Tools – Wrench – screwdriver – or driver therefor – Pivoted outer jaw
Utility Patent
1999-09-07
2001-01-02
Morgan, Eileen P. (Department: 3723)
Tools
Wrench, screwdriver, or driver therefor
Pivoted outer jaw
Utility Patent
active
06167784
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a spanner, more particularly to a spanner with an enhanced strength and an enhanced clamping effect on a workpiece.
2. Description of the Related Art
FIGS. 1
to
3
illustrate a conventional spanner for operating a workpiece, such as a screw fastener. The spanner is shown to include an elongated first clamping member
10
, a second clamping member
11
, a pivot shaft
14
, and a torsion spring
13
. The first clamping member
10
has a handle portion
12
and a first jaw portion
121
at a front end of the handle portion
12
. The first jaw portion
121
has a toothed first clamping face
122
, and a pivot plate portion
123
with a reduced thickness relative to the handle portion
12
. The pivot plate portion
123
has a first pivot hole
124
formed through top and bottom surfaces thereof, and an insert hole
125
formed in the top surface adjacent to the pivot hole
124
. The second clamping member
11
has a second jaw portion
117
with a toothed second clamping surface
112
, and a pair of spaced-apart pivot lobes
114
extending from the second jaw portion
117
to define an opening
111
with the second jaw portion
117
. The pivot lobes
114
are formed with aligned second pivot holes
115
, and cooperatively define a receiving space
113
to permit extension of the pivot plate portion
123
thereinto so as to align the first pivot hole
124
with the second pivot holes
115
. The pivot shaft
14
extends through the first and second pivot holes
124
,
115
for mounting pivotally the first clamping member
10
on the second clamping member
11
. The second clamping surface
112
confronts the first clamping surface
122
. The torsion spring
13
is sleeved on the pivot shaft
14
, and is disposed between the pivot lobes
114
. The torsion spring
13
has a first leg
131
at one end, and a second leg
132
at the other end. The first leg
131
is inserted into the insert hole
125
for retention at the pivot plate portion
123
of the first clamping member
10
. The second leg
132
extends out of the receiving space
113
, and is retained at a retaining slit
116
formed in an outer surface of the second clamping member
11
adjacent to the receiving space
113
. As shown in
FIG. 4
, in use, the second clamping member
11
is moved pivotally about the pivot shaft
14
against the biasing action of the torsion spring
13
so as to move the second jaw portion
117
away from the first jaw portion
121
such that a clamping space
15
is formed between the first and second clamping surfaces
122
,
112
to permit extension of a workpiece
20
, such as a screw fastener, thereinto. The torsion spring
13
biases the second jaw portion
117
toward the first jaw portion
121
such that the workpiece
20
can be clamped tightly between the first and second clamping surfaces
122
,
112
, thereby permitting operation, such as turning, of the workpiece
20
via the spanner.
However, it is noted that the conventional spanner suffers from the following disadvantages:
(1) Since the torsion spring
13
is received in the receiving space
113
, together with the pivot plate portion
123
of the first clamping member
10
, a clearance
16
should be formed between the pivot plate portion
123
and one of the pivot lobes
114
for accommodating the torsion spring
13
. Therefore, the pivot plate portion
123
of the first clamping member
10
should be reduced in thickness. The strength of the pivot plate portion
123
is thus reduced.
(2) As the thickness of the pivot plate portion
123
is reduced, the surface area of the first clamping surface
122
is reduced accordingly, thereby adversely affecting the clamping effect of the spanner on the workpiece
20
.
(3) As the second leg
132
of the torsion spring
13
extends out of the receiving space
113
, it is likely to be moved by an adjacent article when the spanner is operated, thereby affecting operation of the torsion spring
13
.
SUMMARY OF THE INVENTION
Therefore, the object of the present invention is to provide a spanner that is capable of solving the aforementioned problems.
Accordingly, the spanner of the present invention includes an elongated first clamping member, a second clamping member, a pivot shaft, and a torsion spring. The first clamping member has a first jaw portion and a handle portion connected to the first jaw portion. The first jaw portion has a pivot plate portion with top and bottom surfaces and a first pivot hole formed through the top and bottom surfaces. The pivot plate portion of the first clamping member has a thickness measured between the top and bottom surfaces. The second clamping member has a second jaw portion and a pair of pivot lobes connected to the second jaw portion. The pivot lobes cooperatively define a receiving space therebetween to permit the pivot plate portion of the first clamping member to extend thereinto. Each of the pivot lobes is formed with a second pivot hole that is aligned axially with the first pivot hole. Each of the pivot lobes has an inner surface that confronts the other one of said pivot lobes. The receiving space has a width which is measured between the inner surfaces of the pivot lobes. The pivot shaft extends through the first and second pivot holes for mounting pivotally the second clamping member on the first clamping member. The torsion spring is sleeved on the pivot shaft, and is disposed in the receiving space for biasing the second jaw portion of the second clamping member to move toward the first jaw portion of the first clamping member. One of the top and bottom surfaces of the pivot plate portion of the first clamping member is formed with a recess confining wall that defines a recess around the first pivot hole. The torsion spring is received in the recess so as to be concealed by the recess confining wall, and has a first end retained at the first clamping member and a second end retained at the second clamping member. The width of the receiving space of the second clamping member is substantially equal to the thickness of the pivot plate portion of the first clamping member.
REFERENCES:
patent: 728945 (1903-05-01), Levy
patent: 1333174 (1920-03-01), Henry
patent: 1486981 (1924-03-01), Magnan
patent: 2742808 (1956-04-01), Haberle
patent: 2875659 (1959-03-01), Haberle
patent: 2958246 (1960-11-01), Osborn
Danganan Joni B.
Merchant & Gould P.C.
Morgan Eileen P.
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