Modular stamped parts transfer gripper

A mounting bracket for a fluid actuated parts gripper having a body, a body member portion and a plurality of longitudinally extending fasteners is provided. The body member portion is removably attached to the body. A first through-opening is configured to receive the fluid actuated parts gripper and a second through-opening is configured to receive a support. The body has a variable slot configured to reduce and increase the diameter of the second through-opening to lock and unlock the support. The plurality of longitudinally extending fasteners removably attach the body member portion to the body.

 

What is claimed is:

1. A mounting bracket to hold a fluid actuated parts gripper which comprises:

a body having first and second through-openings, the first through-opening configured to receive the fluid actuated parts gripper and the second through-opening configured to receive a support;

longitudinally extending fasteners each of which is disposed substantially parallel to each other and are spaced apart from each other by a distance greater than the diameter of the second through-opening, said fasteners also extending through the body on opposed sides of the second through-opening;

wherein the second through-opening has a single variable space extending from the second through-opening and through the body to its periphery; and

wherein one of the longitudinally extending fasteners extends through the variable space to vary the diameter of the second through-opening to lock and unlock in position the support with respect to the mounting bracket.

2. The mounting bracket of claim 1, wherein the body having variable space disposed therein in communication with the first through-opening to vary the diameter of the first through-opening.

3. The mounting bracket of claim 1, wherein the first through-opening is cylindrical shaped and the second through-opening is circular with a semi-spherical concave shaped recess disposed therein.

4. The mounting bracket of claim 3, wherein the second through-opening comprises a semi-spherical collar.

5. The mounting bracket of claim 1, wherein one of the longitudinally extending fasteners locks and unlocks the support.

6. A mounting bracket to hold a fluid actuated parts gripper which comprises:

a body having first and second through-openings, the first through-opening configured to receive the fluid actuated parts gripper and the second through-opening configured to receive a support;

wherein the first and second through-openings are of unequal diameters;

said body comprising first and second coupled plate members having opposed facing surfaces extending to first and second segments each of the first and second coupled plate members, respectively;

wherein opposed facing surfaces of each of the first and second coupled plate members define the second through-opening; and

wherein the opposed facing surfaces of the first segments of the first and second coupled plate members form a slot opening, and the opposed facing surfaces of the second segments of the first and second coupled plate members abut each other;

bolts coupling the pair of coupled plate members together, the bolts being located on opposite sides of the second through-opening,

wherein one of the bolts is disposed through the opposed facing surfaces of the second segments of the first and second coupled plate members to securely abut the opposed facing surfaces together; and

wherein another of the bolts is disposed through the opposed facing surfaces of the first segments of the first and second coupled plate members to reduce or enlarge the slot opening to, respectively, lock and unlock in position the support with respect to the mounting bracket.

7. The mounting bracket of claim 6, wherein the body having a variable space in communication with the first through-opening to vary the diameter of the first through-opening.

8. The mounting bracket of claim 6, wherein the first through-opening is cylindrical shaped and the second through-opening is circular with a semi-spherical concave shaped recess disposed therein.

9. The mounting bracket of claim 8, wherein the second through-opening comprises a semi-spherical collar.

10. The mounting bracket of claim 6, wherein one of the bolts locks and unlocks the support.

11. A mounting bracket to hold a fluid actuated parts gripper which comprises:

a body having first and second through-openings, the first through-opening configured to receive the fluid actuated parts gripper and the second through-opening configured to receive a support;

wherein the first and second through-openings are of unequal diameters;

a semi-spherical collar disposed in the second through-opening;

said body comprising first and second coupled plate members having opposed facing surfaces extending to first and second segments each of the first and second coupled plate members, respectively;

wherein opposed facing surfaces of each of the first and second coupled plate members define the second through-opening; and

wherein the opposed facing surfaces of the first segments of the first and second coupled plate members form a first single slot opening in communication with the second through-opening, and the opposed facing surfaces of the second segments of the first and second coupled plate members abut each other; and

wherein the opposed facing surfaces of the first segments of the first and second coupled plate members form a second single slot opening in communication with the first through-opening;

bolts coupling the coupled plate members together, wherein the bolts are located on opposite sides of the second through-opening,

wherein one of the bolts is disposed through the opposed facing surfaces of the second segments of the first and second coupled plate members to securely abut the opposed facing surfaces together; and

wherein another of the bolts is disposed through the opposed facing surfaces of the first segments of the first and second coupled plate members to reduce or enlarge the slot opening to, respectively, lock and unlock in position the support with respect to the mounting bracket.

12. A mounting bracket for a workpiece holder according to claim 11 wherein the body is made from a material which is softer than a material from which the semi-spherical collar is made.

13. A mounting bracket for a workpiece holder according to claim 12 wherein the semi-spherical collar has an outer surface which is roughened.

