A gripper tooling including a gripper, at least one slider, and at least one tooling member configured for gripping a workpiece. Each tooling member including a base slideably mounted to the at least one slider, at least one middle segment pivotally connected to the base, a distal segment pivotally connected to the at least one middle segment, an adducting tendon having a proximal end attached to the at least one slider and a distal end attached to the distal segment, and an abducting tendon having a proximal end attached to the base and a distal end attached to the distal segment. The at least one tooling member is configured for autonomously gripping the workpiece as the at least one jaw moves toward the workpiece and the at least one tooling member autonomously returns to an ungripped position as the at least one jaw moves away from the workpiece.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a non-provisional application based upon U.S. provisional patent application Ser. No. 62/682,471, entitled “AUTONOMOUSLY ENCAPSULATING GRIPPER TOOLING”, filed Jun. 8, 2018, which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to gripper tooling, and, more particularly, to self-articulating grippers.

2. Description of the Related Art

Grippers are mechanical devices which generally include jaws that are moved together or apart by motive devices, such as electric motors or pneumatic pistons. Tooling is typically fastened to the jaw to provide some degree of conformal contact between the surface of the tool and one or more surfaces of a gripped workpiece. Once the jaws have moved the fastened tooling into a position of contact with the gripped workpiece, the jaws produce a force against the tooling which is transferred by the tooling to retain the workpiece so that the position of the workpiece might be subsequently translated or rotated. It is often desirable that the tooling fully or partially encapsulate the profile of the workpiece to prevent relative motion from occurring between the workpiece and tooling as the workpiece is subsequently translated or rotated or external forces are applied to the workpiece.

It is known in the art to construct the tooling with a complimentary contacting surface profile which corresponds to the profile of the workpiece to better encapsulate a gripped workpiece. This method of encapsulation typically renders the tooling suitable for gripping only a single shape of workpiece or a series of similarly shaped workpieces that share a common surface profile. Generally, tooling must be removed and replaced if a noncompatible shape of workpiece is to be subsequently gripped, resulting in an undesirable increase in downtime and reduced throughput for the manufacturing or material handing operation of which the gripper is a part.

What is needed in the art is a cost-effective gripper for automatically accommodating the shape of the workpiece and gripping the workpiece.

SUMMARY OF THE INVENTION

The present invention provides a gripper tooling capable of autonomously adjusting to conform to the gripped profile of the workpiece, so as to encapsulate a broad spectrum of shapes and sizes of workpieces. The gripper tooling furthermore derives the motive force necessary to adjust solely from the motion of the gripper jaws to which the tooling is attached. This manner of force derivation simplifies the connection between the tooling and the gripper as the tooling need only to be mechanically fastened to the gripper in order to operate as desired. Such manner of simple attachment allows the tooling to be used with numerous types of commercial grippers by only changing the mounting pattern of the tooling to match the pattern of the gripper jaws.

The invention in one form is directed to a gripper tooling including a gripper having a gripper body and at least one jaw connected and linearly sliding relative to the gripper body, at least one slider connected to the at least one jaw, and at least one tooling member configured for gripping a workpiece. Each tooling member including a base slideably mounted to the at least one slider, at least one middle segment pivotally connected to the base, a distal segment pivotally connected to the at least one middle segment, an adducting tendon having a proximal end attached to the at least one slider and a distal end attached to the distal segment, and an abducting tendon having a proximal end attached to the base and a distal end attached to the distal segment. The at least one tooling member is configured for autonomously gripping the workpiece as the at least one jaw moves toward the workpiece and the at least one tooling member autonomously returns to an ungripped position as the at least one jaw moves away from the workpiece.

The invention in another form is directed to a gripper tooling including a gripper having a gripper body and at least one angular jaw, at least one rotor rotatably connected to the at least one angular jaw, and at least one tooling member configured for gripping a workpiece. Each tooling member including a base pivotally connected to the at least one rotor, at least one middle segment pivotally connected to the base, a distal segment pivotally connected to the at least one middle segment, an adducting tendon having a proximal end attached to the at least one rotor and a distal end attached to the distal segment, and an abducting tendon having a proximal end attached to the base and a distal end attached to the distal segment. The at least one tooling member is configured for autonomously gripping the workpiece as the at least one angular jaw rotates toward the workpiece and the at least one tooling member autonomously returns to an ungripped position as the at least one angular jaw rotates away from the workpiece.

The invention in yet another form is directed to a method for gripping a workpiece including a step of providing a gripper tooling including a gripper having a gripper body and at least one jaw moveably connected to the gripper body, at least one mount moveably connected to the at least one jaw, and at least one tooling member configured for gripping the workpiece, each tooling member including a base moveably mounted to the at least one mount, at least one middle segment pivotally connected to the base, a distal segment pivotally connected to the at least one middle segment, an adducting tendon having a proximal end attached to the at least one mount and a distal end attached to the distal segment, and an abducting tendon having a proximal end attached to the base and a distal end attached to the distal segment. The method also includes the steps of gripping the workpiece by the adducting tendon upon moving the base, by the at least one jaw, to be immobilized by the workpiece, and ungripping the workpiece by the abducting tendon upon moving the base, by the at least one jaw, away from the workpiece.

