GB985732A - Improvements in or relating to folding brakes - Google Patents

Abstract

985,732. Angular bending. KEETON SONS & CO. Ltd. Feb. 18, 1964 [Feb. 28, 1963], No. 8094/63. Heading B3E. In a folding brake of the kind described in Specification 957,853 having a pair of forming members 7, 8, Fig. 3, pivoted about a common axis 11, Fig. 5, and operated in unison to fold a sheet metal or like workpiece 22 about a hold down ram 21, the members 7, 8 are connected by links 10, 41, to a common actuating member 44 which is movable towards and away from the pivot axis to effect pivotal movement of the forming members. The latter are adjustably mounted in slideways on trunnions 10 pivoted on fixed pins; height setting of the members is effected by adjustment screws 18, Fig. 2. Member. 44 comprises a cross beam connected at each end by links 51 to an hydraulic ram 45. The rams 45 are supplied by a motor driven pump 54, Fig. 1 (not shown), through a control valve 56 closable by a handle 57 and having a catch 58 which can be tripped to open the valve by a collar 59 or rod 60 connected to one of the rams. Collar 59 is adjustable against a scale 63, Fig. 2, and when it opens the valve 56 pressure is released from the rams and the members 7, 8 are returned by gravity. Hold down ram 21, Figs. 2, 3, comprises separate carbon-steel blades 35 mounted in a cross bar 34 actuated by an hydraulic system or preferably by lead screws 25 driven through chain drives by an electric motor 28, Fig. 1 (not shown), fitted with a magnetic brake. The motor is stopped automatically by a rod 30 actuating upper and lower limit switches 32, 33. Work setting brackets 39 are mounted on either of the forming members. The hold down ram may be a cylindrical mandrel attached by a flange to the cross bar 34. Straining bars 37 are fitted to the ram 21 and the folding members 7, 8.