14. An assembly for mounting a workpiece holder to a support member which comprises:

a workpiece holder including at least one movable jaw and a body having a cylindrical portion;

a mounting bracket comprising a plurality of coupled plate members each having opposed facing surfaces and first and second spaced apart through-openings provided between the coupled plate members;

wherein the through-openings are defined in the opposed facing surfaces of the plurality of coupled plate members, wherein the first through-opening has a cylindrical bore, the second through-opening has a partial spherical shaped bore, and the cylindrical portion of the workpiece holder body is positioned within the first through-opening;

wherein the support member is positioned within the second through-opening; and

bolts coupling the plurality of coupled plate members together, the bolts located at opposite ends of the plurality of coupled plate members, wherein the support member can independently rotate 360 degrees and pivot within the second through-opening when one of the bolts located adjacent the second through-opening is loosened.

15. The assembly for mounting a workpiece holder to a support according to claim 14, wherein the workpiece holder can independently rotate 360 degrees within the first through-opening when one of the bolts located adjacent the first through-opening is loosened.

16. A mounting bracket for a workpiece holder which comprises:

a plurality of plate members having opposed facing surfaces and have first and second spaced apart through-openings provided between the plurality of plate members and defined adjacent the opposed facing surfaces thereof;

the first through-opening having a cylindrical bore and the second through-opening having a partial spherical shaped bore; and

a plurality of bolts that join the plurality of plate members together;

wherein the plurality of plate members can be uncoupled by removing the bolts.

17. The mounting bracket for a workpiece holder according to claim 16, wherein the plurality of plate members are coupled together by bolts which are located on opposite sides of the second through-opening.

18. A mounting bracket for a workpiece holder according to claim 16, wherein the first through-opening has a diameter which is larger than a diameter of the second through-opening.

19. An assembly for mounting a workpiece holder to a support which comprises:

a workpiece holder including at least one movable jaw member and a body having a cylindrical portion;

a mounting bracket including a plurality of coupled plate members having opposed facing surfaces and first and second spaced apart through-openings provided between the plurality of coupled plate members;

wherein the through-openings are defined adjacent the opposed facing surfaces of the plurality of coupled plate members;

wherein the first through-opening has a cylindrical bore, the second through-opening has a semi-spherical shaped bore, and the cylindrical portion of the workpiece holder body is positioned within the first through-opening; and

longitudinally extending fasteners located at each of the facing surfaces on opposite sides of each of the second through-opening for coupling the plurality of plate members.

TECHNICAL FIELD

The present disclosure relates to fluid pressure actuated grippers of the type employed in automated workpiece handling devices which clampingly grip and transfer a workpiece from one station to another. More particularly, the present disclosure relates to fluid pressure actuated grippers which can be locked in either or both of their closed or open positions and which are assembled from a plurality of modular or interchangeable components.

BACKGROUND AND SUMMARY

Fluid pressure actuated grippers are widely employed and typically take the form of a pneumatic or hydraulic differential motor whose cylinder is fixedly mounted to a transfer device. At the forward or rod end of the cylinder housing, a gripper jaw mounting structure is fixedly mounted on the cylinder to pivotally support a pair of opposed gripper jaws which are coupled to the piston rod of the motor by a linkage so arranged that upon movement of the piston in one direction the jaws are pivoted to an open position and upon movement of the piston in the opposite direction the jaws are driven to a closed workpiece gripping position.

In typical operation, the gripper jaws will be closed upon a workpiece near the edge of the workpiece and the gripper will be advanced to position the gripped workpiece in operative relationship with a work station. The gripper will then be opened to release the workpiece and the transfer device will retract the gripper from the work station while the work operation is performed. At the conclusion of the work operation, the gripper will then advance back into the work station and the jaws will again close upon the workpiece and carry it away from the work station. Opening and closing the gripper jaws thus takes place when the gripper is in its closest proximity to tooling at the work station.

There are basically two types of linkage arrangements used in fluid pressure actuated grippers to connect the gripper jaws to the piston rods and effect movement of the gripper jaws. These are pivotable link arrangements and pivotal cam arrangements. An example of a pivotal link arrangement can be found in U.S. Pat. No. 5,152,568 to Blatt which discloses pivotal links 36 and 40 that cooperate with gripper jaws 12A and 12B as shown in FIG. 3.

U.S. Pat. No. 4,518,187 to Blatt et al. discloses a pivotal cam arrangement in which jaw plates 45 and 47 are pivoted by the cooperation of cam slots 61 provided in the jaw plates and a pivot pin 37 (and rollers 39) attached to the piston rod.

