GB607140A - Improvements in and relating to guards for machine tools - Google Patents

Abstract

607,140. Machinery guards. COLE, Ltd., E. K., and STEWARD, A. Jan. 26, 1946, No. 2618. [Classes 80 (ii) and 80 (iv)] Guarding means for bending machines or the like comprises a bracket 12 and guard 13, the latter being slidable over the former, the parts 12, 13 being locked in guarding position when the machine is started, and the guard 13 being raised during the latter part of the stroke of the tool F. Before starting the machine, a control lever 1, pivoted on an arm 2 of a transverse shaft 4, is pulled down to rotate the shaft 4 and release a pawl 5 from engagement with a slot in a disc 6 on the driving shaft C. At the same time a pawl 27, Fig. 3, connected by links 7, 8 to the. shaft 4 is moved out of the path of an arm 41 to permit actuation of the machine brake and clutch mechanism. Also arms 2, 2a on the shaft 4 carrying rods 10 connected to the bracket 12, move the latter downwardly. During this movement the bracket 12 is locked to the guard 13 by spring-actuated pawls 19, which are pivoted on the bracket 12 and engage stops 21 on the guard 13. As the guard is now in full guarding position, the machine is ready for actuation by the movement of the clutch control lever 33, Fig. 2. Movement of lever 33 actuates the arm 41 via a two-part link 31 and crank 40, and the beam E and tool F then make a working stroke. As the beam E descends brackets 20 thereon engage nuts 35 on rods 18, and collars 23 on the latter disengages the pawls and stops 19, 21, and on further downward movement nuts 38 on the rods 18 engage and pivot the levers 15, which by rods 16 partly raise the guard 13 to permit the work to be bent. As the beam E moves upwardly, the guard 13 drops back again to its full guarding position. Operating clutches.-To permit of only a single working stroke, one part of the link 31 carries a pivoted hook 30 which engages a pin 43 on the other link part. The hook 30 is connected to one end of a sliding rod 29, the other end of which lies in the path of an abutment 28 on the fly-wheel J of the machine. Thus, when a working cycle is nearly completed, the abutment 28 strikes and depresses the rod 29 to uncouple the parts of the link 31, whereupon counterweights (not shown) cause the crank 40 and arm 41 to return into the position to engage the brake and release the clutch. The bracket and guard 12, 13 return to the guarding position and the safety pawl 5 re-engages the slot in the disc 6. The bracket 12 may be in two parts, one at each end of the member, and the guard 13 may carry an adjustable extension 14.