1. Field of the Invention
The present invention relates to a hand tool and, more particularly, to a combination wrench for driving a workpiece, such as a screw, nut and the like.
2. Description of the Related Art
A conventional wrench in accordance with the prior art shown in
In accordance with the present invention, there is provided a wrench comprising a wrench body provided with a hollow mounting hole. The mounting hole of the wrench body is mounted on a workpiece which has a plurality of outer sides and a plurality of corners. The mounting hole of the wrench body has an entrance end and an opening end. The mounting hole of the wrench body is provided with a plurality of locking edges each corresponding to the respective outer side of the workpiece and a plurality of receiving grooves each corresponding to the respective corner of the workpiece. Each of the receiving grooves of the wrench body is located between and connected with two of the locking edges. Each of the locking edges of the wrench body extends in the opening end toward a respective one of a plurality of first imaginary lines, with an inclined section being defined between each of the locking edges of the wrench body and the respective first imaginary line. Each of the first imaginary lines is parallel with the respective outer side of the workpiece. Each of the locking edges and each of the receiving grooves of the wrench body has an connection which is formed with a respective one of a plurality of second imaginary lines, with a rotation space being defined between each of the second imaginary lines and each of the first imaginary lines.
According to the primary advantage of the present invention, the receiving grooves of the wrench body receive the corners of the workpiece to prevent the wrench body from directly contacting the corners of the workpiece, so that the corners of the workpiece will not be rubbed or worn when the wrench body drives the workpiece, thereby enhancing the lifetime of the workpiece.
According to another advantage of the present invention, the locking edges of the wrench body press and provide a force to drive the outer sides of the workpiece so that the wrench body can be used to drive the workpiece whose corners have been worn out, without producing slip during operation.
Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.
Referring to the drawings and initially to
The mounting hole 31 of the wrench body 3 has an entrance end 311 and an opening end 312. The mounting hole 31 of the wrench body 3 is provided with a plurality of locking edges 32 each corresponding to the respective outer side 42 of the screw 4 and a plurality of receiving grooves 33 each corresponding to the respective corner 41 of the screw 4. Each of the receiving grooves 33 of the wrench body 3 is located between and connected with two of the locking edges 32.
The locking edges 32 and the receiving grooves 33 of the wrench body 3 are arranged in a staggered manner and are extended from the entrance end 311 to the opening end 312 of the mounting hole 31. The locking edges 32 and the receiving grooves 33 of the wrench body 3 are connected to form the mounting hole 31 which has a polygonal endless shape.
Each of the locking edges 32 of the wrench body 3 extends in the opening end 312 toward a respective one of a plurality of first imaginary lines 34, with an inclined section “A1” being defined between each of the locking edges 32 of the wrench body 3 and the respective first imaginary line 34. Preferably, the inclined section “A1” has an angle ranged between one degree and ten degrees)(1°-10°). In the preferred embodiment of the present invention, the inclined section “A1” has an optimum angle of seven degrees)(7°). Each of the first imaginary lines 34 is parallel with the respective outer side 42 of the screw 4.
Each of the locking edges 32 and each of the receiving grooves 33 of the wrench body 3 has an connection which is formed with a respective one of a plurality of second imaginary lines 35, with a rotation space “A2” being defined between each of the second imaginary lines 35 and each of the first imaginary lines 34. Preferably, the rotation space “A2” has an angle ranged between ninety degrees and one hundred and seventy degrees)(90°-170°). In the preferred embodiment of the present invention, the rotation space “A2” has an optimum angle of one hundred and one degrees)(101°).
In operation, referring to
On the other hand, referring to
Referring to
Referring to
In the preferred embodiment of the present invention, the entrance end 311 of the mounting hole 31 has a diameter equal to that of the opening end 312 of the mounting hole 31.
In another preferred embodiment of the present invention, the entrance end 311 of the mounting hole 31 has a diameter greater than that of the opening end 312 of the mounting hole 31, so that the mounting hole 31 of the wrench body 3 has a tapered shape and gradually reduces from the entrance end 311 to the opening end 312. Preferably, the mounting hole 31 of the wrench body 3 has a tapered angle ranged between one degree and 5 degrees) (1°-5°).
Accordingly, the receiving grooves 33 of the wrench body 3 receive the corners of a workpiece, such as a screw, nut and the like to prevent the wrench body 3 from directly contacting the corners of the workpiece, so that the corners of the workpiece will not be rubbed or worn when the wrench body 3 drives the workpiece, thereby enhancing the lifetime of the workpiece. In addition, the locking edges 32 of the wrench body 3 press and provide a force to drive the outer sides of the workpiece so that the wrench body 3 can be used to drive the workpiece whose corners have been worn out, without producing slip during operation.
Although the invention has been explained in relation to its preferred embodiment(s) as mentioned above, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the present invention. It is, therefore, contemplated that the appended claim or claims will cover such modifications and variations that fall within the true scope of the invention.