In a typical production line, there are numerous work stations with one or more fluid pressure actuated gripper devices positioned between adjacent work stations. During operation, all of the gripper devices are synchronized so that they simultaneously remove a workpiece from one work station and transfer the workpiece to the next work station. In such an operation, a problem can occur if any one of the gripper devices fails to properly grip a workpiece. For example, if a workpiece slips from its initial gripped position it can become sufficiently out of alignment to prevent its transfer to a succeeding gripper device. A more serious problem can occur if a workpiece is transferred in a misaligned manner and subsequently positioned at a work station in a misaligned fashion. Such an incident can damage the work station. Another problem which can occur is completely losing grip of a workpiece and dropping the workpiece. Losing grip of a workpiece can occur when there is a leak or failure of fluid pressure supplied to the piston rod actuator.

Fluid pressure actuated grippers are generally designed for use with particular workpieces to be transferred and with specific work stations. For example, some workpieces and/or work stations may require wider or narrower gripper jaws, different types of gripper jaws, gripper jaws that open at different angles, different clearance requirements, etc. Because of the wide variety of design or performance options required of grippers, manufacturing facilities which utilize fluid actuated grippers typically have numerous sets of grippers which are designed to transport different workpieces between specific work stations. The requirement of stocking multiple sets of grippers adds to the manufacturer's costs.

Accordingly, an illustrative embodiment of the present disclosure provides a mounting bracket for a fluid actuated parts gripper which comprises a body, a body member portion and a plurality of longitudinally extending fasteners. The body member portion is removably attached to the body and is adjacent first and second through-openings. The first through-opening is configured to receive the fluid actuated parts gripper and the second through-opening configured to receive a support. The body has a pair of variable slots such that one of the variable slots is configured to reduce and increase the diameter of the first through-opening to lock and unlock the parts gripper, respectively. The other of the variable slots is configured to reduce and increase the diameter of the second through-opening to lock and unlock the support, respectively. The plurality of longitudinally extending fasteners removably attach the body member portion to the body.

Other illustrative embodiments may further provide the first through-opening being cylindrical shaped and the second through-opening being circular with a semi-spherical concave shaped recess disposed therein; one of the plurality of fasteners locks and unlocks the support; and the second through-opening comprises a semi-spherical collar.

Another illustrative embodiment of the present disclosure provides a mounting bracket to hold a fluid actuated parts gripper which comprises a bracket body, a body member, and first and second longitudinally extending fasteners. The bracket body has first and second through-openings. The first through-opening is configured to receive the fluid actuated parts gripper and the second through-opening is configured to receive a support. The body member is removably attached to the bracket body. The body member comprises a portion of the first and second through-openings and comprises first and second segments each adjacent to and extending from the portion of the second through-opening. Each of the first and second segments is also positioned facing corresponding first and second segments of the bracket body. A variable space is provided between the first segments of the body member and the bracket body. The second segments of the body member and the bracket body abut each other, and the second through-opening comprises a diameter that is variable when the second segments of the body member and the bracket body abut each other. The first longitudinally extending fastener extends into the first segments of the body member and the bracket body and the variable space. The second longitudinally extending fastener extends into the second segments of the body member and bracket body. The first longitudinally extending fastener varies the size of the variable space which is proportional to the variable diameter of the second through-opening. A reduction in both the variable space and in the variable diameter of the second through-opening secures the mounting bracket to the support, while the second longitudinally extending fastener maintains abutment of the second segments of the body member and the bracket body. In addition, an increase in both the variable space and the variable diameter of the second through-opening loosens the mounting bracket to the support also while the second longitudinally extending fastener still maintains abutment of the second segments of the body member to the bracket body.

Other illustrative embodiments may further provide the bracket body having a second variable space between the bracket body and body member which is proportional to a variable diameter of the first through-opening; the first through-opening is cylindrical shaped and the second through-opening is circular with a semi-spherical concave shaped recess disposed therein; one fastener locks and unlocks the support; and the second through-opening comprising a semi-spherical collar.

Another illustrative embodiment of the present disclosure provides a mounting bracket to hold a fluid actuated parts gripper which comprises a body and longitudinally extending fasteners. The body has first and second through-openings. The first through-opening is configured to receive the fluid actuated parts gripper and the second through-opening is configured to receive a support. Each of the longitudinally extending fasteners is disposed substantially parallel to each other and are spaced apart from each other by a distance greater than the diameter of the second through-opening. The fasteners also extend through the body on opposed sides of the second through-opening. The second through-opening has a single variable space extending from the second through-opening and through the body to its periphery. One of the longitudinally extending fasteners extends through the variable space to vary the diameter of the second through-opening to lock and unlock in position the support with respect to the mounting bracket.

Other illustrative embodiments may further provide the body having variable space disposed therein in communication with the first through-opening to vary the diameter of the first through-opening; the first through-opening being cylindrical shaped and the second through-opening being circular with a semi-spherical concave shaped recess disposed therein; one of the longitudinally extending fasteners locks and unlocks the support; and the second through-opening comprises a semi-spherical collar.