An advantage of the present invention is that the gripper tooling fingers self-articulate, via the usual operational motion of the gripper jaws, to autonomously encapsulate a plethora of differently-shaped workpieces.

Another advantage of the present invention is that the self-articulating gripper tooling fingers can be easily and efficiently attached to numerous types of gripper jaws by only changing the mounting pattern of the gripper tooling fingers to match the mounting pattern of the gripper jaws.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, and more particularly toFIG. 1, there is shown one embodiment of the gripper tooling mounted to an illustrative gripper with parallel jaw travel50, such as the GRH series gripper manufactured by the PHD Corporation. Left tooling member100consists of a single gripper “finger” including a base101to which is attached a chain of multiple identical articulated segments110, capped by an articulated distal segment120. A slider102attaches left tooling member100to the left jaw51of gripper50with threaded fasteners (not shown, see alsoFIG. 11). Right tooling member200consists of a base201to which is attached two gripper fingers comprising multiple identical articulated segments210, capped by identical articulated distal segments220. A slider202attaches right tooling member200to the right jaw52of gripper50with threaded fasteners (not shown). Although the embodiment illustrates similar finger construction for the left and right fingers, it will be understood by one skilled in the art that the articulated segments comprising the left and right fingers can also differ in quantity, overall dimensions, construction, and physical arrangement from those illustrated. It is also understood that left and right fingers need not be of similar construction to one another and that the quantity of fingers present on each tooling member can be varied without affecting the fundamental nature of the invention.

Referring now toFIGS. 2-6, there is shown the left tooling member100. Ribs protruding from the sides of slider102are disposed into complementary slots in the base101so as to prevent the rotation of the base101with respect to the slider and limit the translation of the base101in all directions except along the longitudinal axis of slider102. A bevel on the forward edge of slider102acts to lift any portion of the workpiece that the slider may contact out of the path of the slider as the slider, mechanically fastened to the left jaw51of gripper50, moves towards the workpiece.

The left tooling member100may include an adducting tendon104having a proximal end connected to the slider102and a distal end connected to the distal segment120. The adducting tendon104may be in the form of a cable104. A lower knurled cylindrical cleat103may mechanically fasten the proximal end of the cable104to the slider102. However, in addition or alternatively to such mechanical attachment, the cable104may be attached with a suitable adhesive applied between the cable104and the slider102. The cable104may be composed of any desired material. In one embodiment, the cable104is a polymer cable which offers the advantages over traditional steel cable of improved resistance to fatigue and corrosion, greater flexibility, improved dissipation of mechanical shock, and lower cost.

A set of pulleys105, supported by pivot pins106pressed into complimentary holes in body101, route the motion of cable104so that as the proximal end of the cable104is pulled by the motion of slider102relative to body101, cable104is drawn through the central passages of articulated segments110. Although pulleys105are shown as being directly supported by pivot pins106, it is understood that a suitable commercial bearing bushing, radial ball bearing, or needle bearing could be interposed between the pulley and pin when the size of pulley105is sufficiently large to allow doing so.

Pivot pins107pass though complimentary holes in base101and segments110and120to attach common segments110to base101, to each other, and to distal segment120, forming a chain of pinned articulated segments radiating outwards from base101. Although segments110and segment120are shown as being directly supported by pivot pins107, it is understood that a suitable commercial bearing bushing, radial ball bearing, or needle bearing could be interposed between the pivot hole in the segments and pin107when the size of segment is sufficiently large to allow doing so.

The upper, distal end of the cable104may be mechanically fastened to the distal segment120with an upper knurled cylindrical cleat108. It is understood that such mechanical attachment could also be affected with a suitable adhesive applied between the cable104and the segment120. Cable104passes over pulleys109disposed within each identical segment110. In this manner, cable104, suitably attached between slider102and distal segment120, effectively forms the taut adducting tendon104located on one side of segment pivot pins107. Although pulleys109are shown as being directly supported by pivot pins106pressed into complimentary holes in segments110, it is understood that a suitable commercial bearing bushing, radial ball bearing, or needle bearing could be interposed between the pulley and pin when the size of pulley109is sufficiently large to allow doing so.

The left tooling member100may include an abducting tendon111. An external strip111may effectively form the abducting tendon111, which is located on the opposing side of pivot pins107. The external strip111may be composed of a suitable elastomeric material. The distal end of the strip111is attached in any desired way, such as thermal or adhesive bonding, into a complimentary groove in distal segment120. The proximal end of elastomeric strip111is disposed within a complementary slot in body101and is attached to body101by the clamping action of set-screw112or by other suitable thermal or adhesive bonding. The portion of strip111between the distal and proximal attached ends is unconstrained and free to stretch or relax. The strip111is stretched during installation to create a tension in the strip111which acts to pull distal segment120toward base101. This pull induces a torque in distal segment120and common segments110which acts to rotate each segment counterclockwise (CCW) with respect to pivot pins107. It should be understood by one skilled in the art that strip111could be replaced by one or more helical extension springs or a flexible, but non-stretchable tensile member attached to a suitable spring to provide the same function as an elastomeric strip.

