| 摘要 |
A safety device comprising an obstacle-detecting sensor and a plate cam pivotally coaxially mounted on a forceful reciprocation machine which has a stationary block and a reciprocating member adapted for vertical reciprocation thereto, the plate cam and the sensor being turned coextensively over a first angular range until the sensor reaches the stationary block and thereafter the plate cam alone continuing to be turned over a second angular range, whereupon a deflection formed on the periphery of the plate cam is brought into engagement with a switch roller thereby activating the reciprocating member. |
