GB1014082A - Power operated rotary impact tool - Google Patents

Abstract

1,014,082. Nut runners. S. B. MAURER. Dec. 14, 1961, No. 7482/65. Divided out of 1,014,081. Heading B3N. [Also in Division F2] A rotary impact tool comprises a housine 10, an air motor formed by a reaction shaft 18, and a rotor assembly 13, including a hammer 14 surrounding and being capable of limited rotary motion relative to the shaft, to drive an anvil 11, the shaft and rotor assembly being rotatable relative to the housing. Shaft 18 is keyed to anvil 11, and the air motor comprises a cylinder 22 closed at its ends by a plate 23 and hammer 14. A vane 27, Fig. 6, is carried in a slot 26 in shaft 18, and a spring-urged vane 29 is carried in cylinder 22, thus dividing the cylinder into two chambers 30, 31. A hub 54 is slidably keyed to shaft 18 and frictionally engages a neoprene ring 56, which in turn frictionally engages a drum 57, these members forming an overload slip clutch. Mounted on drum 57 is a spring clutch 59, the forward end 60 of the spring being confined in a slot 62 in a bush 63 and the rearward end 61 being free to move slightly in a circumferential direction in a clearance groove 64. Hub 57 can move in the clockwise direction but is restrained from counterclockwise motion. When a manually operated button 65 is pushed inwardly, hub 54, ring 56, drum 57, and clutch 59, are moved and end 60 is moved out of slot 62, and end 61 moves into the slot thus reversing the action of clutch 59. In operation air is admitted to chamber 30 of the motor, and chamber 31 is exhausted through port 35, bore 38, port 39, and holes 40, Figs. 4, 8. Vane 29 and therefore cylinder 22 are moved in the counterclockwise direction until the vane passes the exhaust port 35, Fig. 5, at which time chamber 30 is connected to atmosphere, and chamber 31 is sealed off. Rotor 13 coasts in a counter-clockwise direction due to its kinetic energy. The rotor is first decelerated and then accelerated in the clockwise direction due to the pressure in chamber 31, until vane 29 again passes port 35. Hammer 14 impacts anvil 11, in a clockwise direction, and the rotor assembly rebounds to start a further cycle. Port 36, Fig. 5, is used for exhausting, when the tool rotates in the reverse direction. U.S.A. Specification 2,898,791 is referred to.