Tools – Wrench – screwdriver – or driver therefor – Handle clutched to head
Reexamination Certificate
1999-11-30
2001-04-24
Hail, III, Joseph J. (Department: 3723)
Tools
Wrench, screwdriver, or driver therefor
Handle clutched to head
C081S063100, C081S063000, C081S061000
Reexamination Certificate
active
06220123
ABSTRACT:
BACKGROUND OF THE INVENTION
a) Technical Field of the Invention
The present invention relates to a wrench structure, and in particular, to a ratchet wrench capable of providing high torque movement.
b) Description of the Prior Art
As shown in
FIG. 1
, a common conventional wrench
10
has a plurality of engaging notches
11
formed as one unit with the wrench
10
and the notches
11
moves together with the wrench
10
to rotate a nut
12
. When the wrench
10
is rotated to a certain degree, as a result of restriction by object around the wrench
10
, the wrench
10
has to be lifted up and placed at the original position and then repeat the process in order to rotate the nut
12
. As a result of repeating engagement and disengagement of the wrench
10
with the nut
12
, the notch
11
of the wench
10
is often dislocated in the process of tightening or loosening of the nut
12
.
FIG. 2
is another prior art wrench
10
having a bent structure to provide convenient holding of the handle of the wrench
10
by a user. However, this type of wrench
10
has the drawback as that of FIG.
1
and the wrench
10
is often dislocated from the nut
12
. Besides, the process of tightening and loosening of nut
12
by using this wrench
10
is slow.
FIGS. 3 and 4
show another types of wrench
20
having a head portion being provided with a circular opening
201
to contain a ratchet wheel
21
. A cavity
202
is provided to the circular opening
201
, adjacent to the one lateral side of the rod body to contain a restrictive teeth structure
22
and a spring
23
. If the ratchet wheel
21
is to rotate clockwise, as the teeth of the ratchet wheel
21
is in engagement with that of the restrictive teeth structure
22
, and one side of the restrictive teeth structure
22
is restricted by the wall of the cavity
202
, thus, the ratchet wheel
21
cannot rotate clockwise, but the wrench
20
can rotate clockwise to drive the ratchet wheel
21
to rotate the nuts. If the ratchet wheel
21
rotates counterclockwise, as the teeth of the ratchet wheel
21
is in engagement with that of the restrictive teeth structure
22
, and one side of the restrictive teeth structure
22
is restricted by the spring
23
and the spring
23
is compressible, thus, ratchet wheel
21
can rotate freely in a counterclockwise direction, and t e eth-skidding is resulted by the teeth of the restrictive teeth structure
22
with that of the ratchet wheel.
The advantage of this wrench
20
is no repeating of engagement and disengagement of the nut
12
with the wrench
20
, and the operation of the wrench
20
is faster. However, if a reverse direction of the nut is required, the wrench
20
has to be changed to another face such that the ratchet wheel
21
can be rotated in a reverse direction. In view of the need of reversing the rotation of the wrench
20
, it cannot be made into the shape of the wrench
10
as shown in
FIG. 2
to provide a bent angle so that the application of the wrench
20
is smooth. The drawback is also found in U.S. Pat. No. 5,636,557.
FIG. 5
is another ratchet wrench
30
having a ratchet wheel
31
provided with a restrictive teeth structure
32
. Two sides of the restrictive teeth structure
32
are provided with teeth for the engagement with that of the ratchet wheel
31
. The restrictive teeth structure
32
can rotate about a center to a certain degree. The restrictive teeth structure
32
causes the ratchet wheel
31
to produce a single direction rotation. If frequent reverse of direction of rotation is required, the restrictive teeth structure
32
rotates to a certain angle about the center, and at this instance, the teeth at one side of the restrictive teeth structure
32
can engage with the teeth of the ratchet wheel
31
and the restrictive teeth structure
32
causes the ratchet wheel
31
to produce a free rotation. Thus, the rotation of the restrictive teeth structure
32
is used to cause a change of rotation direction. Thus, the wrench having multiple angle shown
FIG. 2
can be fabricated. However, this design has other drawback. The engagement of the restrictive teeth structure
32
and the ratchet wheel
31
is depend on a few teeth to provide rotation, if the torque is too great, the restrictive teeth
32
or the engaged teeth of the ratchet wheel
31
may be damaged. U.S. Pat. Nos. 5,884,538, 5,626,062 and 5,782,147 disclose this type of wrench.
U.S. Pat. Nos. 5,533,427 and 5,230,262 provides the advantages that shown in
FIGS. 3 and 5
. In U.S. Pat. No. 5,533,427, the ratchet wheel
40
of the disclosed wrench
10
is in engagement with the restrictive teeth structure
50
which can resist a larger torque. By using the reverse direction control
60
,
70
, the position of the engagement of the restrictive teeth structure
50
with that of the ratchet wheel
40
is changed so as to change the rotation direction of the ratchet wheel
40
. Unlike the wrench in
FIG. 3
, a reverse of the wrench is required. The wrench
10
can be made into a shape as shown in
FIG. 2
to provide smooth use for the user. However, the drawback of such wrench
10
is that the head portion
20
is larger than that shown in
FIG. 3
for the reason that the head portion
20
is used to contain the ratchet wheel
40
, a directional control
60
and the restrictive teeth structure
50
. The design principle of U.S. Pat. No. 5,230,262 is similar to that of U.S. Pat. No. 5,533,427. These two patents disclose wrenches with high torque.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to prove structure of a ratchet wrench, wherein the ratchet wrench provides a high torque driving.
Further features of the present invention will become apparent from a careful reading of the detailed description provided hereinbelow, with appropriate reference to the accompanying drawings.
REFERENCES:
patent: 4336728 (1982-06-01), Deibert
patent: 5477757 (1995-12-01), Maresh
patent: 5913954 (1999-06-01), Arnold et al.
patent: 5957009 (1999-09-01), McCann
patent: 6044731 (2000-04-01), Hsieh
A & J
Berry Jr. Willie
Hail III Joseph J.
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