Bosses113, protruding from the sides of common segments110, engage complimentary slots114, in body101and segments110to constrain the angle of CCW rotation of the segment pinned to base101and each successive pinned segment in the segment chain, relative to the prior segment. Thusly constrained by the action of bosses113within slots114, the segments cannot rotate CCW about pivots107beyond a position in which the segments are in a straight, vertical alignment with one another.

Clockwise (CW) rotation of any segment under the influence of an external torque causes additional stretching of strip111, with a resulting increase in the torque applied by the strip to the CW rotated segment. In this manner, strip111functions as an abducting tendon which constantly applies a torque to segments110and120about pivot pin107to restore the segments into straight vertical alignment with one another. Downward motion of adductor cable104through the central passages of segments110induces a CW torque in segments110and120that causes the segments to rotate CW about pivot pins107, further stretching abductor strip111.

Pads115are suitably bonded into complimentary recesses in segments110. Pads115are constructed of a material such as a suitable elastomer or a nanodiamond impregnated metal substrate, possessing a high coefficient of static friction, so as to enhance the frictional forces generated between the pad and any surface of the gripped workpiece that the pad might contact.

Dimension20indicates the orthogonal distance between the center of pivot pin107connecting the proximal most common segment110to base101and the centerline of adductor cable104. Dimension21indicates the orthogonal distance between the respective pivot pins107of the remaining segments and the centerline of cable104. Dimension22indicates the orthogonal distance between the pivot pins107of the remaining segments and the centerline of abductor strip111. The CW acting torque about pivot pins107applied to the various segments by the tension in adductor cable104is equal to the product of the tension in the cable and the orthogonal distance between the respective pivot pin and the centerline of the adductor cable104. In an analogous manner, the CCW acting torque about pivot pins107applied to the various segments by the tension in abductor strip111is equal to the product of the tension in the strip and the orthogonal distance between the respective pivot pin and the centerline of the abductor strip. It will be evident to one skilled in the art that as the tension in cable104when pulled upon is constant along the entire length of the cable, only the orthogonal distance between the center of the respective pivot pin107and cable centerline needs be varied to control the torque applied by cable104to any given segment. It will also be evident that the local tension in abductor strip111is a function of the cross-sectional area of the strip at that locality, so that the local tension in the strip can be controlled by selectively varying the cross-sectional area of strip111along the length of the strip. Therefore, the net torque acting on any given segment can be chosen by controlling the local cross-sectional area of strip111, the distance between the respective pivot pin107of the segment and the centerline of abductor strip111, and the distance between the respective pivot pin107of the segment and the centerline of adductor cable104. It will also be evident that in the absence of any external torques acting upon the segments, the segment with the greatest net applied CW torque will rotate toward the workpiece first, with each remaining segment successively rotating in descending order of net applied CW torque.

The cleat108mechanically fastens the distal end of adductor cable104to distal segment120. Cleat108is comprised of central cylinder108C the outer diameter of which receives a straight knurl or other friction enhancing treatment such as a nanodiamond impregnated plating. Bosses108A and108B flank central cylinder108C (FIG. 2).

After installation of the cleat108into distal segment120, the surface of boss108A rests against complimentary surface120A in the cleat cavity within segment120, while the surface of boss108B similarly rests against complimentary surface120B. A complimentary relief120C forms a cleat cavity120C within segment120to prevent any portion of the central cylinder108C of cleat108from contacting any portion of segment120(FIGS. 2 and 6). Central cylinder108C is free to contact the surface of cable104which is pressed into contact with surface120D of segment120by the action of central cylinder108C. Angle26denotes the angle formed by surfaces120A and120B and cable contact surface120D in segment120. Angle26is chosen to be shallow, in the range of 10 to 30 degrees. Arrow27indicates the force applied to cleat central cylinder108A to install cleat108into cleat cavity120C of distal segment120. While cable104is held taut, Force27is applied to the left of the axis of central cylinder108C as cleat108is guided into the mouth of recess120C, causing the surface of cylinder108C to roll CCW against the surface of cable104while surfaces108A and108B slide against surfaces120A and120B, respectively. The acute nature of angle26creates a wedging action which decreases the space between surfaces120A and120B and120D as cleat108moves progressively into recess120C. This decrease in space progressively compresses cable104between the surface of cleat central cylinder108C and surface120D of segment120as the cleat108rolls along the surface of the cable104, until the cable104becomes completely jammed against surface120D, stopping the entry of the cleat108into recess120C. Arrow28indicates the direction of external tension in cable104as the cable is pulled by the action of slider102(FIGS. 2, 4, and 6). Tension applied in the direction of arrow28causes cleat108to rotate CW, with surfaces108A and108B rolling against surfaces120A and120B, respectively, which causes further compression of cable104against surface120C by cylinder108C. In this manner, any external tension applied to cable104in the direction of arrow28acts to proportionally increase the jamming force applied by cleat108against cable104to retain cable104against surface120D.

It is understood that the same wedging mechanism used by cleat108to retain the distal end of cable104within distal segment120is also used to by the lower cleat103to retain the proximal end of cable104in slider102.

