| 摘要 |
<p>A deadman switch (4) comprises a push plate (5), a shaft (7) provided on the push plate (5), a dog plate (6) fitted onto the shaft (7), a plurality of bosses (34), a spacer (9) fitted onto the shaft (7), a spring (8) provided on an outer periphery of the shaft, and three-point type limit switches (41, 42) mounted on a rear plate (3) and constructed such that the dog plate (6) can engage with dogs (41a, 42a) to turn the limit switches off with the dogs kept free, to turn the limit switches on when the dog plate (6) pushes the dogs (41a, 42a) slightly, and to turn the limit switches off when the dog plate (6) further push the dogs (41a, 42a) against the spacer (9) and the spring (8). It is possible to provide a fail-safe hand-held operating unit for robots which is exceedingly safe, since the limit switches are surely turned off in a panic such as runaway of robots and the like even when an operator strongly holds the hand-held operating unit tight in his hand. <IMAGE></p> |
