Patent GB-1469444-A (GB)
Title: Production line apparatus for perforating girders
IPC: B21D28/24
Filed: 1974-06-18
Abstract: 1469444 Punching C BEHRENS AG 18 June 1974 [6 July 1973] 26968/74 Heading B3W A production line for perforating girders, Fig. 1, comprises means 6, 7 for feeding and guiding girders along a feed path and at least one mechanically and/or hydraulically actuated punching machine A located adjacent, and to one side of, the path, the tools of the or each machine being mounted in a frame which is horizontally movable relative to the machine at right angles to the feed path. The punching machine A, Fig. 4, for perforating the horizontally disposed web 17 of a girder 15 comprises a C frame 22 slidable in a fixed C-frame 21 by a motor driven worm gear 40 or a rack (not shown). The frame 22 carries guides 42, 43 slidable in grooves in frame 21 and runs on spring-loaded shoes 45. Turrets 36, 37 with drive 38 and a station selector 39 are mounted in the frame 22. Each punch has a cam-controlled stripper sleeve (51), Fig. 5. The punch drive is by motor driven crank-shaft 28 and incorporates an hydraulically-actuated toggle overload protection device 33-35. A girder to be punched is fed on to a driven roller table up to stops 9 by devices 11 which comprise vertically adjustable pushers (114), Figs. 18 and 19 (not shown) hydraulically actuated and maintained in engagement with the centre of the girder flange by cam means (117), (118). The girder is fed against a spring-loaded stop 10 by grippers 6 on a reciprocable slide 5. Each gripper comprises an electromagnetic holder 97 freely movable to engage a girder flange, even if the flange is not parallel with the feed direction, by means of a ball mounting 99 and urged into such engagement by springs (100) and a pneumatic cylinder (102). The holder 97 is clamped in its operative position by slides (103), (104) urged by a pneumatic cylinder (109) against wedge faces on the pin carrying the ball 99. The grippers can be lowered to avoid fouling a punch, by means of a pneumatic cylinder (110). Electric switches (111-113), Fig. 15, limit the movements of the grippers. Engagement of the girder with the stop 10 causes a pneumatic cylinder to lower the stop out of the path of the girder which is then fed at a lower speed to the punching machine A. A sensing device 13 comprising a roller (124), Fig. 23 (not shown) pressed against the girder flange 16 by a fluid cylinder (129) actuates a measuring unit (128) when the flange deviates from a predetermined line. The unit (128) is connected to a numerical control device which controls the travel of the frame 22 normally to the feed path. A sensing device 14 (Figs. 4 and 24, not shown) acts on the opposite flange. Following the web punching machine A are horizontally-acting punching machines B and C for perforating the girder flanges 16, 16<SP>1</SP> respectively. The machines B and C are mounted on a cross-beam 57 which is movable vertically with them and along which they are horizontally movable. Each machine comprises a rotary turret 78 with punches 58 surrounded by spring-actuated strippers 88 and driven by a crank to coact with dies 59. A forked tool (95) is provided for removing spring- loaded retaining pins (93) and then the die from a die shoe (91), Figs. 11-14 (not shown). Rollers 67, Fig. 8, engaging the flange to be perforated actuate an hydraulic cylinder 65 to move the respective punching machine, via an hydraulic copying valve 66, until the flange is centred in the gap between the selected die and punch. The beam 57 is then lowered and the machine moved horizontally to locate the die against the flange to be punched. Sensors (69), (70) associated with the rollers cause the machine to be retracted if at least one registers the absence of girder to be punched. Further sensors (71), (72) cause retraction if a girder with a web width greater than that of the previous girder is fed to the machine.