| 摘要 |
<p>PCT No. PCT/GB86/00241 Sec. 371 Date Dec. 30, 1986 Sec. 102(e) Date Dec. 30, 1986 PCT Filed May 7, 1986 PCT Pub. No. WO86/06664 PCT Pub. Date Nov. 20, 1986.Friction welding apparatus comprises a housing (1, 2) and a workpiece support (20', 24) rotatably and axially movably mounted in the housing. An air driven motor (20) is coupled to the workpiece support (20', 24) to cause the workpiece support to rotate relatively to the housing. A compression spring (33) urges the workpiece support in a first axial direction relatively to the housing while a piston (7) responsive to air pressure is provided to move the workpiece support (20', 24) relatively to the housing (1, 2) in a second axial direction opposite to the first direction. Air under pressure is communicated through a common inlet (6) in the housing (1, 2) to a valve arrangement (8, 9, 13, 14) so that air is conveyed along a first path to the drive motor (20) and along a second path to the piston (7). The valve arrangement is such that axial movement of the piston (7) relatively to the housing (1, 2) causes the valve gradually to close thereby gradually stopping rotation of the motor (20). The second path remains open.</p> |
