BACKGROUND

Technical Field

The disclosure relates to a linear actuator, particularly to a linear actuator with a quick-releasing mechanism.

Related Art

Linear actuators have been widely applied in medical equipment such as hospital beds and electric chairs. In addition, in order to deal with a medical emergency, linear actuators are installed with a quick-releasing mechanism to make a telescopic tube of actuator be capable of rapidly retracting. Thus, fast adjustments and changes can be implemented.

Furthermore, a related-art quick-releasing mechanism utilizes a pulling rod or rope to drive the rotating element to engage and disengage and finally to interrupt the transmission of torque, so that an effect of quick release can be accomplished. However, when the related-art quick-releasing mechanism is used, the pulling rod or rope must be forced to keep the status of transmission interruption. This causes inconvenience in use.

In view of this, the inventors have devoted themselves to the above-mentioned related art, researched intensively and cooperated with the application of science to try to solve the above-mentioned problems. Finally, the disclosure which is reasonable and effective to overcome the above drawbacks is provided.

SUMMARY

An object of the disclosure is to provide a linear actuator with a restrainable quick-releasing mechanism, which may restrain the releasing mechanism to keep a status of quick release.

To accomplish the above object, the linear actuator with a restrainable quick-releasing mechanism of the disclosure includes a transmission mechanism, a releasing mechanism and a toggle restraining mechanism. The transmission mechanism includes a motor, a gear set driven by the motor and a screw rod driven by the gear set. The releasing mechanism is disposed between the gear set and the screw rod and includes a driving gear connecting the gear set, a first clutch associated on the driving gear, a second clutch associated on the screw rod, and a sliding sleeve being connectable with the first clutch and the second clutch. The toggle restraining mechanism is disposed on a side of the releasing mechanism and includes a stem, a rotating element driven by the stem and a restraining assembly. The rotating element includes a restraining hole and a rotating arm. The restraining assembly includes a restraining presser associated on the rotating element, a restraining spring disposed in the restraining presser and an engaging element elastically pushed by the restraining spring. The stem is moved by an external force to rotate the rotating element. The rotating arm is rotated with the rotating element to push the sliding sleeve. The sliding sleeve is pushed by the rotating arm to separate from the second clutch. The engaging element is engaged in the restraining hole to restrain the rotating element from rotating when the rotating element is rotated to a specific angle.

In comparison with the related art, the linear actuator of the disclosure is provided with a toggle restraining mechanism including a stem, a rotating element and a restraining assembly. The stem is moved by an external force to rotate the rotating element so as to make the rotating arm push the sliding sleeve to make the second clutch be disengaged from transmission to interrupt the transmission. Also, at the same time, the engaging element is engaged to restrain the rotation of the rotating element to accomplish the effect of restraining the releasing mechanism. Thus, a status of quick release may be kept without an external force and the utility of the disclosure is increased.

