Patent GB-582076-A (GB)
Title: Improvements relating to guards for tool-presses
IPC: F16P3/04
Filed: 1944-07-31
Abstract: 582,076. Machinery guards RUBERY, OWEN, & CO., Ltd., and ARMSTRONG, T. W. July 31, 1944, No. 14557. [Class 80 (iv)] In a tool press the usual push-pull rod or the like, which controls the clutch and brake mechanism, includes a controllable coupling which is operable by the guard control mechanism so that, provided there is no obstruction to the guard, the clutch and brake control means is operated only at each alternate depression of the main control pedal. For a tool press having stationary and movable tools 12, 13, Fig. 1, guardplates 18 are connected to levers 20 mounted on a shaft 21 which has fixed to it plates 42, Fig. 6, the tips 41 of which engage a catch 40 to hold the guard plates 18 in their unguarding position. A shaft 35, Fig. 10, carrying the catch 40 also has a catch 33 cooperating with a pawl 32 pivoted at 36 to a body 28 and biassed by a spring 38. A spring 29 biasses a pin 30 on the body 28 against a stop 31 and the catch 33 against a peg 34. The body 28 is connected by a cable 25 to a pedal 17. A coupling 15 serves to couple and uncouple rods 14, 16, of which rod 16 is connected to the pedal 17 and 14 leads to the clutch-and-brake mechanism of the press. The coupling 15 includes a plate 68 pivoted at 67 to the rod 14 and having a slot 69 engageable with a pin 65 on the rod 16. Plate 68 also has a V-shaped slot 71 engaged by a pin 72 on a plunger 62 which is spring-biassed downwardly. A cable 26 is connected at one end to the plunger 62 and at the other end to a quadrant 55 on a shaft 54, Fig. 8. The latter has a trip plate 53 co-operating with a catch-plate 46, Fig. 6, free on the shaft 21 and connected by a tension spring 48 to the plates 42. A catch 49 pivoted on a pin 79 on the plates 42 co-operates with an abutment block 51 and carries rollers 43, 44. The latter engage a cam 45 on a shaft 58 which moves with the press shaft and also has a cam 59 engageable with a roller 60 on the trip plate 53. In operation, with the guard 18 raised the tips 41 of the plates 42 engage the catch 40 and the catch plate 46 engages the trip plate 53 so that the plunger 62 is in its highest position with the pin 72 holding the plate 68 out of engagement with the pin 65 on rod 16. Depression of the pedal 17 therefore actuates only the cable 25 to trip the catch 33 and release the catch 40 from the plates 42. The guard 18 thus descends under gravity and the plates 42 move clockwise, Fig. 6. If, and only when, there is a full movement of the guard the catch 49 engages under the abutment 51 and the plates 42 engage the catch plate 46 at 47 and free it from the trip plate 53 permitting the plunger 62, on release of the pedal 17, to move downwardly and move the plate 68 to unconnect the rods 14, 16. A second depression of the pedal 17 will thus, through the parts 14, 15, 16, actuate the press so that the shaft 58 rotates. The cam 45 thereon, through the rollers 43, 44, disengages the catch 49 from the abutment 51 and lifts the plates 42 and guard 18. The adjustment of this cam 45, which may have a vernier adjusting device, is such that the guard will be raised just before the tools act on the work. After completion of the press cycle the cam 59 strikes the roller 60 on the trip plate 53 to rock the shaft 54 and disconnect the rods 14, 16. At the same time the catch plate 46 under the action of the spring 48 moves to hold the trip plate 53. The various parts of the mechanism are arranged so that safety is ensured even if failure of parts thereof occurs Specification 547,349 is referred to.