Device for gripping and installing wire
View Patent ↗A wire pulling grip easy and reliably grips wire for pulling the same through a conduit or the like. The grip has cams which maintain contact with the wire even when tension is not applied and regardless of the orientation of the grip, significantly reducing the likelihood that the connection with the wire is lost. The cams are selectively releasable to allow the wire to be easily removed from the grip.
1. A wire pulling grip comprising:
a body having a bore through which a wire may be passed, the body encompassing the bore;
a plurality of cams pivotably attached to the body, the plurality of cams being pivotable relative to the body between a first position where the plurality of cams extend into the bore of the body so as to grip the wire inserted in a first direction into the bore of the body and a second position where the plurality of cams extend outwardly from the body so as to release the wire to withdraw the wire from the bore of the body in a second direction opposite the first direction; and
a biasing element which biases the plurality of cams into the first position.
2. The wire pulling grip of claim 1 , wherein the biasing element is selectively movable between a first position adjacent the plurality of cams to contact and apply a force to the plurality of cams to bias the plurality of cams into the bore of the body and a second position away from the plurality of cams so that the biasing element does not contact the plurality of cams and does not apply the force to the plurality of cams.
3. The wire pulling grip of claim 1 , wherein the biasing element is a ring which extends around an outside of the body and contacts the plurality of cams.
4. The wire pulling grip of claim 1 , wherein the biasing element is disposed on an exterior portion of the body which is tapered so as to slope towards a pivot of the plurality of cams.
5. The wire pulling grip of claim 1 , further comprising a tube formed of a plurality of inter-woven wires, the tube comprising:
a first end attached to the body such that the wire may be passed through the body and into a lumen defined by the tube; and
a second end attachable to a pulling line.
6. The wire pulling grip of claim 1 , wherein the body further comprises a plurality of slots formed therein, and wherein each of the plurality of cams is disposed in one of the plurality of slots, and wherein the plurality of cams are pivotable so as to pass through the plurality of slots.
7. The wire pulling grip of claim 6 , wherein the biasing element extends around an exterior of the body and contacts the plurality of cams.
8. The wire pulling grip of claim 1 , wherein the plurality of cams are disposed radially about a single point along the length of the body.
9. A wire pulling grip comprising:
a generally tubular body having a bore therethrough, the body encompassing the bore;
a plurality of cams pivotably attached to the generally tubular body, the plurality of cams being pivotable relative to the generally tubular body between a first position where the plurality of cams extend into the bore of the generally tubular body so as to grip a wire inserted in a first direction into the bore of the generally tubular body and a second position where the plurality of cams extend outwardly from the generally tubular body so as to release the wire to withdraw the wire from the bore of the generally tubular body in a second direction opposite the first direction;
a biasing element for biasing the plurality of cams towards the center of the bore of the generally tubular body; and
a plurality of cables attached to an end of the generally tubular body, the plurality of cables being woven together so as to form a tube having a bore, and wherein the bore of the generally tubular body is in communication with the bore through the tube.
10. The wire pulling grip of claim 9 , wherein the biasing element is movable between a first position to contact and apply a biasing force to the plurality of cams and a second position where the biasing element does not contact the plurality of cams and does not apply the biasing force to the plurality of cams.
11. The wire pulling grip of claim 10 , wherein the biasing element is disposed around an exterior of the generally tubular body.
12. The wire pulling grip of claim 11 , wherein the biasing element is disposed around a portion of the generally tubular body which is tapered such that the biasing element reduces in size as the biasing element moves axially towards the plurality of cams.
13. The wire pulling grip of claim 9 , wherein each of the plurality of cams is disposed in a slot formed through the generally tubular body, and wherein the biasing element extends around the generally tubular body so as to contact the plurality of cams.
14. The wire pulling grip of claim 9 , wherein the plurality of cams are spaced out radially about a single point along the length of the generally tubular body.
15. The wire pulling grip of claim 9 , further comprising a loop for connecting the wire pulling grip to a pulling line, the loop being disposed at an end of the tube opposite the generally tubular body.
16. The wire pulling grip of claim 15 , wherein the loop is formed from a proximal end of the plurality of cables.
17. A wire pulling grip comprising:
a body having a bore therethrough, the body encompassing the bore;
a plurality of cams pivotably attached to the body, the plurality of cams being pivotable relative to the body between a first position where the plurality of cams extend into the bore of the body so as to grip a wire inserted in a first direction into the bore of the body and a second position where the plurality of cams extend outwardly from the bore and the body so as to release the wire to withdraw the wire from the bore of the body in a second direction opposite the first direction;
a biasing element for biasing the plurality of cams towards the bore of the body; and
a tube formed of woven wires attached to the body, the tube defining a lumen which is aligned with the bore of the body.
18. The wire pulling grip of claim 17 , wherein the biasing element is movable to a position where the biasing element does not contact the plurality of cams and does not bias the plurality of cams.