Tools – Wrench – screwdriver – or driver therefor – Handle clutched to head
Reexamination Certificate
2002-12-03
2004-11-23
Hail, III, Joseph J. (Department: 3723)
Tools
Wrench, screwdriver, or driver therefor
Handle clutched to head
C081S059100, C081S063100, C081S063200
Reexamination Certificate
active
06820520
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a ratchet wrench having a rigid locking structure, and more particularly to a ratchet wrench having a rigid locking structure, wherein the support blocks of the pawl member are urged on the wall of the receiving chamber of the wrench body, thereby forming a double-support or multi-support structure between the pawl member and the wall of the receiving chamber of the wrench body, so that the locking teeth of the pawl member are engaged with the ratchet teeth of the ratchet wheel actually, closely, rigidly and stably.
2. Description of the Related Art
A conventional ratchet wrench in accordance with the prior art shown in
FIGS. 6 and 7
comprises a wrench body
90
, a ratchet wheel
93
, a pawl member
95
, and a restoring member
96
. The wrench body
90
has a driving head
91
having an inner wall formed with a receiving recess
92
and a receiving chamber
94
. The ratchet wheel
93
is mounted in the receiving recess
92
of the driving head
91
of the wrench body
90
and has an outer wall formed with a plurality of ratchet teeth
930
. The pawl member
95
is mounted in the receiving chamber
94
of the wrench body
90
and has a first side formed with a plurality of locking teeth
950
engaged with the ratchet teeth
930
of the ratchet wheel
93
and a second side formed with an arcuate resting face
97
. The restoring member
96
is mounted in the receiving chamber
94
of the wrench body
90
and urged between the pawl member
95
and the wall of the receiving chamber
94
of the wrench body
90
. Thus, a support force “F” is formed between the arcuate resting face
97
of the pawl member
95
and the wall of the receiving chamber
94
of the wrench body
90
.
As shown in
FIG. 6
, the contact position of the arcuate resting face
97
of the pawl member
95
and the wall of the receiving chamber
94
of the wrench body
90
is located at the left end of the pawl member
95
.
As shown in
FIG. 7
, the contact position of the arcuate resting face
97
of the pawl member
95
and the wall of the receiving chamber
94
of the wrench body
90
is located at the mediate portion of the pawl member
95
.
However, the conventional ratchet wrench in accordance with the prior art has the following disadvantages.
1. The contact position of the arcuate resting face
97
of the pawl member
95
and the wall of the receiving chamber
94
of the wrench body
90
deflects and deviates as shown in
FIGS. 6 and 7
, so that the pawl member
95
is not engaged with the ratchet wheel
93
closely, rigidly and stably.
2. The contact position of the arcuate resting face
97
of the pawl member
95
and the wall of the receiving chamber
94
of the wrench body
90
is almost a point, thereby producing a stress concentration on the wall of the receiving chamber
94
of the wrench body
90
, and thereby decreasing the lifetime of the ratchet wrench.
3. The contact position of the arcuate resting face
97
of the pawl member
95
and the wall of the receiving chamber
94
of the wrench body
90
is almost a point, thereby decreasing the torque of the ratchet wrench.
SUMMARY OF THE INVENTION
The present invention has arisen to mitigate and/or obviate the disadvantage of the conventional ratchet wrench.
The primary objective of the present invention is to provide a ratchet wrench having a rigid locking structure, wherein the support blocks of the pawl member are urged on the wall of the receiving chamber of the wrench body, thereby forming a double-support or multi-support structure between the pawl member and the wall of the receiving chamber of the wrench body, so that the locking teeth of the pawl member are engaged with the ratchet teeth of the ratchet wheel actually, closely, rigidly and stably.
Another objective of the present invention is to provide a ratchet wrench having a rigid locking structure, wherein the multiple support forces evenly support the pawl member, thereby preventing from producing a stress concentration on the wall of the receiving chamber of the wrench body, so that the pawl member is locked with the ratchet wheel actually and stably without slip or detachment.
A further objective of the present invention is to provide a ratchet wrench having a rigid locking structure, wherein the multiple support forces produce a larger force resistant area between the pawl member and the wall of the receiving chamber of the wrench body, thereby increasing the efficient torque of the ratchet wrench.
A further objective of the present invention is to provide a ratchet wrench having a rigid locking structure, wherein the multiple support forces evenly support the pawl member, thereby producing a larger force resistant area, and thereby preventing from producing a stress concentration on the wall of the receiving chamber of the wrench body, so as to increase the lifetime of the ratchet wrench.
A further objective of the present invention is to provide a ratchet wrench having a rigid locking structure, wherein the multiple support blocks evenly support the pawl member, so that the pawl member is moved on the wall of the receiving chamber of the wrench body smoothly and conveniently and is engaged with the ratchet wheel rapidly and rigidly, thereby facilitating the user operating the ratchet wrench.
In accordance with the present invention, there is provided a ratchet wrench having a rigid locking structure, comprising a wrench body, a ratchet wheel, a pawl member, and a restoring member, wherein:
the wrench body has a driving head having an inner wall formed with a receiving recess and a receiving chamber located beside and communicated with the receiving recess;
the ratchet wheel is mounted in the receiving recess of the driving head of the wrench body and has an outer wall formed with a plurality of ratchet teeth;
the pawl member is mounted in the receiving chamber of the driving head of the wrench body and has a first side formed with a plurality of locking teeth engaged with the ratchet teeth of the ratchet wheel and a second side formed with a plurality of convex support blocks each rested on a wall of the receiving chamber of the driving head of the wrench body;
the restoring member is mounted in the receiving chamber of the driving head of the wrench body and urged between the pawl member and the wall of the receiving chamber of the driving head of the wrench body.
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.
REFERENCES:
patent: 6647832 (2003-11-01), Hu
Grant Alvin J.
Hail III Joseph J.
Rosenberg , Klein & Lee
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