| 摘要 |
<p>1,139,156. Machinery safety devices. MAY-PRESSENBAU G.m.b.H. 22 March, 1967 [26 March, 1966], No. 13506/67. Heading F2J. A safety device for a press having a ram 16 driven from a crank-shaft 24 by a connecting rod 20 comprises a pivoted safety member 50 which, on an unwanted stroke of the press, blocks the path of a stop 32 on shaft 24, the member 50 then acting on a push rod 72 which causes extrusion of a deformation member 66, thereby absorbing the energy of the machine. The safety member 50 is moved to and from its blocking position by a compressed air operable cylinder piston system 52. Three electro-switches 86, 88, 90 are arranged to be actuated by cams 96, 98, 100 fixed to a follower 58 of control member 52. Safety member 50 moves to its safety position if a power failure occurs, or if the machine control is switched off, the control circuit being closed in this position by switch 88. If the machine is switched to singlestroke operation and the operating buttons are pressed, the control device 52 rotates the safety member 50 to its release position, shown dotted. In the final phase of this rotating movement, cam 96 engages switch 86 which closes a circuit for starting the machine. When ram 16 reaches its lower dead centre position another switch actuates control device 52 so that safety member 50 is returned to its blocking position. When safety member 50 is lowered by stop 32, the circuit for the drive of the machine is switched off by cam 100 engaging switch 90, so that the drive is not subjected to any further load or stress if the working ram is blocked.</p> |
