1. Field of the Invention
The present invention relates to a device for locking the jaws of an adjustable wrench around a pipe to minimize the possibility that the wrench will slip or fall loose from the pipe. More particularly, the invention relates to a detachable jaw-locking device for a pipe wrench having an extendable locking member which extends across the jaw opening of the wrench to enclose the open end of the wrench and lock the jaws around the pipe.
2. The Prior Art
The use of pipe wrenches at substantial heights by workmen on a construction site is a common occurrence. The fact that such wrenches have an open side and rely on applied pressure from the user to maintain a grip on the pipe, creates serious safety hazzards to both workmen and other persons below the work site. Often, the wrenches are carelessly released or may simply be left engaged around a pipe or other object. In either case, the wrenches can easily slip, or otherwise become dislodged and fall. This risk is further exaggerated by the substantial weight of the pipe wrench as compared with other wrenches or tools of common use.
U.S. Pat. Nos. 504,232 and 2,517,041 disclose wrenches having spring biased jaws for better gripping, but neither was intended to solve the additional problems described hereabove. Even though spring biased jaws help lessen the risk of dislodging a pipe wrench engaged around a pipe, the jaw opening of the engaged wrench provides a potential escape route for any such wrench when released, jarred or otherwise disturbed.
From the foregoing, it will be appreciated that what is needed in the art is a device which is capable of enclosing the open end of an adjustable pipe wrench and firmly locking its jaws around a pipe, regardless of the size of the jaw spread. Such an invention is described herebelow.