Capstan

Abstract

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.

1 . A capstan comprising:
 a frame;   a reel for reeling a cable;   a bolt for supporting the reel on the frame so that the stress in the cable gets larger as the strain in the bolt gets larger;   a driving device maneuverable to rotate the reel on the bolt;   a strain gauge attached to the bolt for measuring the strain in the bolt;   a control box for calculating the stress in the cable based on the strain in the bolt; and   a display for showing the stress in the cable under the control of the control box.   
   
   
       2 . The capstan according to  claim 1  wherein the frame is a U-shaped element. 
   
   
       3 . The capstan according to  claim 1  wherein the reel is formed with a gear, and the driving device comprises a shaft rotationally disposed on the frame, a pinion secured to the shaft and engaged with the gear and a rocker maneuverable for rotating the shaft. 
   
   
       4 . The capstan according to  claim 3  wherein the rocker is movable between an active position for driving the shaft and a neutral position for releasing the shaft. 
   
   
       5 . The capstan according to  claim 4  wherein the driving device comprises an elastic element for pushing the rocker to the active position. 
   
   
       6 . The capstan according to  claim 5  wherein the shaft is formed with a head so that the elastic element is compressed between the rocker and the head. 
   
   
       7 . The capstan according to  claim 6  wherein the driving device comprises a washer located between the elastic element and the head. 
   
   
       8 . The capstan according to  claim 1  wherein the reel comprise two discs and a tube between the discs. 
   
   
       9 . The capstan according to  claim 1  wherein one of the discs defines an aperture through which an end of the cable is inserted. 
   
   
       10 . The capstan according to  claim 9  comprising a plate for pressing the end of the cable against the disc. 
   
   
       11 . The capstan according to  claim 10  comprising threaded bolts and nuts engaged with the threaded bolts for pressing the plate against the disc. 
   
   
       12 . The capstan according to  claim 3  wherein the rocker and the display are disposed on a same side of the frame so that a user can observe the while maneuvering the rocker.