Patent Description:
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.

<CIT> discloses a mechanical finger having a base adapted to be connected to an actuator for being displaced in at least one degree of actuation, and two or more phalanges. <CIT> discloses a multitude of link bars that are sequentially interconnected from a link base to provide a multi-nodal link row. A slide shaft engaged with a shaft hole in the link base is fixed to a substrate, and tension springs are hung over both sides of the link base. Document <CIT> discloses another document with a swinging mechanism that improves the gripping action.

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

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.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

Referring now to the drawings, and more particularly to <FIG>, there is shown one embodiment of the gripper tooling mounted to an illustrative gripper with parallel jaw travel <NUM>, such as the GRH series gripper manufactured by the PHD Corporation. Left tooling member <NUM> consists of a single gripper "finger" including a base <NUM> to which is attached a chain of multiple identical articulated segments <NUM>, capped by an articulated distal segment <NUM>. A slider <NUM> attaches left tooling member <NUM> to the left jaw <NUM> of gripper <NUM> with threaded fasteners (not shown, see also <FIG>). Right tooling member <NUM> consists of a base <NUM> to which is attached two gripper fingers comprising multiple identical articulated segments <NUM>, capped by identical articulated distal segments <NUM>. A slider <NUM> attaches right tooling member <NUM> to the right jaw <NUM> of gripper <NUM> with 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 to <FIG>, there is shown the left tooling member <NUM>. Ribs protruding from the sides of slider <NUM> are disposed into complementary slots in the base <NUM> so as to prevent the rotation of the base <NUM> with respect to the slider and limit the translation of the base <NUM> in all directions except along the longitudinal axis of slider <NUM>. A bevel on the forward edge of slider <NUM> acts 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 jaw <NUM> of gripper <NUM>, moves towards the workpiece.

The left tooling member <NUM> may include an adducting tendon <NUM> having a proximal end connected to the slider <NUM> and a distal end connected to the distal segment <NUM>. The adducting tendon <NUM> may be in the form of a cable <NUM>. A lower knurled cylindrical cleat <NUM> may mechanically fasten the proximal end of the cable <NUM> to the slider <NUM>. However, in addition or alternatively to such mechanical attachment, the cable <NUM> may be attached with a suitable adhesive applied between the cable <NUM> and the slider <NUM>. The cable <NUM> may be composed of any desired material. In one embodiment, the cable <NUM> is 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 pulleys <NUM>, supported by pivot pins <NUM> pressed into complimentary holes in body <NUM>, route the motion of cable <NUM> so that as the proximal end of the cable <NUM> is pulled by the motion of slider <NUM> relative to body <NUM>, cable <NUM> is drawn through the central passages of articulated segments <NUM>. Although pulleys <NUM> are shown as being directly supported by pivot pins <NUM>, 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 pulley <NUM> is sufficiently large to allow doing so.

Pivot pins <NUM> pass though complimentary holes in base <NUM> and segments <NUM> and <NUM> to attach common segments <NUM> to base <NUM>, to each other, and to distal segment <NUM>, forming a chain of pinned articulated segments radiating outwards from base <NUM>. Although segments <NUM> and segment <NUM> are shown as being directly supported by pivot pins <NUM>, 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 pin <NUM> when the size of segment is sufficiently large to allow doing so.

The upper, distal end of the cable <NUM> may be mechanically fastened to the distal segment <NUM> with an upper knurled cylindrical cleat <NUM>. It is understood that such mechanical attachment could also be affected with a suitable adhesive applied between the cable <NUM> and the segment <NUM>. Cable <NUM> passes over pulleys <NUM> disposed within each identical segment <NUM>. In this manner, cable <NUM>, suitably attached between slider <NUM> and distal segment <NUM>, effectively forms the taut adducting tendon <NUM> located on one side of segment pivot pins <NUM>. Although pulleys <NUM> are shown as being directly supported by pivot pins <NUM> pressed into complimentary holes in segments <NUM>, 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 pulley <NUM> is sufficiently large to allow doing so.

The left tooling member <NUM> may include an abducting tendon <NUM>. An external strip <NUM> may effectively form the abducting tendon <NUM>, which is located on the opposing side of pivot pins <NUM>. The external strip <NUM> may be composed of a suitable elastomeric material. The distal end of the strip <NUM> is attached in any desired way, such as thermal or adhesive bonding, into a complimentary groove in distal segment <NUM>. The proximal end of elastomeric strip <NUM> is disposed within a complementary slot in body <NUM> and is attached to body <NUM> by the clamping action of set-screw <NUM> or by other suitable thermal or adhesive bonding. The portion of strip <NUM> between the distal and proximal attached ends is unconstrained and free to stretch or relax. The strip <NUM> is stretched during installation to create a tension in the strip <NUM> which acts to pull distal segment <NUM> toward base <NUM>. This pull induces a torque in distal segment <NUM> and common segments <NUM> which acts to rotate each segment counterclockwise (CCW) with respect to pivot pins <NUM>. It should be understood by one skilled in the art that strip <NUM> could 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.

