T-joint fitting

Claim 1

In a T-joint fitting for attachment to and making a communication with an existing length of pipe, said fitting comprising a housing having a first semi-cylindrical face for engaging a portion of the circumference of said pipe, a clamping member having a second semi-cylindrical face for engaging an opposite portion of said circumference, as well as bolts for forcing said housing and said clamping member into sealing engagement with said pipe at a selected spot thereon, a first passage in said housing, extending transversely with respect to said semi-cylindrical surface and extending to both sides thereof, a second passage in said housing located at an angle to and communicating with said first passage, a piston defined by a front cutting edge and a back face, located in said first passage for axial displacement therein, said piston having a transversely extending passage, the improvement comprising, external threads on an open ended portion of said housing enclosing said first passage, the length of said portion being selected so with respect to the length of said piston, that said front cutting edge thereof will rest upon the outer surface of said piping, when the back face of said piston is about level with the open end of said portion of the housing, an explosive charge enclosed in a disc-shaped shell, said shell having a diameter larger than the diameter of said first passage and being provided with a socket for a firing cap, eccentrically located in the face of said shell to be turned outwards in use, and a cup shaped nut having internal threads mating with the external threads on said portion of the housing and having in its inward bottom face a recess for the reception of said firing cap containing socket, said recess being further adapted to make said cap accessible to a firing pin.