming part of an. auxiliary frame for v supporting certain parts of the feeder as a unit;

1i Fig. 7 is an enlarged side elevation, partly in section, of control means for the feeder starting stopping device illustrated in Figs. 2, 3

and 6;

Fig. 8 is an enlarged view illustrating diagrammatically the complete hydraulic pile elevating system and control means therefor illustrated in Figs, 1, 2 and 4;

Figs. 9 and 10 are enlarged diagrammatic views of the valve illustrated in Fig. 8;

Fig. 11 is a fragmentary side elevation partly in section, of mechanism for manually operating the valve illustrated in Figs. 8, 9 and 10;

Figs. 12 and 12 are complementary side elevations of a sheet feeder constituting another embodiment of the present invention;

Figs. 13 and 13 are complementary top plan views of the sheet feeder illustrated in Figs. 12

and 12' and showing another hydraulic pile elevator actuating means embodying the presentinvention;

Fig. 14 is a fragmentary rear elevation showing the driving mechanism for the feeder illustrated in Figs. 12 to 13";

Fig. 15 is an enlarged end view, partly in section, of the hydraulic pile elevator actuating means shown in Fig. 13 looking from the left thereof;

Fig. 16 is an enlarged view illustrating diagrammatically the complete hydraulic pile elevating system and control means therefor shown in Figs.'13 and 13;

Figs. 17 and 18 are enlarged vertical sectional views of the pile elevator pneumatic control means illustrated in Figs. 12. 13 and 16;

Figs. 19 and 20 are enlarged diagrammatic views of the control valve illustrated in Fig. 16;

Fig. 21 is an enlarged end view, partly in section, of the mechanism shown in Figs. 13 and 16 for manually operating the control valve;

Fig. 22 is a horizontal sectional view on the line 22--22 of Fig. 21; and

Fig. 23 is a fragmentary rear elevation of the hydraulic pile elevator actuating means.

Referring first to Figs. 1 to 11 inclusive, which illustrate one embodiment of the present invention and wherein like reference characters designate like parts throughout the several views, the various movable parts of the feeder therein shown as well as certain stationary parts thereof may be mounted on a frame of any suitable construction and the movable parts may be actuated or driven by any suitable means. Said frame and driving means are preferably constructed as follows.

As shown in Figs. 1 to 4, the feeder frame is comprised by front uprights indicated broadly at and rear uprights 5 connected together by side members indicated broadly at 1. These front uprights 5 and side members 1 are each comprised by a pair of

steel plates

8, 9 and II], II respectively, the plates H), II being secured to or formed integrally with the

plates

8, 9 at the tops thereof. The plates 8, 3 and I0, H of each front upright 5 and side member I are spaced apart and bolted together by spacers l2 and bolts l3 located at suitable points along said plates. The upper ends of the rear uprights 6 extend between the plates H), II and are bolted or otherwise suitably secured thereto. The uprights 5 and B are bolted or otherwise suitably secured to the machine foundation, the front uprights 5 being connected together by cross beams l4 and I5. The cross beam I4 is bolted or otherwise suitably secured to the plates 9. The cross beam I5 is bolted or otherwise suitably secured at opposite ends thereof to pairs of spaced brackets l6, l6 and l6, l6 which, in turn, are bolted or otherwise suitably secured to the plates 9 of the front uprights 5. It will thus appear that-the spaced

plates

8, 9 and II), II and the rear uprights 6 form a frame of rigid construction with a minimum amount of material.

The cross beam I4 has bolted or otherwise suitably secured thereto the lower end of a metal apron or plate |1 against which the front side of a supply or pile of metal or other sheets |8 bears during elevation of the same by mechanism to be hereinafter described. The upper end of the metal apron or plate I! is bolted or otherwise suitably secured to a cross beam M which forms part of an auxiliary frame indicated broadly at 20 (Figs. 1, 2, 3, 5 and 6). This auxiliary frame 20 is disposed between the front uprights 5 near the tops thereof and includes side brackets 2i and 22 which are bolted or otherwise suitably secured to the plates 9 and connected together by the cross beam I9.

Referring now more particularly to Figs. 1 and 6, the drive for the feeder is preferably comsource of power (not shown) and passing around a sprocket24 which is fixed on the outwardly projecting end of a short shaft 25. This short shaft 25 is journalled in suitable bearings in the plates 8, 3 of the adjacent front upright 5 and in the side bracket 2| through which said shaft extends. Disposed within the bracket 2| and fixed on the opposite end of the short shaft 25 is a spur pinion 26 which meshes with a spur gear 21 also disposed within said bracket and fixed on a cam shaft 28 projecting therein. This cam shaft 28 extends transversely of the feeder and is journalled in suitable bearings in the side brackets 2|, 22 of the auxiliary frame 20. The cam shaft 28 is utilized to operate various parts of the feeder to be hereinafter described. The pile of sheets I8 is supported on a pile elevator which is operated by hydraulically actuated means. Said pile elevator and hydraulically actuated operating means therefor arc, in accordance with one aspect of the present invention, preferably mounted and constructed as follows.

Bolted or otherwise suitably secured to the top of cross beam l5 adjacent one end thereof is a tank 29 (Figs. 1, 2, 4 and 8) adapted to contain a supply of oil, water or other suitable motive fluid as indicated at 30. Connected with the tank 29 and extending therein is one end of a conduit 3| the opposite end of which is connected, as by a connector 32, with the housing 33 of a plunger pump indicated broadly at 34. This plunger pump 34 is bolted or otherwise suitably secured to a metal shelf 35 and, as hereinafter described, is utilized to impart intermittent raising movement hydraulically to a pile elevator and pile of sheets I8 thereon. The shelf 35 is bolted or otherwise suitably secured at its rear end to the cross beam I5, the front end of said shelf being supported by a pair of rods 35 which are connected with the shelf and adjustably secured at their lower ends in brackets 31 that are bolted or otherwise suitably secured to the lower cross beam l4.