Bosses <NUM>, protruding from the sides of common segments <NUM>, engage complimentary slots <NUM>, in body <NUM> and segments <NUM> to constrain the angle of CCW rotation of the segment pinned to base <NUM> and each successive pinned segment in the segment chain, relative to the prior segment. Thusly constrained by the action of bosses <NUM> within slots <NUM>, the segments cannot rotate CCW about pivots <NUM> beyond 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 strip <NUM>, with a resulting increase in the torque applied by the strip to the CW rotated segment. In this manner, strip <NUM> functions as an abducting tendon which constantly applies a torque to segments <NUM> and <NUM> about pivot pin <NUM> to restore the segments into straight vertical alignment with one another. Downward motion of adductor cable <NUM> through the central passages of segments <NUM> induces a CW torque in segments <NUM> and <NUM> that causes the segments to rotate CW about pivot pins <NUM>, further stretching abductor strip <NUM>.

Pads <NUM> are suitably bonded into complimentary recesses in segments <NUM>. Pads <NUM> are 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.

Dimension <NUM> indicates the orthogonal distance between the center of pivot pin <NUM> connecting the proximal most common segment <NUM> to base <NUM> and the centerline of adductor cable <NUM>. Dimension <NUM> indicates the orthogonal distance between the respective pivot pins <NUM> of the remaining segments and the centerline of cable <NUM>. Dimension <NUM> indicates the orthogonal distance between the pivot pins <NUM> of the remaining segments and the centerline of abductor strip <NUM>. The CW acting torque about pivot pins <NUM> applied to the various segments by the tension in adductor cable <NUM> is 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 cable <NUM>. In an analogous manner, the CCW acting torque about pivot pins <NUM> applied to the various segments by the tension in abductor strip <NUM> is 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 cable <NUM> when pulled upon is constant along the entire length of the cable, only the orthogonal distance between the center of the respective pivot pin <NUM> and cable centerline needs be varied to control the torque applied by cable <NUM> to any given segment. It will also be evident that the local tension in abductor strip <NUM> is 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 strip <NUM> along 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 strip <NUM>, the distance between the respective pivot pin <NUM> of the segment and the centerline of abductor strip <NUM>, and the distance between the respective pivot pin <NUM> of the segment and the centerline of adductor cable <NUM>. 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 cleat <NUM> mechanically fastens the distal end of adductor cable <NUM> to distal segment <NUM>. Cleat <NUM> is comprised of central cylinder 108C the outer diameter of which receives a straight knurl or other friction enhancing treatment such as a nanodiamond impregnated plating. Bosses 108A and 108B flank central cylinder 108C (<FIG>).

After installation of the cleat <NUM> into distal segment <NUM>, the surface of boss 108A rests against complimentary surface 120A in the cleat cavity within segment <NUM>, while the surface of boss 108B similarly rests against complimentary surface 120B. A complimentary relief 120C forms a cleat cavity 120C within segment <NUM> to prevent any portion of the central cylinder 108C of cleat <NUM> from contacting any portion of segment <NUM> (<FIG> and <FIG>). Central cylinder 108C is free to contact the surface of cable <NUM> which is pressed into contact with surface 120D of segment <NUM> by the action of central cylinder 108C. Angle <NUM> denotes the angle formed by surfaces 120A and 120B and cable contact surface 120D in segment <NUM>. Angle <NUM> is chosen to be shallow, in the range of <NUM> to <NUM> degrees. Arrow <NUM> indicates the force applied to cleat central cylinder 108A to install cleat <NUM> into cleat cavity 120C of distal segment <NUM>. While cable <NUM> is held taut, Force <NUM> is applied to the left of the axis of central cylinder 108C as cleat <NUM> is guided into the mouth of recess 120C, causing the surface of cylinder 108C to roll CCW against the surface of cable <NUM> while surfaces 108A and 108B slide against surfaces 120A and 120B, respectively. The acute nature of angle <NUM> creates a wedging action which decreases the space between surfaces 120A and 120B and 120D as cleat <NUM> moves progressively into recess 120C. This decrease in space progressively compresses cable <NUM> between the surface of cleat central cylinder 108C and surface 120D of segment <NUM> as the cleat <NUM> rolls along the surface of the cable <NUM>, until the cable <NUM> becomes completely jammed against surface 120D, stopping the entry of the cleat <NUM> into recess 120C. Arrow <NUM> indicates the direction of external tension in cable <NUM> as the cable is pulled by the action of slider <NUM> (<FIG>, <FIG>, and <FIG>). Tension applied in the direction of arrow <NUM> causes cleat <NUM> to rotate CW, with surfaces 108A and 108B rolling against surfaces 120A and 120B, respectively, which causes further compression of cable <NUM> against surface 120C by cylinder 108C. In this manner, any external tension applied to cable <NUM> in the direction of arrow <NUM> acts to proportionally increase the jamming force applied by cleat <NUM> against cable <NUM> to retain cable <NUM> against surface 120D.