Referring now toFIGS. 7-10, there is shown the right tooling member200. Ribs protruding from the sides of slider202are disposed into complementary slots in base201so as to prevent the rotation of the base201with respect to the slider and limit the translation of base201in all directions except along the longitudinal axis of slider202. A bevel on the forward edge of slider202acts to lift any portion of the workpiece that the slider may contact out of the path of the slider as the slider, mechanically fastened to the right jaw52of gripper50, moves towards the workpiece.

Pivot pins207pass though complimentary holes in base201and segments210and220to attach common segments210to base201, to each other, and to distal segment220, forming two chains of pinned articulated segments radiating outwards from base201. Although segments210and segment220are shown as being directly supported by pivot pins207, it is understood that a suitable commercial bearing bushing, radial ball bearing, or needle bearing could be interposed between the pivot hole in the segments and pin207when the size of segment is sufficiently large to allow doing so.

The right tooling member200may include an adducting tendon204having a proximal center portion connected to the slider202and distal ends connected to the distal segments220. The adducting tendon204may be in the form of a cable204. The proximal center portion of cable204is routed around pulleys216which are supported by pivot pins206pressed into complimentary holes in slider202. In one embodiment cable204is a polymer cable which offers the advantages over traditional steel cable of improved resistance to fatigue and corrosion, greater flexibility, improved dissipation of mechanical shock, and lower cost. Pulleys205, supported by pivot pins206pressed into complimentary holes in body210, route the motion of each end of cable204so that as the proximal center of the cable204is pulled by the motion of slider202relative to body201, each end of cable204is drawn through the central passages of articulated segments210of one of the two segment chains. Although pulleys205are shown as being directly supported by pivot pins206, it is understood that a suitable commercial bearing bushing, radial ball bearing, or needle bearing could be interposed between the pulley and pin when the size of pulley205is sufficiently large to allow doing so.

Each distal end of cable204can be mechanically fastened to distal segment220of one segment chain with knurled cylindrical cleat208. It is understood that such mechanical attachment could also be affected with a suitable adhesive applied between the cable204and the segment220. It is further understood that the same wedging mechanism used by cleat108to retain the distal end of cable104within distal segment120is also used to by cleats208to retain each distal end of cable204in distal segments220.

Cable204passes over pulleys209disposed within each identical segment210. In this manner, each side of cable204, suitably attached between slider202and distal segment220, effectively forms a taut adducting tendon located on one side of segment pivot pins207. Although pulleys209are shown as being directly supported by pivot pins206pressed into complimentary holes in segments210, it is understood that a suitable commercial bearing bushing, radial ball bearing, or needle bearing could be interposed between the pulley and pin when the size of pulley209is sufficiently large to allow doing so.

It is desirable that each of the two segment chains of tooling member200may contact and conform to the profile of a gripped workpiece independently of one another. Such independent conformance assists during the gripping of workpieces possessing a plurality of asymmetric profiles by maximizing the number of contact points between the tooling and workpiece. The articulated motion of any segment chain ceases when that chain fully conforms to the profile of the gripped workpiece, causing motion of the end of cable204attached to the fully conformed segment chain to correspondingly cease and become stationary. The ability of cable204to laterally translate across pulleys216, as denoted by arrow17inFIG. 10, subsequently allows the length of the cable to shift from the free end to the stationary end, allowing the free end of cable204to continue to be pulled by the action of slider202translating relative to body201. Once both segments chains have completely conformed to the workpiece, the ability of cable204to translate laterally across pulleys216further provides a way of equalizing the tension between the two ends of the cable204.

The strip211, constructed of a suitable elastomeric material, effectively forms an abducting tendon located on the opposing side of pivot pins207. The distal end of strip211is attached by suitable means, such as thermal or adhesive bonding, into a complimentary groove in distal segment220. The proximal end of elastomeric strip211is disposed within a complementary slot in body201and is attached to body201by the clamping action of set-screw212or by other suitable thermal or adhesive bonding. The portion of strip211between the distal and proximal attached ends is unconstrained and free to stretch or relax. The strip211is stretched during installation to create a tension in the strip which acts to pull distal segment220toward base201. This pull induces a torque in distal segment220and common segments210which acts to rotate each segment CW with respect to pivot pins207(FIG. 9). It should be understood by one skilled in the art that the strip211could be replaced by one or more helical extension springs or a flexible, but non-stretchable tensile member attached to a suitable spring to provide the same function as an elastomeric strip. It should be appreciated that the orientation of member200is reversed inFIG. 7when compared toFIG. 9.

Bosses213, protruding from the sides of common segments210, engage complimentary slots214, in body201and segments210to constrain the angle of CW rotation of the segment pinned to base201and each successive pinned segment in the segment chain, relative to the prior segment. Thusly constrained by the action of bosses213within slots214, the segments cannot rotate CW about pivots207beyond a position in which the segments are in a straight, vertical alignment with one another.

CCW rotation of any segment under the influence of an external torque causes additional stretching of strip211, with a resulting increase in the torque applied by the strip to the CCW rotated segment. In this manner, strip211functions as an abducting tendon which constantly applies a torque to segments210and220about pivot pin207to restore the segments into straight vertical alignment with one another. Downward motion of adductor cable204through the central passages of segments210induces a CCW torque in segments210and220that causes the segments to rotate CCW about pivot pins207, further stretching abductor strip211.

