GB356453A - Improvements relating to guards for presses and other like machines - Google Patents

Abstract

356,453. Controlling machinery guards. UDAL, J. P., 91, Oakfield Road, Selly Park, Birmingham. Aug. 27, 1930, No. 25557. [Class 80 (iv).] In guards for presses &c. of the kind having a main guard-member b, c, i pivoted on the machine frame to swing outwardly and a secondary guardmember f, g, h pivoted on the main member, the secondary member alone is positively driven from a moving part of the press &c., the main part being moved against gravity or a spring d only if the operator's hand is trapped between the bars h, i of the two members, the actuating-linkage being preferably designed to impart greater movement when the hand is so caught. In one form, an arm m on the crank shaft n drives through a link o a bell-crank lever p, q of adjustable angularity mounted on the pivot a of the main guard-part b &c., the lever-arm q being connected by a link r to the secondary part f &c. The links are so proportioned that normally, when the part f &c. swings freely through the part b &c., as shown in Fig. 2, the links q, r come into alignment, but if the hand is caught, causing movement of the main guard-part, the links q, r are not aligned, whereby greater movement is imparted, as shown in Fig. 3. The member b &c. is held in its idle position by an adjustable stop x contacting with the machine frame under the spring d. In a modification, Figs. 4-6 (not shown), motion is taken from a bracket on the slide k by similar linkage, which may be augmented for larger guards by an intermediate bell-crank lever pivoted on one of the side-members b and linked to the secondary guard and bell-crank lever p, q.