It is understood that the same wedging mechanism used by cleat <NUM> to retain the distal end of cable <NUM> within distal segment <NUM> is also used to by the lower cleat <NUM> to retain the proximal end of cable <NUM> in slider <NUM>.

Referring now to <FIG>, there is shown the right tooling member <NUM>. Ribs protruding from the sides of slider <NUM> are disposed into complementary slots in base <NUM> so as to prevent the rotation of the base <NUM> with respect to the slider and limit the translation of base <NUM> in all directions except along the longitudinal axis of slider <NUM>. A bevel on the forward edge of slider <NUM> acts 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 jaw <NUM> of gripper <NUM>, moves towards the workpiece.

Pivot pins <NUM> pass though complimentary holes in base <NUM> and segments <NUM> and <NUM> to attach common segments <NUM> to base <NUM>, to each other, and to distal segment <NUM>, forming two chains of pinned articulated segments radiating outwards from base <NUM>. Although segments <NUM> and segment <NUM> are shown as being directly supported by pivot pins <NUM>, 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 pin <NUM> when the size of segment is sufficiently large to allow doing so.

The right tooling member <NUM> may include an adducting tendon <NUM> having a proximal center portion connected to the slider <NUM> and distal ends connected to the distal segments <NUM>. The adducting tendon <NUM> may be in the form of a cable <NUM>. The proximal center portion of cable <NUM> is routed around pulleys <NUM> which are supported by pivot pins <NUM> pressed into complimentary holes in slider <NUM>. In one embodiment cable <NUM> is 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. Pulleys <NUM>, supported by pivot pins <NUM> pressed into complimentary holes in body <NUM>, route the motion of each end of cable <NUM> so that as the proximal center of the cable <NUM> is pulled by the motion of slider <NUM> relative to body <NUM>, each end of cable <NUM> is drawn through the central passages of articulated segments <NUM> of one of the two segment chains. Although pulleys <NUM> are shown as being directly supported by pivot pins <NUM>, 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 pulley <NUM> is sufficiently large to allow doing so.

Each distal end of cable <NUM> can be mechanically fastened to distal segment <NUM> of one segment chain with knurled cylindrical cleat <NUM>. It is understood that such mechanical attachment could also be affected with a suitable adhesive applied between the cable <NUM> and the segment <NUM>. It is further understood that the same wedging mechanism used by cleat <NUM> to retain the distal end of cable <NUM> within distal segment <NUM> is also used to by cleats <NUM> to retain each distal end of cable <NUM> in distal segments <NUM>.

Cable <NUM> passes over pulleys <NUM> disposed within each identical segment <NUM>. In this manner, each side of cable <NUM>, suitably attached between slider <NUM> and distal segment <NUM>, effectively forms a taut adducting tendon located on one side of segment pivot pins <NUM>. Although pulleys <NUM> are shown as being directly supported by pivot pins <NUM> pressed into complimentary holes in segments <NUM>, 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 pulley <NUM> is sufficiently large to allow doing so.

It is desirable that each of the two segment chains of tooling member <NUM> may 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 cable <NUM> attached to the fully conformed segment chain to correspondingly cease and become stationary. The ability of cable <NUM> to laterally translate across pulleys <NUM>, as denoted by arrow <NUM> in <FIG>, subsequently allows the length of the cable to shift from the free end to the stationary end, allowing the free end of cable <NUM> to continue to be pulled by the action of slider <NUM> translating relative to body <NUM>. Once both segments chains have completely conformed to the workpiece, the ability of cable <NUM> to translate laterally across pulleys <NUM> further provides a way of equalizing the tension between the two ends of the cable <NUM>.

