ROERSAMLING

摘要

1473232 Pipe fitting WAVIN BV 26 April 1974 [27 April 1973] 18505/74 Heading F2G A pipe fitting comprises a female part, e.g. a double socket 1 of thermoplastic material including a tubular portion having an open end 4 and adapted to receive an end of a male pipe part 2, the tubular portion having internally an abutment 8 spaced from and facing towards open end 4 and having on its outside a centering formation for enabling the tubular portion to be centred and aligned reliably in a suitable holding device when inserting male pipe part 2 into the socket. The centering formation comprises an abutment face 9 or 911 on the exterior of the tubular portion, spaced from end 4 and facing towards end 4 and a bearing surface coaxial with the internal surface of the tubular portion and extending from abutment face 9 or 911 towards open end 4, the bearing surface being cylindrical 10 or 1011 or frusto-conical 101 increasing in diameter towards open end 4 of the tubular portion. The cylindrical surfaces may have helical ridges 11 to enable the holding device to be screwed on to the tubular portion and the frusto-conical bearing surfaces may be provided with transverse ridges 12 whereby the fitting can be gripped in the holding device. In the embodiment shown in Fig. 1 the double socket 1 can be regarded as two tubular portions connected together in the region of abutment 8 to provide two sockets. The double socket 1 may have a barrel-like shape externally, the radius of curvature of which, in an axial plane, may be from 6 to 12 times the internal diameter of each tubular portion and the total length of double socket 1 being equal to the outer diameter of pipe 2. The internal surfaces 61, 6 of the sockets are frusto-conical surfaces, whose generatrices make an angle up to 2À5 degrees with the longitudinal axis of the socket and the frusto-conical surfaces have their greatest outer circumference at the open ends 4 of the tubular portions. In other embodiments the pipe fitting is in the form of a bend, a branch piece, a T-piece or a stopper all of which have an external centering formation comprising an an abutment face and a bearing surface.