GB655733A - Improvements in or relating to elevators, conveyors, hoists and the like of the endless chain type - Google Patents

Abstract

655,733. Endless-chain elevators. BULK PRODUCTS, Ltd. Aug. 24, 1948, Nos. 22315 and 32608. [Class 78 (i)] In an elevator having one or more endless carriers there is provided at each of several intermediate stations in the height of the elevator, two tension-relieving devices in the form of rotary or endless tracking members arranged in engagement with the rising and falling stretches respectively of the endless carriers, and coupled together for driving in unison in appropriate directions to those of travel of the two stretches. In the form shown in Fig. 2, each station comprises two endless driving chains 27, the driving dogs 24 of which engage pins 14 on two pairs of elevator chains 11 and 12 constituting respectively the rising and falling stretches and each pair supporting between them buckets 10. The driving chains 27 are mounted on upper and lower sprockets 22, 23, the upper ones being coupled together by a chain connection 29. Alternatively the driving chains may be replaced by sprockets engaging the rollers of the elevator chains. Such sprockets may be arranged as shown in Fig. 3 where 38, 39 are the driving sprockets and 36, 37 are idler sprockets. Preferably the pairs of driving sprockets are coupled by a differential gearing, Fig. 5, consisting of a bracket 46 on the shaft 40 of sprocket wheels 38, which bracket supports two planet gears 45 meshing with a sun gear 47 on a shaft 48 coupled by chains 44 to shaft 41 of sprockets 39. The planet gears also engage a ring gear 49 loosely mounted on shaft 48 which is resiliently held by springs to allow limited differential movement according to varying elevator chain tension. As an alternative to the differential gearing the shafts of the driving sprockets in the various constructions may be spring mounted. Preferably each station has a separate drive motor coupled to one pair of drive sprockets as indicated by the gearing 42. Specifications 588,450 and 638,723 are referred to.