Patent Application
20100205781
The present invention generally relates to a handgrip pivot structure for a hand puller, and particularly to a handgrip pivot structure that makes rotation of handgrip smooth and eliminates jamming and stress concentration.
Cargo vehicles carry cargos that are often secured on a bed by cables or wires. An end of the cable is fixed first and a pre-set tightening force is applied to an opposite end to secure the opposite end. This operation must be carried out elaborately and skilled operators are needed to ensure proper tightening of cargos on the vehicle bed.
Taiwan Utility Model Publication Nos. M320549, M319128, M313048, and M261501 and Invention Publication Nos. 567961, 512809, and 383756 disclose various hand pullers for carrying out tightening of cables. The known hand puller comprises a fixed frame and a movable frame that are jointed through a pivot shaft, which is often of a semi-circular configuration, for effecting reciprocal swaying operation within a given angular range to drive a one-way ratcheting mechanism. The fixed frame has a stop that provides positioning to the ratcheting mechanism so that the cable can be rolled up by the pivot shaft to have the cable tightened and thus securing the cargos.
Referring to
The conventional structure is operated by causing rotation between the shaft 81 and the pivot holes 92 only to prevent the sleeve 82 from rotation with respect to the operator's hand during the operation of the hand puller. However, the contact area between the shaft 81 and the pivot holes 82 is very limited, which may lead severe stress concentration during the rotation of the shaft 81. Consequently, severe wear occurs between the shaft 81 and the pivot holes 92, which may eventually results in jamming or unsmooth operation. Thus, it is desired to overcome such drawbacks by providing a handgrip pivot structure for a hand puller that will further described hereinafter.
The present invention provides a handgrip pivot structure for a hand puller, which comprises a grip collar that is rotatably fit over a shaft arranged between two spaced arms, so as to form two pivoting arrangements respectively between the collar and the shaft and between the shaft and pivot holes defined in the arms, whereby 360 degree turn of the collar can be realized, making the turning smoother than the conventional structure and providing extended service life, and also helpful in overcoming jamming and stress concentration problems of the conventional structure.
The foregoing objective and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts.
Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.
The following descriptions are exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims.
With reference to
A handgrip comprises a metal shaft 20 and a grip collar 30 that is preferably made of plastics, such as a rigid plastic tube rotatably fit over the shaft 20. The shaft 20 has opposite ends that are expanded to form a circumferential flange 21 to which a mounting tube 22 is attached in a co-axial manner. The mounting tubes 22 that are respectively attached to the end flanges 21 of the shaft 20 extend through and are rotatably received in the pivot holes 11 of the arms 10 respectively. Each mounting tube 22 has an end forming an expanded circumferential flange 221 that is fixed to the shaft 20 at the respective circumferential flange 21 of the shaft 20 by means of for example welding or other known measures, whereby the shaft 20 is held between the two arms 10 without undesired separation therefrom. Further, each mounting tube 22 has an opposite end extending beyond an outside surface of the respective arm 10 and the portion of the mounting tube 22 that extends beyond the arm 10 forms external threading 23 for threading engagement with a nut 24. The nut 24 has an outside diameter that is greater than the pivot hole 11, whereby the shaft 20 is prevented from separation from the pivot holes 11 by the two nuts 24. The grip collar 30 is for hand gripping by an operator. The grip collar 30 defines a bore 31 completely extending therethrough in an axial direction for axially and rotatably receiving therein the shaft 20 to hold the grip collar 30 between the two arms 10.
The present invention provides a configuration that comprises a first pivoting arrangement constituted by the rotatable fitting of the collar 30 over the shaft 20 and a second pivoting arrangement between the shaft 20 and the pivot holes 11, whereby when an operator holds the grip collar 30 with a hand and reciprocally sways the arms 10 of the hand puller to gradually tighten or loosen a rope or a cable, the grip collar 30 maintains rotation of full turns around the shaft 20, while the shaft 20 is also rotatable with respect to the pivot holes 11, whereby the rotation of the grip collar 30 with respect to the arms 10 can be made smooth as compared to the known structures. Further, the two pivoting arrangements in accordance with the present invention effectively disperse the force acting on any single one thereof so as to extend the service life thereof and also alleviate the problem of jamming occurring in the conventional structures.
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While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.
