1. Field of the Invention
The present invention relates to an open-end wrench and, in particular, to an open-end wrench including a ratchet mechanism.
2. Description of the Related Art
U.S. Pat. No. 2,700,315, entitled open-end ratchet wrench, shows a wrench including a head with a slot. Two dogs are respectively disposed at two sides of the slot. Each dog is pivotally engaged in a recess with a pivot and is pivotal relative to the head. Each dog is subject to a biasing force of a spring, which facilitates the dog to return to its original position. A shaft is used to fix each spring. However, each dog does not have a strong structure, because it is made with a through hole for pivot. A larger shear force can cause the pivot to break, because the pivot is limited to have a relatively small cross-sectional area. Therefore, the ratchet wrench can't withstand a large torque transmission well. The present invention is, therefore, intended to obviate or at least alleviate the problems encountered in the prior art, as well as to make a simple and cost-saving wrench.
According to the present invention, a simple open-end wrench includes a driving head including first and second jaws, a space delimited between the first and second jaws for receiving an object to be driven by the open-end wrench, first and second recesses extended from the space, a pawl pivotally embedded in the first recess and having a first end thereof defining a joining end abutted against a peripheral wall of the first recess and a second end thereof defining an abutting end interacting with the object to be driven, and a biasing mechanism received in the second recess and abutted against the pawl. The pawl includes the abutting end disposed outside the second recess and extended into the space. The pawl is pivotal to a position with the abutting end thereof disposed within the second recess.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure. The abstract is neither intended to define the invention, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
It is therefore an objective of the present invention to provide a ratchet wrench which better withstands torque transmission and is capable of being operated through a relatively smaller minimum swing angle action.
Other objectives, advantages, and new features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanied drawings.
A pawl 30 is pivotally embedded in the first recess 27. A biasing mechanism 29 is received in the second recess 28 and abutted against the pawl 30. The second recess 28 includes a cavity 291 extended therefrom. The biasing mechanism 29 includes a biasing member 292 and a pusher 293. The biasing member 292 has a first end restrained in the cavity 291 and a second end engaged with the pusher 293, and the pusher 293 is subject to a biasing force of the biasing member 292. The pusher 293 has an end engaged with the pawl 30. The biasing member 292 has a shape including a plurality of coils.
The pawl 30 has a first end thereof defining a joining end 31 abutted against a peripheral wall of the first recess 27 and a second end thereof defining an abutting end 32 interacting with the object 90 to be driven. The joining end 31 of the pawl 30 has a curved periphery abutted against and corresponding to the peripheral wall of the first recess 27. The joining end 31 of the pawl 30 has at least a half circumference abutted against the peripheral wall of the first recess 27. The first recess 27 has a diameter defining a second distance D2, with the diameter passing through a center that the pawl 30 pivots about. The second distance D2 is greater than the first distance D1. The peripheral wall of the first recess 27 includes two extensions 272 protruded therefrom, with one ridge extension 272 extended over a top edge 311 and the other extension 272 extended over a bottom edge 312 of the joining end 31 of the pawl 30 respectively to restrain the pawl 30.
The joining end 31 of the pawl 30 has a radius R1 with respect to a center of curvature thereof. The abutting end 32 of the pawl 30 has a distal end thereof defining a flat edge extending obliquely and including a plurality of teeth extended thereon interacting with the object 90 to be driven, and the serrated distal end enables a better frictional contact and prevents slippage between the abutting end 32 of the pawl 30 and the object 90. Additionally, it is contemplated that the distal end of the abutting end 32 of the pawl 30 define a curved or flat edge, with or without a plurality of teeth extended thereon, for interacting with the object 90 to be driven. The distal end of the abutting end 32 of the pawl 30, which defines a flat edge and without the plurality of teeth extended thereon, has a surface contact with the object 90 to be driven, with the flat edge engaging with and in surface conformity to a peripheral side of the object 90. Therefore, the abutting end 32 of the pawl 30 is prevented from slippage relative to the object 90 to be driven. The abutting end 32 of the pawl 30 includes first and second sections 33 and 34. The pawl 30 includes the abutting end 32 including the first section 33 extended from the joining end 31 and the second section 34 extended from the first section 33. The abutting end 32 of the pawl 30 includes the second section 34 having a periphery defining the distal end thereof for interacting with the object 90.
The joining end 31 and the abutting end 32 of the pawl 30 have the same height.
The pawl 30 includes the abutting end 32 disposed outside the second recess 28 and extended into the space 251. The pawl 30 is pivotal to a position with the abutting end 32 thereof disposed within the second recess 28. When the object 90 is turned with the open-end wrench 10, the pawl 30 includes the abutting end 32 against the object 90 and will not pivot. When the open-end wrench 10 turns relative to the object, the pawl 30 is in a reciprocal pivotal movement, and is pivotal into the second recess 28.
In view of the forgoing, the pawl 30, 30a, 30b, 30c, 30d, and 30e is pivotally retained in the recess 27, 27a, 27b, 27c, 27d, and 27e without any pivot inserting therethrough, and the joining end 31a, 31b, 31c, 31d, and 31e thereof are enlarged in size to achieve a greater surface contact with the peripheral wall of the recess 27, 27a, 27b, 27c, 27d, and 27e, as well as to withstand a larger shear force. Additionally, the pawl 30, 30a, 30b, 30c, 30d, and 30e is prevented from a concentrated shear force, as the joining end 31a, 31b, 31c, 31d, and 31e thereof and the peripheral wall of the recess 27 are both curved and correspond to each other.
While the specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of invention, and the scope of invention is only limited by the scope of the accompanying claims.
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101139701 A | Oct 2012 | TW | national |
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