Tools – Wrench – screwdriver – or driver therefor – Handle clutched to head
Reexamination Certificate
2001-06-25
2004-04-20
Shakeri, Hadi (Department: 3723)
Tools
Wrench, screwdriver, or driver therefor
Handle clutched to head
C192S043200
Reexamination Certificate
active
06722234
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an easy-to-operate and easy-to-assemble ratcheting-type wrench.
2. Description of the Related Art
Several factors are considered in designing wrenches and spanners, including improving the torque-bearing capacity, providing as many teeth as possible for the drive member, and providing an easy-to-manufacture structure.
FIG. 14
of the drawings illustrates a conventional wrench of the type having a handle B′ and a head in which a drive member A′ is rotatably received. A pawl D′ is slidably received in a transverse through-hole C′ in a web between the handle B′ and the head. However, an end of the pawl D′ extends beyond the transverse through-hole C′ and thus adversely affects operation of the wrench when used in a limited space. A two-pawl type wrench was proposed to solve this problem. As illustrated in
FIGS. 15 through 17
, the two-pawl type wrench includes a handle
1
′ and a head
11
′ extended from the handle
1
′. A drive member
2
′ is rotatably received in the head
11
′, a receptacle
12
′ is defined in a web between the handle
1
′ and the head
11
′, and a spring-biased switch member
4
′ is mounted in a cavity
13
′ in the web. Two spaced pawls
3
′ are received in the receptacle
12
′ and are biased by two springs
6
′, respectively. A threaded end cap
5
′ is engaged with a threaded outer end
121
′ of the receptacle
12
′ to enclose the pawls
3
′ and springs
6
′. As illustrated in
FIGS. 16 and 17
, the switch member
4
′ is turned to bias one of the pawls
3
′ to engage teeth
31
′ thereof with the drive member
2
′ to thereby change the ratcheting direction of the wrench. However, it was found that the switch member
4
′ cannot be reliably retained in place and thus tends to disengage from the cavity
13
′. In addition, the pawl
3
′ engaged with the drive member
2
′ is not engaged with an inner longitudinal wall that defines the transverse through-hole and that faces the drive member
2
′. As a result, the torque-bearing capacity of the wrench is poor. Furthermore, the outer pawl
3
′ (
FIGS. 16 and 17
) tends to get stuck when the threaded end cap
5
′ is mounted too close to the switch member
4
′. On the other hand, if the threaded end cap
5
′ is too far away from the switch member
4
′, the pawl
3
′ cannot be firmly engaged with the drive member
2
′. Further, the threaded end cap
5
′ tends to be disengaged from the web between the handle
1
′ and the head
11
′, as the former is in threading engagement with the threaded outer end
121
′ of the receptacle
12
′.
FIGS. 18 through 20
illustrate another conventional wrench having a substantially V-shape transverse through-hole
25
′ in a web between a handle
20
′ and a head
21
′ thereof. The head
21
′ includes a compartment in which a drive member
22
′ is rotatably received. A spring-biased pawl
23
′ is received in each limb of the V-shape transverse through-hole
25
′. A switch member
30
′ includes a stem
35
′ pivotally received in a cavity
24
′ in the web and a thumb-piece
32
′ extending from the stem
35
′ for manual operation, thereby switching the switch member
30
′ between two positions corresponding to two opposite ratcheting directions of the wrench. The thumb piece
32
′ of the switch member
30
′ includes a downwardly facing receptacle
36
′ (
FIG. 20
) for receiving a spring
37
′ and a ball
38
′ that is biased by the spring
37
′ to be positioned in one of two positioning recesses
281
′ (
FIG. 19
) in a sector-like recessed area
28
′ (
FIG. 18
) of the web. The switch member
30
′ may be retained in place reliably. However, a C-clip
33
′ is required for mounting the switch member
30
′ in place. In addition, processing of the sector-like recessed area
28
′ in the web and the V-shape transverse through-hole
25
′ is difficult. Mounting of the switch member
30
′ as well as the pawl
23
′ and associated springs
26
′ and threaded end caps
27
′ are troublesome and time-consuming. The sector-like recessed area
28
′ in the web results in an increase in the overall thickness of the wrench, which limits application of the wrench in limited spaces.
U.S. Pat. No. 6,282,991 discloses a biasing arrangement for a pawl of a reversible ratchet-type wrench. However, the pawl protrudes beyond the handle during change in the ratcheting direction and thus adversely affects operation of the wrench in a limited space, as the protruded portion of the pawl tends to impinge on an object in the limited space.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an easy-to-operate and easy-to-assemble ratcheting-type wrench.
In accordance with a first aspect of the invention, a wrench comprises:
a handle comprising a first lateral side and a second lateral side opposite to the first lateral side;
a head extended from the handle, a web being defined between the handle and the head, the head including a compartment, the web including a transverse through-hole having an intermediate portion communicated with the compartment, the transverse through-hole extending from the first lateral side to the second lateral side of the handle, a cavity being defined in the web and communicated with the transverse through-hole;
a drive member rotatably mounted in the compartment of the head and including a plurality of teeth on an outer periphery thereof;
a switch member mounted in the cavity and rotatable relative to the handle between two positions corresponding to two opposite ratcheting directions of the handle; and
a pawl mounted in the transverse through-hole and slidable along a lengthwise direction of the transverse through-hole, with the pawl remaining in the transverse through-hole during operation, the pawl including a first lateral side facing the compartment and a second lateral side facing away from the compartment, the first lateral side of the pawl including a first toothed portion and a second toothed portion that are selectively engaged with the teeth of the drive member according to one of the positions of the switch member relative to the handle, a groove being defined in the second lateral side of the pawl and including a first corner and a second corner;
the handle including an upper side, the cavity including a vertical portion extending to the upper side of the handle, the switch member including a column rotatably received in the vertical portion of the cavity, the column having a transverse hole that faces the groove of the pawl;
a coil spring mounted in the transverse hole of the column and having an enlarged portion abutting against an outer periphery of the column and surrounding the transverse hole of the column; and
a pin having a first end received in the coil spring and a second end received in the groove of the pawl, the second end of the pin being biased by the coil spring to be selectively, securely engaged in one of the first corner and the second corner of the groove of the pawl that corresponds to said one of the positions of the switch member relative to the handle.
In accordance with a second aspect of the invention, a wrench comprises:
a handle comprising a first lateral side and a second lateral side opposite to the first lateral side;
a head extended from the handle, a web being defined between the handle and the head, the head including a compartment, the web including a transverse through-hole having an intermediate portion communicated with the compartment, the transverse through-hole extending from the first lateral side to the second lateral side of the handle, a cavity being defined in the web and comm
Kamrath Alan
Shakeri Hadi
LandOfFree
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