Slidably mounted in the housing 33 of pump 34 is a plunger 38 (Fig. 8) which projects upwardly through the housing and is provided on the upper end with a head 39. The housing 33 has bolted or otherwise suitably secured to the top thereof a cover plate 40 having a tubular guide 4| formed on opposite sides thereof for the upper end of the plunger 38. The lower end of the plunger 38 extends into a chamber 42 provided in the housing 33 and which communicates with the conduit 3| through a port 43 formed in said housing. A spring 44, encircling the upper portion of the tubular guide 4| and interposed between the cover plate 40 and the plunger head 39, normally tends prised by a. chain 23 driven from any suitable to raise the plunger 38.

Reciprocating pumping action is imparted to the plunger 38 by the spring 44 and an eccentric 45 adapted to engage the head 38 of said plunger. This eccentric 45 is fixed on one end of the shaft 46 of a combined air and vacuum pump 41 (Figs. 2 and 4) which is bolted or otherwise suitably secured to the shelf 35. Fixed on the opposite end of the shaft 46 is a sprocket 43 around which passes a chain '43 that also passes around a sprocket 5|] that is fixed on the armature. shaft 5| of an electric motor 52 connected with a suitable source of current and controlled for starting and stopping purposes by suitable switch means (not shown). The electric motor 52 is bolted or otherwise suitably secured to the cross beam l5. It will thus appear that through rotation of the eccentric 45 by the described driving connections therefor with the motor 52, and expanding action of the spring 44, the plunger 38 will be raised and lowered during each revolution of the eccentric 45.

Under these conditions fluid is intermittently drawn from the tank 23 through the conduit 3|,

connector 32, and port 43 into the chamber 42 of housing 33. Fluid so drawn into the chamber 42 is intermittently forced therefrom and directed under pressure into a cylinder 53 atv the left hand end thereof as viewed in Figs. 2 and 8. For this purpose the housing 33 of pump 34 has connected therewith, as by a connector 54 (Fig. 8), one end of a conduit 55 which communicates with the chamber 42 through a port 56 formed in the housing. The opposite end of the conduit 55 is connected, as by a fitting 51, with one end of a conduit 58 the opposite end of which is connected with a cover plate 59 that is bolted or otherwise suitably secured to the cylinder 53. The conduit 58 communicates with the interior of the cylinder 53 through a port 68 formed in the cover plate 59. The connector 32 for conduit 3| is provided with an inwardly opening spring pressed ball check valve 6| (Fig. 8) to prevent return flow of fluid from the chamber 42. The

connector 54 for conduit 55 is provided with an outwardly opening spring pressed ball check valve .62 to prevent return flow of fluid. from the cylinder 53 through'said conduit.

As shown in Fig. 2, the cylinder '53 is arranged horizontally in the sheet feeder and formed with

brackets

63 and 64 through the medium of which said cylinder is bolted or otherwise suitably secured to the lower cross beam l4 at one end thereof. Due to the required length of the cylinder 53 the left hand portion thereof, as viewed in Fig. 2, projects beyond the adjacent front upright through suitable openings formed in the

plates

8, 9 of said upright. Slidably mounted in the cylinder 53 is a hydraulically actuated piston 65 (Fig. 8) having a piston rod 65. The piston rod 66 projects through a cylinder head 6I bolted or otherwise suitably secured to said cylinder, and through and outwardly beyond a packing gland 68 adjustably secured to said cylinder head. Secured in any suitable manner to the outwardly projecting end of the piston rod 66 is a yoke 69 (Fig. 2) having journalled thereon as at ID a sheave I| provided with suitable grooves for the reception of four pile elevator supporting cables I2, I3, I4 and I5 (Figs. 1 to 4). These cables I2,

I3, I4 and I5 have corresponding ends anchored as at I6, 11, I8 and I9 in a block 89 (Figs 1 and 2) which is bolted or otherwise suitably secured to the cross beam l4 and further braced by the bracket 63 of cylinder 53.

As shown in Fig. 2 the cables I2, I3, I4 and I5 extend from the block 88 beneath and along the cylinder 53 through suitable openings formed in the

brackets

63, 64 and in a guide block 8|, and then pass around the sheave II on yoke 69. The guide block 8| is bolted or otherwise suitably secured to the cross beam |4. From the sheave II the cables I2, I3, I4 and I5 extendback over the cylinder 53, and then pass under and around a suitably grooved sheave 82 which is disposed between the brackets l6, l6 and journalled on a pin 83 secured in any suitable manner in said brackets. The sheave 82 and cables I2, I3, I4 and I5 passing around the same project into the space between the

plates

8, 9 of the adjacent front upright 5 through a suitable opening provided in the plate 9. From the sheave 82 the cables I2 and I3 extend upwardly between the

plates

8, 9 to the top of the feeder at which point said cables pass around a suitably grooved sheave. 84 (Figs. 1 to 3) which is disposed between said plates and journalled thereon as at 85. From the sheave 84 the cable I2 extends rearwardlybetween the plates II), II of the adjacent side member I and then passes around a suitably grooved sheave 86 (Figs. 1 and 3) which is disposed between said plates and journalled thereon as at 81. The cables I2 and I3 then extend downwardly from the

sheaves

86 and 84 respectively, and have their lower free ends connected in any suitable manner to the rear and front ends, respectively, of a pile elevator side member 88.

The cables I4 and I5 (Fig. 2) which pass around the sheave 82 as previously described, extend transversely of the feeder to the opposite side thereof and then pass under and around a suitably grooved sheave 89 which is disposed be tween the brackets l6, l6 and journalled on a pin 98 secured in any suitable manner in said brackets. The sheave 89 and cables I4, I5 passing around the same project into the space between the

plates

8, 9 of the adjacent upright 5 through a suitable opening provided in the plate 9. From the sheave 89 the cables I4 and I5 extend upwardly between the

plates

8, 9 to the top of the feeder at which point said cables pass around a suitably grooved sheave 9| (Figs. 2

and 3) which is disposed between said plates and journalled thereon as at 92. From the sheave 9| the cable I4 extends rearwardly between the plates H), II of the adjacent side member I and then passes around a suitably grooved-sheave 93 (Fig. 3) which is disposed between said plates and journalled thereon as at 94. The cables I4 and I5 (Fig. 3) then extend downwardly from the

sheaves

93 and 9 respectively, and have their lower free ends connected in any suitable manner to the rear and front ends respectively, of a pile elevator side member 95. 6

The pile elevator comprises the side members 88 and and cross members 96 (Fig. 1) engaged over said side members and adapted to receive a pile board 91 which, together with the pile of metal or other sheets |8 is positioned on said elevator through the rear of the feeder when the elevator is lowered by means for this purpose hereinafter described. It is to be noted, that due to the particular arrangement of the

sheaves

84, 86 and 9|, 93 the downwardly extending portions of the. cables 13 and I5 are disposed between the

plates

8, 9 of the front uprights 5 and beyond the pile guiding plate l1, and the downwardly extending portions of the cables I2 and I4 are disposed well to the rear of the feeder. In this manner both sides of the feeder frame are unobstructed, enabling positioning of the pile board 91 and pile of sheets l8 on the pile elevator through either side of the feeder if desired.

