PURPOSE: To connect two pipes together having a relatively small wall thickness by using a cylindrical driver made of shape memory alloy and an insert interposed between this driver and two pipes to be joined, constituting a pipe fitting which accomplishes connection of pipes by means of pressing of these driver and insert, therein embodying the insert from a plurality of rings held at a certain spacing with the aid of retainers.
CONSTITUTION: An insert 2 in the form of corrugated pipe made of stainless steel etc. is fitted in a cylindrical driver 1 made of a shape memory alloy in stainless steel series, and pipes to be joined 10 are inserted from the two sides of this insert 2. The insert 2 consists of a plurality of rings 3 held at a certain spacing with the aid of retainers 4. The driver 1 is dia. contracted by heating, and the pipes 10 are squeezed from the periphery by the insert 2. Thus the pipes 10 are deformed, which generates a resistant force working against being drawn out, and also seal is provided by the insert 2. As a result, the wall thickness of the driver made of shape memory alloy can be lessened, and the cost be suppressed.
ONO YOSHIMI
HONMA HIROSHI
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