GB302061A - Improvements in means for safeguarding operators on power presses - Google Patents

Abstract

302,061. Wells, A. W. J. Dec. 22, 1027. Safety devices requiring both hands of operator to be occupied in starting and stopping machinery. - In power presses started by simultaneous actuation of two spaced handles, release of either before the ram has descended a safe distance trips the clutch and positively locks the driven shaft. Each of two actuating- handles M is coupled by arms M<1>, N<1>, a rock-shaft N, and an arm N<2> to one of a pair of spring-pressed bolts G, normally lying in the path of an arm F, which is pulled by a spring E<2> and is pivoted on a collar E fast on the press shaft A. The half-round clutch-key F<3>, adapted on depression of both bolts to coact with a notched driving-pulley (not shown), is operated by a complementary part F<2> of the pivot of arm F, on which is pivoted at H<1> a trigger H, pressed by a spring H<2>. Should either bolt G be prematurely released, it contacts with the tail H<4> of the trigger and projects the end H<3>, which is caught by a detent K, so rocking the arm F and key F<3>, the shaft A being arrested by an adjustable constantly-acting brake L and also positively locked. On withdrawing, by one hand, a spring-pin from a hole K<3> in the frame, the detent may be swung by the other hand about its pivot K<1> against spring- action, as shown by broken lines, so releasing the trigger H and allowing the press to finish its stroke. A lug K<4> on the detent obstructs a pin N<3> to prevent actuation of one bolt G while the safety device is inoperative.