Ratchet wrench structure having a high torsion driving action along dual directions

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a ratchet wrench structure, and more particularly to a ratchet wrench structure having a high torsion driving action along dual directions.

2. Description of the Related Art

The closest prior art of which the applicant is aware is disclosed in U.S. Pat. No. 5,626,062, entitled “SOCKET AND RATCHET WRENCH”. However, the locking pawl and the ratchet wheel are engaged with each other by fewer teeth only. Thus, if the torque is too large, the engaging teeth of the locking pawl or the ratchet wheel are easily worn out due to the large torque, so that the ratchet wrench is inoperative.

Other prior arts of which the applicant is aware are disclosed in Taiwanese Patent Publication No. 262785, entitled “DRIVING STRUCTURE OF A HAND TOOL”, in the U.S. Pat. No. 5,230,262, entitled “RATCHET WRENCH”, and in the Taiwanese Patent Publication No. 386476, entitled by “IMPROVEMENT OF RATCHET WRENCH STRUCTURE”. However, when the ratchet wrench is rotated, some teeth of the locking pawl are slightly detached from the engaging teeth of the ratchet wheel, so that the locking pawl is not rigidly and tightly engaged with the ratchet wheel, thereby reducing the entire load bearing 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 wrenches.

The primary objective of the present invention is to provide a ratchet wrench structure which can be assembled easily and quickly.

Another objective of the present invention is to provide a ratchet wrench structure which can operate a workpiece rigidly and stably.

In accordance with the present invention, there is provided a ratchet wrench structure, comprising:

a wrench body having a drive head defining a receiving hole for receiving a ratchet wheel, the receiving hole having one side defining a receiving recess for receiving a locking pawl, a resting block, and two elastic members, the receiving recess formed with an arcuate resting face so that one end of the resting block is rested on the arcuate resting face of the receiving recess;

the ratchet wheel having an outer periphery provided with engaging teeth;

the locking pawl substantially semi-arc-shaped, and having a first side formed with locking teeth capable of engaging the engaging teeth of the ratchet wheel, and a second side formed with an arcuate inner face;

the resting block substantially having an elongated shape, and having a first end rested on the arcuate resting face of the receiving recess, and a second end formed with a resting end rested on the arcuate inner face of the locking pawl; and

the two elastic members received in two sides of the resting block, the resting block and the two elastic members being arranged to form a substantially X-shaped combination, so that a first elastic member is rested on the arcuate resting face of the receiving recess, and a second elastic member is rested on the arcuate inner face of the locking pawl.

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.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1

is a perspective assembly view of a ratchet wrench structure in accordance with a first embodiment of the present invention;

FIG. 2

is an exploded perspective view of the ratchet wrench structure as shown in

FIG. 1

;

FIG. 3

is a top plan view of the ratchet wrench structure as shown in

FIG. 1

;

FIG. 3A

is a partially enlarged view of the ratchet wrench structure as shown in

FIG. 3

;

FIG. 4

is a top plan view of the ratchet wrench structure as shown in

FIG. 1

;

FIG. 4A

is a partially enlarged view of the ratchet wrench structure as shown in

FIG. 4

;

FIG. 5

is a top plan view of the ratchet wrench structure as shown in

FIG. 1

;

FIG. 5A

is a partially enlarged view of the ratchet wrench structure as shown in

FIG. 5

;

FIG. 6

is an exploded perspective view of a ratchet wrench structure in accordance with a second embodiment of the present invention;

FIG. 7

is an exploded perspective view of a ratchet wrench structure in accordance with a third embodiment of the present invention; and

FIG. 8

is a top plan view of a ratchet wrench structure in accordance with a fourth embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings and initially to

FIGS. 1-3

, a ratchet wrench structure in accordance with a first embodiment of the present invention comprises a wrench body having a drive head

10

defining a receiving hole

11

for receiving a ratchet wheel

20

. The receiving hole

11

has a bottom end formed with an annular locking flange

12

having a smaller inner diameter. The receiving hole

11

has one side located adjacent to the shank

16

of the wrench body and defining a receiving recess

13

for receiving a locking pawl

30

, a resting block

40

, and two elastic members

50

. The receiving recess

13

is formed with an arcuate resting face

14

so that one end of the resting block

40

may be rested on the arcuate resting face

14

of the receiving recess

13

.

