Tools – Wrench – screwdriver – or driver therefor – Spanner
Reexamination Certificate
2002-10-17
2004-08-24
Wilson, Lee D. (Department: 3723)
Tools
Wrench, screwdriver, or driver therefor
Spanner
C081S124200, C081S125100, C081S461000
Reexamination Certificate
active
06779424
ABSTRACT:
FIELD OF THE INVENTION
The invention is generally related to apparatus for engaging a fitting. More particularly, the invention relates to wrench-likes tools for engaging a locknut such as employed with electrical connectors.
BACKGROUND OF THE INVENTION
Locknuts are typically screwed against the end of a pipe fitting or other conduit to hold the latter securely so as to provide an electrical ground. They commonly take the form of a collar having internal threads and may be constructed of various materials (e.g., metal, plastic) and come in a variety of shapes (e.g., hexagonal, square, round) and sizes.
One common application of locknuts is the securing of sections of electrical connectors within electrical junction boxes. A junction box thereby serves to join different runs of raceway or cable and provides space for the connection and branching of the enclosed conductors.
Locknuts used in association with electrical conduit are typically annular metal rings. The locknut includes a threaded inner surface for engaging a complementary threaded outer surface on the electrical connector. A series of projections known as lugs, commonly six or eight, extend radially from the ring. Between the lugs are rounded openings or scallops.
Conventional methods of tightening and loosening or removing locknuts include placing a screwdriver or similar device against one of the lugs and hitting the screwdriver with a hammer. This method, while effective, does not guarantee a tight fitting and has some inherent safety concerns.
One tool for engaging a locknut is disclosed in U.S. Pat. No. 2,522,038, issued to Houghton. Houghten discloses a wrench having a cage connected to a shank with a suitable handle thereon. An annular member is secured to the cage. A plurality of lug extensions extend therefore in spanner wrench fashion. The position of the extensions is such that they fit into the spaces between a pair of lugs of the locknut.
U.S. Pat. No. 2,575,779, issued to Young, discloses an electrician's wrench and reamer having a tool head which includes a pair of spaced prongs that are set apart so as to readily straddle a nut and fit the scallops. Each prong is configured to fit between a pair of adjacent lugs.
U.S. Pat. No. 5,524,511, issued to Taka's, discloses a locknut tool having a C-shaped handle. The handle includes a pair of shoulders that engage a lug when the wrench is fitted over a locknut. The position of the shoulders is such that they fit into the spaces between a pair of lugs of the locknut.
Because they result in only a limited amount of torque, these prior art tools are limited in their ability to tighten or remove a locknut. The need exists for a simple, efficient tool for tightening and removing locknuts.
SUMMARY OF THE INVENTION
One aspect of the invention provides a tool and method for engaging a nut, the nut being configured for engaging an abuting surface and having at least one laterally-extending projection. The tool comprises a base and a plurality of upstanding axially projecting tangs extending from the base for alternatively engaging opposing sides of the laterally-extending projection.
In one embodiment, the base is carried by a wrench. The base can be configured for releasable attachment to a socket wrench. The socket wrench can permit the apparatus to engage the nut in a ratcheting fashion.
Another aspect of the invention provides a tool and method for engaging a nut, the nut being configured for engaging an abuting surface and having at least one laterally-extending projection. The tool comprises a handle and a head carried by the handle and having a plurality of upstanding axially projecting tangs for alternatively engaging opposing sides of the projection.
According to yet another aspect of the invention, a second head is carried by the handle and has a plurality of upstanding axially projecting tangs for alternatively engaging opposing sides of the projection. The first and second heads may be of the same or of different size and configuration. Further, the first and second heads may have the same or different number of upstanding axially projecting tangs.
REFERENCES:
patent: 1752074 (1930-03-01), Gagne
patent: 2386011 (1945-10-01), Stanley
patent: 2496591 (1950-02-01), Maxwell
patent: 2522038 (1950-09-01), Houghton
patent: 2575779 (1951-11-01), Young
patent: 3161091 (1964-12-01), Searcy
patent: 3768345 (1973-10-01), Barnes
patent: 4848195 (1989-07-01), Hockenbery
patent: 5492040 (1996-02-01), Bellas
patent: 5524511 (1996-06-01), Taka's
patent: 6044732 (2000-04-01), Astle
patent: 6176157 (2001-01-01), Ure
patent: 2001/0022778 (2001-09-01), Ito et al.
Ryan Kromholz & Manion S.C.
Wilson Lee D.
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