US3846997A

US3846997A - Stock feeder

Info

Publication number: US3846997A
Application number: US00381502A
Authority: US
Inventors: A Leis
Original assignee: LEIS A CO Inc
Current assignee: LEIS A CO Inc
Priority date: 1973-07-23
Filing date: 1973-07-23
Publication date: 1974-11-12
Anticipated expiration: 1991-11-12

Abstract

A strip of stock is precisely advanced into a punch press or other processing machine by a set of fluid diaphragm actuated grippers, one of which is supported for reciprocating movement relative to the other. The reciprocating gripper is connected by a link to an adjustable eccentric fitting mounted on the shaft of a rotary fluid actuator or motor. The grippers are alternately actuated by a fluid control system which includes a main control valve having a depressible valve member. The fluid control system is also effective to oscillate the rotary actuator in response to a predetermined fluid pressure produced alternately within the grippers and to provide for releasing the fluid in both of the grippers when the main control valve actuating member is further depressed.

Description

United States Patent 1191 Leis 1 Nov. .12, 1974 STOCK FEEDER Primary ExahzinerC. W. Lanham Assistant ExaminerRobert M. Ro ers 76 I 1; Ath F.L .F.L g 1 men or 2 gigs s, g D ga O Attorney, Agent, or Firm-Jacox & Meckstroth Ohio 45414 7 s C 5 AB TRA T [22] Filed: July 23, 1973 1 A strip of stock 15 precisely advanced into a punch PP 381,502 press or other processing machine by a set offluid diaphragm actuated grippers, one of which is supported 52 U.S.Cl 72/6 72/422 226/150 for reciprocating movement YehhiYe to the other- The 226/162 reciprocating gripper is connected by a link to an ad- 51 1m. (:1 821d 43/10 Jumble eccentric fitting mounted the Shaft of [58] Field of Search 0 72/422 DIG 11 423 tary fluid actuator or motor. The grippers are alternately actuated a Control system ll'l- 13/1 13 cludes a main control valve having a depressible valve member. The fluid control system is also effective to [56] References Cited oscillate the rotary actuator in response to a predetermined fluid pressure produced alternately within the UNITED STATES PATENTS grippers and to provide for releasing the fluid in both 2: 3 226/162 of the grippers when the main control valve actuating a an 3,793,972 2 1974 Miller 226/[50 member further depressed 15 Claims, 13 Drawing Figures PAIENTEBHuv 12 2914 3.84639? SHE? 10F 2 FIG-7' I STOCK FEEDER The present invention relates to a stock feeder of the general type disclosed in US. Pat. No. 3,597,959 which issued to the inventor of the present invention. In such a stock feeder, it has been found desirable to provide for advancing the stock in precise step-by-step increments which can be conveniently adjusted, and to provide for smooth high speed operation of the feeder without any significant vibrations so that precision feeding is maintained. It is also desirable for the stock feeder to provide for advancing the stock at a rate which is independent of the rate of movement of a component of the machine receiving the stock, and to provide for a compact mechanism which produces substantial gripping and feeding forces.

In addition, when a stock feeder is usedfor feeding stock provided with pilot holes for receiving precision alignment pilot pins projecting from a punch, it is also desirable for the stockfeeder to provide for releasing the gripping force exerted on the stock as the pilot pins enter the pilot holes so that the stock is free to shift slightly and be precisely aligned by the pilot pins. While various forms of stock feeders have been either proposed or used in addition to the stock feeder shown in the above patent, for example, as shown in US. Pat. No. 3,038,645, it has been found that none of these stock feeders provides all of the desirable features mentioned above.

SUMMARY OF THE INVENTION The present invention is directed to an improved stock feeder which provides all of the desirable features mentioned above and which is adapted to be operated from a fluid supply such as a supply of pressurized air. In particular, the stock feeder of the invention is compact and constructed to operate at a high speed with minimum vibrations and jolts to the stock so that the stock may be advanced in rapid step-by-step increments without slippage of the stock relative to the stock feeder. The stock feeder is also constructed to apply a substantial gripping force so that only an edge portion of the strip may be gripped thereby permitting the advancement of a strip having substantial width. As another important feature, the stock feeder of the invention provides a fluid operated control system which assures positive gripping of the stock before either forward or reverse movement of the reciprocating stock gripper. In addition, the stock feeder provides for automatic releasing of a stock strip having pilot holes as the locating pilot pins enter the holes.