Another illustrative embodiment of the present disclosure provides a mounting bracket to hold a fluid actuated parts gripper which comprises a body and bolts. The body has first and second through-openings. The first through-opening is configured to receive the fluid actuated parts gripper and the second through-opening is configured to receive a support. The first and second through-openings are of unequal diameters. The body comprises first and second coupled plate members having opposed facing surfaces extending to first and second segments each of the first and second coupled plate members, respectively. Opposed facing surfaces of each of the first and second coupled plate members define the second through-opening. The opposed facing surfaces of the first segments of the first and second coupled plate members form a slot opening. The opposed facing surfaces of the second segments of the first and second coupled plate members abut each other. The bolts couple the pair of coupled plates together and the bolts are located on opposite sides of the second through-opening. One of the bolts is disposed through the opposed facing surfaces of the second segments of the first and second coupled plate members to securely abut the opposed facing surfaces together. Another of the bolts is disposed through the opposed facing surfaces of the first segments of the first and second coupled plate members to reduce or enlarge the slot opening to, respectively, lock and unlock in position the support with respect to the mounting bracket.

Other illustrative embodiments may further provide the body having a variable space in communication with the first through-opening to vary the diameter of the first through-opening; the first through-opening being cylindrical shaped and the second through-opening being circular with a semi-spherical concave shaped recess disposed therein; one of the bolts locks and unlocks the support; and the second through-opening comprising a semi-spherical collar.

Another illustrative embodiment of the present disclosure provides a mounting bracket to hold a fluid actuated parts gripper which comprises a body, a semi-spherical collar and bolts. The body has first and second through-openings. The first through-opening is configured to receive the fluid actuated parts gripper and the second through-opening is configured to receive a support. The first and second through-openings are of unequal diameters. The semi-spherical collar is disposed in the second through-opening. The body comprises first and second coupled plate members having opposed facing surfaces extending to first and second segments each of the first and second coupled plate members, respectively. Opposed facing surfaces of each of the first and second coupled plate members define the second through-opening. The opposed facing surfaces of the first segments of the first and second coupled plate members form a first single slot opening in communication with the second through-opening, and the opposed facing surfaces of the second segments of the first and second coupled plate members abut each other. The opposed facing surfaces of the first segments of the first and second coupled plate members form a second single slot opening in communication with the first through-opening. The bolts couple the coupled plates together such that the bolts are located on opposite sides of the second through-opening. One of the bolts is disposed through the opposed facing surfaces of the second segments of the first and second coupled plate members to securely abut the opposed facing surfaces together. Another of the bolts is disposed through the opposed facing surfaces of the first segments of the first and second coupled plate members to reduce or enlarge the slot opening to, respectively, lock and unlock in position the support with respect to the mounting bracket.

Other illustrative embodiments may further provide the body being made from a material which is softer than a material from which the semi-spherical collar is made; and the semi-spherical collar having an outer surface which is roughened.

Another illustrative embodiment of the present disclosure provides a mounting bracket for a workpiece holder comprising a plurality of coupled plate members. The plurality of coupled plate members having opposed facing surfaces and first and second spaced apart through-openings provided between the coupled plate members and defined in the opposed facing surfaces thereof. The first through-opening has a cylindrical bore and the second through-opening has a semi-spherical shaped bore and the second through-opening is beveled at opposed ends.

Another illustrative embodiment of the present disclosure provides an assembly for mounting a workpiece holder to a support which comprises a workpiece holder, a mounting bracket and a spherical collar. The workpiece holder includes at least one movable jaw and a body having a cylindrical portion. The mounting bracket includes a plurality of coupled plate members having opposed facing surfaces. First and second spaced apart through-openings are provided between the coupled plate members in which each of the through-openings is defined in the opposed facing surfaces of the plurality of coupled plates. The first through-opening has a cylindrical bore, the second through-opening has a partial spherical shaped bore, and the cylindrical portion of the workpiece holder body is positioned within the first through-opening. The spherical collar is positioned in the second through-opening. Other illustrative embodiments may further provide the second through-opening being beveled at opposed ends.

Another illustrative embodiment of the present disclosure provides an assembly for mounting a workpiece holder to a support member which comprises a workpiece holder, a mounting bracket, and bolts. The workpiece holder includes at least one movable jaw and a body having a cylindrical portion. The mounting bracket comprises a plurality of coupled plate members each having opposed facing surfaces and first and second spaced apart through-openings provided between the coupled plate members. The through-openings are defined in the opposed facing surfaces of the coupled plates, wherein the first through-opening has a cylindrical bore, the second through-opening has a partial spherical shaped bore, and the cylindrical portion of the workpiece holder body is positioned within the first through-opening. The support member is positioned within the second through-opening. The bolts couple the plurality of coupled plate members together, the bolts located at opposite ends of the coupled plate members, wherein the support member can independently rotate 360 degrees and pivot within the second through-opening when one of the bolts located adjacent the second through-opening is loosened. Other illustrative embodiments may further provide the workpiece holder being independently rotatable 360 degrees within the first through-opening when one of the bolts located adjacent the first through-opening is loosened.

