GB288398A - An improved power press - Google Patents

Abstract

288,398. Boorne, W. H. Feb. 3, 1927. Presses, mechanical.-Relates to power presses of the type wherein the ram plate is carried by oppositely disposed vertical toggles connected at their knees to horizontal toggles actuated by a vertical reciprocatory element, and consists in providing sets of toggles extending across the ram plate with the innermost toggles connected at their knees to the other toggles of their set by links; also the provision of differential gear for actuating the reciprocatory element. As shown, the ram plate is suspended on sets of toggles 17 hung from pivots 18 and having the knees of the innermost toggles connected to the others by links and also connected to horizontal toggles 16, the joints of which are pivotally connected to a vertical threaded shaft 10. A shaft 1 drives through a worm 3 a gear 4 carrying bevel pinions 7 engaging a crown wheel 5 fixed to a sleeve 8 splined to the shaft 10 and a crown wheel 6 fixed to a threaded sleeve 11. A beam 21 is connected at its upper and lower ends to arms carrying dogs 14, adapted to 'engage respectively with recesses 12 and 13 in the sleeves 8 and 11 whereby the sleeve 8 may be held to cause descent of the shaft 10 or the sleeve 11 held for its ascent, or both may be disengaged to give a dwell. The beam 21 is operated by a hand or foot lever or by automatic timing mechanism comprising an arm 31, Fig. 2, connected at one end to dogs 32 on the beam and furnished at the other with a roller 30 engaging a stepped cam 29 having surfaces 34 - - 37 corresponding to pressure, dwell, lift and dwell respectively. Step-by-step movement is imparted to the cam by a spring pawl 27 which is rocked by interchangeable dogs 23, 24, 25 on a disc 22 integral with the gear 4, the pawl being shifted by a link 33 connected to the arm 31 to bring a projection 26 into range of the appropriate dog. For large presses the shafts 10 are duplicated and are operated by threaded sleeves turned in one direction or the other by a rack controlled by timing-gear.