US 6,745,648 B2Granted

Lock-nut wrench

AssigneeSpecialty Welding & Fabricating of New York, Inc.

InventorRandal J. Stier

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Abstract

A lock-nut wrench has an elongated handle and a head at one or both ends of the handle. The head or heads have right and left arcuate jaws with distal ends that define a gap and each jaw has a first radially inwardly directed tooth at its distal end and a second radially inwardly directed tooth spaced proximally from it, defining spaces to accommodate diametrically opposed lugs. An offset can join each head to the handle. The inside of the head, that is, the inside of the jaws proximal of the second teeth, define a cylindrical surface that matches the radial outer extent of the lock nut lugs. The wrench can operate as a spanner, and can accommodate either a six- or an eight-lug lock nut. The handle is coated with an insulating plastic material. The ends of the jaws can be snubbed or hog-nosed. The wrench head may be adapted for use with a socket wrench handle. The wrench can be formed by laser-machining sheet or plate metal stock.

Claims14

Dependent claims

A lock-nut wrench for tightening lock nuts that secure metal conduit to a metal electrical box, in which the lock nuts have a generally annular body with a female thread that engages a male thread on the conduit and a plurality of regularly spaced, radially-directed lugs, at least some of which have a portion that engages a metal wall of the electrical box when rotated tight on the conduit;

said lock-nut wrench comprising handle means for permitting the wrench to be gripped by an electrician for turning, and a head situated at one end of said handle means, said head including right and left arcuate jaws having distal ends that define an opening sufficient to pass over the associated conduit, and each said jaw having a first radially inwardly directed tooth at its distal end and a second radially inwardly directed tooth spaced proximally therefrom;
said first and second teeth of each jaw defining therebetween a space to accommodate one lug of said lock nut, with the space of each jaw being diametrically opposed with the corresponding space of the other jaw;
with the remainder of said jaws proximal of said second teeth being free of further teeth and defining a cylindrical surface, of at least about 90 degrees of arc, that matches the outer extent of at least one lug of said lock nut.

Dependencies are inferred from the claim text.