Pads215are suitably bonded into complimentary recesses in segments210. Pads215are constructed of a material such as a suitable elastomer or a nanodiamond impregnated metal substrate, possessing a high coefficient of static friction, so as to enhance the frictional forces generated between the pad and any surface of the gripped workpiece that the pad might contact.

Dimension23indicates the orthogonal distance between the center of pivot pin107connecting the proximal most common segment210to base201and the centerline of adductor cable204. Dimension24indicates the orthogonal distance between the respective pivot pins207of the remaining segments and the centerline of cable204. Dimension25indicates the orthogonal distance between the pivot pins207of the remaining and the centerline of abductor strip211. In analogous manner to member100, the cross-sectional area of corresponding abductor strip211and orthogonal distances between the pivot pins207and centerlines of strip211and abductor cable204can be similarly chosen to control the rotational order of each segment chain.

Referring now toFIGS. 11-13, there is shown the gripper tooling in its sequence operation as the gripper tooling engages an example of a workpiece30. InFIG. 11, the left jaw51and right jaw52move the left tooling member100and the right tooling member200toward cylindrical workpiece30, in the direction of arrows12and13, respectively. During this motion, the segments comprising the left tooling member100and the right tooling member200are held in straight vertical alignment by the tension of the stretched elastomeric strips111and211, respectively. So long as all segments are vertically aligned, cables104and204remain taut, which prevents any relative motion between sliders102and base101and slider202and base201, as any relative motion between the sliders and bases require CW rotation of segments about pivot pins107or CCW rotation of the segments about pivot pins207(see alsoFIGS. 4 and 9). The bases101and201therefore move in conjunction with respective sliders102and202, as denoted by arrows14and15, respectively.

FIG. 12shows tooling members100and200at the moment of initial contact with the workpiece30. As pad115on segment110contacts workpiece30, the finger formed by segments110and distal segment120pinned together by pivot pins107is brought to rest. Base101is also brought to rest by the action of segment110acting through the pinned connection to base101established by pivot pin107. However, slider102remains free to translate under the influence of jaw51, to which it is fastened, as denoted by arrow12. In an analogous manner, as pad215on segment210contacts workpiece30, the finger formed by segments210, distal segments220, and pivot pins207is brought to rest by contact with workpiece30. Base201is brought to rest by the action of segment210acting through the pinned connection to base201established by pivot pin207, while slider202remains free to translate under the influence of jaw52, as denoted by arrow13.

Referring now collectively toFIGS. 11-17, there is shown the tooling members100and200gripping the workpiece30. Once base101is brought to rest by the segment chain, including segments110and120and pins107, acting against workpiece30, slider102continues to translate under the action of gripper jaw51, relative to stationary base101. Such relative motion pulls adductor cable104, routed around pulleys105, downward through the central passages of segments110. Downward motion of cable104induces a CW torque in segments110and120that causes the segments to rotate CW in the direction of arrow16about pivot pins107, stretching abductor strip111and forcing pads115bonded to segments110and strip111bonded onto distal segment120into conformal contact with the surface of workpiece30.

Once base201is brought to rest by either segment chain, including segments210and220and pins207, contacting the workpiece30, slider202continues to translate under the action of gripper jaw52, relative to stationary base201. Such relative motion pulls adductor cable204, routed around pulleys205, downward through the central passages of segments210. Downward motion of cable204induces a CCW torque in segments210and220that causes the segments to rotate CCW in the direction of arrow17about pivot pins207, stretching abductor strip211and forcing pads215bonded to segments210and strip211bonded onto distal segment220into conformal contact with the surface of workpiece30.

Referring now toFIGS. 15 and 17, there is shown the tooling members100,200in the actuated, encapsulating position. The small black arrows denote both the direction of motion and the direction of the corresponding motive tension of adductor cables104,204as the cables104,204are drawn through the respective central passages of segments110,210.

In one form of the embodiment, the cross-sectional area of strip111is kept constant along the length of the strip and orthogonal distance22is kept constant for all segments while the value of orthogonal distance20for the proximal most segment110pinned to base101is chosen to be greater than the value of distance21for the remainder of the segments. The cross-sectional area of strip211is chosen to match that of strip111and the values for the orthogonal distances23,24, and25are chosen to match the values chosen for distances20,21, and22, respectively.

This form increases the force applied to the gripped workpiece by the proximal most segments110and210while reducing the forces applied to the workpiece by the remaining segments. Concentrating the force distribution toward the proximal end of the segment chains provides the advantage of reducing the moments generated about sliders102and202, by the finger chains during gripping, reducing the reaction forces between the bases and sliders and the frictional losses that arise from these reaction forces which reduce the efficiency of the gripper.

In another form of the embodiment, the cross-sectional area of strips111and211is progressively reduced from the proximal end to the distal end of each strip and orthogonal distances22and25are kept equal for all segments. The values of orthogonal distances20and23for the proximal most segments are made equal to values for distances21and24for the remainder of the segments.