It will thus appear that when fluid is intermittently forced under pressure into the left hand end of the cylinder 53 and against the left face of the piston 65 as viewed in Fig. 8, by the inter mittent action of the plunger pump 34, the piston 65 will be moved step by step toward the right hand and of said cylinder. During this movement fluid on the opposite side of the piston 65 will be discharged from the cylinder 53 and returned to the tank 29 in a manner to be hereinafter described. As the piston 65 moves step by step toward the right, the piston rod 66, yoke 69 and sheave II will also move toward the right and those portions of the cables I2, I3, I4 and I5 extending from the block 80, aroundthe sheave "II, to the sheave 82 will be lengthened. This obviously shortens those portions of the cables I2, I3, I4 and I5 between the

sheaves

84, 86, 9| 93 and the

elevator side members

88 and 95 resulting in intermittent raising of the elevator and pile of sheets thereon. The piston rod 66 is guided for right line movement by a pair of spaced guide brackets 98 (Fig. 2) which are bolted or otherwise suitably secured to the lower cross beam I4 and provided with suitable grooves 99 slidably engaged by the yoke 69. It will be noted that since the cables I2, I3, I4 and 15 are anchored stationary at one end in the block 80, then extend from said block beneath the cylinder 53, around the sheave I I, and then back over the cylinder, a movement twice that of the piston 65 will be imparted to the pile elevator, thereby enabling employment of a relatively shorter cylinder and piston.

The elevator and pile of sheets I8 thereon are raised intermittently as the sheets are fed off the top of said pile by sheet separating and forwarding means hereinafter described, and to keep the top of said pile at a predetermined level for the operation of said means, the elevator and its operating mechanism are controlled pneumatically by compressed air actuated means of the general type disclosed in the United States Fatent No. 2,156,648 granted May 2, 1939, to Leonard Baker, George A. Martin and Leo C. Williams. This pneumatic control means and source of compressed air therefor is preferably mounted, constructed and operated as follows.

Bolted or otherwise suitably secured on the plates H of side members I are brackets I to which are pivoted, as at IN, a frame indicated broadly at I02 (Figs. 1 and 3). This frame I02 comprises side members I03 and a. rear cross member I04 mounted on said side members and adjustable therealong to various positions. The frame I02 is supported at the rear thereof by pins I05 secured in the rear uprights 6. Secured to, and adjustable along, the rear cross member'IM is a bracket I06 having mounted thereon a vertically adjustable valve housing 801 (Figs. 3 and 8) Connected with the valve housing I01 is one end of a flexible conduit I00 the opposite end of which is connected with one end of a conduit I09. The opposite end of this conduit I09 is secured in and communicates with a conduit IIO (Fig. 5) formed in the side bracket 22 of the auxiliary frame 20.

Air under pressure is continuously maintained in the conduits I08, I09 and H0 by the pump (H which, as previously described, is driven by the electric motor 52 through the described driving connections between said motor and said pump. For this purpose, the air pressure side of the pump 41 has connected therewith one end of a conduit II I (Figs. 2 and 4) the opposite end of which is connected with a compressed air tank II2 through the medium of a flexible conduit H3. The compressed air tank H2 is supported at opposite ends thereof by angle bars II4 (Figs. 1 and 2) which are bolted or'otherwise suitably secured to the cross beam I4 and extend forwardly therefrom. Displacement of the compressed air tank II2 from the angle bars H4 is prevented by clamps I I5 which are engaged over the rims of said tank and bolted or otherwise suitably secured to said bars. The compressed air tank II2 has connected therewith one end of a flexible conduit II6 the opposite end of which is connected with the side bracket 22 and communicates with the conduit IIO formed therein (Figs. 2 and 5) Slidably mounted in the housing I0! is a valve III the stem of which projects downwardly through the housing and is provided on. the lower end with asocket H8 in which is freely mounted a ball II9 of steel, glass or other non-yielding material that rests on the top of the pile of sheets I8 (Figs. 1 and 8). The valve III is provided with a reduced portion I20 and the valve housing I01 is provided in the bore thereof with a chamber I2I, When the top of the pile of sheets I8 is at proper height the valve III through engagement of ball II9 with the pile will be positioned as shown in Fig. 8 wherein it will be noted that the reduced portion I20 of the valve is disposed slightly above chamber I2I so that air under pressure supplied in the valve housing and around the reduced portion of the valve by conduit I00 cannot reach the chamber I2I.

As sheets are fed one after another from the top of the pile, and with ball I I9 engaged therewith, the valve II'I will lower by gravity so that when a suflicient number of sheets have been so fed, the reduced portion I20 of the valve will extend or drop into the chamber I2I thus establishing communication between the latter and the conduit I00. Under these conditions, air under pressure will be delivered into a flexible con-' duit I22 having one end connected with the chamber I2I and the opposite end connected with one end of a conduit I23 (Figs. 2, 3 and 8) The opposite end of this conduit I23 is connected with a housing I24 at the bottom thereof, and said housing is secured to or formed integrally with a bracket I25 which is bolted or otherwise suit ably secured to the plunger pump housing 33. Mounted in the housing I24 and projecting upwardly therethrough is a plunger I26 (Fig. 8) provided on the bottom thereof with a reduced portion I21 which normally engages a V-shaped bottom of the housing when no compressed air is being supplied therein through the conduit I23.

