Patent Application
20130032008
The present invention relates to a wrench, and more particularly, to a ratchet wrench functioned at one direction.
A conventional ratchet wrench 70 is shown in
U.S. Pat. No. 7,044,029 discloses a wrench wherein the first recess has a groove defined in the mediate portion thereof and a C-clip is engaged with the groove. The C-clip has a rod extending perpendicularly to the axis of the first recess so that the spring has one end mounted to the rod and the other end of the spring contacts the pawl. However, the groove has to be made by further machining process which increases the manufacturing cost, and there are two further grooves have to be made in the inside of the first recess so as to remove the surplus material. In other words, there are three grooves defined in the inside of the first recess. Generally, the thickness of the function end of the wrench is 10 mm and the depth of the first recess is 6 mm. Three grooves have to be made within the 6 mm thickness of the inside of the first recess and this definitely reduces the structure strength of the function end. For a smaller scale wrench, the function end is less than 8 mm and the depth of the first recess is only 4 mm. Each groove requires 1 mm so that it is difficult to make three grooves in the 4 mm thickness of the inside of the first recess. The C-clip is located in the first recess and faces the wrench wheel, the C-clip is narrower and moves inward after a period of use, the C-clip directly contacts the ratchet teeth of the ratchet wheel and affects the operation of the ratchet wheel. The spring has to be mounted to the rod of the C-clip and this assembling step is difficult in the small space in the first recess. Furthermore, the spring has to be made to have a ring to be mounted to the rod, and this increases the manufacturing cost to the spring.
The present invention intends to provide a wrench which is easily manufactured and assembled.
The present invention relates to a ratchet wrench and comprises a first recess defined in the function end thereof and a second recess is defined in the inside of the first recess. A ratchet wheel is located in the first recess, and a pawl and a resilient member are located in the second recess. The resilient member is connected between the pawl and the inside of the second recess. The resilient member biases the pawl to be engaged with the ratchet wheel. A C-shaped restriction member is engaged with the first recess and has a rod which is inserted into the second recess. A space is defined between the inside of the first recess and the rod. The second end of the resilient member is located in the space so as to position the resilient member in the second recess.
The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.
Referring to
A ratchet wheel 20 is located in the first recess 11 and includes ratchet teeth 21 define in the outside of the mediate portion thereof. An engaging recess 22 is defined in a top of the ratchet wheel 20 and is a polygonal recess so as to be engaged with an object. A second positioning groove 23 is defined in the outside of a top portion of the ratchet wheel 30 and is located corresponding to the first positioning groove 13. A contact portion 24 extends from the bottom of the ratchet wheel 20 and is engaged with the inside of the flange 110.
A pawl 30 and a resilient member 50 are located in the second recess 12. The pawl 30 includes ratchet teeth 31 defined in the mediate portion of the front side thereof and a smooth plain surface 33 is formed on an end of the front side of the pawl 30. The ratchet teeth 31 of the pawl 30 are engaged with the ratchet teeth 21 of the ratchet wheel 20. A connection portion 32 is a slot and defined in the rear side of the pawl 30.
A flexible C-shaped restriction member 40 located within the first recess 11 and a diameter of the restriction member 40 is larger than that of the first groove 14 so that when the restriction member 40 is engaged with the first groove 14, an outward tension is generated from the restriction member 40. The restriction member 40 is located corresponding to the contact portion 24. The restriction member 40 has a rod 41 extending along a direction parallel to the axis of the second recess 12 and the rod 41 is inserted into the second recess 12. A space 16 is defined between the inside of the first recess 11 and the rod 41, the second end of the resilient member 50 is located in the space 16 and positioned in the second recess 12. The rod 41 is perpendicular to the restriction member 41 and a height of the rod 41 is longer than a depth of the second recess 12.
The resilient member 50 has a first end contacting the pawl 30 and a second end of the resilient member 50 contacts the inside of the second recess 12. The resilient member 50 biases the ratchet teeth 31 of the pawl 30 to be engaged with ratchet teeth 21 of the ratchet wheel 20. The resilient member 50 is restricted between the plain surface 33 and the rod 41 so that the resilient member 50 dies not disengage from the second recess 12.
A positioning member 60 is engaged with the first and second positioning grooves 13, 23 so as to position the ratchet wheel 20 in the first recess 11.
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The present invention uses the first and second grooves to position the restriction member 40 and the resilient member 50, and this does not need to machine four grooves as mentioned in the prior art. The restriction member 40 is engaged with the grooves and located corresponding to the smooth contact portion 24 so that when the restriction member 40 fatigues, it does not wear out the ratchet teeth 21. The restriction member 40 is engaged with the grooves and the resilient member 50 is located in the second recess 12. The resilient member 50 is biased between the pawl 30 and the space 16, the assembling steps are easy. The resilient member 50 is restricted by the space 16 and does not need to make a ring so that it can be made at low cost. A resilient member rather than a spring can also be used. The plain surface 33 of the pawl 30 stops the resilient member 50, so that when the ratchet wheel 20 moves backward, the resilient member 50 is compressed and bent toward the inside of the second recess 12, the resilient member 50 does not contact the ratchet teeth 21.
While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.