Another illustrative embodiment of the present disclosure provides a mounting bracket for a workpiece holder which comprises a plurality of coupled plate members. The plurality of coupled plate members having opposed facing surface. The coupled plate members also have first and second spaced apart through-openings provided between the plurality of coupled plate members and defined adjacent the opposed facing surfaces thereof. The first through-opening has a cylindrical bore and the second through-opening has a partial spherical shaped bore.

Other illustrative embodiments may further provide the plurality of coupled plate members being coupled together by bolts which are located on opposite sides of the second through-opening, and the plurality of coupled plate members can be uncoupled by removing the bolts; and the first through-opening has a diameter which is larger than a diameter of the second through-opening.

Another illustrative embodiment of the present disclosure provides an assembly for mounting a workpiece holder to a support which comprises a workpiece holder, a mounting bracket and longitudinally extending fasteners. The workpiece holder including at least one movable jaw and a body having a cylindrical portion. The mounting bracket including a plurality of coupled plate members having opposed facing surfaces, and first and second spaced apart through-openings provided between the plurality of coupled plate members. The through-openings are defined adjacent the opposed facing surfaces of the plurality of coupled plates. The first through-opening has a cylindrical bore, the second through-opening has a semi-spherical shaped bore, and the cylindrical portion of the workpiece holder body is positioned within the first through-opening. The longitudinally extending fasteners are located at each of the facing surfaces on opposite sides of each of the second through-opening for coupling the plurality of plate members.

Additional features and advantages of the gripper assembly will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrated embodiment exemplifying the best mode of carrying out the gripper assembly as presently perceived.

BRIEF DESCRIPTION OF DRAWINGS

The present disclosure will be described hereafter with reference to the attached drawings which are given as non-limiting examples only, in which:

FIG. 1 is an exploded view of a gripper device;

FIG. 1a is an exploded view of the piston assembly of the gripper device of FIG. 1;

FIG. 2 is a cross-sectional view of the gripper device of FIG. 1 with the jaws in a closed position;

FIG. 3 is a cross-sectional view of the gripper device of FIG. 1 with the jaws in an open position;

FIG. 4 is a partial cross-sectional view of FIG. 2 taken along plane IV--IV;

FIG. 5 is an exploded view of a gripper device;

FIG. 5a is an exploded view of the piston assembly of the gripper device of FIG. 5;

FIG. 6 is a cross-sectional view of the gripper device of FIG. 5 with the jaws in a closed position;

FIG. 7 is a cross-sectional view of the gripper device of FIG. 5 with the jaws in an open position;

FIG. 8 is a partial cross-sectional view of FIG. 6 taken along plane IV--IV;

FIGS. 9a and 9b are side views of an adjustable gripper tip arrangement;

FIG. 10 is an exploded prospective view which depicts components of a modular gripper;

FIGS. 11a-11g are schematic views which depict a pivotal gripper jaw having a recessed tip seat;

FIGS. 12a and 12b are schematic views which depict embodiments of cone gripper tips;

FIGS. 13a-13c are schematic views which depict embodiments of receiver point gripper tips;

FIGS. 14a, 14b, 15a and 15b are schematic views which depict embodiments of padded gripper tips;

FIGS. 16a-16d and 17a-17d are schematic views which depict embodiments of diamond point pad gripper tips;

FIGS. 18a-18d and 19a-19e are schematic views which depict embodiments of reversible gripper tips that have double cone points and double diamond point pads;

FIGS. 20a-20c are schematic views which depict a reversible double padded gripper tip;

FIGS. 21a and 21b are schematic views which depict a modular fluid activated gripper having upper and lower gripper jaws that can pivot 45.degree. outward from the closed position;

FIGS. 22a and 22b are schematic views which depict a threaded plug that is designed to be inserted into bottom of the pneumatic or hydraulic cylinder;

FIGS. 23a-23c are schematic views which depict a reversible threaded plug that is designed to be inserted into bottom of the pneumatic or hydraulic cylinder;

FIGS. 24a and 24b are schematic views which depict a modular gripper secured in a mounting plate;

FIGS. 25a-25d are schematic views which depict a self aligning gripper tip according to the present disclosure; and

FIGS. 26a and 26b are schematic views which depict a modular fluid activated gripper having an upper pivotal gripper jaw 100c and a lower stationary gripper jaw 100i. FIG. 26a is a side view of the modular fluid activated gripper. FIG. 26b is a bottom view of the modular fluid activated gripper.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrate embodiments of the gripper assembly, and such exemplification is not to be construed as limiting the scope of the gripper assembly in any manner.