In general, the above features and advantages are provided in a stock gripper which incorporates a hous ing or body for supporting a stationary diaphragm actuated stock gripper and two parallel spaced guide rods on which is mounted a movable diaphragm actuated stock gripper. The body encloses an oscillating vanetype fluid-actuator or motor which has a shaft supporting an adjustable bracket eccentrically connected by a link member to the movable stock gripper. The housing or body also encloses a fluid control system including a main control valve having a valve member adapted to be depressed by downward movement of a component of a press receiving the stock. The control valve system provides for automatically oscillating the fluid motor shaft in response to a predetermined fluid pressure produced alternately in the diaphragm actuated stock grippers. Further depression of the main control valve member is effective to actuate a dumping valve so that the stock is released by both stock grippers and may be precisely positioned by pilot pins carried by a punch.

Other features and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a stock feeder constructed in accordance with the invention; 2

FIG. 2 is an elevational view of the right end of the stock gripper shown in FIG. I;

FIG. 3 is an elevational view of the left end of the stock gripper shown in FIGS. 1 and 2';

FIG. 4 is an elevational front view of the stock gripper shown in FIGS. l-3; 6

FIG. 5 is a section taken generally on the line 5-5 of FIG. 1; j

FIG. 6 is a fragmentary section taken generally on the line 6-6 of FIG. 5;

FIG. 7 is a section taken generally on the line 77 of FIG. 5';

FIG. 8 is asection taken generally on the line 8-8 of FIG. I;

FIG. 9 is a section'taken generally. on the line 9-9 of-FIG. 1;

FIG. '10 is a fragmentary section takenlgenerally on I the line 10-10 of FIG. 3; x I

FIG. 11 is a section taken generally on the line l111 of FIG. 1 j I FIG. 12 is a section taken generally on the line 1212 of FIG. 1; and i FIG. 13 is a diagrammatic illustration of the fluid control system for operating the stock gripper shown in FIGS. 1-12.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The stock gripper shown in elevation in FIGS. l-4, includes a cast metal housing or body 20 formed by a main body portion 22 which integrally connects parallel spaced and forwardly projecting

endbody portions

23 and 24. The end body portion 24 includes an outwardly projecting integral L-shaped flange 26 which is provided with a set of holes 27 for receiving'screws (not shown) to secure the body 20 to a lower die shoe mounted on a punch press, as shown in the abovementioned patent, or to another machine which receives the stock.

As shown in FIGS. 3 and 11, the end portion 24 of the housing 20 also includes an integral diaphragm housing portion 29 which projects outwardly over'the base flange 26 and forms part of a stationary stock gripper 30. The gripper 30 further includes a vertical rod is flat and opposes the upper flat surface of a lower stock gripping shoe 36. The shoe 36 includes an integral cylindrical portion 37 which projects into a bore formed within the base flange 26 and is secured by a set screw 38. The upper end portion of 'the rod 32 is secured to a circular plate 41 (FIG. 11) which engages a flexible rubber diaphragm 42 having an outer peripheral portion secured to the housing portion 29 by a cover plate 44. A compression spring 45 is confined within the housing portion 29 and urges upwardly on the plate 41 so that the rod 32 and upper gripper shoe 34 are normally retracted upwardly, opposite to the gripping position shown in FIG. 11. I

A fluid passage 46 is formed within the cover plate 44 and connects with a horizontal passage 47 and a vertical passage 48 formed within the end portion 24 of the housing or body 20. When pressurized fluid or air is supplied through the

passages

48, 47 and 46 to the top side of the diaphragm 42, the upper gripping shoe 34 is pressed downwardly towards the lower shoe 36 for positively gripping the stock which is illustrated in FIGS. 1-4 in the form of a continuous sheet metal strip S.

A pair of vertically spaced horizontal guide rods 52 are rigidly supported on opposite ends by the

end portions

23 and 24 of the body 20 as shown in FIGS. 1 and 4. The rods 52 support a movable or slidable stick gripper 55 (FIGS. 4 and 12) which is constructed in a manner similar to the stationary sock gripper 30 except that it includes a generally C-shaped body or carriage 56 (FIG. 12) which is supported for reciprocating movement by the guide rods 52. The movable stock gripper 55 incorporates components which are identical to the components of the stationary stock gripper 30 and are therefore indicated by corresponding reference numbers. In place of the cover plate 44 of the stationary gripper 30, the movable stock gripper 55 includes a cover plate 58 which receives pressurized fluid or air through an L shaped fitting 59 and a flexible hose or tube 61.

