1. Field of the Invention
The present invention relates to a wrench.
2. Description of the Prior Art
A conventional wrench is subjected to be used through the cooperative engagement of a cam portion disposed at the bottom of a movable jaw and another cam portion disposed at the top of a handle. However, under a required huge torque, such an engagement between the cam portions can easily lead to the collapse of the cam portions and the abrasion of the cam portions after a prolonged use of the cam portions.
In this regard, a wrench disclosed in patent U.S. Pat. No. 1,434,754 is provided to improve the above problem, in which a spring is disposed in a slot, and rivets are secured to plates and located in the slot. However, since the cooperating projections are located below the slot, and so is the cam shaped projection, the force applied to the movable jaw by the cam shaped projection concentrates mostly at the cooperating projections, the cam shaped projection slantedly and downwardly push the cooperating projections, and only about half the force is used to drive the cooperating projections moving horizontally. In other words, when the wrench which is provided without the use of the engagement of the cam portions is used, it is difficult to operate because only a small part of the force is delivered to the movable jaw and the fixed jaw.
In addition, since the movable jaw and the fixed jaw are secured between two plates, two slots are required, and two rivets are secured to the movable jaw and the fixed jaw and are located in the slot, respectively, to complete the assembly of the wrench. The structure of the wrench is quite complex, thus increasing the manufacturing costs and assembly difficulty.
The present invention is, therefore, arisen to obviate or at least mitigate the above mentioned disadvantages.
The main object of the present invention is to provide a wrench which is simple in structure and has excellent effects of use.
To achieve the above and other objects, a wrench of the present invention includes a main body, a slidable member and a handle.
The main body has a fixed jaw.
The slidable member is formed at the bottom portion of the movable jaw and slidably mounted to the main body, and the slidable member defines a changeable opening with the fixed jaw.
The slidable member includes an upper small portion and a first lower enlarged portion, the upper small portion extends laterally from and is located at the bottom portion of the movable jaw, the upper small portion has a first end and a second end, the first lower enlarged portion extends laterally from and is located at the bottom portion of the upper small portion and is near the first end of the upper small portion, and the first lower enlarged portion has a first end and a second end.
A part of the upper small portion near the second end thereof and the first end of the first lower enlarged portion define a driving space, an another part of the upper small portion and the main body define an evading space, and the evading space is comparatively near the second end of the upper small portion.
The handle has a toggle member disposed at one end thereof. When the handle is at a driving position, the toggle member is located in the driving space and engages against the first end of the first lower enlarged portion, and the changeable opening has the smallest width. When the handle is at a releasing position, the toggle member is located away from the first end of the first lower enlarged portion and moves into the evading space from the driving space smoothly, and the movable jaw is capable of moving away from or toward the fixed jaw.
Whereby, the structure of the wrench of the present invention is simple, the manufacturing costs is decreased, and the force applied by the user can be sufficiently delivered to the movable jaw and the fixed jaw. Furthermore, the slidable member is provided with the evading space, so that the travel distance for which the movable jaw moves away from the fixed jaw is not limited.
The present invention will become more obvious from the following description when taken in connection with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiment(s) in accordance with the present invention.
As shown in
The main body 1 has a fixed jaw 11. The main body 1 may further include a sliding slot 12, a through hole 13 and a through recess 14 for the assembly of other parts. The sliding slot 12, the through hole 13 and the through recess 14 communicate with each other, and the through hole 13 is located between the sliding slot 12 and the through recess 14. In addition, an axis of the through hole 13 is perpendicular to the direction in which the sliding slot 12 extends.
The slidable member 3 is integrally formed at the bottom portion of the movable jaw 2 and slidably mounted to the main body 1, more specifically, slidably mounted in the sliding slot 12 of the main body 1. The movable jaw 2 defines a changeable opening with the fixed jaw 11, and the width of the changeable opening can change when the slidable member 3 slides, thus allowing the clamping of a nut, a screw or the like, as shown in
Preferably, the slidable member 3 includes an upper small portion 31 and a first lower enlarged portion 32. The upper small portion 31 integrally extends laterally from and is located at the bottom portion of the movable jaw 2, and has a first end 311 and a second end 312. The first lower enlarged portion 32 integrally extends laterally from and is located at the bottom portion of the upper small portion 31, and is near the first end 311 of the upper small portion 31. The extending length of the first lower enlarged portion 32 is smaller than that of the upper small portion 31, and the first lower enlarged portion 32 has a first end 321 and a second end 322. The first lower enlarged portion 32 has a slot 323 extending laterally along a longitudinal axis thereof, and the longitudinal axis is substantially parallel to the sliding axis. A central line 8 is defined according to a direction in which the slot 323 extends. A part of the upper small portion 31 near the second end 312 thereof and the first end 321 of the first lower enlarged portion 32 define a driving space A, and an another part of the upper small portion 31 and the main body 1 define an evading space B, wherein the central line 8 passes through the driving space A. The evading space B is comparatively near the second end 312 of the upper small portion 31 and communicates with the driving space A. Preferably, the slidable member 3 further includes a second lower enlarged portion 33 integrally extending laterally from and is located at the bottom portion of the upper small portion 31 and is near the second end 312 of the upper small portion 31. In other words, the second lower enlarged portion 33 is located at the another part near the second end 312 of the upper small portion 31. The second lower enlarged portion 33 has a first end 331 and a second end 332. The first end 331 of the second lower enlarged portion 33 is near the second end 312 of the upper small portion 31, and the second end 332 of the second lower enlarged portion 33 is formed with a chamfer, wherein the chamfer and the main body 1 define the evading space B.
The blocking member 4 is connected to the main body 1, located in the slot 323 and near the first end 311 of the first lower enlarged portion 32. The blocking member 4 is preferably a pin.
The spring member 5 is disposed in the slot 323, and two ends of the spring member 5 engage against the blocking member 4 and a sidewall of slot 323, respectively, in which the sidewall is near the second end 322 of the first lower enlarged portion 32.
The handle 6 is rotatably mounted to the main body 1 and has a toggle member 61 disposed at one end thereof. The toggle member 61 is preferably a single projection. In this embodiment, the toggle member 61 is a single projection protruding from one end of the handle 6, and the end of the handle 6 is formed with a round hole 62. In fabrication, the toggle member 61 is disposed into the through recess 14, and a pin 63 is disposed through the through hole 13 of the main body 1 and the round hole 62 of the handle 6, so that the handle 6 can rotate around the pin 63 between a driving position and a releasing position. In addition, since the axis of the through hole 13 is perpendicular to the direction in which the sliding slot 12 extends, the direction in which the pin 63 extends is perpendicular to the sliding axis.
The operation of the wrench of the present invention for driving the nut 7 is described as following. As shown in
As shown in
The wrench of the present invention is simple in structure. In addition, it needs only to rotate the handle to enable the toggle member to engages against the first end of the first lower enlarged portion, so as to retain the nut or the like in an assembly or disassembly process. With the simple structure, the invention has characteristics of easy manufacturing, low manufacturing costs, lower-threshold requirements for skill, smaller gap(s) between parts and high stability, and this facilitates the manufacture of the wrench and it has excellent effects of use. More important, the invention is free of the disadvantageous issues of gear engagement and gear slippage when the gears engage with or disengage from each other, and the wrench is of better tactile property and high quality.
Furthermore, the slidable member is provided with the evading space, and the evading space allows the toggle member move into or even to traverse through. The spring force provided by the spring member disposed in the slot can force the movable jaw to tend to move toward the fixed jaw, and the travel distance for which the movable jaw moves away from the fixed jaw is not limited.
Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.