The strip <NUM>, constructed of a suitable elastomeric material, effectively forms an abducting tendon located on the opposing side of pivot pins <NUM>. The distal end of strip <NUM> is attached by suitable means, such as thermal or adhesive bonding, into a complimentary groove in distal segment <NUM>. The proximal end of elastomeric strip <NUM> is disposed within a complementary slot in body <NUM> and is attached to body <NUM> by the clamping action of set-screw <NUM> or by other suitable thermal or adhesive bonding. The portion of strip <NUM> between the distal and proximal attached ends is unconstrained and free to stretch or relax. The strip <NUM> is stretched during installation to create a tension in the strip which acts to pull distal segment <NUM> toward base <NUM>. This pull induces a torque in distal segment <NUM> and common segments <NUM> which acts to rotate each segment CW with respect to pivot pins <NUM> (<FIG>). It should be understood by one skilled in the art that the strip <NUM> could 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 member <NUM> is reversed in <FIG> when compared to <FIG>.

Bosses <NUM>, protruding from the sides of common segments <NUM>, engage complimentary slots <NUM>, in body <NUM> and segments <NUM> to constrain the angle of CW rotation of the segment pinned to base <NUM> and each successive pinned segment in the segment chain, relative to the prior segment. Thusly constrained by the action of bosses <NUM> within slots <NUM>, the segments cannot rotate CW about pivots <NUM> beyond 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 strip <NUM>, with a resulting increase in the torque applied by the strip to the CCW rotated segment. In this manner, strip <NUM> functions as an abducting tendon which constantly applies a torque to segments <NUM> and <NUM> about pivot pin <NUM> to restore the segments into straight vertical alignment with one another. Downward motion of adductor cable <NUM> through the central passages of segments <NUM> induces a CCW torque in segments <NUM> and <NUM> that causes the segments to rotate CCW about pivot pins <NUM>, further stretching abductor strip <NUM>.

Dimension <NUM> indicates the orthogonal distance between the center of pivot pin <NUM> connecting the proximal most common segment <NUM> to base <NUM> and the centerline of adductor cable <NUM>. Dimension <NUM> indicates the orthogonal distance between the respective pivot pins <NUM> of the remaining segments and the centerline of cable <NUM>. Dimension <NUM> indicates the orthogonal distance between the pivot pins <NUM> of the remaining and the centerline of abductor strip <NUM>. In analogous manner to member <NUM>, the cross-sectional area of corresponding abductor strip <NUM> and orthogonal distances between the pivot pins <NUM> and centerlines of strip <NUM> and abductor cable <NUM> can be similarly chosen to control the rotational order of each segment chain.

Referring now to <FIG>, there is shown the gripper tooling in its sequence operation as the gripper tooling engages an example of a workpiece <NUM>. In <FIG>, the left jaw <NUM> and right jaw <NUM> move the left tooling member <NUM> and the right tooling member <NUM> toward cylindrical workpiece <NUM>, in the direction of arrows <NUM> and <NUM>, respectively. During this motion, the segments comprising the left tooling member <NUM> and the right tooling member <NUM> are held in straight vertical alignment by the tension of the stretched elastomeric strips <NUM> and <NUM>, respectively. So long as all segments are vertically aligned, cables <NUM> and <NUM> remain taut, which prevents any relative motion between sliders <NUM> and base <NUM> and slider <NUM> and base <NUM>, as any relative motion between the sliders and bases require CW rotation of segments about pivot pins <NUM> or CCW rotation of the segments about pivot pins <NUM> (see also <FIG> and <FIG>). The bases <NUM> and <NUM> therefore move in conjunction with respective sliders <NUM> and <NUM>, as denoted by arrows <NUM> and <NUM>, respectively.

<FIG> shows tooling members <NUM> and <NUM> at the moment of initial contact with the workpiece <NUM>. As pad <NUM> on segment <NUM> contacts workpiece <NUM>, the finger formed by segments <NUM> and distal segment <NUM> pinned together by pivot pins <NUM> is brought to rest. Base <NUM> is also brought to rest by the action of segment <NUM> acting through the pinned connection to base <NUM> established by pivot pin <NUM>. However, slider <NUM> remains free to translate under the influence of jaw <NUM>, to which it is fastened, as denoted by arrow <NUM>. In an analogous manner, as pad <NUM> on segment <NUM> contacts workpiece <NUM>, the finger formed by segments <NUM>, distal segments <NUM>, and pivot pins <NUM> is brought to rest by contact with workpiece <NUM>. Base <NUM> is brought to rest by the action of segment <NUM> acting through the pinned connection to base <NUM> established by pivot pin <NUM>, while slider <NUM> remains free to translate under the influence of jaw <NUM>, as denoted by arrow <NUM>.

