GB427569A - Improvements in or relating to friction couplings - Google Patents

Abstract

427,569. Friction couplings. HALL, C. T., and MOLINS MACHINE CO., Ltd., 2, Evelyn Street, Deptford, London. Dec. 21, 1933, No. 35951. [Class 80 (ii)] A friction coupling comprises a pair of shoes 4 pivotally or slidably mounted on a flange 1 of the driving (or driven) shaft 2 and normally urged by spring means into contact with a driven (or driving) drum 3 so as to provide a slipping drive, control means being provided whereby the shoes can, at will, be moved positively against the drum so as to provide a substantially non-slipping drive. As shown, the free end of each shoe is acted on by one arm of a lever 6 pivoted on the flange 1, the other arm of the lever pivotally carrying a bell-crank lever 8, one arm of which carries a roller 13 engaging a control sleeve 14 slidable on the shaft 2 and having two conical parts 15 and 16 separated by a cylindrical part 17. The other arm of the lever 8 carries an adjustable screen 10, a spring 12 being interposed between the lever 6 and a flange 11 of the screw 10. A spring 24 tends to move the shoes away from the drum 3. The screw 10 is so adjusted that, so long as the roller 13 contacts with the part 15 or 17 of the sleeve 14, the screw 10 does not contact with the lever 6, and the latter is thus controlled by the spring 12. But when the sleeve 14 is moved to bring the roller 13 into contact with the part 16, the screw 10 contacts with the lever 6 and the levers 6 and 8 thus function as a rigid unit. Alternatively, the lever 6 may be actuated directly by the sleeve 14, a spring acting directly on the shoe or on the end of the lever ; or two sets of shoes may be provided, one set being spring loaded and the other set being positively actuated.