The ratchet wheel

20

has an outer periphery provided with multiple engaging teeth

22

, and has a center formed with a polygonal recess

21

to mate with a workpiece (not shown).

The locking pawl

30

is substantially semi-arc-shaped, and has a first side formed with locking teeth

31

capable of engaging the engaging teeth

22

of the ratchet wheel

20

, and a second side formed with an arcuate inner face

32

. The resting end

41

of the resting block

40

may be rested on the arcuate inner face

32

of the locking pawl

30

, so that the locking pawl

30

may engage the ratchet wheel

20

rigidly and stably.

The resting block

40

substantially has an elongated shape, and has a first end rested on the arcuate resting face

14

of the receiving recess

13

, and a second end formed with a resting end

41

rested on the arcuate inner face

32

of the locking pawl

30

. The resting block

40

has two sides formed with two receiving spaces

42

for receiving the two elastic members

50

. The resting block

40

and the two elastic members

50

are arranged to form a substantially X-shaped combination, so that one elastic member

50

is rested on the arcuate resting face

14

of the receiving recess

13

, and the other elastic member

50

is rested on the arcuate inner face

32

of the locking pawl

30

.

After the parts of the ratchet wrench structure in accordance with the present invention have been assembled as shown in

FIG. 2

, a panel (not shown) may be provided to cover the drive head

10

of the wrench body, thereby preventing the parts contained in the drive head

10

of the wrench body from being detached from the drive head

10

of the wrench body.

Alternatively, the resting block

40

may be integrally formed with the two elastic members

50

. Thus, after the ratchet wheel

20

is placed into the receiving hole

11

and the locking pawl

30

is placed into the receiving recess

13

, the resting block

40

together with the two elastic members

50

is placed into the receiving recess

13

simultaneously, so that the ratchet wrench structure of the present invention may be assembled easily and quickly.

In operation, referring to

FIGS. 3 and 3A

, the resting block

40

and the two elastic members

50

form a substantially X-shaped combination.

When the resting end

41

of the resting block

40

is rested on the right side of the arcuate inner face

32

of the locking pawl

30

as indicated by arrow “A” in

FIG. 3

, the other end of the resting block

40

is rested on the left side of the arcuate resting face

14

of the receiving recess

13

. At the same time, one elastic member

50

is rested on the left side of the arcuate inner face

32

of the locking pawl

30

, while the other elastic member

50

is rested on the right side of the arcuate resting face

14

of the receiving recess

13

.

The one elastic member

50

rested on the left side of the arcuate inner face

32

of the locking pawl

30

and the other elastic member

50

rested on the right side of the arcuate resting face

14

of the receiving recess

13

may force the locking pawl

30

to displace to one side face of the receiving recess

13

of the drive head

10

of the wrench body by the elastic force of the elastic members

50

, so that the drive head

10

of the wrench body may drive the locking pawl

30

to drive the ratchet wheel

20

to rotate in the counterclockwise direction as shown in FIG.

3

.

Referring to

FIGS. 4 and 4A

, the drive head

10

of the wrench body is rotated in the clockwise direction. The ratchet wheel

20

itself is retained by the workpiece (not shown). The other elastic member

50

rested on the right side of the arcuate resting face

14

of the receiving recess

13

may be compressed, so that the drive head

10

of the wrench body cannot drive the locking pawl

30

to drive and rotate the ratchet wheel

20

in the clockwise direction. In such a manner, the ratchet wheel

20

is detached from the locking pawl

30

as shown in

FIG. 4

, and the resting block

40

is rotated about point “C”(see

FIG. 4A

) through a small angle. Thus, the drive head

10

of the wrench body may drive the ratchet wheel

20

to rotate in the counterclockwise direction only.

Referring to

FIGS. 5 and 5A

, the resting end

41

of the resting block

40

is rested on the left side of the arcuate inner face

32

of the locking pawl

30

as indicated by arrow “A” in

FIG. 5

, while the other end of the resting block

40

is rested on the right side of the arcuate resting face

14

of the receiving recess

13

. At the same time, one elastic member

50

is rested on the right side of the arcuate inner face

32

of the locking pawl

30

, while the other elastic member

50

is rested on the left side of the arcuate resting face

14

of the receiving recess

13

.

