GB688435A - Improvements in presses, punches or the like - Google Patents

Abstract

688,435. Operating clutches. MASCHINENFABRIK WEINGARTEN AKT.-GES. March 7, 1951 [March 22, 1950; March 22, 1950], No. 5515/51. Class 80 (ii). In a clutch for a power press, punch or like machine, the driving flywheel 5 is arranged between a conical friction surface of a collar 11 adjustably secured to the machine shaft 1 and a flat friction surface of a sleeve 3 which is mounted on quick-pitch threads 2 on the shaft 1 and which constantly abuts, through a thrust bearing 10, against a non-rotating disc 8 between which and a second non-rotating disc 7 are arranged pre-stressed springs 6, the disc 7 co-operating with a conical friction surface of a collar 9 secured to the shaft 1. With the sleeve 3 arrested by a pawl 15 engaging a tooth 3a on the sleeve, the latter is displaced away from the flywheel to disengage the clutch and compress the springs 6, applying the brake disc 7 strongly against the shaft collar 9. If, however, the pawl is tilted to free the sleeve 3, the latter is displaced on the threads 2 by the springs 6 towards the flywheel to engage the clutch, the disc 7 remaining in light frictional contact with the collar 9 and the friction effect of the flywheel on the collar 11. being greater than that on the sleeve 3. The pawl carrier 16 is mounted on a rubber buffer 17. The pawl 15 is normally held in the path of the tooth 3a by a spring 22 and is tilted out of the path when an electromagnet 18 .is energised to attract a pivoted armature having a projection 19 engaging a bar 21 pivoted to the pawl. A cam 26 on the sleeve 3 coacts with an arm 20 to move the bar 21 positively back towards the end of the revolution so that, if the magnet has been de-energised, the clutch is disengaged and the brake applied at the end of the revolution. By means of other teeth 36-3e, the clutch may be disengaged, on de-energisation of the magnet, at various stages during the downstroke of the press.