Referring now collectively to <FIG>, there is shown the tooling members <NUM> and <NUM> gripping the workpiece <NUM>. Once base <NUM> is brought to rest by the segment chain, including segments <NUM> and <NUM> and pins <NUM>, acting against workpiece <NUM>, slider <NUM> continues to translate under the action of gripper jaw <NUM>, relative to stationary base <NUM>. Such relative motion pulls adductor cable <NUM>, routed around pulleys <NUM>, downward through the central passages of segments <NUM>. Downward motion of cable <NUM> induces a CW torque in segments <NUM> and <NUM> that causes the segments to rotate CW in the direction of arrow <NUM> about pivot pins <NUM>, stretching abductor strip <NUM> and forcing pads <NUM> bonded to segments <NUM> and strip <NUM> bonded onto distal segment <NUM> into conformal contact with the surface of workpiece <NUM>.

Once base <NUM> is brought to rest by either segment chain, including segments <NUM> and <NUM> and pins <NUM>, contacting the workpiece <NUM>, slider <NUM> continues to translate under the action of gripper jaw <NUM>, relative to stationary base <NUM>. Such relative motion pulls adductor cable <NUM>, routed around pulleys <NUM>, downward through the central passages of segments <NUM>. Downward motion of cable <NUM> induces a CCW torque in segments <NUM> and <NUM> that causes the segments to rotate CCW in the direction of arrow <NUM> about pivot pins <NUM>, stretching abductor strip <NUM> and forcing pads <NUM> bonded to segments <NUM> and strip <NUM> bonded onto distal segment <NUM> into conformal contact with the surface of workpiece <NUM>.

Referring now to <FIG> and <FIG>, there is shown the tooling members <NUM>, <NUM> in the actuated, encapsulating position. The small black arrows denote both the direction of motion and the direction of the corresponding motive tension of adductor cables <NUM>, <NUM> as the cables <NUM>, <NUM> are drawn through the respective central passages of segments <NUM>, <NUM>.

In one form of the embodiment, the cross-sectional area of strip <NUM> is kept constant along the length of the strip and orthogonal distance <NUM> is kept constant for all segments while the value of orthogonal distance <NUM> for the proximal most segment <NUM> pinned to base <NUM> is chosen to be greater than the value of distance <NUM> for the remainder of the segments. The cross-sectional area of strip <NUM> is chosen to match that of strip <NUM> and the values for the orthogonal distances <NUM>, <NUM>, and <NUM> are chosen to match the values chosen for distances <NUM>, <NUM>, and <NUM>, respectively.

This form increases the force applied to the gripped workpiece by the proximal most segments <NUM> and <NUM> while 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 sliders <NUM> and <NUM>, 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 strips <NUM> and <NUM> is progressively reduced from the proximal end to the distal end of each strip and orthogonal distances <NUM> and <NUM> are kept equal for all segments. The values of orthogonal distances <NUM> and <NUM> for the proximal most segments are made equal to values for distances <NUM> and <NUM> for the remainder of the segments.

This form causes the distal segments <NUM> and <NUM> to 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 distances <NUM> and <NUM> for the proximal most segments to be less than the values of distances <NUM> and <NUM> for the remainder of the segments, with the local values of distances <NUM> and <NUM> progressively 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 strips <NUM> and <NUM>.

Referring now to <FIG>, there is shown another embodiment of a gripper tooling in which the tooling members <NUM> and <NUM> upon gripper <NUM> are juxtaposed. This form provides for gripping during the opening, rather than the closing, of the gripper jaws <NUM> (not shown) and <NUM>. 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 sliders <NUM> and <NUM> and a magnet sensing switch is added to bases <NUM> and <NUM>, 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 jaws <NUM>, <NUM> to 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 to <FIG>, there is shown another embodiment of the present invention which includes left and right tooling members <NUM>, <NUM>. The segment chains are chosen to resemble the number, size, shape, and physical proportions of a representative human finger or thumb. Right tooling member <NUM> comprises a single segment chain while left tooling member <NUM> comprises two or more segment chains. The segment chain of tooling member <NUM> can be chosen to comprise a proximal <NUM>, middle <NUM> and distal segment <NUM> to resemble a human finger or only a proximal <NUM> and distal <NUM> segment to resemble a human thumb. Each segment chain of tooling member <NUM> comprises a proximal <NUM>, middle <NUM> and distal segment <NUM> to resemble a human finger.