Extending over, and engageable by, the upper end of plunger I26 is one arm I28 of a bell crank detent I29 (Fig. 8) which is pivotally mounted on a pin I30 secured in any suitable manner on the bracket I25. The other arm I3I of bell crank detent I29 extends downwardly and has itslower end normally engaged with the head 39 of pump plunger 38 so that the latter is held in its lowermost position and against operation by the spring 44 and eccentric 45 to supply fluid under pressure to the cylinder 53. The length of the arm I3I is so proportioned that when the pump plunger 38 is actuated to its lowermost position by the high part ofthe eccentric. 45, the head 39 on said plunger is disposed slightly below the lower end of the arm I3I to'enable engagement of said arm with said head. Under operating conditions and when the pile elevator is at rest,

the spring 44 holds the head 39 in engagementwith the arm i3l, and during each revolution of the eccentric 45 the high part of said eccentric imparts a slight downward movement to the pump plunger 38 suflicient to free the arm I3I from the head 39 but not sumcient to create a pumping action.

When air under pressure is admitted in the conduit I23, however, as previously described, said air enters the housing I24 and raises the plunger I26, thus swinging the bell crank detent I29 clockwise as viewed in Fig. 8 and disengaging the arm I3I from the head 39 upon subsequent engager'nent of the high part of the eccentric 45 with said head. When the arm I3I is disengaged from the head 39, the plunger pump 34 through expanding action of the spring 44 and continued rotation of the eccentric 45 will intermittently supply fluid under pressure into the left hand end of the cylinder 53 as viewed in Figs. 2 and 8 from the tank 29 through the described conduits between said tank, said pump and said cylinder. The piston 65 will thus be actuated step by step toward the right, and through corresponding linear movement of the piston rod 66 and sheave 1|, the cables 12, I3, 14 and 15 will, as previously described, raise the elevator and pile of sheets until the top of the pile is at the proper height.

As the pile thus raises, the valve H1 is lifted, thus raising the reduced portion I out of the chamber I2I and disconnecting the source of air under pressure from the housing I24. The plunger I26 and arm I28 then drop by gravity so that the lower end of the arm- I3I is again engaged with the head 39 of pump plunger 38 to prevent further operation of the plunger pump 34. The eccentric 45 then rotates idly until further elevation of the pile is necessary at which time said pie w ll again be elevated as previously described. Excess swinging movement of the bell crank detent I29 in opposite directions is prevented by a pin I32 (Fig. 8) threaded in the bracket I and adapted to be engaged by the arm I3I, and an adjusting screw I33 threaded'in the free end of the arm I28 and adapted to engage the upper end of the housing I24. The adjusting screw I33 may be locked in adjusted position by a lock nut I34. When the elevator and pile of sheets I8 thereon are raised to the proper height and the plunger pump 34 is rendered inoperative as previously described. the fluid previously admitted into the cylinder 53 to intermittently raise said elevator is trapped therein by the ball check valve '62 which prevents return flow of the fluid, thus maintaining theelevator and pile of sheets in raised position.

The sheets of pile I8 are separated one after another at the rear by suction separating devices hereinafter referred to, but before this operafion takes place the rear upper corners of the pile are winded to preliminarily separate the upper sheets of the pile by compresed air that is directed through vertically disposed blow pipes I35 (Fig. 1). These blow pipes- I35 are carried in brackets I36 (Fig. 3) engaged over, and slidoted frame I02. The upper ends of the blow pipes I35 have connected therewith corresponding ends of flexible conduits I31 the opposite ends .of which areconnected with a conduit I38 closed at its outer end and having an inner end secured n and communicating with a conduit I39 (Fig. 5) formed in the side bracket 22 of the auxiliary frame 20. This conduit I39 communicates with a port I40 formed in the side bracket 22 and opening outwardly therefrom through one side thereof. Spaced from the port I40 is another port I4I formed in the side bracket 22 and opening outwardly through the same side thereof as the port I40. This port I communicates with the conduit IIO which, as previously described, is continuously supplied with air under pressure from the compressed air tank II2 through the conduit II6.

Delivery of compressed air at the required predetermined intervals to the blow pipes I35 is effected by a rotary valve I42 (Figs. 2 and 3) loosely-mounted on the cam shaft 28 and connected with a driving disk I43 that is secured to and continuously rotated by said cam shaft. The valve I42 is provided on the inner side thereof with an arcuate shaped port (not shown) which, through rotation ofsaid valve, passes over the ports I40, I4I in the side bracket 22 once during able along the rear cross member I04 of the piveach cycle of operation of the feeder. This establishes communication between conduits IIII, I39 (Fig. 5) and through the deseribed connections for the conduit I39 with the blow pipes I35 compressed air is delivered through said pipes against the upper rear corner portions of the pile of sheets I8. When, through continued rotation of the valve I42, the ports I40, I4I no longer communicate with each other the air under pressure is prevented from entering the blow pipes I35 until'the valve, in the next cycle of operation of the feeder, again rotates to bring said ports into register.

While the upper rear corner portions of the pile are being winded as just described, the top sheet of the pile is engaged and lifted by vacuum sheet separating devices comprised by cylinders I44 (Figs. 1 and 3) carried by the brackets I36, and suction cups I45 that are raised and lowered through the making and breaking of vacuum in said cylinders. These sheet separating devices are constructed and operated in thesame manner as the sheet separating devices disclosed in the United States Patent No. 2,156,648 above referred to and need no detail description herein. It might be pointed out, however, that the cylinders I44 have connected therewith corresponding ends of flexible conduits I46 the opposite ends of which are connected, as by a tubular fitting I41, with the valve body I48 of a rotary valve mechanism indicated broadly at I49 (Figs. 2 and 3). This rotary valve mechanism I49 controls the making and breaking of vacuum in the cylinders I44 of the sheet separating devices and in sheet forwarding devices hereinafter referred to, and said valve mechanism is substantially the same in construction and operation as the valve mechanism disclosed in the United States Patent No. 2,156,648 above referred to except that in the 7 present case separate valves I50 and I5I are proby tubular shafts I52, I53 which extend transversely of the feeder and are secured at their opposite ends in the side brackets 2|, 22 of the auxiliary frame 20. The tubular shaft I53 which is closed at both ends forms a vacuum conduit and communicates with the interior of the valve body I48. Vacuum is continuously created in the tubular shaft I53 and the valve body I48 by the pump 41, and for this purpose, the vacuum side of said pump has connected therewith one end of a flexible conduit I54 (Fig. 2). The opposite end of this flexible conduit I54 is connected with the side bracket 2| of the auxiliary frame 20 and communicates with a conduit I55 (Fig. 6) which is formed in said side bracket and connected with the tubular shaft I53.