DETAILED DESCRIPTION

The present disclosure is directed to fluid pressure actuated grippers of the type employed in automated workpiece handling devices which clampingly grip and transfer a workpiece from one station to another. The gripper devices of the present disclosure include a pneumatic or hydraulic differential motor which drives a piston rod in a reciprocal fashion, and a pair of jaws which are attached to the piston rod by a mechanical linkage that effects opening and closing of the jaws as the piston rod undergoes reciprocal motion.

The mechanical linkage which connects the gripper jaws to the piston rod and effects opening and closing of the jaws is a pivotal cam type linkage. That is, the gripper jaws include a cam slot which receives a cam pin that is attached to the piston rod. As the piston rod is moved in a reciprocal manner by the pneumatic or hydraulic differential motor, the cam pin slides through the cam slots causing the gripper jaws to open and close. According to the present disclosure, the cam slots are designed to have a particular shape which effects opening and closing of the gripper jaws, and which further causes the gripper jaws to become locked in either or both a closed position or an open position. "Locked" in position means that the position of the jaws in a closed and/or open position cannot be easily changed except by normal fluid operation of the pneumatic or hydraulic differential motor. As will be better understood from the following description, this "locking" feature prevents the gripper devices from failing in the event that fluid pressure to the pneumatic or hydraulic differential motor becomes interrupted.

The present disclosure is further directed to fluid pressure actuated grippers which are assembled from a plurality of modular or interchangeable components. For example, the modular grippers of the present disclosure include a common body having a yoke structure, a common piston assembly which moves in a reciprocal manner in the yoke structure, a cam pin coupled to the piston assembly, and a plurality of interchangeable components which can be assembled to the yoke structure and piston assembly to provide modular fluid pressure activated grippers having diverse performance characteristics. The interchangeable components of the modular grippers include gripper jaws, gripper tips, reversible gripper tips, pneumatic or hydraulic cylinder end closures or plugs, reversible pneumatic or hydraulic cylinder end closures or plugs, and side or impact plates.

FIG. 1 is an exploded view of a gripper device. The gripper device includes a yoke structure 1 which is coupled to a pneumatic or hydraulic differential motor cylinder 2 (FIG. 2). The yoke structure 1 includes a through-bore 3 in the bottom portion thereof for receiving a pneumatic or hydraulic differential motor piston assembly 4 (FIG. 2). The yoke structure 1 further includes a bore 5 for receiving cross piece support plate 7 which is attached to piston assembly 4. Piston assembly 4 is received in pneumatic or hydraulic differential motor cylinder 2 (FIG. 2), in a conventional manner. As shown in FIG. 1a, piston assembly 4 includes a piston 4a and piston shaft 4b attached thereto. Cross piece support plate 7 is received on the end of piston shaft 4b and supports cross piece 8. A threaded screw 6 extends through piston 4a, piston shaft 4b, cross piece support plate 7 and is secured to cross piece 8 by inserting threaded end 9 thereof into threaded bore 10 in cross piece 8.

The cross piece 8 moves within yoke structure 1 as the cross piece support plate 7 moves reciprocally in bore 5, under operation of the pneumatic or hydraulic differential motor. The cross piece 8 includes opposite ends which have cutout central portions 11, as shown, for receiving gripper jaws 12. In this regard, the gripper jaws 12 include stepped or narrow portions 13 which are received in the cutout central portions 11 at the ends of cross piece 8. The narrow portions 13 of the gripper jaws 12 include cam slots 14. The cam slots 14 have a particular shape which effects the opening, closing and locking of the gripper jaws 12 as will be discussed below. The cam slots 14 are symmetrical to one another. Aligned through-bores 15 are provided in the ends of cross piece 8 as shown. These through-bores 15 receive pivot pins 16 which pass through cam slots 14 and link the gripper jaws 12 to the cross piece 8.

As shown in FIG. 1, the upper portion of gripper jaws 12 are approximately as wide as the gap 17 in yoke structure 1. Through-bores 18 are provided in the wide portion of gripper jaws 12. These through-bores 18 receive pivot pins 19 which pivotally connect the gripper jaws 12 to yoke structure 1, so that the gripper jaws 12 can pivot within yoke gap 17. FIG. 1 depicts bores 20 in the yoke structure 1 which receive pivot pins 19. Pivot pins 19 can be secured in bores 20 in any convenient manner, such as snap rings, cooperating threaded structures, etc.

Also illustrated in FIG. 1 are adjustable slide plates 21. These plates can be adjustable so that edge 22 thereof extends slightly beyond surface 23 of the yoke structure 1. In operation, there is a tendency for surface 23 of yoke structure 1 to become worn as it repeatedly contacts workpieces. Slide plates 21 can be positioned so that workpieces come into contact with edge 22 thereof, thus preventing wear on surface 23 of yoke structure 1. Slide plates 21 can be adjustably positioned by loosening screws 24 which pass through elongated slots 25 and into threaded bores 26 and are preferably made from a tempered or otherwise hard metal. Slide plates 21 can be easily adjusted and replaced as required.