As shown in FIGS. 1 and 2, the stock or strip S is directed between the upper shoe 34 and lower shoe 36 of each of the

stock grippers

30 and 55 by-a pair of guide rollers 63. The rollers 63 are mounted for lateral adjustments within a series of corresponding slots 64 formed within the horizontal flange of an angle-shaped elongated support bracket 66. The vertical flange of the bracket 66 is secured to the body end portion 23 by a set of screws 67 (FIG. 2) which extend through corresponding adjustment slots 68 formed within the flange. The adjustment of the rollers 63 on the bracket 66, and the horizontal adjustment of the bracket 66 on the body 20, provide for accommodating stock strips of various widths, for example, between one-eighth inch and six inches.

The housing or body 20 also encloses a rotary fluid actuator 70 (FIGS. and which is constructed similar to an oscillating vane-type fluid motor. The actuator 70 includes a shaft 72 which is positioned within the center of a cylindrical chamber 73. The shaft 72 is rotatably supported by the body and a closure plate 74 cavities which are adapted to receive alternately the opposite edge portions of the shoe 79 when the actuator vane 78 is oscillated. As shown in FIG. 5, the outer end surfaces of the projections 84 are closely fit relative to the inner cylindrical surface of the shoe 79 so that the cavities form fluid dampening or air cushion chambers at the limits of arcuate movement of the actuator vane 78 and sliding shoe 79.

A slide block or bracket 88 (FIGS. 9, 10 and 12) is secured to the projecting end portion of the shaft 72 and slidably supports aconnector element 89 (FIGS. 9 and 12) which is linearly adjustable relative to the bracket 88 by releasing clamping screws 92 (FIG. 9) and adjusting a set screw 93 (FIG. 12) with a suitable Allen wrench. The connector element v89 has a set of eccentrically located holes 94 (FIG. 9) for selectively receiving a pin 96 which forms a pivot connection for 'one end portion of a link member 98. The connecting pin 96 is retained within one of the holes 94 by the head of a screw 99. The outer end portion of the link member 98 is pivotally connected by a pin 101 to an ear of the carriage 56 of the movable gripper 55, as shown in FIG. 10. When the pin 96 is positioned within the innermost hole 94(FIG. 9), the adjustment of the set screw 93 provides a first range of movement of the gripper 55, for example, between zero and one inch. When the connecting pin 96 is positioned within the outermost hole 94, the adjustment of the set screw 93 provides for reciprocation of the gripper 55 within a second range of movement, for example, 1 inch to 2 inch travel.

As mentioned above, the stock feeder of the invention is adapted to be operated by a source of pressurized fluid such as air supplied under pressure at 100 psi. This supply of pressurized air is effective to operate the

stock grippers

30 and 55 and the rotary actuator 70 in a predetermined sequence in response to a fluid 0r pneumatic control system shown somewhat diagramsecured to the body 20 by a series of screws 76. An actuating vane 78 is formed as an integral part of the shaft 72 and carries an arcuate shoe 79 (FIG. 5) which slidably engages the inner cylindrical surface defining the chamber 73. An arcuate shaped block or fitting 82 projects into the chamber 73 and is supported by a set of screws extending through the closure plate 74.The fitting 82 includes a set of projections 84 which form stops for limiting the rotative movement of the actuating vane 78. The projections 84 also cooperate with the cylindrical surface defining the chamber 73 to define matically in FIG. 13. This control system includes a main actuator or control valve 105 (FIG. 5) which includes a pin-like actuating valve stem or member 106 slidably supported within a vertical chamber or bore 107 formed within the body 20. The valve member 106 projects upwardly through a retaining collar 108 which is secured within a counterbore formed within the body 20.

A hollow cylindrical cap member 110 is slidably mounted on the upper portion of the valve member 106 and has external threads for receiving an adjustable sleeve 112. The sleeve is clamped to the cap member 110 by a set screw 113 and includes a vertical slot 114 which receives a cross pin 116 extending diametrically through the valve stem or member 106. The pin 116 has a length slightly less than the CD. of the cap member 110 so that the sleeve 112 is free to move with the cap member 110 on the valve member 106. A compression spring 117 is confined within a hole formed with the top of the valve member 106 and urges upwardly on the cap member 110 until the lip 114 of the sleeve 112 engages the cross pin 116.

