(a) Field of the Invention
The present invention relates to an adjustable wrench, and more particularly to an adjustable wrench with a ratchet function.
(b) Description of the Prior Art
In general, when an adjustable wrench is used, the roller is firstly adjusted so that a clamping opening between the fixed jaw and the movable jaw fits the size of a nut followed by performing screw locking (loosening) operation.
However, if in a constrained space, it is generally impossible to continuously rotate the handle of the wrench in the same direction to quickly complete the work, whereas the roller must be slightly screw loosened to enlarge the clamping opening so that it can fit with another two opposing clamping surfaces of the nut to allow continuous rotation. But such repeated operation is significantly inconvenient.
To overcome the drawbacks of the above-mentioned adjustable wrenches, adjustable wrenches with a ratchet function are available on the market. One of them is as shown in FIG. 7, which mainly has a handle 96 to be held by an operator. The handle 96 has a fixed jaw 98 on one end, and a movable jaw 92 is disposed on one side of the fixed jaw 98. The movable jaw 92 engages a roller 91 so as to drive the movable jaw 92 to move. The roller 91 is propped by a compression spring 94 so as to provide a resilient force that moves the movable jaw 92 back and forth in a limited space. A curved spring plate 95 is disposed at the middle section of the handle 96. One end of the spring plate 95 is fixed at the handle 96, and the bottom of the other end thereof is provided with a projecting portion 951 connected to a spring lock 93. One end of the spring lock 93 extends to one side of the roller 91 and is formed with a stopper portion 931 to stop the movement of the roller 91, so as to provide a fixed opening between the fixed jaw 98 and the movable jaw 92 for convenience of rotating workpieces. Pressing the spring plate 95 at the middle section of the handle 96 would release the stopper portion 931 of the spring lock 93 on stopping the roller 91, so that the movable jaw 92 can move freely for convenience of rotating the adjustable wrench.
Nevertheless, defects in structural design of the above-mentioned adjustable wrench may cause the problems such as failure in operation and false touches in practical use. As shown in FIG. 8, since there is an elongated space 97 significantly exposed and located between the spring plate 95 of the wrench and the side face of the handle 96, dusts and trash from the workplace will be accumulated therein after long time use, so that the spring plate 95 is stuck and cannot be effectively pressed to cause the problem of failure in operation.
In addition, as shown in FIGS. 7 and 8, both of the above-mentioned spring plate 95 and spring lock 93 are designed as elongated strips and exposed from the surface of the wrench. Hence, it is easy to cause deformation when the spring plate 95 or the spring lock 93 is hit by an external force. Once the spring plate 95 or the spring lock 93 is deformed, this would cause the problem of failure in operation.
Moreover, the spring plate 95 is located on one side face of the handle 96. Therefore, when the wrench needs to be used on its reverse side due to the working environment, this is bound to have the difficulty in pressing the spring plate.
USPTO Backgrounds
USPTO Backgrounds