A GUARD MEANS FOR MACHINES, MORE PARTICULARLY PRESSBRAKES, GUILLOTINES, STAMPING MACHINES AND THE LIKE

摘要

A guard means for machines, more particularly pressbrakes,guillotines, stamping machines and the like in the case ofwhich a first machine part (10) performs working movementstoward a second machine part (11). Between the machine partsa photoelectric detector arrangement {19 and 20) is positionedand is attached to the moving machine part (10), a stop meansbeing adapted to halt working motion of the moving machinepart on interruption of a light beam. A control means for theworking movement of the moving machine part (10) reduces thespeed immediately prior to light beam interruption by theother machine part (11) to below a threshold limit speed. Bymeans of a speed measuring means (25 and 26) the working speedis measured and the stop means is deactivated below thepredetermined threshold limit speed at least partially inorder to be able to complete the working movement even in thecase of interruption of the light beam by the other machinepart (11). Such a speed measuring means may be also fittedexternally to existing plant in a simple manner.