The present invention relates to a wrench, and more particularly to a roller type reversible adjustable wrench.
In prior art, when using an adjustable wrench to turn a nut (or a bolt), it has to disengage the nut after turning an angle. And then, turns the adjustable wrench reversibly and engages the adjustable wrench to the nut again for driving the nut to turn. User has to repeat the procedures described above to turn tight or to turn loose the nut.
FIG. 1 shows a conventional reversible adjustable wrench 90, which is capable of turning a nut without having to disengage and reengage the nut. The adjustable wrench 90 disposes two round channels 911 and 921 at the fixed jaw 91 and the movable jaw 92 respectively. Two racket rods 93 and 94, which have teeth faces 931 and 941 on outer ends thereof, are slidable received in the round channels 911 and 921 respectively. Two elastic members 95 and 96 are disposed at the fixed jaw 91 and the movable jaw 92 respectively for pushing the racket rods 93 and 94 respectively.
In use, user drives the movable jaw 92 moving toward the fixed jaw 91 to make the teeth faces 931 and 941 of the fixed jaw 91 and the movable jaw 92 holding a nut N. After that, user can turn the adjustable wrench 90 clockwise to drive the nut N to turn. On the contrary, when user turns the adjustable wrench 90 counterclockwise, the nut N will drive the racket rods 93 and 94 sliding into the round channels 911 and 921, such that the adjustable wrench 90 can turn backward but without driving the nut N to turn. Thus, the adjustable wrench 90 can turn a nut or a bolt without having to disengage and reengage the nut or the bolt repeatedly.
Hereunder are the disadvantages of the conventional reversible adjustable wrench 90 as described above:
1. The adjustable wrench 90 defines the teeth faces 931 and 941 of the racket rods 93 and 94 to hold the edges of the nut N. It will easy to damage the nut N when turning.
2. The adjustable wrench 90 is to turn the nuts in a range of different dimensions. There will be nuts of specific dimensions cannot be held by the teeth faces 931 and 941 stably.
3. If user drives the movable jaw 92 too close to the fixed jaw 91, the racket rods 93 and 94 will be pushed into the round channels 911 and 921 to cause the fixed jaw 91 and the movable jaw 92 will be against the nut N directly. Thus, the adjustable wrench 90 will loose the capability of repeated turning the nut.
4. The reversible adjustable wrench 90 is to hold the nut N by the teeth faces 931 and 941 of the racket rods 93 and 94 respectively, the nut N is suspended and not parallel to the fixed jaw 91 and the movable jaw 92. But the normal adjustable wrench is to hold the nut by fixed jaw and the movable jaw directly, where the nut is supported by the handle and is parallel to the fixed jaw and the movable jaw. The reversible adjustable wrench 90 had an operating mode different from conventional adjustable wrench that will make user can not get used to it rapidly.
The primary object of the present invention is to provide a reversible adjustable wrench, which has the capability of reversible turning a nut or a bolt but without the drawbacks as described above.
According to the objective of the present invention, a reversible adjustable wrench comprises a handle, which has a fixed jaw and a guiding groove at an end thereof. The fixed jaw has a chamber, which has an opening at a side of the fixed jaw. The chamber has a guiding face therein, which has a stop portion at an end thereof closing to the tip end of the fixed jaw. A movable jaw has an end thereof slidable received in the guiding groove of the handle. An adjusting worm is pivoted at the handle for driving the movable jaw moving toward and away from the fixed jaw. A roller is received in the chamber of the fixed jaw, which has a part thereof exposed out of the chamber via the opening and is against the guiding face at opposite side, and at least one elastic member is disposed between the fixed jaw and the roller for providing the roller a force substantially orientating to the tip end of the fixed jaw, whereby the roller will be stopped by the stop portion and only be driven to move along the guiding face.