This form causes the distal segments120and220to rotate first when the segment chain contacts the workpiece, with the remainder of the respective segment chains rotating in succession from the distal most to the proximal most segments. This manner of progressive distal to proximal rotation provides the advantage of pushing the contacted workpiece progressively toward the gripper, so that the gripped workpiece rests as closely as possible to the gripper.

It will also be apparent that the same manner of progressive distal to proximal segment rotation can be accomplished by choosing the values for orthogonal distances20and23for the proximal most segments to be less than the values of distances21and24for the remainder of the segments, with the local values of distances21and24progressively increasing from the proximal end to the distal end of each respective segment chain. This proximal to distal progression of pivot pin to adductor cable spacing can be performed either independently or in conjunction with the proximal to distal cross-sectional tapering of abductor strips111and211.

Referring now toFIG. 18, there is shown another embodiment of a gripper tooling in which the tooling members100and200upon gripper50are juxtaposed. This form provides for gripping during the opening, rather than the closing, of the gripper jaws51(not shown) and52. Such a manner of gripping is desirable when the workpiece is hollow such as a pipe, hoop or torus and needs to be gripped from the interior opening.

In another embodiment of the present invention, a magnet is added to sliders102and202and a magnet sensing switch is added to bases101and201, allowing each switch to detect the position of the respective slider relative to the respective base. Detecting relative motion between each respective slider and base provides a desirable means of electronically communicating the onset of contact between each tooling member and the gripped workpiece. This allows the gripper jaws51,52to move rapidly toward the workpiece, but then slow down to allow for a more precise gripping and/or for the gripping force to be limited until contact with a workpiece is detected and/or verified to be in a desired location in order to enhance operational concerns.

Referring now toFIGS. 19-20, there is shown another embodiment of the present invention which includes left and right tooling members300,400. The segment chains are chosen to resemble the number, size, shape, and physical proportions of a representative human finger or thumb. Right tooling member300comprises a single segment chain while left tooling member400comprises two or more segment chains. The segment chain of tooling member300can be chosen to comprise a proximal330, middle340and distal segment350to resemble a human finger or only a proximal330and distal350segment to resemble a human thumb. Each segment chain of tooling member400comprises a proximal430, middle440and distal segment450to resemble a human finger.

Referring now toFIGS. 21-24, there is shown another embodiment of the present invention which is configured to mount to an illustrative gripper with angular jaw travel70, such as the GRB series gripper manufactured by the PHD Corporation. Left tooling member500generally includes a single finger having a base501to which is attached a chain of multiple identical articulated segments510, capped by articulated distal segment520. Rotor502attaches left tooling member500to the left jaw71of gripper70with threaded fasteners73(not shown inFIG. 21). Right tooling member600generally includes a base601to which is attached two fingers having multiple identical articulated segments610, capped by identical articulated distal segments620. Rotor602attaches right tooling member600to the right jaw72of gripper70with threaded fasteners73(only one of two is shown inFIG. 21). Although the present embodiment illustrates similar finger construction for the left and right fingers, it should be appreciated by one skilled in the art that the articulated segments having the left and right fingers can also differ in quantity, overall dimensions, construction, and physical arrangement from those illustrated. It is also understood that left and right fingers need not be of similar construction to one another and that the quantity of fingers present on each tooling member can be varied without affecting the fundamental nature of the invention.

Referring now toFIG. 22, there is shown the left tooling member500. The pins517pass through complimentary holes in base501and are pressed into complementary holes in rotor502so as to allow the rotation of the rotor502with respect to the base501while preventing the translation of base501with respect to rotor502. Complimentary countersunk holes in rotor502allow the rotor to be mechanically fastened with threaded fasteners73(not shown inFIG. 22) to the left jaw71of gripper70.

The left tooling member500may include an adducting tendon504having a proximal end connected to the rotor502and a distal end connected to the distal segment520. The adducting tendon504may be in the form of a cable504. The cylindrical cleat518mechanically fastens the proximal end of the cable504to rotor502by compressing the cable504against cleat plate519, the vertical sides of which are disposed within complimentary slots within rotor502. The cylindrical ends of cleat518are suitably retained within angled complimentary slots within rotor502. In this manner, cable502is held frictionally captured by the action of cleat518against plate519. It should be appreciated that such mechanical attachment could also be affected with a suitable adhesive applied between the cable and the rotor. In one embodiment, the cable504is a polymer cable which offers the advantages over traditional steel cable of improved resistance to fatigue and corrosion, greater flexibility, improved dissipation of mechanical shock, and lower cost. Pulleys505, supported by pivot pins521pressed into complimentary holes in body501, route the motion of cable504so that as the proximal end of the cable is pulled by the rotation of rotor502relative to body501, cable504is drawn through the central passages of articulated segments510. Although pulleys505are shown as being directly supported by pivot pins506, it is understood that a suitable commercial bearing bushing, radial ball bearing, or needle bearing could be interposed between the pulley and pin when the size of pulley505is sufficiently large to allow doing so.