The lower portion of the valve member 106 includes a set of circumferential grooves 121 and 122 which define corresponding chambers and which are sealed by an O-ring 123 located within another groove formed in the valve member 106. A bore 126 of reduced diameter, projects from the bottom of the bore 107, and a compression spring 128 projects upwardly from the bore 126 into a hole or passage 129 extending axially within the valve member 106 to a radial port 131. The spring 128 urges the valve member 106 upwardly from the depressed position shown in FIG. to a normal position where a shoulder on the valve member engages the collar 108. The supply fluid or air is directed" into the housing through a passage 132 (FIG. 5). An upper passage 133 and a lower passage 134 extend horizontally from the bore 107 to the rotary actuator 70 through a pair of corresponding pressure actuated control valves 135 (FIGS. 5-7). A corresponding set of connecting air passages 137 (FIG. 5) are formed within the fitting 82 and extend in crossing nonintersecting directions to the chamber 73 on opposite sides of the actuating vane 78 and shoe 79.

Referring to FIGS. 6 and 7, each of the pressure actuated control valves 135 includes a tubular fitting 139 which is inserted into a bore 141 formed within the main body portion 22. Each fitting 135 includes an inner frusto-conical valve seat 143 against which a ball 144 isurged by a light compression spring 147. The spring 147 extends between the ball 144 and a plug-like fitting 148 forminga closure for the outer end of the bore 141. Another compression spring 151 extends between the inner end of the bore.141 and the inner end of the fitting 139 and exerts an axial forcesubstantially greater than that of the spring 147 so that the fitting 139 seats normally against the fitting 148, as illustrated by the upper valve 135 shown in FIG. 7'. A radial port 154 (FIG. 6) is formed within each fitting 148 and is connected by a corresponding passage 156 to the corresponding passage 133. A vertical passage 158 is formed within the body portion 22 and connects the upper passage 133 to an elbow fitting 159 (FIGS. 1 and 4) which receives the opposite end of the flexible conduit or hose 61. Another angular passage 162 (FIG. 6) connects the inner end of each bore 141 to the corresponding passage-133 or 134 and the corresponding passage 137 within the fitting 82 of the rotary actuator 70.

Referring to FIG; 8, another vertical bore 166 is formed within the body portion 22 adjacent the bore 107, but is somewhat smaller in diameter. A valve plunger or member 168 is slidably supported within the bore 166 and is urged upwardly against the collar 108 by a compression spring 169 extending between the bottom of the bore 166 and the inner end of the valve member 168. A pin 172 projects upwardly from the upper end portion of the valve member 168 through an opening within the collar 108 and is adapted to be engaged by the sleeve 112 when the cap member 110 on the actuator valve member 106, is further depressed, as will be explained later.

A circumferential groove 173 (FIG. 8) is formed on the lower end portion of the 'valve member 168 and provides a normally open fluid path for pressurized air from the passage 134 through a passage 174 (FIG. 13) to the

passages

47 and 48 extending to the stationary stock gripper 30. An axially extending hole 176 is formed within the lower end portion of the valve member 168 and connects with a radial port 177 at its inner or upper end. When the valve member 168 is depressed against the spring 169 by depressing the pin 172, the port 177 connects with the passage 174, and the pressurized air to the stationary gripper 30 is exhausted through the port 177, hole 176, the inner end of the bore 166 and an exhaust passage 178 which connects with the reduced bore 126 of the main actuator or control valve and is open to atmosphere as shown in nection with FIG. 13 which illustrates the condition of the control system at the end of the forward stroke of the stock gripper 55. As mentioned-above, pressurized fluid or air is supplied to the passage 131 (FIG. 5 After the valve member 106 is depressed downwardly, for example, with the downward movement of the upper die shoe on a punch press, the pressurized air is supplied through the groove 122 and the passage 134 (FIG. 5) to the lower pressure actuated valve (FIG. 7). The valve 135 is normally closed so that the air does not continue to flow through the passage 134 to the rotary actuator 70. The pressurized air within the passage 134 is supplied through the passage 174 and the. groove 173 within the valve member 168 to the

passages

48, 47 and 46 connected to the chamber above the diaphragm 42 of the stationary stock gripper 30.

