20090056508 | Power Adjustable Wrench - An electric adjustable spanner comprises a spanner body, an adjustable jaw, an electromotor, a power supply, a switch and a gear transmission mechanism the spanner body is provided with a fixed jaw at the front end, the fixed jar is connected with the adjustable jaw to form an adjustable jaw space, the adjustable jaw is equipped with worm gear at the bottom to be engaged with a worm for driving said adjustable jaw to move back and forth, the output end of the gear transmission mechanism is engaged with said worm, the shaft of the electromotor is connected with the input end of the gear transmission mechanism. The electromotor, power supply and switch form a driving control circuit. The electric adjustable spanner is featured by that the gear transmission mechanism has at least three pairs of reduction gears. Compared with existing technologies, this invention has the advantages as follows: due to use of the gearing down transmission, the advancing speed of the adjustable jaw is optimized, the revolutions of the electromotor are reduced and the electric work efficiency is improved, the moving speed is stable with low noise, one end of the worm is fixed when the worm is rotated to the end, no buffering mechanism is required. | 03-05-2009 |