초록 ▼

The coupling of two tubular elements is achieved by welding them together by energization of an electrical resistance element, the one element comprising a male end, the other a socket end. The coupling operation is carried out by means of a composite connecting piece comprising two rings which are

The coupling of two tubular elements is achieved by welding them together by energization of an electrical resistance element, the one element comprising a male end, the other a socket end. The coupling operation is carried out by means of a composite connecting piece comprising two rings which are fitted on one another, one acting as a support for a bifilar electrical resistance element and the other as a sheath. The electrical resistance element is thus uniformly coated in plastic material and is accurately centered, thereby ensuring uniform heating and welding. This coupling method is for use in coupling discharge pipelines for waste water and rain water and for conduits for industrial fluids.

대표청구항 ▼

A connecting piece for electrical resistance welding of an inserted male end of one plastic pipe to the socket end of a second plastic pipe, said connecting piece constituting a sealing member interfitted between the male end and the socket end of said plastic pipes and comprising: two complementary

A connecting piece for electrical resistance welding of an inserted male end of one plastic pipe to the socket end of a second plastic pipe, said connecting piece constituting a sealing member interfitted between the male end and the socket end of said plastic pipes and comprising: two complementary concentric plastic rings fitted one to the other, said complementary rings comprising an internal ring having grooves on its radially exterior periphery, an electrical heating resistance element mounted within the base of said grooves, and an outer ring froming the sheath of the connecting piece and having an internal surface defining an attachment cavity which is cylindrical and smooth and having an inner diameter corresponding to the outer diameter of the inner ring, and wherein said internal ring is axially received by such outer ring and is concentric therewith, whereby said electrical heating resistance element is centered between said concentric pipe ends to insure by energizing said electrical heating resistance element uniform melting of the inner and outer rings and high integrity welding of the male end and socket ends of said pipes together.