Also illustrated in FIG. 1 is a mounting plate 27 for mounting the gripper device to an articulated support or transfer device. Mounting plate 27 includes two plate portions 28 which can be secured together, by screws or bolts which extend into threaded bores 29. As shown in FIG. 2, the pneumatic or hydraulic differential motor cylinder 2 of the gripper device is defined by a wall 30 that includes a stepped or narrow portion 31. This narrow portion 31 is cylindrical, as opposed to the overall general rectangular shape of the wall 30. When secured together, mounting plates 28 define an opening 32 which extends around narrow cylindrical portion 31 so that the gripper device freely rotates with respect to the mounting plate 27. Mounting plate 27 also includes an opening 33 which can receive a spherical collar 34 that can be clamped therein in a fixed orientation and used to mount the gripper device to an articulated structure.

FIG. 2 is a cross-sectional view of the gripper device of FIG. 1 with the gripper jaws 12 in a closed position. As depicted, gripper tips 35 and 36 secure a workpiece 37 therebetween. Gripper tip 35 is a serrated point tip and is attached to the gripper jaw 12 by a threaded screw 38a which is inserted into threaded bore 38b provided in the gripper jaws 12. Threaded screw 38a is received into corresponding threaded bore provided in the gripper tip 35. Gripper tip 36 is a cone point tip which is threaded directly into threaded bore 38b. The illustrated gripper tips are presented as examples of various other tips which can be used in conjunction with the gripper device.

FIG. 2 depicts one manner in which pneumatic or hydraulic differential motor cylinder 2 can be defined by end walls which are secured, e.g., threaded, into cylinder bore 3.

As illustrated in FIG. 2, piston 4 is urged upward by fluid pressure which is applied to port 39 of pneumatic or hydraulic differential motor cylinder 2. As piston 4 moves upwardly as depicted in FIG. 2, cam pins 16 connected to cross piece 8 slide through cam slots 14 in gripper jaws 12, causing the gripper jaws 12 to pivot about pivot pins 19. This upward or forward movement of piston 4 causes the gripper jaws 12 to pivot into a closed position.

FIG. 3 is a cross-sectional view of the gripper device of FIG. 1 with the gripper jaws 12 in an open position. As depicted in FIG. 3, piston 4 is urged downward by fluid pressure which is applied to port 40 of pneumatic or hydraulic differential motor cylinder 2. As piston 4 moves downward as depicted in FIG. 3, cam pins 16 connected to cross piece 8 slide through cam slots 14 in gripper jaws 12, causing the gripper jaws 12 to pivot about pivot pins 19. This downward or rearward movement of piston 4 causes the gripper jaws 12 to pivot into an open position as shown.

FIG. 4 is a partial cross-sectional view of FIG. 2 taken along plane IV--IV. FIG. 4 depicts the manner in which the cross piece 8 is received in gap 17 of yoke structure 1 and how the narrow portions 13 of gripper jaw 12 are received in the cutout portions 11 of the cross piece 8 and pivotally secured therein by cam pins 16.

The embodiment of the gripper device depicted in FIGS. 1-4 is designed to lock in both the closed and open position. This locking function is achieved in part by the particular design or shape of the cam slots 14. That is, the cam slots 14 depicted in FIGS. 2 and 3 include three distinct segments, including two locking segments at either end and a central pivoting segment. When the cam pins 16 are positioned in either of the locking segments at the ends of the cam slots 14, the gripper jaws 12 are locked in corresponding closed or open positions. In these locked positions, the gripper jaws 12 cannot be pivoted about pivot pins 19. For example, as can be seen in FIG. 2, when the piston 4 is moved to its full upward or forward position, cam pins 16 are positioned at one end of the cam slots 14. This segment of the cam slots 14, identified by reference numeral 41, causes the gripper jaws 12 to be locked in their closed position, because the configuration of locking segments 41 prevents the gripping jaws 12 from pivoting about pivot pins 19. As can be seen from FIG. 2, gripper jaws 12 can only pivot about pivot pins 19 when cam pins 16 are moved slightly downward by piston 4. In a similar manner, when cam pins 16 are in locking segments 42 of cam slots 14 as shown in FIG. 3, the gripper jaws 12 cannot be pivoted about pivot pins 19.

As the cam pins 16 move between locking segments 41 and 42 of the cam slots 14, gripping jaws 12 are pivoted between their closed and open positions. Thus, the central cam slot segments between the locking segments are referred here to central pivoting segments 43.

