| 摘要 |
PURPOSE:To simplify the constitution and to reduce the cost by bringing a counter weight moving relatively to a base into close contact with a guide rail by means of a couple of shaking members, a single coil spring and roller pairs. CONSTITUTION:The counter weight 50 moved relatively to the base moving vertically a disc grip means is guided by a rail 49 and a couple of vertical shaking members 55 are loaded to the end via a bracket 55a. A re-shaking member 55 is energized closely by a single coil spring 57, roller pairs 56 and roller pairs 59 are brought into contact with the inner face of the rail 49 so as to constitute a means for bringing the counter weight 50 into close contact onto the rail 49. Thus, the constitution of the energizing means is simple because one coil spring 57 is enough, and the cost is reduced. |
