| 摘要 |
<p>The method is for manufacturing piston rings of steel from a thin narrow strip with parallel edges. This is bent into a uniform curve about an axis (X) at right angles to the centre line of the strip, by passing it between rollers whose axes are parallel to the axis (X). The curved strip is then subjected to a second bending operation but to a radius varying progressively over its length. The variable value of the second radius is determined by a rotary cam (10) driven in synchronism with the strip. In addition to the rollers (4,5,8) performing the first bending operation, there can be a second pair (11,12), whose axes (E,F) are parallel to the axis (X), but slightly offset in the travel direction (D) of the strip (31).</p> |
