Patent Application
20130326847
1. Field of Invention
The present invention relates to an apparatus for tensioning a strap for bonding cargo and, more particularly, to a strap-tensioning apparatus equipped with a strap-damping unit.
2. Related Prior Art
As disclosed in Patent Application Publication DE 10 201 0 002 052, a fastener 10 includes a strap-damping device 22 provided between a shaft 12 and a reeling device 13. The strap-damping device 22 includes a rod 22a, a shaft 22b separated from the rod 22a by a gap, and a clamping element 22c supported on the shaft 22b. A strap 20 can be clamped by the rod 22a and the clamping element 22c.
It is the primary objective of the present invention to provide a safe-to-use strap-tensioning apparatus.
To achieve the foregoing objective, the strap-tensioning apparatus includes a frame, an automatic reel and a strap-damping unit. The automatic reel is supported on the frame and used to wind a strap. The strap is inserted through and damped by the strap-damping unit. The strap-damping unit is operable for adjusting the damping on the strap.
Other objectives, advantages and features of the present invention will be apparent from the following description referring to the attached drawings.
The present invention will be described via detailed illustration of the preferred embodiment referring to the drawings wherein:
Referring to
The frame 20 includes a first end 21 and a second end 23. The frame 20 includes a crossbar 22 extending between two parallel walls. Each wall of the frame 20 includes a first circular opening defined therein near the first end 21, a second circular opening defined therein near the second end 23, and a slot defined therein between the ends 21 and 23. Each wall of the frame 20 further includes a ridge that includes two portions 53 and 54 near the second end 23.
The handle 50 includes two parallel leaves. Each leaf includes a slot defined therein and a circular opening defined therein corresponding to the second circular opening of a respective wall of the frame 20.
The manual reel 24 includes a slot 28 defined therein. Each end of the manual reel 24 is inserted in the second circular opening of a respective wall of the frame 20 and the circular opening of a respective leaf of the handle 50.
Two ratcheted wheels 51 are connected to the manual reel 24. Each ratcheted wheel 51 includes ratchets 55 formed thereon.
A detent 26 includes two wings each movably inserted in the slot of a respective wall of the frame 20 so that the detent 26 is movably supported on the frame 20. The detent 26 is biased toward the ratcheted wheels 51 by a spring.
Another detent 52 includes two wings each movably inserted in the slot of a respective leaf of the handle 50 so that the detent 52 is movably connected to the handle 50. The detent 52 is biased toward the ratcheted wheels 51 by another spring.
The automatic reel 29 is supported on the walls of the frame 20. The automatic reel 29 includes an axle 27, a coil spring 12 and a drum 14. The axle 27 is non-rotationally supported on the walls of the frame 20. The coil spring 12 includes an internal end connected to the axle 27 and an external end connected to the drum 14.
Referring to
The torque spring 39 includes two rectilinear portions extending from a helical portion.
The shackle 40 includes a disc 44, an eccentric boss 43 extending from a side of the disc 44, an axle 42 extending from an opposite side of the disc 44, and two apertures 41 defined in the discs 42 and 44.
The strap-damping unit 30 is placed between the manual reel 24 and the automatic reel 29. The axle 42 is placed in an aperture 38 defined in a wall of the frame 20. The axle 37 is placed in an aperture 38 defined in the other wall of the frame 20. The neck of each anchor 36 is placed in a respective aperture 41 while the head is placed beyond the disc 44. The helical portion of the torque spring 39 is placed on one of the rods 34. One of the rectilinear portions of the torque spring 39 is placed against the frame 20 while the other rectilinear portion of the torque spring 39 is inserted through the gap 35 and placed against the rods 34. Therefore, the rods 34 are biased by the torque spring 39.
Before use, a first end of a short strap (not shown) is connected to the crossbar 22 and a second end of the short strap is connected to a hook (not shown). Moreover, a first end of a long strap 25 is connected to the drum 14 and a second end of the long strap 25 is connected to another hook (not shown). The long strap 25 includes an idle section wound on the automatic reel 29 and an active section unwound from the automatic reel 29 and inserted through the gap 35 and the slot 28.
Each hook is engaged with a portion of a truck for example. The idle section of the long strap 25 is automatically wound by the automatic reel 29. The handle 50 is pivoted on the frame 20 in an active direction so that the detent 52 engages with the ratcheted wheels 51 to rotate the manual reel 24 to wind and tension the long strap 25. Then, the handle 50 is pivoted on the frame 20 in an opposite neutral direction so that the detent 52 rattles on the ratcheted wheels 51 without rotating the manual reel 24 that would otherwise reel out and loosen the long strap 25. The handle 50 is pivoted to and fro on the frame 20 to tension the active section of the long strap 25.
Referring to
Referring to
The portions of the long strap 25 in contact with the rods 34 are larger as the strap-damping unit 30 is in the first position than the second position.
Accordingly, the long strap 25 encounters a larger damping force from the strap-damping unit 30 in the first position than the second position. The strap-damping unit 30 is placed in the first position when the coil spring 12 starts winding the long strap 25 onto the drum 14 since the coil spring 12 exerts large torque on the long strap 25 via the drum 14. The strap-damping unit 30 is placed in the second position when the coil spring 12 almost finishes winding the long strap 25 onto the drum 14 since the coil spring 12 exerts small torque on the long strap 25 via the drum 14. By operating the strap-damping unit 30 between the first and second positions, the rate of the winding of the long strap 25 onto the drum 14 is contained in a save range.
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.
