Tools – Wrench – screwdriver – or driver therefor – Handle clutched to head
Reexamination Certificate
2001-09-05
2002-05-07
Hail, III, Joseph J. (Department: 3723)
Tools
Wrench, screwdriver, or driver therefor
Handle clutched to head
Reexamination Certificate
active
06382051
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a ratchet wrench and, more particularly, to an improved structure of ratchet wrench.
As shown in
FIG. 1
, a conventional ratchet wrench
1
is generally comprised of a wrench body
10
, a ratchet wheel
20
, a stop block
30
, and a spring
40
. The two ends of the spring
40
are inserted to a hole
11
of the wrench body
10
and a hole
31
of the stop block
30
respectively to force the stop block
30
into engagement with the ratchet wheel
20
, enabling the ratchet wheel
20
to be rotated in the wrench body
10
in one direction only. The spring
40
is mass-produced by machine, having the determined length. However, because the processing of the hole
11
is disposed inside the wrench body
10
, its processing is not easy. A special machine tool is needed to make the hole
11
. When processing the hole
11
, it is difficult to control the depth of the hole
11
. Therefore, the fabrication of this structure of ratchet wrench may encounter the following problems.
1. If the depths of the holes
11
and
31
are excessively deep, the spring
40
cannot be properly compressed to support the stop block
30
positively in positive, and the ratchet wheel
20
may disengage from the stop block
30
when operating the ratchet wrench to turn a bolt or nut.
2. On the contrary, if the depths of the holes
11
and
31
are excessively short, the spring
40
will be maintained in a compressed condition before the stop block
30
receiving a pressure. In this case, the ratchet wrench loses its precision of torsion.
3. When making the holes
11
and
31
, it requires much effort to carefully examine the depths of the holes
11
and
31
, enabling the holes
11
and
31
to match the spring
40
perfectly.
SUMMARY OF THE INVENTION
The primary objective of the present invention is to provide a ratchet wrench, which has a stable torsion structure that achieves high performance. It is another object of the present invention to provide a ratchet wrench, which is easy to manufacture.
To achieve these objects of the present invention, the ratchet wrench comprises a wrench body having a receiving portion, an open chamber inside the receiving portion, and a blind hole in one sidewall of the open chamber, a ratchet wheel rotatably mounted in the receiving portion of the wrench body, the ratchet wheel having a toothed peripheral wall, a stop block mounted in the open chamber of the wrench body and adapted to engage the toothed peripheral wall of the ratchet wheel and to limit the direction of rotation of the ratchet wheel, and a spring member mounted in the open chamber to support the stop block and to force the stop block into engagement with the ratchet wheel. The diameter of the midsection of the spring member is greater than the diameter of the blind hole of the open chamber, and the diameter of one end of the spring member is smaller than the diameter of the blind hold such that said end can be inserted into the blind hole and the midsection is stopped by the sidewall of the open chamber.
REFERENCES:
patent: 1194471 (1916-08-01), Boosinger
patent: 3265171 (1966-08-01), Kilness
patent: 4991468 (1991-02-01), Lee
patent: 6109141 (2000-08-01), Nurmi
Browdy and Neimark , P.L.L.C.
Danganan Joni B.
Hail III Joseph J.
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