Referring now to <FIG>, there is shown another embodiment of the present invention which is configured to mount to an illustrative gripper with angular jaw travel <NUM>, such as the GRB series gripper manufactured by the PHD Corporation. Left tooling member <NUM> generally includes a single finger having a base <NUM> to which is attached a chain of multiple identical articulated segments <NUM>, capped by articulated distal segment <NUM>. Rotor <NUM> attaches left tooling member <NUM> to the left jaw <NUM> of gripper <NUM> with threaded fasteners <NUM> (not shown in <FIG>). Right tooling member <NUM> generally includes a base <NUM> to which is attached two fingers having multiple identical articulated segments <NUM>, capped by identical articulated distal segments <NUM>. Rotor <NUM> attaches right tooling member <NUM> to the right jaw <NUM> of gripper <NUM> with threaded fasteners <NUM> (only one of two is shown in <FIG>). 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 to <FIG>, there is shown the left tooling member <NUM>. The pins <NUM> pass through complimentary holes in base <NUM> and are pressed into complementary holes in rotor <NUM> so as to allow the rotation of the rotor <NUM> with respect to the base <NUM> while preventing the translation of base <NUM> with respect to rotor <NUM>. Complimentary countersunk holes in rotor <NUM> allow the rotor to be mechanically fastened with threaded fasteners <NUM> (not shown in <FIG>) to the left jaw <NUM> of gripper <NUM>.

The left tooling member <NUM> may include an adducting tendon <NUM> having a proximal end connected to the rotor <NUM> and a distal end connected to the distal segment <NUM>. The adducting tendon <NUM> may be in the form of a cable <NUM>. The cylindrical cleat <NUM> mechanically fastens the proximal end of the cable <NUM> to rotor <NUM> by compressing the cable <NUM> against cleat plate <NUM>, the vertical sides of which are disposed within complimentary slots within rotor <NUM>. The cylindrical ends of cleat <NUM> are suitably retained within angled complimentary slots within rotor <NUM>. In this manner, cable <NUM> is held frictionally captured by the action of cleat <NUM> against plate <NUM>. 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 cable <NUM> is 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. Pulleys <NUM>, supported by pivot pins <NUM> pressed into complimentary holes in body <NUM>, route the motion of cable <NUM> so that as the proximal end of the cable is pulled by the rotation of rotor <NUM> relative to body <NUM>, cable <NUM> is drawn through the central passages of articulated segments <NUM>. Although pulleys <NUM> are shown as being directly supported by pivot pins <NUM>, 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 pulley <NUM> is sufficiently large to allow doing so.

Pivot pins <NUM> pass though complimentary holes in base <NUM> and segments <NUM> and <NUM> to attach common segments <NUM> to base <NUM>, to each other, and to distal segment <NUM>, forming a chain of pinned articulated segments radiating outwards from base <NUM>. Although segments <NUM> and segment <NUM> are shown as being directly supported by pivot pins <NUM>, 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 pin <NUM> when the size of segment is sufficiently large to allow doing so.

The distal end of cable <NUM> is mechanically fastened to distal segment <NUM> with knurled cylindrical cleat <NUM>. However, it should be appreciated that such mechanical attachment could also be affected with a suitable adhesive applied between the cable and the segment. Cable <NUM> passes over pulleys <NUM> disposed within each identical segment <NUM>. In this manner, cable <NUM>, suitably attached between rotor <NUM> and distal segment <NUM>, effectively forms a taut adducting tendon located on one side of segment pivot pins <NUM>. Although pulleys <NUM> are shown as being directly supported by pivot pins <NUM> pressed into complimentary holes in segments <NUM>, 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 pulley <NUM> is sufficiently large to allow doing so.

The strip <NUM>, constructed of a suitable elastomeric material, effectively forms an abducting tendon located on the opposing side of pivot pins <NUM>. The distal end of strip <NUM> is attached by suitable means, such as thermal or adhesive bonding, into a complimentary groove in distal segment <NUM>. The proximal end of elastomeric strip <NUM> is disposed within a complementary slot in body <NUM> and is attached to body <NUM> by the clamping action of set-screws <NUM> or by other suitable thermal or adhesive bonding. The portion of strip <NUM> between the distal and proximal attached ends is unconstrained and free to stretch or relax. Strip <NUM> is stretched during installation to create a tension in the strip which acts to pull distal segment <NUM> toward base <NUM>. This pull induces a torque in distal segment <NUM> and common segments <NUM> which acts to rotate each segment counterclockwise (CCW) with respect to pivot pins <NUM>. It should be appreciated that the strip <NUM> could 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 bosses <NUM>, protruding from the sides of common segments <NUM>, engage complimentary slots <NUM>, in body <NUM> and segments <NUM> to constrain the angle of CCW rotation of the segment pinned to base <NUM> and each successive pinned segment in the segment chain, relative to the prior segment. Thusly constrained by the action of bosses <NUM> within slots <NUM>, the segments cannot rotate CCW about pivots <NUM> beyond a position in which the segments are in a straight, vertical alignment with one another.

