Patent Application
20140047957
1. Field of Invention
The present invention relates to a torque-indicating and, more particularly, to a robust torque-indicating wrench.
2. Related Prior Art
Referring to
In operation, a nut or screw is placed in a socket that is engaged with the selective one-way driving mechanism 30. Then, the handle 10 is pivoted to and fro to rotate the nut or screw. There is however a time lag between the start of the pivoting of the handle 10 and the start of the rotation of the nut or screw since the handle 10 can be pivoted relative to the pivoting element 20. Because of this time lag, a user inevitably pivots the handle 10 fast and hits the pivoting element 20 hard with the handle 10 before he or she actually pivots the nut or screw. The hitting of the pivoting element 20 with the handle 10 brings about uncomfortable feeling for the user and damages for the parts. Even when the torque-indicating wrench is not in use, the head pivoting element 20 tends to pivot and hit the handle 10, thus causing damages. The elastic element 40, which is made of plastics generally, is intended to reduce the uncomfortable feeling and the damages. However, the elastic element 40 could soon be damaged due to hits or aging.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.
It is the primary objective of the present invention to provide a robust torque-indicating wrench.
To achieve the foregoing objective, the torque-indicating wrench includes a handle, a strain gauge, a lever, a head and a driving mechanism. The strain gauge is placed in the handle. The lever including a first end inserted in and pivotally connected to the handle and abutted against the strain gauge and a second end placed out of the handle. The head includes a tubular portion non-pivotally placed around and on the handle. The driving mechanism includes a bit-rotating element pivotally placed in the head and formed with a crank pivotally connected to the second end of the lever.
Other objectives, advantages and features of the present invention will be apparent from the following description referring to the attached drawings.
The present invention will be described via detailed illustration of three embodiments versus the prior art referring to the drawings wherein:
Referring to
The lever 60 is substantially inserted in the handle 50 so that a first end thereof is abutted against the strain gauge 55 while a second end 65 thereof is placed out of the handle 50. The second end 65 of the lever 60 is a rounded end. An aperture 62 is defined in a circular enlarged portion 64 of the lever 60. The width of the lever 60 is smaller than an internal width of the handle 50 so that the lever 60 can be pivoted in the handle 50. An external diameter of the circular enlarged portion 64 of the lever 60 is identical to the internal width of the handle 50 so that the circular enlarged portion 64 of the lever 60 is in contact with the interior of the handle 50 so that the pivoting of the lever 60 in the handle 50 is smooth.
The head 70 is formed with a tubular portion 72. An aperture 71 is defined in the tubular portion 72 of the head 70. The tubular portion 72 of the head 70 is placed around the handle 50. An internal width of the tubular portion 72 of the head 70 is identical to an external width of the handle 50 so that the tubular portion 72 of the head 70 cannot be pivoted on the handle 50. A fastener 51 is driven in the aperture 62 through the aperture 52 and further through the aperture 71 to keep the lever 60 in the handle 50 and the head 70 on the handle 50.
The driving mechanism includes a bit-rotating element 80 and a detent-controlling element 83. The bit-rotating element 80 is a cup-shaped element with a crank 81 extending from the periphery transversely. An arched recess 82 is defined in the crank 81. The bit-rotating element 80 further includes two necks 84 between which the crank 81 is placed.
A first end of the detent-controlling element 83 is inserted in the bit-rotating element 80 while a second end of the detent-controlling element 83 is placed out of the bit-rotating element 80. A detent (not shown) is substantially placed in the bit-rotating element 80. The detent includes a first portion in contact with the detent-controlling element 83 and a second portion movable out of the bit-rotating element 80 via an aperture defined in the bit-rotating element 80. The detent is used to keep a bit on the bit-rotating element 80.
The detent-controlling element 83 is placed in the head 70. Each of the necks 84 is inserted through a bushing 73 placed in the head 70 to render the rotation of the detent-controlling element 83 in the head 70 smooth. The detent-controlling element 83 is kept in the head 70 by a cover 75 secured to the head 70 by two screws 74. The detent-controlling element 83 however extends beyond the cover 75.
In operation, a nut or screw is placed in a socket that is engaged with the bit-rotating element 80. Then, the handle 50 is pivoted in a direction shown in
Referring to
Referring to
Advantageously, the head 70 cannot be pivoted relative to the handle 50. That is, the head 70 does not hit the handle 50 so that they do not damage each other. Therefore, the torque-indicating wrench of the present invention is robust and durable.
The present invention has been described via the detailed illustration of the embodiments. Those skilled in the art can derive variations from the embodiments without departing from the scope of the present invention. Therefore, the embodiments shall not limit the scope of the present invention defined in the claims.