The air pressure above the diaphragm 42 causes the corresponding rod 32 and shoe 34 to move downwardly so that the stock orstrip S is positively gripped or clamped with substantial force by the

shoes

34 and 36 of the stationary stock gripper 30. As soon as the air pressure within the gripper 30 reaches the air supply pressure and the stock ispositively gripped, the lower valve 135 moves to an open position (FIG. 7) as a result of an inward movement of the fitting 139 against the force exerted by the compression spring'151. The pressurized air then continues through-the passage 134 to the corresponding passage 137 (FIG. 5') so that one side of the vane 78 of the rotary actuator 70'is pressurized. This causes the vane 78 and the shaft 72 to rotate clockwise (FIG. 5) approximately 180 so that the corresponding passage 137 and passage 133 and through the check valve within the upper pressure actuated valve 135 (FIG. 5). The air within the passage 133 (FIG. 5) is directed into the groove 121 of the valve member 106 and through the port 131 and the center hole 129 within the valve member 106 to the exhaust passage 178. After the stock gripper 55 has reached the rearward end of its stroke or returned to its home position, and the valve member 106 is moved upwardly, pressurized air is directed from the supply passage 131 through the groove 122 and the upper passage 133 (FIG. 5) to the upper pressure actuated valve 135. The pressurized air is then directed to the chamber above the diaphragm .42 for the movable stock gripper 55 so that the stock or strip S is gripped by the gripper 55. The upward movement of the valve member.

106 is also effective to release the air pressure-behind the diaphragm 42 on the stationary stock gripper 30 by an exhaust of the air through the

passages

134 and 178 under the lower end of the valve member 106. After the stock is gripped by the movable stock gripper 55, the rotary actuator 70 is pressurized on the opposite side of the vane 78 so that the stock is advanced by forward movement of the stock gripper 55. Thus the stock S is automatically advanced in precise step-by-step increments in response to actuation of the main control valve 105.

As mentioned above, it is sometimes desirable to have the stock released from both of the

stock grippers

30 and 55 when the stock is provided with pilot holes for receiving pilot locating pins in the die set. This feature is accomplished by adjusting the axial position of the sleeve 112 on the cap member 110 so that a slight over travel of the cap member 110 after the valve member 106 has reached its lower position (FIG. causes the sleeve 112 to depress the pin 172 (FIG. 8) and the valve member 168. This causes the port 177 to align with the passage 174 and exhausts the passage 174 to atmosphere'through the exhaust passage 178. The release of the air pressure within the passage 174 is effective to release the pressure within the passages 46-48 so that the diaphragm 42 and the gripper rod 32 of the stock gripper 30 are urged upwardly by the compression spring 45. Thus when the passage 174 is open to atmosphere or exhausted through the valve member 168, there is no air pressure to both of the

grippers

30 and 55 and the corresponding gripping shoes 34 are retracted upwardly for releasing the strip 8. As soon as the adjustable sleeve 112 moves upwardly with the cap member 110, the valve member 168 (FIG. 8) returns to its normal upper position (FIG. 8) by the spring 169 so that the passage 174 is open to the passages 46-48 through the groove 173, as illustrated in FIG. 13.

From the drawings and the above description, it is apparent that a stock feeder constructed in accordance with the present invention provides desirable features and advantages. For example, in addition to the simple harmonic movement of the stock gripper 55, which provides for a gradualacceleration and deceleration of movement of the stock gripper at the limits of its stroke, each of the

stock grippers

30 and 55 provides a substantial gripping force of the stock in a compact space as a result of the corresponding diaphragmactuated gripping shoe 34.

Another important feature is provided by the automatic control system which assures that the stock is positively gripped with the substantial force before the stock gripper 55 is advanced or retracted. That is, the pressure-responsive valves 135 provide for alternately actuating the

stock grippers

30 and 55 before the rotary actuator 70 is operated or oscillated to assure that there is no movement of the stock gripper 55 before the stock is positively gripped by the gripping shoes of at least one of the stock grippers.

The rotary actuator 70 also incorporates an air cushion or dampening means as a result of the cooperation between the shoe 79 of the actuator and the inner pockets or chambers defined by the projections 84 of the actuator fitting 82. That is, the stock gripper 55 not only moves with gradual acceleration and deceleration at the end of each stroke, but an air cushion is provided at each end of the stroke. As a result, the stock feeder operates with minimum vibration during reciprocating movement of the stock gripper 55.