The pads <NUM> are suitably bonded into complimentary recesses in segments <NUM>. Pad <NUM> is suitably bonded into a complimentary recess in base <NUM>. The pads <NUM> and <NUM> are 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 cleat <NUM> mechanically fastening the distal end of cable <NUM> onto segment <NUM>, the cleat <NUM> fastens the distal end of cable <NUM> onto segment <NUM>. It should be appreciated that the same wedging action used by the cleat <NUM> to retain the distal end of cable <NUM> within distal segment <NUM> is also used by the cleat <NUM> to retain the proximal end of cable <NUM> in rotor <NUM>.

Referring now to <FIG>, there is shown the right tooling member <NUM>. The pins <NUM> pass through complimentary holes in base <NUM> are pressed into complementary holes in rotor <NUM> so as to allow the rotation of the rotor with respect to the base while preventing the translation of base <NUM> with respect to rotor <NUM>. Complimentary countersunk holes in rotor <NUM> allow the rotor to be mechanically fastened with threaded fasteners <NUM> (not shown in <FIG>) to the right jaw <NUM> of gripper <NUM>.

The right tooling member <NUM> may include an adducting tendon <NUM> having a proximal end connected to the rotor <NUM> and a distal end connected to the distal segment <NUM>. The adducting tendon <NUM> may be in the form of a cable <NUM>. The proximal center portion of cable <NUM> is routed around pulleys <NUM> which are supported by pivot pins <NUM> pressed into complimentary holes in rotor <NUM>. In one embodiment, the cable <NUM> is 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 pulleys <NUM>, supported by pivot pins <NUM> pressed into complimentary holes in body <NUM>, route the motion of each end of cable <NUM> so that as the proximal center of the cable is pulled by the motion of rotor <NUM> relative to body <NUM>, each end of cable <NUM> is drawn through the central passages of articulated segments <NUM> of one of the two segment chains. Although pulleys <NUM> and <NUM> are shown as being directly supported by pivot pins <NUM> and <NUM> respectively, 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 pulley <NUM> and/or <NUM> is sufficiently large to allow doing so.

Each distal end of cable <NUM> can be mechanically fastened to distal segment <NUM> of one segment chain with knurled cylindrical cleat <NUM>. 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 cleat <NUM> to retain the distal end of cable <NUM> within distal segment <NUM> is also used to by the cleats <NUM> to retain each distal end of cable <NUM> in distal segments <NUM>.

Cable <NUM> passes over pulleys <NUM> disposed within each identical segment <NUM>. In this manner, each side of cable <NUM>, suitably attached between rotor <NUM> and distal segment <NUM>, effectively forms a taut adducting tendon located on one side of segment pivot pins <NUM>. Although pulleys <NUM> are shown as being directly supported by pivot pins <NUM> pressed into complimentary holes in segments <NUM>, 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 pulley <NUM> is sufficiently large to allow doing so.

It may be desirable that each of the two segment chains of tooling member <NUM> may 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 cable <NUM> attached to the fully conformed segment chain to correspondingly cease and become stationary. The ability of the cable <NUM> to laterally translate across pulleys <NUM> subsequently allows the length of the cable to shift from the free end to the stationary end, allowing the free end of cable <NUM> to continue to be pulled by the action of rotor <NUM> rotating relative to body <NUM>. Once both segments chains have completely conformed to the workpiece, the ability of cable <NUM> to translate laterally across pulleys <NUM> further provides a way of equalizing the tension between the two ends of the cable <NUM>.

The strip <NUM>, constructed of a suitable elastomeric material, effectively forms an abducting tendon located on the opposing side of pivot pins <NUM>. The distal end of strip <NUM> is can be attached by any desired fastener or adhesive, such as thermal or adhesive bonding, into a complimentary groove in distal segment <NUM>. The proximal end of elastomeric strip <NUM> is disposed within a complementary slot in body <NUM> and is attached to body <NUM> by the clamping action of set-screws <NUM> or by other suitable thermal or adhesive bonding. The portion of strip <NUM> between the distal and proximal attached ends is unconstrained and free to stretch or relax. Strip <NUM> is stretched during installation to create a tension in the strip which acts to pull distal segment <NUM> toward base <NUM>. This pull induces a torque in distal segment <NUM> and common segments <NUM> which acts to rotate each segment CW with respect to pivot pins <NUM>. It will be understood by one skilled in the art that strip <NUM> could 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 bosses <NUM>, protruding from the sides of common segments <NUM>, engage complimentary slots <NUM>, in body <NUM> and segments <NUM> to constrain the angle of CW rotation of the segment pinned to base <NUM> and each successive pinned segment in the segment chain, relative to the prior segment. Thusly constrained by the action of bosses <NUM> within slots <NUM>, the segments cannot rotate CW about pivots <NUM> beyond 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 strip <NUM>, with a resulting increase in the torque applied by the strip to the CCW rotated segment. In this manner, strip <NUM> functions as an abducting tendon which constantly applies a torque to segments <NUM> and <NUM> about pivot pin <NUM> to restore the segments into straight vertical alignment with one another. Downward motion of adductor cable <NUM> through the central passages of segments <NUM> induces a CCW torque in segments <NUM> and <NUM> that causes the segments to rotate CCW about pivot pins <NUM>, further stretching abductor strip <NUM>. It should be appreciated that the orientation of member <NUM> is reversed in <FIG> when compared to <FIG>.

