Abstract: A retractable column structure includes an outer tubular member (10), a retaining bracket (20) and an inner tubular member (30). The outer tubular member (10) includes a wall (11) having outer (111), inner (112) and end (113) surfaces. The outer tubular member (10) includes slots (114) extending from the end surface (113) to the inner surface (112). A rear end of each slot (114) includes a protrusion (115) protruding out of the inner surface (112). The retaining bracket (20) includes a frame member (21) abutted against the wall (11) and locking hooks (22) inserted into the inner surface (112) and locked onto each corresponding protrusion (115). The inner tubular member (30) moveably penetrates into the retaining bracket (20) disposed between the tubular members and is concealed inside the outer tubular member (10). Accordingly, excellent support of inner and outer tubular members can be achieved for stable sliding therebetween.

Abstract: An elevating post includes a transmission (10), a driver (20), an outer tube (30) and a moving assembly (40). The driver (20) is connected to the transmission (10). The outer tube (30) receives the transmission (10) and the driver (20) and has a tube body (31) with a longitudinal trough (311). Two closed sections (312, 313) are separately disposed outside two ends of the longitudinal trough (311). The moving assembly (40) is operatably connected to the transmission (10) and has a plate (43) protruding from the tube body (31) by passing through the longitudinal trough (311) and being movable in the longitudinal trough (311).

Abstract: A linear actuator includes a sliding rod, a motor and a buffer assembly. The motor connects the sliding rod to drive the sliding rod. The buffer assembly is disposed at an end of the sliding rod and includes an elastic element and an outer sleeve. The elastic element is received in the outer sleeve. The sliding rod connects the outer sleeve. The outer sleeve is movable along an axial direction of the sliding rod. The elastic element separately pushes an inner wall of the outer sleeve and the sliding rod. The elastic element is pre-compressed along the axial direction of the sliding rod. The buffer assembly can absorb vibration and impact caused by the motor driving the sliding rod.

Abstract: An actuator with switchable releasing speed includes an actuation rod, a screw, and a motor. The motor drives the screw rotating so that the actuation rod axially moves relative to the screw. The motor includes a stator, a rotor, a plurality of commutators, and at least three brushes. The at least three brushes have a positive brush, a negative brush, and at least one auxiliary brush. The positive brush is connected to a positive DC voltage. One of the negative brush and the least one auxiliary brush is adjusted to connect to a negative DC voltage so as to change a rotational speed of the rotor, thereby controlling a movement speed of the actuation rod. Accordingly, the releasing speed of the actuator is switchable.

Abstract: A linear actuator includes a housing, motors, actuator members, clutch members, a base, a clutch driver, and a pulling handle. The motors are disposed in the housing. The actuator members are respectively disposed in the housing and corresponding to a respective one of the motors. Each clutch member is connected between a respective one of the motors and a respective corresponding one of the actuator members. The base is disposed on an outer surface of the housing, a flange is disposed on an outer surface of the base, and a guiding slot is formed on the base. The clutch driver is in the base and connected to each of the clutch members. A cam contacting against the flange is formed on an end of the pulling handle, and a shaft is inserted through the end. The shaft is inserted through the guiding slot to connect the clutch driver.