Ratchet wrench with three operative positions

Abstract

 A ratchet wrench includes a drive member rotatably received in a body. Two pawls are releasably engaged with teeth of the drive member. A control member is pivotable between first, second, and third operative positions about a pivot axis to change the driving direction of the ratchet wrench. When the control member is in the second operative position, the pawls are engaged with the teeth of the drive member, allowing the drive member to rotate in either of two directions driving the fastener, and not allowing free rotation of the drive member in either of the two directions without driving the fastener. The control member includes a control section having first and second outer corners selectively engaged with the pawls. An angle between a first line (L₁) passing through the first outer corner and the pivot axis and a second line (L₂) passing through the second outer corner and the pivot axis is not greater than 100°.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] The present invention relates to a ratchet wrench and, more particularly, to a ratchet wrench that includes three operative positions.

2. The Prior Arts

[0002] Taiwan Patent Publication No. 589241 entitled "IMPROVED RATCHET WRENCH STRUCTURE" discloses a ratchet wrench including a handle having an engaging hole in an end thereof. The end of the handle further includes a compartment in communication with the engaging hole and a coupling groove in communication with the compartment. A driving device is mounted in the engaging hole. Two pawls are slideably mounted in the compartment and selectively engaged with the driving device. Each pawl includes a peg formed thereon. A manually operable control member is mounted in the coupling groove and includes a control groove with two outer corners. The control member is pivotable about a pivot axis between first and second operative positions to control the driving direction and free rotational direction of the ratchet wrench by biasing one of the pawls to engage with the driving device. When the control member is in the first operative position, one of the outer corners presses against the peg of one of the pawls and, thus, disengages the pawl from the driving device, and the other pawl is engaged with the driving device. On the other hand, when the control member is in the second operative position, the other outer corner presses against the peg of the other pawl and, thus, disengages the other pawl from the driving device, and the pawl is engaged with the driving device.

[0003] Although such a ratchet wrench can drive fasteners such as bolts, nuts, etc. in one of two operative directions (clockwise and counterclockwise) while allowing free rotation in a reverse direction, the ratchet wrench can not be utilized as a conventional wrench of the type capable of driving fasteners in either direction and not allowing free rotation in the reverse direction, which may be required in some cases. As an example, when it is desired to proceed with slight tightness adjustment of a fastener by rotating the fastener in the tightening direction and/or loosening direction before the desired tightness is obtained, a user has to frequently switch the control member between the two operative positions to change the driving direction of the ratchet wrench, which is time-consuming and laborsome. Furthermore, the control groove has a wide opening extending across a large angle. Specifically, an angle between a line passing through one of the two outer corners and the pivot axis and another line passing through the other outer corner and the pivot axis is about 120°. Further, an angle between the peg of the pawl engaged with the driving device and the outer corner of the control groove disengaged from the pawl is about 50° such that the control member has to pivot idly about 50° before coming in contact with the peg of the disengaged pawl for the changing the driving direction, leading to time-consuming, inconvenient operation.

[0004] Thus, a need exists for a ratchet wrench that allows easy operation in the change of the driving direction and in the slight tightness adjustment.

SUMMARY OF THE INVENTION

[0005] The present invention solves this need and other problems in the field of easy operation of wrenches by providing, in a preferred form, a ratchet wrench including a body having a driving portion and a handle interconnected to the driving portion. The driving portion includes a first compartment, a second compartment in communication with the first compartment, and a third compartment in communication with the second compartment. A drive member is rotatably received in the first compartment and includes a plurality of teeth in an outer periphery thereof. First and second pawls are slideably received in the second compartment and each includes an inner face facing the teeth of the drive member. The inner face of each of the first and second pawls includes a plurality of teeth releasably engaged with the teeth of the drive member. An elastic element is mounted between the first and second pawls to bias the first and second pawls away from each other to engage the teeth of the first and second pawls with the teeth of the drive member. A control member is pivotably mounted in the third compartment and pivotable between first, second, and third operative positions about a pivot axis. The second operative position is intermediate the first and third operative positions. The control member includes a control section having first and second outer corners. An angle between a first line passing through the first outer corner and the pivot axis and a second line passing through the second outer corner and the pivot axis is not greater than 100°.

