초록 ▼

The present invention relates to a method and a mould for forming an expansion, such as a socket, in a plastic pipe, and a plastic pipe. According to the method, the heated end of the pipe is placed in an external mould (2) and pressed against the mould surface (6) to form a socket. Two grooves (8,

The present invention relates to a method and a mould for forming an expansion, such as a socket, in a plastic pipe, and a plastic pipe. According to the method, the heated end of the pipe is placed in an external mould (2) and pressed against the mould surface (6) to form a socket. Two grooves (8, 9) can be formed in the socket by a simple method, using a mould ring (12) which is separate from the other parts (3, 4) of the mould and by means of which the grooves of the socket are formed. The ring is simultaneously locked into the socket (7), thereby functioning as a reinforcement ring.

대표청구항 ▼

In a method for forming an expansion in a plastic pipe in a mould provided with an inner mould surface and including a ring shaped mould body having only two axially successive parts relatively moveable in the axial direction of the said mould body for closing and opening said mould, the improvement

In a method for forming an expansion in a plastic pipe in a mould provided with an inner mould surface and including a ring shaped mould body having only two axially successive parts relatively moveable in the axial direction of the said mould body for closing and opening said mould, the improvements comprising the steps of: inserting a mould ring into said mould body, the surface of said mould ring forming at least a part of said inner mould surface; closing said mould body; heating at least the part of said pipe which is to be formed as an expansion; placing said pipe part in said mould body; applying an internal pressure inside said pipe part to expand the same against said inner mould surface and thereby form said expansion and to lock said mould ring to said expansion; cooling said pipe part; opening said mould body; and removing said pipe part from said mould together with said mould ring which is locked to said expansion.