A further advantage is provided by the air dumping or releasing valve system shown in FIG. 8. As men tioned above, slight over travel of the main control valve head or cap member 110 is effective to move the valve member 168 so that the air pressure to the stationary stock gripper 30, is released at the same time the air pressure to the movable stock gripper 55 is released. This feature is desirable in feeding a stock hav- While the form of stock feeder herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of stock feeder, and that changes may be made therein without departing from the scope and spirit of the invention as defined in the appended claims.

The invention having thus been described, the following is claimed:

1. A device for feeding stock in precise step-by-step increments into a metal working press or the like, comprising a first fluid actuated stock gripper and a second fluid actuated stock gripper, means supporting said second stock gripper for reciprocating movement between predetermined limits relative to said first stock gripper, a rotatably supported shaft, a fluid actuator connected to rotate said shaft, means for connecting said shaft to said second stock gripper to reciprocate said second stock gripper in response to rotation of said shaft to ef fect gradual acceleration and deceleration of said second stock gripper adjacent said limits, and fluid control means for operating said fluid actuator in response to a predetermined pressure in at least said second stock gripper.

2. A device as defined in claim 1 wherein each of said first and second fluid actuated stock grippers, comprises a rod,,and means including a flexible diaphragm for moving said rod axially in responseto the application of pressurized fluid on said diaphragm.

3. A device as defined in claim 1 wherein said fluid actuator comprises a fluid motor including a vane connected to said shaft, and said fluid control means is connected to oscillate said vane of said motor.

4. A device as defined in claim 1 wherein said fluid control means and said fluid actuator are effective to oscillate said shaft to cause reciprocating movement of said second stock gripper.

5. A device as defined in claim 1 including means for dampening the operation of said fluid actuator when said second stock gripper approaches said predetermined limits of movement.

6. A device as defined in claim l wherein said fluid control means comprise a plunger type valve including a valve member adapted to be moved axially in response to movement of a component of the press, and means for releasing the pressurized fluid applied to both of said stock grippers in response to predetermined movement of said valve member.

7. A device as defined in claim 1 wherein said fluid control means comprise a main control valve including a valve member adapted to be moved in response to the movement of a component of the press, said fluid actuator is effective to osciallate said shaft to effect reciprocation of said second stock gripper, and said fluid control means further include a set of fluid actuated valves which produce alternating actuation of said first and second stock grippers and oscillation of said shaft in response to movement of said valve member of said main control valve.

8. A device as defined in claim 1 wherein said means supporting said second stock gripper for reciprocating movement, comprise a set of parallel spaced rods, a housing supporting the end portions of said rods, and

said fluid actuator comprises an oscillating vane-type fluid motor formed within said housing, and valve means for osciallating said motor in response to alternate actuation of said first and second stock grippers.

tion of said second stock gripper adjacent said limits,

and fluid control means within said housing for operating said actuator and said first and second stock grippers in predetermined sequence.

10. A device as defined in claim 9 wherein each of said first and second fluid actuated stock grippers,

comprises a gripping shoe, and means including a flexible diaphragm for moving said shoe in response to the application of pressurized fluid on said diaphragm.

11. A device as defined in claim 9 wherein said control means is also effective to release the fluid pressure to both of said grippers simultaneously in response to predetermined actuation.

12. A device for feeding stock in precise step-by-step increments into a metal working press or the like, comprising a housing supporting a first fluid diaphragm actuated stock gripper, a second fluid diaphragm actuated stock gripper, means on said housing and supporting said second stock gripper for reciprocating movement between predetermined limits relative to said first stock gripper, a rotatably supported shaft, a fluid actuator connected to rotate said shaft, means for connecting said shaft to said second stock gripper to reciprocate said second stock gripper in response to rotation of said shaft to effect gradual acceleration and deceler ation of said second stock gripper adjacent said limits, fluid control means within said housing and including a valve member adapted to be moved in response to operation of the press, and said fluid actuator and said first and second stock grippers being actuated in predetermined sequence in response to movement of said valve member.