Making and breaking of vacuum in the cylinders I44 of the sheet separating devices at predetermined intervals is e-fiected by the rotary valve I58 that is connected with and rotated by a driving disk I56 (Fig. 2) fixed on the cam shaft 28 which extends loosely through the valve body I48. The rotary valve I50, during rotation of the same. connects and disconnects the cylinders I44 from the vacuum side of the pump 41 through the described connections for said cylinders with the valve body I48 and the described connections for the latter with said pump.

After the top sheet of the pile has been lifted at the rear thereof by the suction cups I45, the lifted sheet is winded to completely separate it from the next sheet therebelow by compressed air that is delivered through vertically disposed blow pipes I51 (Fig. 1) carried in the brackets I36. The upper ends of the blow pipes I51 have connected therewith corresponding ends of flexible conduits I58 (Fig. 3) the opposite ends of which are connected with a conduit I59 that is closed at its outer end. 'Ihe inner end of the conduit I59 is secured in and communicates: with a conduit I60 (Fig. formed in the side bracket 22 of the auxiliary frame 20. This conduit I60 communicates with a port I6I opening outwardly through the side of the side bracket 22 in which.

the ports I40, I4I are formed. Spaced from the port I6I' is another port I62 which opens outwardly through the same side of the side bracket 22. The ports IBI, I62 are disposed substantially 180 degrees apart from the ports I40, I, and the port I62 communicates with the conduit IIO which, as previously described, is continuously supplied with air under pressure from the compressed air tank 5 I2.

Delivery of compressed air at the required predetermined intervals to the blow pipes I51 is effected by the rotary valve I42 which, through continued rotation thereof, connects the ports I6I, I62 so that air under pressure is delivered from the conduit IIO to the conduits I60, I59 and through the blow pipes I51. The compressed air delivered through the blow-pipes I51 is directed between the separated sheet and the one therebelow so that said uppermost sheet is completely lifted from the pile. When, through continued rotation of the valve I42, the ports I6I, I 62 no longer communicate with each other, the air under pressure is prevented from entering the blow pipes I51 until the valve, in the next cycle of operation of the feeder, again rotates to bring the ports I 6|, I62 into register.

When the separated sheet has been winded it is forwarded from the pile by vacuum sheet forwarding devices comprised by cylinders I63 (Figs. 1 and 2) and suction cups I64 that are moved up and down relative to said cylinders through the making and breaking of vacuum therein. These sheet forwarding devices are also constructed and operated in the same manner as the sheet forwarding devices disclosed in the United States Patent No. 2,156,648 above referred to and need no detail description herein. It is pointed out, however, that the sheet forwarding devices have swinging movement to advance the sheets that have been separated from the pile I8 by the sheet separating devices. For this purpose, the cylinders I63 are secured to arms I65 which, in turn, are fixed on a rock shaft I66 that extends transversely of the feeder and is journalled in suitable hearings in the brackets I00. The sheet forwarding devices are rocked rearwardly by a. cam I61 (Figs. 2, 3 and '1) that is fixed on and rotated by the cam shaft 28. This cam I61 engages a roller I68 journalled on a cam strap I69 extending over the cam shaft 26 and connected with an arm I10 that i fixed on the rock shaft I65. The sheet forwarding devices are rocked forwardly by a pull spring "I having one end connected with the arm I10 and the opposite end connected in any suitable manner with the tubular shaft I53.

The making and breaking of vacuum in the cylinders I63 of the sheet forwarding devices is effected at proper intervals by the rotary valve I5I (Figs. 2 and 3), and for this purpose the cylinders I63 have connected therewith corresponding ends of flexible conduits I12 the opposite ends of which are connected, as by a tubular fitting I13, with the valve body I48 of the rotary valve mechanism I49. The rotary valve I5I is loosely mounted on the cam shaf t 28 and arranged at the side of the valve body I48 opposite'that engaged by the rotary valve I50 which controls the making and breaking of vacuum in the cylinders I44 of the sheet separating devices. Rotation is imparted to the rotary valve I5I by a driving disk I14 which is connected with said valve and fixed on the cam shaft 28. The operation of the rotary valve I5I is so timed that vacuum is established in the cylinders I63 to move the suction cups I64 into engagement with the top sheet of the pile when the sheet forwarding devices have been swung rearwardly, and is maintained therein until said devices have completed their forward movement and delivered the shet engaged thereby in proper position on a conveyor, to be hereinafter described, at which time the vacuum is broken in said cylinders.

The sheets separated from the pile I8 by the sheet separating devices are taken by the sheet forwarding devices and delivered thereby to a sheet conveyor that advances the sheets to the machine or other instrumentality with which the feeder is associated. This conveyor includes feed rollers I15, drop rollers I16, and conveyor tapes I11 passing around said feed rollers (Figs. 1 and 2). The feed rollers I15 are fixed in spaced relation on a shaft I18 which extends transversely of the feeder and is journalled in suitable bearings in the side brackets 2I, 22 of the auxiliary frame 20. The shaft I18, the feed rollers I15 fixed thereon, and the conveyor tapes I11 passing around said rollers are driven by suitable gearing including a gear I19 (Figs. 1 and 6) that is fixed on said shaft and disposed within the side bracket 2I. This gear I19 meshes with a similar gear I also disposed within the side bracket 2| and which is secured to or formed integrally with the gear 26 that is rotated by the short drive shaft 25.

The drop rollers I 16 are journalled on arms I88 (Fig. 2) fixed on a rock shaft I82 which extends transversely of the feeder and is journalled in suitable bearings in the side brackets 2|, 22 of the auxiliary frame 20. The drop rollers I16 are raised and lowered by a cam I83 secured to or formed integrally with the valve driving disk I16 and which engages a roller I84 journalled on an arm I85 that is fixed on the rock shaft I82. An additional support and bearing for the rock shaft I82 is provided by the valve body I48.

