GB971872A - Improved self-levelling device for receiving,storing and dispensing articles - Google Patents

Abstract

971,872. Self-balancing platforms; spring drums. AMERICAN MACHINE & FOUNDRY CO. Aug. 9, 1961 [Aug. 16, 1960; Oct. 26, 1960], No. 28838/61. Heading B8B. A self-levelling dispenser comprises a supporting platform 12, Fig. 1, guided for vertical movement by rollers 48 engaging vertical tracks 18 on a supporting base 10 and resiliently held in a position to maintain the top of the supported articles, material &c. at a constant height by means of flexible cables or bands 46 passing over pulleys 37 associated with a torsion spring. In one example the flexible bands 46 comprise steel strip fixed to an adjustable attachment 41 on the machine frame 40a, which may be rotated by a handle 43 to wind strip 46 on or off the pulley 37 to vary the effective radius arm according to the weight and dimensions of articles to be supported. The required setting is indicated by graduations 57 adjacent a slot 56 through which the wound strip 46 is visible. The handle 43 is locked in position by a pin (not shown). The torsion spring device comprises a coiled spring 30, Fig. 5, contained within a fixed tubular housing 22 forming part of the support 21 for the platform 12. One end of the spring 30 is attached by a pin 31 to a shaft 25 carrying the pulleys 37. The other end of the spring 30 is rotatably adjustable for varying the spring tension according to the load to be supported. For this purpose the spring is attached to a bush 29 rotatable by pins 32, Fig. 6, projecting through a slot 36 in the housing 22 and engaged in alternative recesses 33. In a modification, a similar spring housing 128, Fig. 11, may be mounted on the support frame 126 and supports the platform through cables 150 wound over conical drums 144 for varying the moment arm throughout the range of movement. With this arrangement the cable ends 150b, Fig. 13, are coupled to reels 156 which are rotatably adjustable by a shaft 157 on the platform 112 for varying the range over which the radius of the drums 144 operate according to the weights and dimensions of the articles to be supported. Notched members 122 may be interchangeably attached to the vertical tracks for engagement by the rollers at predetermined levels so that the carriage tends to come to rest at exact positions.