1. Field of the Invention
The present invention relates to a cable tension device and, more particularly, to a cable tension device for tightening a cable to bind a cargo.
2. Description of the Related Art
A conventional cable tension device comprises a fixing seat, a rotation shaft rotatably mounted on the fixing seat to wind and unwind a cable, a ratchet unit secured on the rotation shaft to rotate the rotation shaft, a movable seat rotatably mounted on the rotation shaft, an locking plate mounted on the fixing seat and detachably engaged with the ratchet unit to allow the ratchet unit to rotate forward in one direction only, an elastic engaging board mounted on the movable seat and detachably engaged with the ratchet unit to drive the ratchet unit to rotate forward in the one direction only.
In operation, when the movable seat is rotatable relative to the fixing seat forward, the engaging board is rotatable with the movable seat to drive the ratchet unit to rotate forward to rotate the rotation shaft forward so as to wind the cable. At this time, the locking plate is engaged with the ratchet unit to prevent the ratchet unit from being rotated backward. On the contrary, when the movable seat is rotatable relative to the fixing seat backward, the engaging board is rotatable with the movable seat to pass through the ratchet unit without interfering with operation of the ratchet unit. Thus, the movable seat is rotatable relative to the fixing seat forward successively to rotate the rotation shaft forward to wind and tighten the cable successively so as to bind a cargo.
However, the user easily applies an excessive force on the movable seat to tighten the cable too excessively by successive rotation of the movable seat, so that the cargo is easily worn or broken due to the excessive force applied by the cable.
The primary objective of the present invention is to provide a cable tension device having a tension adjustable function.
Another objective of the present invention is to provide a cable tension device, wherein when the cable is tightened to a determined extent by rotation of the movable seat, the force applied by the cable on the ratchet unit is greater than that applied by the engaging board and the push board on the ratchet unit, so that the engaging board is pushed and deflected by the ratchet unit to pass by the ratchet unit, and the movable seat performs an idle rotation, thereby preventing the cable from being tightened too excessively.
A further objective of the present invention is to provide a cable tension device, wherein the tension adjustment knob is rotatable relative to the movable seat to adjust the tension applied by the compression spring on the push board to adjust the force applied by the engaging board and the push board on the ratchet unit so as to adjust the force for tightening the cable, thereby preventing the cargo from being broken by the cable due to an excessive force.
Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.
Referring to the drawings and initially to
The fixing seat 10 has a mediate portion formed with an elongated slideway 50 in which the safety locking plate 50 movable.
The rotation shaft 30 is rotatably mounted on a first end of the fixing seat 10 to wind and unwind a cable (not shown), and a push spring 51 is biased between a second end of the fixing seat 10 and the safety locking plate 50 to push the safety locking plate 50 toward the ratchet unit 40.
The ratchet unit 40 is located on two ends of the rotation shaft 30.
The movable seat 20 has a first end rotatably mounted on the rotation shaft 30 and a second end formed with a threaded adjusting hole 23. The movable seat 20 has a mediate portion having two opposite sides each formed with a guide slot 22, two guide channels 21 and a guide groove 24. The guide groove 24 of the movable seat 20 is connected to one of the guide channels 21.
The control member 60 has a face formed with a through hole 62. The control member 60 has a substantially inverted U-shaped cross-sectional profile and has two downward extending slides 64 each movably mounted in the movable seat 20 and each formed with an oblong guide hole 65.
An elastic member 61 is mounted on the control member 60 and biased between the movable seat 20 and the control member 60 to push the control member 60 toward the engaging board 70 and to push the engaging board 70 toward the ratchet unit 40.
The engaging board 70 has a first end formed with an engaging end 74 detachably engaged with the ratchet unit 40 and a second end formed with two upward extending pivot ears 71 pivotally mounted in the control member 60. The engaging board 70 has two opposite sides each formed with a protruding slide edge 72 slidable in the respective guide groove 24 of the movable seat 20.
A pivot pin 63 is extended through the guide slots 22 of the movable seat 20, the guide holes 65 of the control member 60 and the pivot ears 71 of the engaging board 70, so that the control member 60 is movable forward and backward on the movable seat 20 by guidance of the guide slots 22 of the movable seat 20, and is movable upward and downward on the movable seat 20 by guidance of the guide holes 65 of the control member 60. In addition, the engaging board 70 is movable with the control member 60 and is pivotable relative to the control member 60 by pivot of the pivot pin 63.
The push board 80 has a first end formed with a push end 84 rested on the first end of the engaging board 70 and a second end formed with an elongated limit slot 81. The push board 80 has two opposite sides each formed with two protruding slide portions 82 each slidable in the respective guide channel 21 of the movable seat 20.
The cable tension device further comprises a limit pin 66 extended through the through hole 62 of the control member 60 and the limit slot 81 of the push board 80, so that the push board 80 is movable forward and backward relative to the control member 60 by guidance of the limit pin 66, and a restoring spring 67 mounted on the limit pin 66 and biased between the control member 60 and the push board 80 to push the control member 60 upward and downward. The second end of the engaging board 70 is formed with an arcuate recess 76 to receive the limit pin 66.
The compression spring 90 is mounted in the adjusting hole 23 of the movable seat 20 and biased between the tension adjustment knob 91 and the second end of the push board 80.
The tension adjustment knob 91 is a threaded rod screwed into the adjusting hole 23 of the movable seat 20, so that the tension adjustment knob 91 is rotatable relative to the movable seat 20.
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Accordingly, when the cable is tightened to a determined extent by rotation of the movable seat 20, the force applied by the cable on the ratchet unit 40 is greater than that applied by the engaging board 70 and the push board 80 on the ratchet unit 40, so that the engaging board 70 is pushed and deflected by the ratchet unit 40 to pass by the ratchet unit 40, and the movable seat 20 performs an idle rotation, thereby preventing the cable from being tightened too excessively. In addition, the tension adjustment knob 91 is rotatable relative to the movable seat 20 to adjust the tension applied by the compression spring 90 on the push board 80 to adjust the force applied by the engaging board 70 and the push board 80 on the ratchet unit 40 so as to adjust the force for tightening the cable, thereby preventing the cargo from being broken by the cable due to an excessive force.
Although the invention has been explained in relation to its preferred embodiment(s) as mentioned above, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the present invention. It is, therefore, contemplated that the appended claim or claims will cover such modifications and variations that fall within the true scope of the invention.
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