If, for any reason, it is desired to temporarily interrupt the feed of sheets from the top of the pile during the operation of the feeder, this is accomplished without having to disconnect the feeder from its source of power; without disturbing the timing between the feeder and the machine being fed thereby; and without failure of completion of feed of a sheet in process of delivery from the feeder. For this purpose, the side bracket 2| of the auxiliary frame 20 is provided with a relief valve I86 of the poppet type (Fig. 6) which communicates with the conduit I55 formed in said bracket. This relief valve I88 is normally closed, as by a spring I81, to enable operation of the sheet separating and forwarding devices as above described. When the relief valve I86 is opened, however, the conduit I55 is open to atmosphere and thus prevents the operation of the sheet separating and forwarding devices.

Opening of the relief valve I86 is effected by a lever I88 that is pivotally mounted on a pin I89 secured in any suitable manner on the plate 8 of the adjacent front upright 5. The lower end of the lever I88 is provided with an adjustable valve engaging member preferably in the form of a machine screw I98 threaded in said lever and locked in adjusted position by a lock nut I9I. The upper end of the lever I88 has journalled thereon a roller I92 adapted to engage a cam I93 that is ,fixed on a rock shaft I94. This rock shaft I94 extends transversely of the feeder and is journailed in suitable bearings in the

plates

8, 9 of the front uprights 5. The rock shaft I94 has fixed on the ends thereof handles I95 and by turning either of these handles in one direction the shaft I94, cam I93, and lever I88 may be swung to move the relief valve I86.to the dotted line position thereof shown in Fig. 6-thus opening the conduit I I55 to atmosphere and preventing operation of the sheet separating and forwarding devices. Obviously when the rock shaft I94 is swung in the opposite direction by either of the handles I95 the relief valve I88 will close through the expanding action of the spring I 81 so that the sheet separating and forwarding devices may again operate as above described. The cam I93 is provided in its periphery and at opposite ends thereof with recesses I96 adapted to be engaged by the roller I92 in order to hold the rock shaft I94 and cam I93 againstaccidental rotation when rocked to opera tive and inoperative positions. Rocking movement of the rock shaft I94 in opposite directions is limited by pins I91 (Fig. 1) secured in the plates 8 of the front uprights 5 and adapted to be engaged by lugs I98 formed on thehandles I95.

Fixed on the rock shaft I94 is a stop arm I99 (Fig. 7) provided with-shoulders 288 and 2M engageable with a lug 282 formed on the arm 283 of a bell crank 284. This bell crank 284 is pivotally mounted on a pin 285 secured in any suitable manner in the side bracket 2| Fig. 2) and projecting inwardly therefrom. The other arm 28B of bell crank 284 has threaded in the free end thereof a machine screw 201 provided with a lock nut 201' and adapted to be engaged by the free end of the cam strap I69. Th arm 286 of hell crank 284 has connected therewith one end of a pull spring 288 the opposite end of which is connected in any suitable manner with the tubular shaft I53. It will thus appear that the bell crank 284 is operated in one direction by the cam strap I69 to raise arm 283 of said bell crank and in the opposite direction by the spring 288 to lower said r arm.

During normal operation of the feeder and for a major portion of each cycle thereof the bell crank 284 will be positioned as shown in full lines in Fig. 7 wherein it will be noted that the lug 282 on arm 283 is disposed in the path of travel of the shoulder 288 on stop arm I 99 and thereby prevents actuation of the shaft I 94, cam I93. lever 7 I88 and relief valve I86 to interrupt the feeding of sheets from the top of the pile. However, when the sheet forwarding devices are swung to their extreme forward positions to deliver the sheet engaged thereby in proper position between the feed and drop rollers I and I16, the bell crank 284 is swung to the dotted line position thereof shown in Fig. '7 by the cam strap I69. The lug 282 on arm 283 is thus removed from the path of travel of the shoulder 288 on stop arm I99 at which time the shaft I94, the cam I93, the lever I88 and the relief valve I86 may be actuated to interrupt the feeding of sheets from the top of the pile. It will thus appear that the feeding of sheets from the top of the pile cannot be interrupted while a sheet is engaged by the sheet forwarding devices and before it is delivered in proper position thereby on the conveyor.

When the shaft I94 is actuated as previously described to interrupt the feeding of sheets from the top of the pile, the stop arm I99 is moved to the dotted line position thereof shown in Fig. '7, and upon continued rotation of cam I61 to swing the sheet forwarding devices rearwardly, the bell crank 284 is again swung to the full line position thereof shown in Fig. 7 by the action of the spring 288. At this time the lug 282 on arm 283 is disposed in the path of travel of the shoulder 28I on stop arm I99 and thus prevents actuation of the shaft I94 in the opposite direction to start or restart the feeding operation except at the proper time as hereinafter described.

When it is desired to resume feeding operation, actuation of the shaft I94 is only possible when the sheet forwarding devices are swung to their extreme forward positions, and the arm 283 is lifted by the cam strap I69 to remove the lug 282 out of the path of travel of shoulder 28I on stop arm I99. At this time the relief valve I86 is again closed and upon continued rotation of the cam I61 the sheet forwarding devices move rearwardly and into proper position to act on the next sheet of the pile. When the sheet forwarding devices are swung rearwardiy to act on the next sheet of the pile, the arm 283 is again lowered'by the spring 288 to dispose the lug 282 in the path of travel of shoulder 288 on stop arm I99 so that the shaft I94 is again held against movement until the next sheet acted on by the sheet forwarding devices is delivered between the feed and drop rollers I15, I16. It will thus appear that through the described control for the relief valve I86, actuation of said valve to start or stop the feeding of sheets is only possible at the same predetermined point in each cycle of operation of the feeder thus always maintaining the proper timed relation between said feeder and the machine with which it is associated.

