GB713538A - Improvements connected with dynamometers - Google Patents

Abstract

713,538. Rotary-absorption dynamometers. GARRETT, F. A. July 9, 1952 [July 12, 1951], No. 16593/51. Class 106 (2) A hydraulically controlled dynamometer comprises two upright brake levers 14 coupled at their upper ends by fluid pressure operated loading cylinders 25 and at their lower ends by brake shoes 9, the levers 14 being mounted on intermediate pivots 16. The brake drum 5 is mounted in bearings 4 on a fixed base 2, and the brake shoes 9 are pivotally connected together at their lower ends by a pin 10 fitted with rollers 11 bearing on the arcuate upper surfaces 12 of hardened steel plates 13 fixed to the base 2. In operation, with the drum 5 rotating, a pump 34 is operated to apply fluid pressure to the cylinders 25 so that the levers 14 are thrust apart at their upper ends to bring the brake shoes 9-9 into engagement with the drum 5, thus applying a frictional load to the dynamometer. According to the direction of rotation of the drum 5 one or other of the levers 14 will be caused to press at its upper end 30 against one of two reaction cylinders 29, the resulting pressure in the reaction cylinder 29 being transmitted by a pipe 75 to a cylinder and a ram operating a pendant lever 72 of a steelyard arm 68. A loading weight 175 is then shifted along the steelyard arm 68 until the arm is horizontal The reaction cylinders 29 are arranged such that they are tangential to the arcuate path of movement of the levers 14. The free end of the arm 68 moves between electric contacts 79, 80 to control the motor circuit of an electric motor 77 moving the weight 175. The motor 77 is coupled to a counter the reading of which, when a balance has been obtained, is a measure of the torque exerted by the drum 5. Alternatively, the movement of the arm 68 between the contacts 79, 80 is adapted to control the motor circuit of an electric motor 37 driving means for feeding the loader cylinders 25. The fulcrum pins 16 are connected together by arms 17 but are provided with quick release means to release the load on the brake drum 5. Specifications 563,534 and 693,171 are referred to.