The pads <NUM> are suitably bonded into complimentary recesses in segments <NUM>. The pad <NUM> is suitably bonded into a complimentary recess in base <NUM>. The pads <NUM> and <NUM> are 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 to <FIG>, there is shown the tooling members <NUM> and <NUM> gripping the example of the cylindrical workpiece <NUM>. Once the base <NUM> is brought to rest by contact of pad <NUM> with workpiece <NUM>, rotor <NUM> continues to rotate in the direction of arrow <NUM> under the action of gripper jaw <NUM>, relative to stationary base <NUM>. Such relative motion pulls adductor cable <NUM>, routed around pulleys <NUM>, downward through the central passages of segments <NUM>. Downward motion of the cable <NUM> induces a CW torque in segments <NUM> and <NUM> that causes the segments to rotate CW in the direction of arrow <NUM> about pivot pins <NUM>, stretching abductor strip <NUM> and forcing pads <NUM> bonded to segments <NUM> and strip <NUM> bonded onto distal segment <NUM> into conformal contact with the surface of workpiece <NUM>.

Claim 1:
A gripper tooling, comprising:
a gripper (<NUM>) having a gripper body and at least one jaw (<NUM>, <NUM>) connected and linearly sliding relative to the gripper body;
at least one slider (<NUM>, <NUM>) connected to the at least one jaw (<NUM>, <NUM>); and
at least one tooling member (<NUM>, <NUM>, <NUM>, <NUM>) configured for gripping a workpiece (<NUM>), each said tooling member (<NUM>, <NUM>, <NUM>, <NUM>) including:
a base (<NUM>, <NUM>) slideably mounted to the at least one slider (<NUM>, <NUM>);
at least one middle segment (<NUM>, <NUM>, <NUM>, <NUM>) pivotally connected to the base(<NUM>, <NUM>);
a distal segment (<NUM>, <NUM>, <NUM>, <NUM>) pivotally connected to the at least one middle segment (<NUM>, <NUM>, <NUM>, <NUM>);
an adducting tendon (<NUM>, <NUM>) having a proximal end attached to the at least one slider (<NUM>, <NUM>) and a distal end attached to the distal segment (<NUM>, <NUM>, <NUM>, <NUM>); and
an abducting tendon (<NUM>, <NUM>) having a proximal end attached to the base (<NUM>, <NUM>) and a distal end attached to the distal segment (<NUM>, <NUM>, <NUM>, <NUM>) such that the at least one tooling member (<NUM>, <NUM>, <NUM>, <NUM>) is configured for autonomously gripping the workpiece (<NUM>) as the at least one jaw (<NUM>, <NUM>) moves toward the workpiece and the at least one tooling member (<NUM>, <NUM>, <NUM>, <NUM>) is configured to autonomously return to an ungripped position as the at least one jaw (<NUM>, <NUM>) moves away from the workpiece (<NUM>),
the at least one tooling member (<NUM>, <NUM>, <NUM>, <NUM>) being configured to grip the workpiece (<NUM>) once the base (<NUM>, <NUM>) is brought to rest by the at least one tooling member (<NUM>, <NUM>, <NUM>, <NUM>) acting against the workpiece (<NUM>), after which the slider (<NUM>, <NUM>) is configured to continue to translate under the action of the gripper jaw (<NUM>, <NUM>) relative to the stationary base (<NUM>, <NUM>), thereby stretching the abducting tendon (<NUM>, <NUM>),
wherein an external strip composed of an elastomeric material or a spring functions as the abducting tendon (<NUM>, <NUM>) which is configured to constantly apply a torque to segments (<NUM>, <NUM>, <NUM>, <NUM>) to restore the segments.