The feeder is provided with mechanism for map idly lowering and raising the elevator sothat a supply of sheets may be placed on said elevator and moved into proper position for feeding. Thismechanlsm is also utilized to reload the feeder and, in accordance with the present invention, is preferably constructed, operated and controlled as follows. Bolted or otherwise suitably secured to the cross beam I5 and disposed between the fluid supply tank 29 and the electric motor 52 is a rotary fluid pump 289 (Figs. 4 and 8). This rotary fluid pump 289 is a constant displacement pump and is driven continuously and at constant speed by the electric motor 52 through a coupling 2I8 connecting the armature shaft 5I of said motor wtih the shaft 2 of said pump. Connected with the intake side of the rotary fluid pump 289 is one end of a conduit 2I2 the opposite end of which is connected with and extends into the fluid supply tank 29. Upon rotation of the rotary fluid pump 289 fluid is drawn from the supply tank 29 through the conduit2l2 and forced out through a conduit 2I3 having one end connected with the exhaust side of said pump. The opposite end of this conduit H3 is connected with the housing 2I4 of a fluid controlling valve unit indicated broadly at 2I5 which is bolted or otherwise suitably secured to the fluid supply tank 29 at the top thereof. The housing 2I4 of valve unit 2I5 has formed therein chambers and passages such as shown, for example, in Figs. 8, 9 and 10 for receiving and distributing the fluid under pressure to either end of the cylinder 53 or back to the fluid supply tank 29 as hereinafter described.

The end of the conduit 2I3 connected with the housing 2 communicates with a chamber 2l6 formed in said housing. This chamber 2l6 is connected, as by suitably spaced passages 2|1, 2l8 with a cylindrical bore 219 formed in the housing 2l4 and having one end opening outwardly through one side of the housing and the opposite end opening into a chamber 220 also formed in said housing. The cylindrical bore 219 is further connected with the chamber 220 by suitably spaced passages 22! and 222. Surrounding the cylindrical bore 2I9 and suitably spaced therealong are

annular passages

223 and 224. Connected with the housing 2l4 and communicating with the annular passage223 in said housing is one end of a conduit 225 the opposite end of which is connected with the fitting 51 and communicates with the piston chamber of the cylinder 53 through the conduit 58 and port' 60. The other annular passage 224 in the housing 2l4 has connected therewith one end of a condult 226 the opposite end of which is secured in the cylinder 53 at the right hand end thereof (Figs. 2 and 8) and communicates with the piston chamber of said cylinder through a port 221. Connected with the chamber 220 in the housing 214 is one end of a conduit 228 the opposite end of which is connected with and extends into the fluid supply tank 29.

Fitted for reciprocation in the cylindrical bore 2l9 of housing 2| 4 is a valve member 229 provided at one end thereof with a reduced portion 230, and intermediate its ends with reduced portions 23l, 232 and 233 of equal diameters. The reduced portions 23l, 232 and 233, through the action of the fluid pressures against equal shoulders at opposite ends thereof, form

balanced valve elements

234, 235 and 236. The valve element 235 is provided in its periphery with diametrically disposed, alternately arranged grooves or recesses 231 which extend midway across said valve element and open outwardly through opposite ends thereof.

Reciprocating motion is manually imparted to the valve member 229 and for this purpose, the outwardly projecting end of said valve member has pivotally connected therewith corresponding ends of spaced links 238 the opposite ends of which are pivotally connected with the free 'end of an mm 239 that is fixed on a rock shaft 240 (Figs. 1, 2, 4 and 8). This rock shaft 240 extends transversely of the feeder and is journalled in suitable bearings in the plates 9 of the front uprights 5. Fixed on one end of the rock shaft 240 and disposed between the

plates

8, 9 of one of the front uprights is an arm 24! (H s. 4 and 11) having pivotally connected ther with the lower end of a connecting link 242.The upper end of the connecting link 242 is pivotally connected with one arm 243 of a bell crank 244 that is also disposed between the

plates

8, 9 of the adjacent front upright 5 and pivotally mount ed on a pin 245 secured in any suitable manner on the plate 9 thereof. Pivotally connected with the other arm 246 of bell crank 244 is the front end of a rod 241 which extends along one side of the feeder to the rear thereof and passes aeamec while intermittent raising of the elevator and pile of sheets thereon is effected by the plunger pump 34, the valve member 229 will be positioned as shown in Fig. 8 wherein it will be noted that the annular passage 223 in the housing 2! is closed by the valve element 234; that the annular passage 224 is closed by the valve element 235 except for the grooves or recesses 231 in said valve element which at this time communicate with said annular passage; and that the chamber 2l6 in said housing is in communication with the chamber 220 through the reduced portion 233 of valve member 229 and through the passage 2! and 222. Under these conditions fluid under pressure forced into the chamber M5 by the rotary pump 209 cannot enter the conduit 225 or the conduit 226 to effect actuation of the piston in cylinder 53 but, instead, flows from the chamber 2I6 into the chamber 226 and returns to the fluid supply tank' 29 through the conduit 228. If, at this time, fluid should enter the grooves or recesses 231 at the left hand end of the valve element 235 through the passage 2B1 and'reduced portion 23l of valve member 229, said fluid will flow into the annular passage 224 and out again through the grooves or recesses 231' at the right hand end of valve element 235 into the chamber 220 through the reduced portion 232 and passage 22I. It will further be noted that when the piston 65 is actuated by the fluid forced into the left hand end of cylinder 53 (Fig. 8) by the plunger pump 34 to intermittently raise the pile elevator and pile of sheets [8 thereon. the fluid in the right hand end of said cylinder will be discharged from the cylinder by the piston and returned to the fluid supply tank 29 through the port 221, conduit 223, annular passage 224 and grooves or recesses 231 which, as previously described, are open at this time to chamber 220. It will further be noted that with the valve member 229 in the position shown in Fig. 8 and closing of the annular passage 223 in housing 214 by the valve element 234, return flow of fluid from the left hand end of cylinder 53 through the conduit 225 is prevented by valve element 234 and the elevator and pile ofv sheets thereon will thus be held in raised positions.

