Clutch for Pipe Winch

Abstract

A pipe winch includes a shell, a reeling unit and a clutch. The reeling unit includes a spring-biased reel connected to a ratchet. The clutch includes a pedal, a bearing, a shaft, at least one crank, a lever, an axle, a pawl, a returning element and a spring. The shaft is supported on the bearing formed on the shell. The crank extends throughout the shell and connects the pedal to the shaft. The lever is connected to the shaft. The axle extends parallel to an axis of the reel. The pawl is connected to the axle and formed with a tip for engagement with the teeth of the ratchet and a handle in contact with the lever. The returning element is connected to the axle. The spring is arranged between the returning element and the shell.

Claims

1. A pipe winch comprising a shell (1), a reeling unit (11) comprising a spring-biased reel (12) inserted in the shell (1), and a clutch (20) operatively connected to the spring-biased reel (12), the pipe winch being characterized by that the reeling unit (11) further comprises a ratchet (13) coaxially connected to the reel (12) and formed with teeth (14) and that the clutch (20) comprises: a pedal (21) located out of the shell (1); a bearing (24) formed on an internal portion of the shell (1); a shaft (23) rotationally supported on the bearing (24) in the shell (1); at least one crank (22) extending throughout the shell (1) and comprising an end connected to the pedal (21) and another end connected to the shaft (23) so that the crank (22) is not rotatable relative to the shaft (23); a lever (25) connected to the shaft (23); an axle (26) rotationally inserted in the shell (1) parallel to an axis of the reel (12); a pawl (27) connected to the axle (26) and formed with a tip (271) at an end for engagement with the teeth (14) of the ratchet (13) and a handle (272) at another end in contact with the lever (25); a returning element (28) connected to the axle (26) so that they are not rotatable relative to each other; and a spring (29) comprising an end connected to the returning element (28) and another end connected to the shell (1).

2. The pipe winch according to claim 1, wherein the teeth (14) are made by cutting an edge of the ratchet (13).

3. The pipe winch according to claim 1, wherein each of the cranks (22) comprises a non-circular aperture (221), and the shaft (23) comprises a non-circular cross-sectional profile in compliance with the non-circular aperture (221).

4. The pipe winch according to claim 3, wherein each of the cranks (22) comprises a cruciform aperture (221), and the shaft (23) is made with a cruciform cross-sectional profile in compliance with the cruciform aperture (221).

5. The pipe winch according to claim 1, wherein the returning element (28) and the pawl (27) are made in one piece.

6. The pipe winch according to claim 1, wherein the spring (29) is torsion spring.

7. The pipe winch according to claim 6, wherein the spring (29) comprises two rectilinear terminal sections respectively abutted against the returning element (28) and the shell (1).

8. The pipe winch according to claim 7, wherein the returning element (28) comprises an aperture (281) for receiving the corresponding rectilinear terminal section of the spring (29).

9. The pipe winch according to claim 7, wherein the spring (29) comprises a helical middle section provided on and around the axle (26).

10. The pipe winch according to claim 1, wherein the shell (1) comprises at least two restraints (4) abutted against crank (22).

Description

BRIEF DESCRIPTION OF DRAWINGS

[0008] The present invention will be described via detailed illustration of the preferred embodiment referring to the drawings wherein:

[0009] FIG. 1 is a perspective view of a pipe winch according to the preferred embodiment of the present invention;

[0010] FIG. 2 is an exploded view of the pipe winch shown in FIG. 1;

[0011] FIG. 3 is a perspective view of the pipe winch shown in FIG. 1 without a cover;

[0012] FIG. 4 is an enlarged partial view of the pipe winch shown in FIG. 3;

[0013] FIG. 5 is another enlarged partial view of the pipe winch shown in FIG. 3; and

[0014] FIG. 6 is an enlarged partial view of the pipe winch in another position than shown in FIG. 5.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

[0015] Referring to FIGS. 1 through 4, a pipe winch includes a shell 1, a reeling unit 11 and a clutch 20 according to the preferred embodiment of the present invention. The shell 1 includes a front panel 2 and a rear panel (not numbered). Normally, the front panel 2 is connected to the rear panel to conceal and protect other components of the pipe winch. The front panel 2 can be detached from the rear panel to allow access to the other components of the pipe winch. The front panel 2 includes two restraints 4 and a bearing 24 formed on an internal or rear face of the front panel 2. The bearing 24 is located between the restraints 4.

[0016] The reeling unit 11 includes a reel 12 and a ratchet 13 coaxially connected to the reel 12. The reeling unit 11 further includes a coil spring (not shown) connected to the reel 12. The ratchet 13 includes teeth 14 evenly arranged at the edge. The teeth 14 are made by cutting the edge of the ratchet 13.