The one elastic member

50

rested on the right side of the arcuate inner face

32

of the locking pawl

30

and the other elastic member

50

rested on the left side of the arcuate resting face

14

of the receiving recess

13

may force the locking pawl

30

to displace to the other side face of the receiving recess

13

of the drive head

10

of the wrench body by the elastic force of the elastic members

50

, so that the drive head

10

of the wrench body may drive the locking pawl

30

to drive the ratchet wheel

20

to rotate in the clockwise direction as shown in FIG.

5

.

Accordingly, the most important advantage of the present invention is described as follows. Referring to

FIGS. 3 and 5

, when the drive head

10

of the wrench body drives the locking pawl

30

to drive the ratchet wheel

20

to rotate in the counterclockwise or clockwise direction, the resting end

41

of the resting block

40

is urged on the arcuate inner face

32

of the locking pawl

30

as indicated by arrow “A” in

FIGS. 3 and 5

, while the other end of the resting block

40

is urged on the arcuate resting face

14

of the receiving recess

13

, so that the locking teeth

31

of the locking pawl

30

may securely and rigidly engage the engaging teeth

22

of the ratchet wheel

20

without detachment, thereby greatly facilitating the drive head

10

of the wrench body driving the locking pawl

30

to drive the ratchet wheel

20

to operate and rotate the workpiece.

Referring to

FIG. 6

, in accordance with a second embodiment of the present invention, the ratchet wheel

20

has a center formed with a fitting end

23

that can be fitted with a socket (not shown).

Referring to

FIG. 7

, in accordance with a third embodiment of the present invention, a cap

51

is mounted on the front end of each elastic member

50

, so that the elastic member

50

may smoothly contact the arcuate inner face

32

of the locking pawl

30

or the arcuate resting face

14

of the receiving recess

13

.

Referring to

FIG. 8

, in accordance with a fourth embodiment of the present invention, two elastomers

60

are mounted in the end face of the locking teeth

31

of the locking pawl

30

.

Although the invention has been explained in relation to its preferred embodiment as mentioned above, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the present invention. It is, therefore, contemplated that the appended claim or claims will cover such modifications and variations that fall within the true scope of the invention.

Claims

1. A ratchet wrench structure, comprising:a wrench body having a drive head defining a receiving hole for receiving a ratchet wheel, the receiving hole having one side defining a receiving recess for receiving a locking pawl, a resting block, and two elastic members, the receiving recess being formed with an arcuate resting face so that one end of the resting block is rested on the arcuate resting face of the receiving recess; the ratchet wheel having an outer periphery provided with engaging teeth; the locking pawl being substantially semi-arc-shaped, and having a first side formed with locking teeth capable of engaging the engaging teeth of the ratchet wheel, and a second side formed with an arcuate inner face; the resting block substantially having an elongated shape, and having a first end rested on the arcuate resting face of the receiving recess, and a second end formed with a resting end rested on the arcuate inner face of the locking pawl; and the two elastic members being received in two sides of the resting block, the resting block and the two elastic members being arranged to form a substantially X-shaped combination, so that a first elastic member is rested on the arcuate resting face of the receiving recess, and a second elastic member is rested on the arcuate inner face of the locking pawl.
2. The ratchet wrench structure in accordance with claim 1, wherein the receiving hole has a bottom end formed with an annular locking flange.
3. The ratchet wrench structure in accordance with claim 1, wherein the ratchet wheel has a center formed with a polygonal recess.
4. The ratchet wrench structure in accordance with claim 1, wherein the resting block has two sides each formed with a receiving space for receiving each of the two elastic members.
5. The ratchet wrench structure in accordance with claim 1, wherein each elastic member has a front end fitted with a cap.

US Referenced Citations (3)

Number	Name	Date	Kind
3372612	Rozmus	Mar 1968	A
3467231	Haznar	Sep 1969	A
4336728	Deibert	Jun 1982	A

Ratchet wrench structure having a high torsion driving action along dual directions

Information

Patent Number

Date Filed

Date Issued

Inventors

Examiners

CPC

US Classifications

Field of Search

US

International Classifications

Abstract

Description

Claims

US Referenced Citations (3)