When it is desired to rapidly lower the pile elevator to load or reload it, the machine attendant standing at the back of the feeder grips the knob or handle 248 and pulls the rod 241 rearwardly to the dotted line position D thereof shown in Fig. 11. When the rod 241 is moved as aforesaid, the valve member 229 through the described connections therefor with said rod will be shifted from the position thereof shown in Fig. 8 to the position thereof shown in Fig. 9 wherein it will be noted that the passage H8 in the housing 2 is closed by the valve element through a suitable opening formed in the adja- 236; that the annular passage 224 is closed to the passage 22l by the valve element 235 and opened to the passage 2I1 by the reduced portion 23l of valve member 225; and that the annular passage 223 is closed to the passage 2l1 by the valve element 234 and opened to the chamber 220 by the reduced portion 230. Under these conditions, the fluid under pressure forced into the chamber 216 of housing 214 by the rotary pump 209 will flow continuously from said chamber through the passage 2l1, into the annular passage 224. through the conduit 226 and into the right hand end of cylinder 53 (Figs. 2 and 8) through the port 221. The fluid under pressure so forced into the cylinder 53 at the right hand end thereof acts on the right face of the piston 65 and moves said piston rapidly toward the left (Fig. 8) from the dotted line position toward the opposite end of said cylinder. During this move-- ment the fluid previously admitted into'the left hand end of the cylinder 53 is discharged from the cylinder by the piston and returned to the fluid supply tank 29 through the port 69, conduit 58, fitting 51, conduit 225, and annular passage 223 which, as previously described, is open at this time to the chamber 229.

As the piston 55 moves rapidly toward the left (Fig. 8) as previously described, the piston-rod 66, yoke 69 and sheave II likewise move toward the left. Accordingly, those portions of the cables I2, I3, I4 and I5 extending from the block 89 to the sheave 82 (Fig. 2) will, by the weight of the sheets one after another therefrom. During this movement the fluid previously admitted into the right hand end of the cylinder 53 is discharged from the cylinder by the piston and returned to the fluid supply tank 29 through the port 221, conduit 226 and annular passage 224 which, as previously described, is open at this time to the v chamber 220 through the passage 22H.

elevator, become shortened resulting in lowering of the elevator and pile board 91 to the bottom of the feeder. As soon as the elevator and pile board 91 have reached the proper position for loading, the machine attendant moves the rod 241 forwardly to the full line position N thereof (Fig. 11) thereby shifting the valve member 229 back to the position shown in Fig. 8 at which time the flow of fluid under pressure into the cylinder 53 through the conduit 226 is inter"- rupted by the valve element 235 and the piston 55 is stopped. The elevator is then loaded in the usual manner with a supply or pile of sheets positioned thereon through the rear or either side of the feeder. It might be mentioned at this time that when the elevator is rapidly lowered to loading position as previously described, the

,When the top of the pile reaches the proper feeding level, and the pile controlled valve H1 is accordingly raised to its proper operating position thereby, the machine attendant again moves the rod 241 rearwardly to the full line position N thereof (Fig. 11) to shift the valve member 229 back again to the position thereof shown in Fig. 8, whereupon the valve element 234 closes the annular passage 223'in housing 2 and not only interrupts the flow of fluid under pressure into the cylinder 53 through the conduit 225 to stop further movement of the piston 65, but also prevents return flow of fluid from the cylinder through the conduit 225 and dropping of the elevator. Feeding of sheets one after another from the top of the pile may now be resumed through the action of the sheet separating and forwarding devices, during which action interthat air under pressure cannot enter the housing brought into proper position for the normal sheet.

feeding operations. For this purpose, the machine attendant moves the rod 241 forwardly to the dotted line position U thereof (Fig. 11) to shift the valve member 229 from the position thereof-shown in Fig. 8 to the position thereof shown in Fig. 10. In this position of the valve member 229 it will be noted that the passage 2l8 in the housing 2 is closed to the passages 22f,

222 by the valve element 236 and the outer end of said valve member; that-v-the annular passage 224 is closed to the passage 2|I by the valve element 235 and opened to the pasage 22! by the reduced portion 232 of the valve member; and that the annular passage 223 is closed to the chamber 229 by the valve element 234 and opened to the pasasge 2" by the reduced portion 23l.

Under these conditions, the fluid under pressure forced into the chamber 2H5 of housing 2 by the rotary pump 209 will flow continuously from said chamber through the passage 2I'I, into the annular passage 223, through the conduit 225 and into the left hand end of cylinder 53 (Figs. 2 and 8) through the fitting 51, conduit 58 and port 60. The fluid under pressure so forced into the cylinder 53 at the left hand end thereof acts on the left face of the piston 65 and moves said piston rapidly toward the right to raise the elevator and pile of sheets thereon until the top of the pile reaches the'proper level for feeding of the mittent elevation of the elevator and pile of sheets by the plunger pump 34 is continued until it is again necessary to load the elevator at which time the above described operations for rapidly lowering and raising the elevator are repeated.

It is. to be noted that since therotary fluid pump 209 is of the constant displacement type, said pump will deliver a constant volume of fluid under pressure into the cylinder 53 when connected therewith to rapidly lower and raise the elevator. Due, however, to the fact that the fluid contacting area of the piston 65 at the right side thereof (Fig. 8) is reduced. by the area of the piston rod 66, the speed of movement of the piston 65 toward the right hand end of the cylinder 53 to effect raising of the elevator and pile of sheets thereon, while quite rapid, is less than the speed of movement of the piston toward the left hand end of the cylinder to effect lowering of the elevator to the bottom of the feeder for reception of the pile of sheets. In this manner the elevator is quickly lowered to the bottom of the feeder to receive a pile of sheets and thereafter rapidly raised to bring said pile to the proper feeding level with resulting decrease in loading time and increase in output of the feeder.

It will further be noted that the auxiliary frame 29 supports the feeder driving and operating means, the tubular shafts I52, I53, the rotary air controlling valve mechanism, the rotary vacuum controlling valve mechanism, and the feed and drop roller mechanism, all of which may be bench assembled and then hoisted as a unit into proper position on the feeder frame, thus decreasing feeder erecting time.

Referring now to Figs. 12 to 23 inclusive of the drawings, which illustrate another embodiment of the present invention, the feeder therein shown, while capable of general use, is particularly adapted for feeding large and heavy metal sheets to coating machines, 'slitters, and other