Force-responsive elastomeric gripper

Claim 2

In a force-responsive, elastomeric gripper having a rotatable member carrying an axially fixed flange, a flange and sleeve movable axially relative to said fixed flange as a function of the rotational torque applied to said member, cam means for moving said movable flange axially toward said fixed flange as said torque turns said fixed flange relative to said movable flange, and an elongated elastomeric ring supported on said sleeve between said fixed flange and said movable flange to be squeezed axially between said flanges for moving radially for gripping as said movable flange moves toward said fixed flange, the improvement comprising: a. said elastomeric ring extending from said fixed flange to said movable flange; b. said elastomeric ring in unstressed condition having a gripping surface that is crowned in an axially central region and is generally convex in axial cross-section; c. the surface of said elastomeric ring opposite said gripping surface being generally concave in axial cross section in said unstressed condition; d. said sleeve having a generally cylindrical surface engaging and supporting each end region of said elastomeric ring in said unstressed condition, said cylindrical surface being spaced from said axially central region of said elastomeric ring in sAid unstressed condition only by said concavity of said opposite surface; e. said axially central region of said elastomeric ring being forceable radially into engagement with the full axial length of said cylindrical support surface; and f. said support surface of said sleeve and said opposite surface of said elastomeric ring having mating ridges and grooves preventing relative rotation between said sleeve and said elastomeric ring.

Claim 3

The gripper of claim 1 wherein said gripping surface of said elastomeric ring faces radially outward for gripping the inside of a core.

Claim 4

The gripper of claim 1 wherein said gripping surface of said elastomeric ring faces radially inward for gripping the outside of a shaft.

Claim 5

The gripper of claim 1 wherein said mating ridges and grooves of said opposite surface of said elastomeric ring and said support surface of said sleeve are arranged as mating splines.

Claim 6

The gripper of claim 1 wherein said cam means comprises opposed, arcuate, and relatively rotatable cam surfaces having deep central regions and relatively shallow end regions, and ball bearings between said cam surfaces for spreading said cam surfaces apart as a function of the relative rotation of said cam surfaces positioning said ball bearings at various depths in said cam surfaces.

Claim 7

The gripper of claim 5 including a retainer plate between said cam surfaces and having apertures for holding said ball bearings.

Claim 8

The gripper of claim 1 wherein said cam means comprises opposed, linear, and relatively rotatable cam surfaces arranged symmetrically around the axis of rotation of said cam surfaces, said cam surfaces having deep central regions and relatively shallow end regions, and ball bearings between said cam surfaces for spreading said cam surfaces apart as a function of the relative rotation of said cam surfaces positioning said ball bearings at varying depths in said cam surfaces.

Claim 9

The gripper of claim 7 including a retainer plate between said cam surfaces and having apertures for holding said ball bearings.

Claim 10

The gripper of claim 8 having three opposed pairs of said cam surfaces arranged parallel with the legs of an equilateral triangle.

Claim 11

The gripper of claim 1 wherein said cam means comprises pairs of opposed arcuate cam surfaces and a pair of rollers rotatable between said pairs of cam surfaces for spreading said cam surfaces apart as a function of the relative rotation of said cam surfaces positioning said rollers at various rises on said opposed pairs of cam surfaces.

Claim 12

The gripper of claim 1 wherein said member is a shaft having a plurality of said fixed flanges; said sleeve is movable axially of said shaft radially inside said fixed flanges and carries a plurality of said movable flanges; and a plurality of said elastomeric rings are arranged around said sleeve between said fixed flanges and said movable flanges.

Claim 13

The gripper of claim 1 including means for axially adjusting one of said flanges to pretension said elastomeric ring.

Claim 14

The gripper of claim 12 wherein said axial adjustment means comprises two flange parts axially threaded together.

Claim 15

A force-responsive, elastomeric gripper comprising: a. a lifting shaft; b. a flange fixed to a lower region of said lifting shaft; c. a flange and sleeve movable axially relative to said fixed flange and said shaft as a function of the axial lifting force applied to said shaft; d. an elongated elastomeric ring supported on said sleeve and extending between said fixed flange and said moving flange to be squeezed axially between said flanges for moving radially for gripping the inside of a core as the space between said flanges reduces; e. said elastomeric ring in unstressed condition having a gripping surface that is crowned in an axially central region and is generally convex in axial cross section; f. the surface of said elastomeric ring opposite said gripping surface being generally concave in axial cross section in said unstressed condition; g. said sleeve having a generally cylindrical surface engaging and supporting each end region of said elastomeric ring in said unstressed condition, said cylindrical sleeve being spaced from said axially central region of said elastomeric ring in said unstressed condition only by said concavity of said opposite surface; h. said axially central region of said elastomeric ring being forceable radially into engagement with the full axial length of said cylindrical support surface; i. means for firmly engaging the inside of an upper end region of said core to hold said movable flange in place and to initially position said gripper relative to said core; j. said elastomeric ring being further inward into said core from said initial core engaging means; and k. said fixed flange being further inward into said core from said elastomeric ring so that axially upward lifting motion of said shaft relative to said initial core-engaging means raises said fixed flange and squeezes said elastomeric ring radially outward for gripping, in addition to said initial core engaging means, and lifting said core as a function of said lifting force.

Claim 16

A force-responsive, elastomeric gripper comprising: a. a lifting shaft; b. a flange fixed to a lower region of said lifting shaft; c. a flange and sleeve movable axially relative to said fixed flange and said shaft as a function of the axial lifting force applied to said shaft; d. an elongated elastomeric ring supported on said sleeve and extending between said fixed flange and said moving flange to be squeezed axially between said flanges for moving radially for gripping the inside of a core as the space between said flanges reduces; e. said elastomeric ring in unstressed condition having a gripping surface that is crowned in an axially central region and is generally convex in axial cross section; f. the surface of said elastomeric ring opposite said gripping surface being generally concave in axial cross section in said unstressed condition; g. said sleeve having a generally cylindrical surface engaging and supporting each end region of said elastomeric ring in said unstressed condition, said cylindrical sleeve being spaced from said axially central region of said elastomeric ring in said unstressed condition only by said concavity of said opposite surface; h. said axially central region of said elastomeric ring being forceable radially into engagement with the full axial length of said cylindrical support surface; i. means for firmly engaging the inside of an upper end region of said core to hold said movable flange in place and to initially position said gripper relative to said core; j. said elastomeric ring being further inward into said core from said initial core engaging means; and k. said fixed flange being further inward into said core from said elastomeric ring so that axially upward lifting motion of said shaft relative to said initial core-engaging means raises said fixed flange and squeezes said elastomeric ring radially outward for gripping, in addition to said initial core engaging means, and lifting said core as a function of said lifting force.

Claim 17

The gripper of claim 14 wherein said initial core-engaging means includes another one of said elastomeric rings around said sleeve, and means for squeezing said other elastomeric ring radially outward for said firm engagement with said core.