Abstract: An electric adjustable spanner comprises a spanner body, an adjustable jaw, a driving control circuit including an electromotor, a power supply, a switch and a gear transmission mechanism. the switch is a switch for controlling positive and reverse rotation of the electromotor. The switch comprises a button with two return springs at both ends respectively; the button has two parallel conductive contact blocks on the bottom of the button. A circuit board having metal foils on face and back sides thereof is located under the conductive contact blocks. The face metal foil forms a pair of output contact pieces, a pair of input contact pieces and a pair of transmission pieces at the lower part, and a pair of input terminals is riveted on the side of the circuit board against the button. When the button moves upward the output is positive and when the button moves downwards the output is reverse.

Abstract: 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.

Abstract: A power-operated tape measure includes an annular reel pivotally mounted on a fixing shaft in a case, a tape wound on the annular reel, a hook at one end of the tape extending out of the case through an outlet of the case. A motor respectively drives the annular reel and a large wheel for sending the tape via a gear train. A control circuit includes the motor, a power supply unit and a control switch controlling the motor for direct and reverse turning. A button member at the bottom of the case that can float upwards and downwards, inside which a small wheel is pivotally fixed to engage with the large wheel for sending the tape. The control switches control the extending of the tape and the withdrawal of the tape, the switch controlling the extending of the tape engaging the inside part of the button member.