13. A device for feeding stock in precise step-by-step increments into a metal working press or the like, comprising a housing supporting a first fluid actuated stock gripper, a second fluid actuated stock gripper, means on said housing for supporting said second stock gripper for reciprocating movement between predetermined limits relative to said first stock gripper, an oscillating vane-type fluid motor supported by said housing and including a shaft, means including an adjustable bracket for connecting said shaft to said second stock gripper for reciprocating said second stock gripper in response to oscillation of said shaft to effect gradual acceleration and deceleration of said second stock gripper adjacent said limits, and fluid control valve means within said housing for oscillating said fluidmotor in response to producing a predetermined fluid pressure alternately within said stock grippers.

14. A device as defined in claim 13 wherein said fluid control valve means comprises a main control valve including a valve member adapted to be actuated in response to movement of the press, and a set of pressure responsive control valves within passages connected to said fluid motor.

15. A device as defined in claim 13 wherein said fluid motor includes means for dampening the oscillation of said shaft.

Claims

1. A device for feeding stock in precise step-by-step increments into a metal working press or the like, comprising a first fluid actuated stock gripper and a second fluid actuated stock gripper, means supporting said second stock gripper for reciprocating movement between predetermined limits relative to said first stock gripper, a rotatably supported shaft, a fluid actuator connected to rotate said shaft, means for connecting said shaft to said second stock gripper to reciprocate said second stock gripper in response to rotation of said shaft to effect gradual acceleration and deceleration of said second stock gripper adjacent said limits, and fluid control means for operating said fluid actuator in response to a predetermined pressure in at least said second stock gripper.

2. A device as defined in claim 1 wherein each of said first and second fluid actuated stock grippers, comprises a rod, and means including a flexible diaphragm for moving said rod axially in response to the application of pressurized fluid on said diaphragm.

6. A device as defined in claim 1 wherein said fluid control means comprise a plunger type valve including a valve member adapted to be moved axially in response to movement of a component of the press, and means for releasing the pressurized fluid applied to both of said stock grippers in response to predetermined movement of said valve member.

8. A device as defined in claim 1 wherein said means supporting said second stock gripper for reciprocating movement, comprise a set of parallel spaced rods, a housing supporting the end portions of said rods, and said fluid actuator comprises an oscillating vane-type fluid motor formed within said housing, and valve means for osciallating said motor in response to alternate actuation of said first and second stock grippers.

9. A device for feeding stock in precise step-by-step increments into a metal working press or the like, comprising a housing supporting a first fluid actuated stock gripper, a second fluid actuated stock gripper supported by said housing for reciprocating movement between predetermined limits relative to said first stock gripper, a rotary fluid oscillating actuator within said housing and including a shaft, means for connecting said shaft to said second stock gripper to reciprocate said second stock gripper in response to oscillation of said shaft to effect gradual acceleration and deceleration of said second stock gripper adjacent said limits, and fluid control means within said housing for operating said actuator and said first and second stock grippers in predetermined sequence.

10. A device as defined in claim 9 wherein each of said first and second fluid actuated stock grippers, comprises a gripping shoe, and means including a flexible diaphragm for moving said shoe in response to the application of pressurized fluid on said diaphragm.

12. A device for feeding stock in precise step-by-step increments into a metal working press or the like, comprising a housing supporting a first fluid diaphragm actuated stock gripper, a second fluid diaphragm actuated stock gripper, means on said housing and supporting said second stock gripper for reciprocating movement between predetermined limits relative to said first stock gripper, a rotatably supported shaft, a fluid actuator connected to rotate said shaft, means for connecting said shaft to said second stock gripper to reciprocate said second stock gripper in response to rotation of said shaft to effect gradual acceleration and deceleration of said second stock gripper adjacent said limits, fluid control means within said housing and including a valve member adapted to be moved in response to operation of the press, and said fluid actuator and said first and second stock grippers being actuated in predetermined sequence in response to movement of said valve member.

13. A device for feeding stock in precise step-by-step increments into a metal working press or the like, comprising a housing supporting a first fluid actuated stock gripper, a second fluid actuated stock gripper, means on said housing for supporting said second stock gripper for reciprocating movement between predetermined limits relative to said first stock gripper, an oscillating vane-type fluid motor supported by said housing and including a shaft, means including an adjustable bracket for connecting said shaft to said second stock gripper for reciprocating said second stock gripper in response to oscillation of said shaft to effect gradual acceleration and deceleration of said second stock gripper adjacent said limits, and fluid control valve means within said housing for oscillating said fluid motor in response to producing a predetermined fluid pressure alternately within said stock grippers.