CAPSTAN

Description

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to a capstan and, more particularly, to a capstan equipped with a stress indicator.

2. Related Prior Art

Capstans are used to reel cables or chains. However, no capstan is equipped with a stress indicator to the best understanding of the applicant of the present application. Therefore, the stress in the cables or chains cannot be monitored. Should the stress exceed the designed limits of the cables or chains, the cables or chains would very likely be broken. The broken cables or chains inevitably entail the loss of property. What is worse, the broken cables or chains might cause casualty like whips.

Therefore, the present invention is intended to obviate or at least alleviate the problems encountered in prior art.

SUMMARY OF INVENTION

According to the present invention, a capstan includes a frame, a reel for reeling a cable and a bolt for supporting the reel on the frame. The stress in the cable gets larger as the strain in the bolt gets larger. A driving device is operable to rotate the reel on the bolt. A strain gauge is attached to the bolt for measuring the strain in the bolt. A control box calculates the stress in the cable based on the strain in the bolt. A display shows the stress in the cable under the control of the control box.

An advantage of the capstan according to the present invention is the security of property.

An advantage of the capstan according to the present invention is the safety of users.

Other advantages and features of the present invention will become apparent from the following description referring to the drawings.

BRIEF DESCRIPTION OF DRAWINGS

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

FIG. 1 is a perspective view of a capstan according to the preferred embodiment of the present invention;

FIG. 2 is an exploded view of the capstan shown in FIG. 1;

FIG. 3 is a right side view of the capstan shown in FIG. 1;

FIG. 4 is a perspective view of a cable wound on the capstan shown in FIG. 1;

FIG. 5 is a front view of the cable and capstan shown in FIG. 4; and

FIG. 6 is a front view of the cable and capstan in another position than shown in FIG. 5.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring to FIGS. 1 and 2, according to the preferred embodiment of the present invention, a capstan 10 includes a frame 20, a reel 40, a driving device 30, a shaft 50 and a stress indicator 60.

The frame 20 is a U-shaped element including a first wall 21, a second wall 22 and a floor on which the walls 21 and 22 are formed. An aperture 211 is defined in the first wall 21 corresponding to an aperture 221 defined in the second wall 22.

The reel 40 includes a first disc 41, a second disc 42 and a tube 43 between the discs 41 and 42. A gear 411 is formed on the first disc 41. The gear 411 is formed with teeth 412. An aperture 421 is defined in the second disc 42. A plate 423 is attached to the second disc 42 by two threaded bolts 422 engaged with two nuts 424. A tunnel 431 is defined in the tube 43.

Referring to FIG. 3, a bolt 50 is inserted in the apertures 211 and 221 and the tunnel 431 so that the reel 40 is rotationally disposed on the frame 20. The bolt 50 is formed with a head 51 at an end and a thread 52 at an opposite end. The thread 52 of the bolt 50 is engaged with the thread of a nut 53.

Referring to FIG. 4, a cable 70 is wound on the reel 40. An end of the cable 70 is inserted through the aperture 421 and pressed against the second disc 42 by the plate 423.

The driving device 30 includes a shaft 31 formed with a head 34. The shaft 31 is inserted through the walls 21 and 22. A pinion 32 is disposed on the shaft 31 and engaged with the gear 411. A rocker 33 includes a collar at an end and a grip at an opposite end. The collar of the rocker 33 is moved on the shaft 31 between an active position and a neutral position. In the active position, the collar of the rocker 33 can rotate the shaft 31. In the neutral position, the collar of the rocker 33 cannot rotate the shaft 31. A washer 36 is disposed against the head 34. An elastic element 35 is compressed between the washer 36 and the collar of the rocker 33 for pushing the collar of the rocker 33 to the active position.

Referring to FIG. 6, by operating the rocker 33 in a direction, the shaft 31 is rotated in the same direction. The reel 40 is rotated in an opposite direction due to the engagement of the gear 411 with the pinion 32.

The stress indicator 60 includes a strain gauge 62, a control box 61 and a display 611. The strain gauge 62 is attached to the bolt 50. The control box 61 is attached to the second wall 22. The display 611 is attached to the box 61. The control box 61 contains electronic elements electrically connected to the strain gauge 62 on one hand and electrically connected to the display 611 on the other hand.

Referring to FIG. 5, the stress in the cable 70 gets larger as the strain in the bolt 50 gets larger. The strain gauge 62 detects strain in the bolt 50 and notifies the control box 61 of the same. Based on the strain in the bolt 50, the control box 61 calculates the stress in the cable 70. The control box 61 instructs the display 611 to display the stress in the cable 70. A user can maneuver the rocker 33 to reel in the cable 70 while monitoring the stress in the cable 70 on the display 611. The user can decide to stop or continue.

The capstan 10 enables the user to know the stress in the cable 70 for including the strain gauge 62 and the display 611. Moreover, the capstan 10 enables the user to easily monitor the stress in the cable 70 while reeling in the cable 70 since the display 611 and the rocker 33 are on the same side. The user can stop maneuvering the rocker 33 and prevent the rapture of the cable 70 before the stress in the cable 70 reaches its limit. Therefore, the capstan 10 exhibits at least two advantages. Firstly, property is secured. Secondly, the safety of the user is ensured.

The present invention has been described via the detailed 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.