Linear actuator with speed-adjustable quick release mechanism

1. A linear actuator ( 1 ), comprising:

an actuator mechanism ( 10 ) including a motor ( 11 ) and a lead screw ( 12 ) driven by the motor ( 11 );

a telescopic mechanism ( 20 ) including a screw nut ( 21 ) sheathed axially on the lead screw ( 12 ) and a telescopic tube ( 22 ) inserted in the screw nut ( 21 ); and

a quick release mechanism ( 30 , 30 a ) disposed at an outer end of the telescopic tube ( 22 ), comprising;

a transferring set ( 31 , 31 a ) connected with the telescopic tube ( 22 ), and the transferring set ( 31 , 31 a ) having a column ( 311 ) at a lateral side;

a supporting set ( 32 , 32 a ) sleeved on the column ( 311 ), and the supporting set ( 32 , 32 a ) having a pair of lugs ( 321 );

a braking worm gear ( 33 , 33 a ) disposed axially on the transferring set ( 31 , 31 a );

a braking worm shaft ( 34 , 34 a ) disposed between the pair of lugs ( 321 ) and selectively braking the braking worm gear ( 33 , 33 a ); and

an elastic pressing assembly ( 35 , 35 a ) pressing elastically on the worm shaft ( 34 , 34 a ), and the elastic pressing assembly ( 35 , 35 a ) adjusting a pressing force when an external force is applied by a user;

wherein, the restraining force between braking worm gear ( 33 , 33 a ) and the braking worm shaft ( 34 , 34 a ) being determined by the strength of the pressing force, and the retraction speed of the telescopic tube ( 22 ) being adjusted through the restraining force between the braking worm gear ( 33 , 33 a ) and the braking worm shaft ( 34 , 34 a ).

2. The linear actuator according to claim 1 , wherein the quick release mechanism ( 30 , 30 a ) further includes at least one ball bearing ( 37 ) disposed between the transferring set ( 31 , 31 a ) and the supporting set ( 32 , 32 a ), the ball bearing ( 37 ) sleeves on the column ( 311 ) and leans against the supporting set ( 32 , 32 a ) radially.

3. The linear actuator according to claim 2 , wherein the quick release mechanism ( 30 , 30 a ) further includes a blocking plate ( 38 ), the blocking plate ( 38 ) is positioned on the column ( 311 ) and blocking one side of the ball bearing ( 37 ).

4. The linear actuator according to claim 3 , wherein the quick release mechanism ( 30 , 30 a ) further includes a screw post ( 39 ), the column ( 311 ) is provided with a screw hole ( 310 ) correspondingly, and the screw post ( 39 ) is inserted in the blocking plate ( 38 ) and combined in the screw hole ( 310 ).

5. The linear actuator according to claim 1 , wherein the elastic pressing assembly ( 35 , 35 a ) includes a torsion spring ( 351 ) sleeved on the braking worm shaft ( 34 , 34 a ) and a knob ( 352 ), the torsion spring ( 351 ) has a fixed end ( 3511 ) fixed on the supporting set ( 32 , 32 a ) and a free end ( 3512 ) spinning out from the braking worm shaft ( 34 , 34 a ) by a push of the knob ( 352 ).

6. The linear actuator according to claim 5 , wherein the torsion spring ( 351 ) and the knob ( 352 ) are disposed separately on two sides of one of the lugs ( 321 ).

7. The linear actuator according to claim 6 , wherein the knob ( 352 ) is protruded with a toggle plate ( 3521 ), and the lug ( 321 ) is provided with a trough ( 3210 ) correspondingly, the toggle plate ( 3521 ) is inserted in the trough ( 3210 ) and positioned on a side of the free end ( 3512 ).

8. The linear actuator according to claim 7 , wherein the toggle plate ( 3521 ) is a curved piece, and the trough ( 3210 ) is formed in an arc shape.

9. The linear actuator according to claim 5 , wherein the elastic pressing assembly ( 35 , 35 a ) further includes a holder ( 354 ) and a fastener ( 355 ), the holder ( 354 ) is pressed against the fixed end ( 3511 ) of the torsion spring ( 351 ) and is combined with the supporting set ( 32 , 32 a ) through the fastener ( 355 ).

