GB1413984A - Adjustable crank shaft assembly - Google Patents

Abstract

1413984 Adjustable throw cranks; eccentrics; toothed gearing JOSEPH RHODES & SONS Ltd 26 Jan 1973 [8 Feb 1972] 5923/72 Headings F2K and F2Q In a variable throw compound crank or eccentric, particularly for presses, wherein the connecting rod 9 embraces an eccentric bush 7 which is rotatably adjustable on the crank or eccentric 4 of the crank-shaft 1, the throw of the crank or eccentric is power adjusted from a remotely controlled reversible electric motor 51 which via a chain drive 47-50 and disconnectable spur gearing 46-37 drives epicyclic eccentric stepped integral planet gears 31, 30 i.e. floating ring gear 29 meshing sun gears 25, 24 formed on the crank web 5 and bush 7 respectively, the sun 24 planet 30 being of slightly larger diameter and greater number of teeth and different gear ratio than the sun 25 and planet 31 whereby as the floating ring 29 rolls around the sun 25 the bush 7 is driven round the crankpin 4, i.e. adjustably advanced, by a small increment for each revolution of the ring 29. Power drive to the ring gear 29 for crank throw adjustment is effected from the spur gear 37 via a slotted plate 34, 35, drivingly carried thereby, engaging a roller 33 of an eccentric disc 27 joirnalled on the crank web 5 and peripherally engaging the ring gear 29 whereby as the gear 37 rotates on crank-shaft axis AA the eccentric disc 27 having on axis DD is rotated about crank-pin axis BB to roll the ring gear 29 around sun gears 25, 24. A pneumatically operated axially slidable splined sleeve 14 serves to releasably lock the eccentric bush 7 to the crankshaft 1 in any required setting, after adjustment, via coaxial splines 12, 13 formed on the bush 7 and a ring keyed at 13a on the crank web 6. The spur gearing includes a pinion 42 carried by a carriage 43 pivoted about a pinion 41 with which the pinion 42 is in constant mesh. The carriage 43 is controlled by a pneumatic cylinder 44 whereby the carriage 43 may be rocked forward to mesh the pinion 42 with pinion 46 of the electric motor chain drive for power adjustment of the crank throw, or the carriage may be rocked backward (Fig. 2), during normal press operation, to mesh the pinion 42 with an idler pinion 52 meshing a gear 54 of the same size and number of teeth as gear 37 and keyed to the crank-shaft whereby during normal crank-shaft operation of the press the gear 37 is effectively rotatably locked to the crank-shaft to prevent relative rotary movement thereto. During crank throw adjustment, a counter device (not shown) gives a reading directly proportional to the number of revs of gear 41 and hence the degree of crank throw adjustment effected.