Pivot pins507pass though complimentary holes in base501and segments510and520to attach common segments510to base501, to each other, and to distal segment520, forming a chain of pinned articulated segments radiating outwards from base501. Although segments510and segment520are shown as being directly supported by pivot pins507, it should be appreciated that a suitable commercial bearing bushing, radial ball bearing, or needle bearing could be interposed between the pivot hole in the segments and pin507when the size of segment is sufficiently large to allow doing so.

The distal end of cable504is mechanically fastened to distal segment520with knurled cylindrical cleat508. However, it should be appreciated that such mechanical attachment could also be affected with a suitable adhesive applied between the cable and the segment. Cable504passes over pulleys509disposed within each identical segment510. In this manner, cable504, suitably attached between rotor502and distal segment520, effectively forms a taut adducting tendon located on one side of segment pivot pins507. Although pulleys509are shown as being directly supported by pivot pins506pressed into complimentary holes in segments510, it is understood that a suitable commercial bearing bushing, radial ball bearing, or needle bearing could be interposed between the pulley and pin when the size of pulley509is sufficiently large to allow doing so.

The strip511, constructed of a suitable elastomeric material, effectively forms an abducting tendon located on the opposing side of pivot pins507. The distal end of strip511is attached by suitable means, such as thermal or adhesive bonding, into a complimentary groove in distal segment520. The proximal end of elastomeric strip511is disposed within a complementary slot in body501and is attached to body501by the clamping action of set-screws512or by other suitable thermal or adhesive bonding. The portion of strip511between the distal and proximal attached ends is unconstrained and free to stretch or relax. Strip511is stretched during installation to create a tension in the strip which acts to pull distal segment520toward base501. This pull induces a torque in distal segment520and common segments510which acts to rotate each segment counterclockwise (CCW) with respect to pivot pins507. It should be appreciated that the strip511could be replaced by one or more helical extension springs or a flexible, but non-stretchable tensile member attached to a suitable spring to provide the same function as an elastomeric strip.

The bosses513, protruding from the sides of common segments510, engage complimentary slots514, in body501and segments510to constrain the angle of CCW rotation of the segment pinned to base501and each successive pinned segment in the segment chain, relative to the prior segment. Thusly constrained by the action of bosses513within slots514, the segments cannot rotate CCW about pivots507beyond a position in which the segments are in a straight, vertical alignment with one another.

Clockwise (CW) rotation of any segment under the influence of an external torque causes additional stretching of strip511, with a resulting increase in the torque applied by the strip to the CW rotated segment. In this manner, strip511functions as an abducting tendon which constantly applies a torque to segments510and520about pivot pin507to restore the segments into straight vertical alignment with one another. Downward motion of adductor cable504through the central passages of segments510induces a CW torque in segments510and520that causes the segments to rotate CW about pivot pins507, further stretching abductor strip511.

The pads515are suitably bonded into complimentary recesses in segments510. Pad522is suitably bonded into a complimentary recess in base501. The pads515and522are constructed of a material such as a suitable elastomer or a nanodiamond impregnated metal substrate, possessing a high coefficient of static friction, so as to enhance the frictional forces generated between the pad and any surface of the gripped workpiece that the pad might contact.

In an analogous manner to the cleat108mechanically fastening the distal end of cable104onto segment120, the cleat508fastens the distal end of cable504onto segment520. It should be appreciated that the same wedging action used by the cleat108to retain the distal end of cable104within distal segment120is also used by the cleat518to retain the proximal end of cable504in rotor502.

Referring now toFIG. 23, there is shown the right tooling member600. The pins617pass through complimentary holes in base601are pressed into complementary holes in rotor602so as to allow the rotation of the rotor with respect to the base while preventing the translation of base601with respect to rotor602. Complimentary countersunk holes in rotor602allow the rotor to be mechanically fastened with threaded fasteners73(not shown inFIG. 23) to the right jaw72of gripper70.

Pivot pins607pass though complimentary holes in base601and segments610and620to attach common segments610to base601, to each other, and to distal segment620, forming two chains of pinned articulated segments radiating outwards from base601. Although segments610and segment620are shown as being directly supported by pivot pins607, it is understood that a suitable commercial bearing bushing, radial ball bearing, or needle bearing could be interposed between the pivot hole in the segments and pin607when the size of segment is sufficiently large to allow doing so.

The right tooling member600may include an adducting tendon604having a proximal end connected to the rotor602and a distal end connected to the distal segment620. The adducting tendon604may be in the form of a cable604. The proximal center portion of cable604is routed around pulleys616which are supported by pivot pins606pressed into complimentary holes in rotor602. In one embodiment, the cable604is a polymer cable which offers the advantages over traditional steel cable of improved resistance to fatigue and corrosion, greater flexibility, improved dissipation of mechanical shock, and lower cost. The pulleys605, supported by pivot pins621pressed into complimentary holes in body610, route the motion of each end of cable604so that as the proximal center of the cable is pulled by the motion of rotor602relative to body601, each end of cable604is drawn through the central passages of articulated segments610of one of the two segment chains. Although pulleys605and616are shown as being directly supported by pivot pins621and606respectively, it is understood that a suitable commercial bearing bushing, radial ball bearing, or needle bearing could be interposed between the pulley and pin when the size of pulley605and/or616is sufficiently large to allow doing so.