10. The linear actuator according to claim 9 , wherein the holder ( 354 ) has a position slot ( 3540 ), and the fixed end ( 3511 ) of the torsion spring ( 351 ) is inserted in the position slot ( 3540 ).

11. The linear actuator according to claim 1 , wherein the elastic pressing assembly ( 35 , 35 a ) further includes at least one supporter ( 353 ), the supporter ( 353 ) is sleeved on an end of the braking worm shaft ( 34 , 34 a ) and combined at a side of the lug ( 321 ).

12. The linear actuator according to claim 1 , wherein the elastic pressing assembly ( 35 , 35 a ) includes a first pressing piece ( 351 a ) resisting against the braking worm shaft ( 34 , 34 a ), a link ( 352 a ) connecting with the first pressing piece ( 351 a ), a compression spring ( 353 a ) and a second pressing piece ( 354 a ) sleeved on the link ( 352 a ) and a pull rod ( 355 a ) connecting with the second pressing piece ( 354 a ), the second pressing piece ( 354 a ) exerted by the pull rod ( 355 a ) is forced on the first pressing piece ( 351 a ) through the compression spring ( 353 a ).

13. The linear actuator according to claim 12 , wherein the first pressing piece ( 351 a ) has formed with an arc surface ( 3510 a ), the arc surface ( 3510 a ) is abutted on a side of the braking worm shaft ( 34 , 34 a ).

14. The linear actuator according to claim 12 , wherein the second pressing piece ( 354 a ) is located at a middle of the compression spring ( 353 a ) correspondingly.

15. The linear actuator according to claim 12 , wherein the second pressing piece ( 354 a ) has a clip slot ( 3540 a ), and one end of the pull rod ( 355 a ) is snapped in the clip slot ( 3540 a ).

16. A speed adjustable quick release mechanism ( 30 , 30 a ) of a linear actuator, the linear actuator including an actuator mechanism ( 10 ), a telescopic mechanism ( 20 ) driven by the actuator mechanism ( 10 ) and a telescopic mechanism ( 20 ), and the quick release mechanism ( 30 , 30 a ) disposed at an outer end of the telescopic mechanism ( 20 ), the mechanism ( 30 , 30 a ) including:

a transferring set ( 31 , 31 a ) connected with the telescopic mechanism ( 20 ), and the transferring set ( 31 , 31 a ) having a column ( 311 ) at a lateral side;

a supporting set ( 32 , 32 a ) sleeved on the column ( 311 ), and the supporting set having a pair of lugs ( 321 );

a braking worm gear ( 33 , 33 a ) disposed axially on the transferring set ( 31 , 31 a );

a braking worm shaft ( 34 , 34 a ) disposed between the pair of lugs ( 321 ) and selectively braking the braking worm gear ( 33 , 33 a ); and

an elastic pressing assembly ( 35 , 35 a ) pressing elastically on the worm shaft ( 34 , 34 a ), and the elastic pressing assembly ( 35 , 35 a ) adjusting a pressing force when an external force is applied by a user;

wherein, the restraining force between braking worm gear ( 33 , 33 a ) and the braking worm shaft ( 34 , 34 a ) being determined by the strength of the pressing force, and the retraction speed of the telescopic mechanism ( 20 ) being adjusted through the restraining force between the braking worm gear ( 33 , 33 a ) and the braking worm shaft ( 34 , 34 a ).

17. The mechanism to claim 16 , wherein the actuator mechanism includes a motor ( 11 ) and a lead screw ( 12 ) driven by the motor ( 11 ), and the telescopic mechanism ( 20 ) includes a screw nut ( 21 ) sheathed axially on the lead screw ( 12 ) and a telescopic tube ( 22 ) inserted in the screw nut ( 21 ), the transferring set ( 31 , 31 a ) is connected with the telescopic tube ( 22 ).

18. The mechanism to claim 16 , further including at least one ball bearing ( 37 ) disposed between the transferring set ( 31 , 31 a ) and the supporting set ( 32 , 32 a ), wherein the ball bearing ( 37 ) sleeves on the column ( 311 ) and leans against the supporting set ( 32 , 32 a ) radially.