[0017] A user rotates the reel 12 in a sense of direction to reel a flexible pipe (not shown). The user pulls the pipe from the reel 12, thereby rotating the reel 12 in an opposite sense of direction and loading the coil spring. Thus, without the clutch 20 activated, the coil spring would be allowed to automatically rotate the reel 12 to reel the pipe when the user releases the pipe.

[0018] The clutch 20 includes a pedal 21, a shaft 23, a lever 25, an axle 26, a pawl 27, a returning element 28 and a spring 29. The pedal 21 is located out of the shell 1 so that the user can tread the pedal 21. The shaft 23 is inserted in the shell 1. The pedal 21 is connected to the shaft 23 via two cranks 22 that extend throughout two apertures 3 made in the front panel 2. The shaft 23 is rotationally supported on the bearing 24 and extends throughout the cranks 22. The cranks 22 are fitted on the shaft 23 so that translation and rotation of the cranks 22 relative to the shaft 23 are avoided. The cranks 22 are respectively in contact with the restraints 4, thereby preventing the cranks 22 and the shaft 23 from translation relative to the shell 1. The non-rotational relation is caused by the shapes of the shaft 23 and the cranks 22. As shown, the shaft 23 includes a cruciform cross-sectional profile 231 and each of the cranks 22 includes a cruciform aperture 221 in compliance with the cruciform cross-sectional profile 231. Thus, the shaft 23 is pivoted when the pedal 21 is hit due to the use of the cranks 22. The lever 25 is secured to a first end of the shaft 23.

[0019] The axle 26 is inserted in the shell 1, with its axis extending parallel to that of the reel 12. Corresponding to the ratchet 13, the pawl 27 is connected to the axle 26. The pawl 27 includes a tip 271 on a side and a handle 272 on an opposite side. The tip 271 of the pawl 27 is adapted for contacting the teeth 14 of the ratchet 13. The handle 272 is adapted for contacting the lever 25.

[0020] The returning element 28 is secured to the axle 26. As shown, the returning element 28 and the pawl 27 are made in one piece. The returning element 28 is made with an aperture 281. The spring 29 is a torsion spring that includes a helical middle section and two rectilinear terminal sections. The helical middle section of the spring 29 is provided on and around the axle 26. One of the rectilinear terminal sections of the spring 29 is inserted in the aperture 281 of the returning element 28. The other rectilinear terminal section of the spring 29 is abutted against an internal portion of the shell 1.

[0021] Referring to FIG. 5, the spring 29 exerts torque to the pawl 27 via the returning element 28 to keep the tip 271 of the pawl 27 in contact with one of the teeth 14 of the ratchet 13. Thus, the ratchet 13 and the reel 12 are prevented from rotation, the pedal 21 remains horizontal, and the lever 25 is kept in contact with the handle 272 of the pawl 27.

[0022] Referring to FIG. 6, the pedal 21 is trodden to rotate the shaft 23 and the lever 25 in a first sense of direction as indicated by an arrow head A because of the non-rotational relation of the cranks 22 of the pedal 21 to the shaft 23. During the rotation, the lever 25 exerts an upward force on the handle 272 of the pawl 27 to rotate the pawl 27 and the axle 26 in a second sense of direction indicated by an arrow head B and hence load the spring 29. Synchronously, the tip 271 of the pawl 27 is moved away from the teeth 14 of the ratchet 13 so that the ratchet 13 is free to rotate and that the coil spring is allowed to rotate the reel 12 to reel the pipe.

[0023] Referring to FIG. 5 again, the pedal 21 is released, thereby allowing the spring 29 to exert a force on the pawl 27 via the returning element 28 to rotate the pawl 27 and the axle 26 in a sense of direction opposite to the second sense of direction. Thus, the tip 271 of the pawl 27 is engaged with one of the teeth 14 of the ratchet 13 to prevent the ratchet 13 and the reel 12 from rotation. Moreover, the handle 272 of the pawl 27 presses the lever 25, to rotate the shaft 23 in a sense of direction opposite to the first sense of direction and return the pedal 21 to the horizontal position via the cranks 22.

[0024] As discussed above, the pedal 21 can be continuously trodden to allow the coil spring to rotate the reel 12 to reel the pipe in a continuous manner. Alternatively, the pedal 21 can be intermittently trodden and released to cause the coil spring to rotate the reel 12 to reel the pipe in an intermittent manner. The rotation of the reel 12 and hence the reeling of the pipe are stopped whenever the pedal 21 is released. Now, the pipe can be unreeled from the reel 12 a little and set in order. Then, the pedal 21 can be trodden to allow the coil spring to continue to rotate the reel 12 to reel the pipe.

[0025] The present invention has been described via illustration of the preferred embodiment. Those skilled in the art can derive variations from the preferred embodiment without departing from the scope of the present invention. Therefore, the preferred embodiment shall not limit the scope of the present invention defined in the claims.