Actuator and applications of same

An actuator for converting a rotating motion into a linear reciprocating motion, comprising:

• (a) a motor having a front end and an output worm shaft extending from the front end;
• (b) a transmission mechanism comprising:
• a bracket mounted onto the front end of the motor, having a base, and a fixing pin extending from the base along a direction perpendicularly to the worm shaft of the motor;
• a worm wheel having a first side, an opposite, second side, and a polygon-shaped recess defined in the second side and having flat sides and corners, the worm wheel attached onto the base through the fixing pin on the first side, and meshing with the worm shaft of the motor such that when the motor rotates along the worm shaft, the worm wheel rotates along the fixing pin perpendicularly to the worm shaft;
• and
• a connector having a first end portion and a second end portion extending oppositely from the first end portion, the first end portion being a unitary one-piece and formed in a polygon shape substantially complemental to that of the polygon-shaped recess such that the first end portion is tightly received in the polygon-shaped recess, so that when the worm wheel rotates along the fixing pin, the connector rotates together with the worm wheel along the fixing pin;
• and
• (c) an adjustable member operatively connected to the second end portion of the connector of the transmission mechanism, such that when the motor rotates along the worm shaft in one direction, the adjustable member is in an extending movement, and when the motor rotates along the worm shaft in the other direction, the adjustable member is in a retracting movement, wherein each of the extending movement and the retracting movement of the adjustable member is along the fixing pin perpendicularly to the worm shaft.