19. The mechanism to claim 18 , further including a blocking plate ( 38 ), wherein the blocking plate ( 38 ) is positioned at the column ( 311 ) and blocked on a lateral side of the ball bearing ( 37 ).

20. The mechanism to claim 19 , further including a screw post ( 39 ), wherein the column ( 311 ) is provided with a screw hole ( 310 ) correspondingly, the screw post ( 39 ) is inserted in the blocking plate ( 38 ) and combined in the screw hole ( 310 ).

21. The mechanism to claim 16 , wherein the elastic pressing assembly ( 35 , 35 a ) includes a torsion spring ( 351 ) sleeved on the braking worm shaft ( 34 , 34 a ) and a knob ( 352 ), the torsion spring ( 351 ) has a fixed end ( 3511 ) fixed on the supporting set ( 32 , 32 a ) and a free end ( 3512 ) spinning out from the braking worm shaft ( 34 , 34 a ) by a push of the knob ( 352 ).

22. The mechanism to claim 21 , wherein the torsion spring ( 351 ) and the knob ( 352 ) are disposed separately on two sides of one of the lugs ( 321 ).

23. The mechanism to claim 22 , wherein the knob ( 352 ) is protruded with a toggle plate ( 3521 ), and the lug ( 321 ) is provided with a trough ( 3210 ) correspondingly, the toggle plate ( 3521 ) inserts in the trough ( 3210 ) and positioned on a side of the free end ( 3512 ).

24. The mechanism to claim 23 , wherein the toggle plate ( 3521 ) is a curved piece, and the trough ( 3210 ) is formed in an arc shape.

25. The mechanism to claim 21 , wherein the elastic pressing assembly ( 35 , 35 a ) further includes a holder ( 354 ) and a fastener ( 355 ), the holder ( 354 ) is pressed against the fixed end ( 3511 ) of the torsion spring ( 351 ) and is combined with the supporting set ( 32 , 32 a ) through the fastener ( 355 ).

26. The mechanism to claim 25 , wherein the holder ( 354 ) has a position slot ( 3540 ), and the fixed end ( 3511 ) of the torsion spring ( 351 ) is inserted in the position slot ( 3540 ).

27. The mechanism to claim 16 , wherein the elastic pressing assembly ( 35 , 35 a ) further includes at least one supporter ( 353 ), the supporter ( 353 ) is sleeved in an end of the braking worm shaft ( 34 , 34 a ) and combined at a side of the lug ( 321 ).

28. The mechanism to claim 16 , further including a shell ( 70 ), wherein the shell ( 70 ) is sleeved on the supporting set ( 32 , 32 a ).

29. The mechanism to claim 28 , further including an overlay ( 71 ), wherein the overlay ( 71 ) seals the transferring set ( 31 , 31 a ) and seals another side of the shell ( 70 ).

30. The mechanism to claim 16 , wherein the elastic pressing assembly ( 35 , 35 a ) includes a first pressing piece ( 351 a ) resisting against the braking worm shaft ( 34 , 34 a ), a link ( 352 a ) connecting with the first pressing piece ( 351 a ), a compression spring ( 353 a ) and a second pressing piece ( 354 a ) sleeved on the link ( 352 a ) and a pull rod ( 355 a ) connecting with the second pressing piece ( 354 a ), the second pressing piece ( 354 a ) exerted by the pull rod ( 355 a ) is forced on the first pressing piece ( 351 a ) through the compression spring ( 353 a ).

31. The mechanism to claim 30 , wherein the first pressing piece ( 351 a ) has formed with an arc surface ( 3510 a ), the arc surface ( 3510 a ) is abutted on a side of the braking worm shaft ( 34 , 34 a ).

32. The mechanism to claim 30 , wherein the second pressing piece ( 354 a ) is located at a middle of the compression spring ( 353 a ) correspondingly.

33. The mechanism to claim 30 , wherein the second pressing piece ( 354 a ) has a clip slot ( 3540 a ), and one end of the pull rod ( 355 a ) is snapped in the clip slot ( 3540 a ).