Patent ID: 7481139

Claim:
A twisting spanner with an auto positioning assembly comprising: a spring ( 10 ) having two ends; each end of the spring ( 10 ) having a supporting seat ( 11 ); one end of each supporting seat ( 11 ) having a limiting post ( 12 ); the limiting post ( 12 ) being inserted in the spring ( 10 ); another end of each supporting seat ( 11 ) having a positioning body ( 13 ); a hollow cylinder installed at another end of the spring ( 10 ); a roller ( 21 ) being installed within the hollow cylinder ( 20 ) by using a shaft ( 211 ) to pass through the hollow cylinder ( 20 ) and the roller ( 21 ); the hollow cylinder ( 20 ) having two receiving holes ( 22 ) near the roller ( 21 ); each receiving hole ( 22 ) being received with a ball ( 23 ); thereby the roller ( 21 ) can roll easily; a cover ( 24 ) enclosing the hollow cylinder ( 20 ); a lower side of the cover ( 24 ) having a positioning groove ( 241 ); a periphery of the cover ( 24 ) having a round shape; thus, the hollow cylinder ( 20 ) can slide in the cover ( 24 ) smoothly without tilting; a pushing post ( 32 ) being located below the spring ( 10 ); a scale ( 31 ) being located below the pushing post ( 32 ) and an adjustable handle ( 30 ) being rotatably located below the scale ( 31 ); an upper center of the pushing post ( 32 ) having a positioning hole ( 321 ); a main arm ( 41 ) extending from a driving portion ( 40 ); a sleeve ( 42 ) enclosing the main arm ( 41 ), the hollow cylinder ( 20 ), spring ( 10 ) and the push post ( 32 ); one end portion ( 43 ) of the main arm ( 41 ) being extended with a pin ( 44 ) for engagement with the roller ( 21 ); and wherein in assembly, one of the positioning bodies ( 13 ) is located in the positioning groove ( 241 ) of the cover ( 24 ) and the other of the positioning bodies ( 13 ) is received in the positioning hole ( 321 ) of the pushing post ( 32 ) so that the spring ( 10 ) is retained in a straight state; when the pushing post ( 32 ) of the adjustable handle ( 30 ) presses the spring ( 10 ), the spring ( 10 ) still retains straightly; and thus the length of the spring ( 10 ) can be well controlled so that the twisting force for separating the roller ( 21 ) and the pin ( 44 ) at the end of the main arm ( 41 ) can be well adjusted.