Each distal end of cable604can be mechanically fastened to distal segment620of one segment chain with knurled cylindrical cleat608. It should be appreciated that such mechanical attachment could also be affected with a suitable adhesive applied between the cable and the segment. It should be further appreciated that the same wedging mechanism used by the cleat508to retain the distal end of cable504within distal segment520is also used to by the cleats608to retain each distal end of cable604in distal segments620.

Cable604passes over pulleys609disposed within each identical segment610. In this manner, each side of cable604, suitably attached between rotor602and distal segment620, effectively forms a taut adducting tendon located on one side of segment pivot pins607. Although pulleys609are shown as being directly supported by pivot pins606pressed into complimentary holes in segments610, it is understood that a suitable commercial bearing bushing, radial ball bearing, or needle bearing could be interposed between the pulley and pin when the size of pulley609is sufficiently large to allow doing so.

It may be desirable that each of the two segment chains of tooling member600may contact and conform to the profile of a gripped workpiece independently of one another. Such independent conformance assists during the gripping of workpieces possessing a plurality of asymmetric profiles by maximizing the number of contact points between the tooling and workpiece. The articulated motion of any segment chain ceases when that chain fully conforms to the profile of the gripped workpiece, causing motion of the end of cable604attached to the fully conformed segment chain to correspondingly cease and become stationary. The ability of the cable604to laterally translate across pulleys616subsequently allows the length of the cable to shift from the free end to the stationary end, allowing the free end of cable604to continue to be pulled by the action of rotor602rotating relative to body601. Once both segments chains have completely conformed to the workpiece, the ability of cable604to translate laterally across pulleys616further provides a way of equalizing the tension between the two ends of the cable604.

The strip611, constructed of a suitable elastomeric material, effectively forms an abducting tendon located on the opposing side of pivot pins607. The distal end of strip611is can be attached by any desired fastener or adhesive, such as thermal or adhesive bonding, into a complimentary groove in distal segment620. The proximal end of elastomeric strip611is disposed within a complementary slot in body601and is attached to body601by the clamping action of set-screws612or by other suitable thermal or adhesive bonding. The portion of strip611between the distal and proximal attached ends is unconstrained and free to stretch or relax. Strip611is stretched during installation to create a tension in the strip which acts to pull distal segment620toward base601. This pull induces a torque in distal segment620and common segments610which acts to rotate each segment CW with respect to pivot pins607. It will be understood by one skilled in the art that strip611could be replaced by one or more helical extension springs or a flexible, but non-stretchable tensile member attached to a suitable spring to provide the same function as an elastomeric strip.

The bosses613, protruding from the sides of common segments610, engage complimentary slots614, in body601and segments610to constrain the angle of CW rotation of the segment pinned to base601and each successive pinned segment in the segment chain, relative to the prior segment. Thusly constrained by the action of bosses613within slots614, the segments cannot rotate CW about pivots607beyond a position in which the segments are in a straight, vertical alignment with one another.

CCW rotation of any segment under the influence of an external torque causes additional stretching of strip611, with a resulting increase in the torque applied by the strip to the CCW rotated segment. In this manner, strip611functions as an abducting tendon which constantly applies a torque to segments610and620about pivot pin607to restore the segments into straight vertical alignment with one another. Downward motion of adductor cable604through the central passages of segments610induces a CCW torque in segments610and620that causes the segments to rotate CCW about pivot pins607, further stretching abductor strip611. It should be appreciated that the orientation of member600is reversed inFIG. 23when compared toFIG. 24.

The pads615are suitably bonded into complimentary recesses in segments610. The pad622is suitably bonded into a complimentary recess in base601. The pads615and622are constructed of a material such as a suitable elastomer or a nanodiamond impregnated metal substrate, possessing a high coefficient of static friction, so as to enhance the frictional forces generated between the pad and any surface of the gripped workpiece that the pad might contact.

Referring now specifically toFIG. 24, there is shown the tooling members500and600gripping the example of the cylindrical workpiece30. Once the base501is brought to rest by contact of pad522with workpiece30, rotor502continues to rotate in the direction of arrow29L under the action of gripper jaw71, relative to stationary base501. Such relative motion pulls adductor cable504, routed around pulleys505, downward through the central passages of segments510. Downward motion of the cable504induces a CW torque in segments510and520that causes the segments to rotate CW in the direction of arrow31about pivot pins507, stretching abductor strip511and forcing pads515bonded to segments510and strip511bonded onto distal segment520into conformal contact with the surface of workpiece30.

Once base601is brought to rest by contact of pad622with workpiece30, slider602continues to rotate in the direction of arrow29R under the action of gripper jaw72, relative to stationary base601. Such relative motion pulls adductor cable604, routed around pulleys605, downward through the central passages of segments610. Downward motion of cable604induces a CCW torque in segments610and620that causes the segments to rotate CCW in the direction of arrow32about pivot pins607, stretching abductor strip611and forcing pads615bonded to segments610and strip611bonded onto distal segment620into conformal contact with the surface of workpiece30. The motive tension of each adductor cable504,604as the cable504,604is drawn through the respective central passage of segments510,610is directed downwardly.