As can be seen, the locking segments 41 and 42 are configured to prevent pivotal movement of the gripping jaws 12 about pivot pins 19. The central pivoting segment 43 on the other hand generally has a continuous curving shape which can be varied to effect the manner in which the gripping jaws move between their closed and open positions. For example, a portion of the slots having a smaller radius of curvature would cause quicker movement of the gripper jaws than a portion having a larger radius of curvature for a constant piston speed. In addition to effecting the speed or rate at which the gripper jaws move, the curved shape of the cam slots have been varied to effect the amount of torque applied between the gripper jaws. Thus, it is to be understood that the shape of the central pivoting segments 43 of the cam slots 14 can be varied as desired.

FIG. 5 is an exploded view of a gripper device. The gripper device depicted in FIG. 5 can be used with the mounting plate 27 shown in FIG. 1. However, since the mounting plate 27 is not shown in FIG. 5, the narrow cylindrical portion 31 of the pneumatic or hydraulic motor wall 30 can be seen in perspective.

The gripper device of FIG. 5 includes a yoke structure 44 and a piston assembly 58 which moves in a reciprocal manner in the yoke structure 44. Movement of the piston assembly 58 is effected by a pneumatic or hydraulic motor having a cylinder 46 which is formed in the lower portion of the yoke structure 44 (see FIG. 6). Rather than have a cross piece as in the gripper device of FIG. 1, the gripper device of FIG. 5 includes a single cam pin 47 that is attached to supporting cross piece 45, which in turn is attached to the free end of the piston assembly 58. As shown in FIG. 5a, the piston assembly 58 includes a piston 58a and a piston shaft 58b. Supporting cross piece 45 is attached to the end of piston shaft 58b by a threaded screw 6 having a threaded end 9 which is received in a correspondingly threaded bore 9a in supporting cross piece 45. Supporting cross piece 45 includes a through-bore 45a which receives cam pin 47 as depicted. The cam pin 47 passes through cam slots 48 in gripper jaws 49, and the ends of the cam pin 47 are received in bushings 50 which slide freely in a pair of longitudinal slots 51 in the side walls of the yoke structure 44. It is noted that the bushings have flat parallel sides which slide along the inner surfaces of longitudinal slots 51. These flat sides avoid a point contact and allow for the body or yoke structure to be made of a softer material such as an aluminum alloy. The bushings 50 are held in place in the longitudinal slots 51 between the gripper jaws 49 and side plates 52. Side plates 52 can be attached to the yoke structure 44 by mechanical fastener means, such as screws 53. Spherical surfaced bearings 54 are provided on the ends of cam pin 47 to ensure free movement of the cam pin 47 in cam slots 48.

Gripper jaws 49 are pivotally connected to the yoke structure 44 by means of a pivot pin 55 which passes through aligned through-bores 56 in the side walls of the yoke structure 44 and through-bores 57 in the gripper jaws 49.

FIG. 5 also depicts end closure 60 for pneumatic or hydraulic cylinder 46.

FIG. 6 is a cross-sectional view of the gripper device of FIG. 5 with the gripper jaws in a closed position. As depicted, gripper tips 61 and 62 secure a workpiece 63 therebetween. Gripper tip 61 is a serrated point tip and is attached to the gripper jaw 49 by threaded screw 64a which are inserted into threaded bore 64b provided in the gripper jaws 49. Threaded screw is received into corresponding threaded bore provided in gripper tip 61. Gripper tip 62 is a cone point tip and can be directly threaded into threaded bore 64b. The illustrated gripper tips are presented as examples of various other tips which can be used in conjunction with the gripper device.

FIG. 6 depicts one manner in which pneumatic or hydraulic differential motor cylinder 46 can be defined by a bore 66 formed in the bottom of the yoke structure 44 which has an end wall or plug 60 secured, e.g., threaded, in the end of bore 66.

As illustrated in FIG. 6, piston 58 is urged upward by fluid pressure which is applied to port 65 of pneumatic or hydraulic differential motor cylinder 46. As piston 58 moves upwardly as depicted in FIG. 6, cam pin 47 connected to supporting cross piece 45 slides through cam slots 48 in gripper jaws 49, causing the gripper jaws 49 to pivot about pivot pin 55. This upward or forward movement of piston 58 causes the gripper jaws 49 to pivot into a closed position.

FIG. 7 is a cross-sectional view of the gripper device of FIG. 5 with the gripper jaws 49 in an open position. As depicted in FIG. 7, piston 58 is urged downward by fluid pressure which is applied to port 67 of pneumatic or hydraulic differential motor cylinder 46. As piston 58 moves downward as depicted in FIG. 7, cam pin 47 connected to supporting cross piece 45 slides through cam slots 48 in gripper jaws 49, causing the gripper jaws 49 to pivot about pivot pins 55. This downward or rearward movement of piston 58 causes the gripper jaws 49 to pivot into an open position as shown.

FIG. 8 is a partial cross-sectional view of FIG. 6 taken along plane VIII--VIII. FIG. 8 depicts the manner in which the bearings 54 mounted on the ends of the cam pin 47 are positioned in the cam slots 48 of the gripper jaws 49, and how the cam pin 47 extends into bu