| 摘要 |
<p>Pipe elbows of thermoplastic material are obtd. by heating a straight tube to the temp. at which is can most easily be deformed, introducing a mandrel and bending the tube round a former. The mandrel consists of a number of blades which slide relatively to each other, and the fixture for bending the heated pipe has a fixed curved piece against which the pipe is pulled by a lever, the radius of which corresponds to the required curve of the pipe. Method is quicker, simpler, cheaper than filling with sand, low temp. melting metal, or using metal, formers, spiral coils, etc.</p> |