[0006] When the control member is in the first operative position, the teeth of the second pawl are engaged with the teeth of the drive member, and the first outer corner of the control member is engaged with the first pawl to disengage the teeth of the first pawl from the teeth of the drive member, allowing the drive member to rotate in a first direction driving a fastener in the first direction, and allowing the drive member to rotate freely in a second direction reverse to the first direction without driving the fastener.

[0007] When the control member is in the third operative position, the teeth of the first pawl are engaged with the teeth of the drive member, and the second outer corner of the control member is engaged with the second pawl to disengage the teeth of the second pawl from the teeth of the drive member, allowing the drive member to rotate in the second direction driving the fastener in the second direction, and allowing the drive member to rotate freely in the first direction without driving the fastener.

[0008] When the control member is in the second operative position, the teeth of each of the first and second pawls are engaged with the teeth of the drive member, allowing the drive member to rotate in either of the first and second directions driving the fastener, and not allowing free rotation of the drive member in either of the first and second directions without driving the fastener.

[0009] The present invention will become clearer in light of the following detailed description of illustrative embodiments of this invention described in connection with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The illustrative embodiments may best be described by reference to the accompanying drawings where:

[0011] FIG. 1 shows a perspective view of a ratchet wrench with three operative positions according to the preferred teachings of the present invention.

[0012] FIG. 2 shows an exploded, perspective view of the ratchet wrench of FIG. 1.

[0013] FIG. 3 shows a bottom, perspective view of a control member of the ratchet wrench of FIG. 1.

[0014] FIG. 4 shows a partial, cross sectional view of the ratchet wrench of FIG. 1 according to section line 4-4 of FIG. 1.

[0015] FIG. 5 shows a partial, cross sectional view of the ratchet wrench of FIG. 1 according to section line 5-5 of FIG. 4 with the control member in a second operative position.

[0016] FIG. 6 shows a partial, cross sectional view similar to FIG. 5 with the control member in a third operative position.

[0017] FIG. 7 shows a partial, cross sectional view similar to FIG. 5 with the control member in a first operative position.

[0018] FIG. 8 shows a partial, cross sectional view of a ratchet wrench of another embodiment according to the preferred teachings of the present invention.

[0019] FIG. 9 shows a partial, cross sectional view of a ratchet wrench of a modified embodiment according to the preferred teachings of the present invention.

[0020] FIG. 10 shows a partial, cross sectional view of a ratchet wrench of another modified embodiment according to the preferred teachings of the present invention.

[0021] All figures are drawn for ease of explanation of the basic teachings of the present invention only; the extensions of the figures with respect to number, position, relationship, and dimensions of the parts to form the preferred embodiment will be explained or will be within the skill of the art after the following teachings of the present invention have been read and understood. Further, the exact dimensions and dimensional proportions to conform to specific force, weight, strength, and similar requirements will likewise be within the skill of the art after the following teachings of the present invention have been read and understood.

[0022] Where used in the various figures of the drawings, the same numerals designate the same or similar parts. Furthermore, when the terms "first", "second", "third", "inner", "outer", "side", "end", "portion", "section", "annular", "clockwise", "counterclockwise", and similar terms are used herein, it should be understood that these terms have reference only to the structure shown in the drawings as it would appear to a person viewing the drawings and are utilized only to facilitate describing the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] A ratchet wrench according to the preferred teachings of the present invention is shown in the drawings and generally includes a body 10 having a driving portion 11 and a handle 12 interconnected to driving portion 11. Driving portion 11 includes opposite first and second sides 18 and 19 and a first compartment 13 in the most preferred form shown as a through-hole extending from first side 19 through second side 19. An annular groove 131 is defined in an end of a peripheral wall of first compartment 13. According to the most preferred form shown, a second compartment 14 is defined between first and second sides 18 and 19 and in communication with first compartment 13. A third compartment 15 extends from first side 18 toward and spaced from second side 19. Third compartment 15 includes a bottom wall 28 intermediate first and second sides 18 and 19. A fixing hole 151 extends from bottom wall 28 through second side 19. According to the most preferred form shown, fixing hole 151 includes a first enlarged portion 58 formed in bottom wall 28 and in communication with third compartment 15, a second enlarged portion 62 formed in second side 19, and a main portion 60 between the first and second enlarged portions 58 and 62. Bottom wall 28 further includes a receiving hole 152 in the most preferred form shown as a blind hole. Second compartment 14 is intermediate first and third compartments 13 and 15. Furthermore, third compartment 15 is spaced from first compartment 13 by a bridge 16 that is a part of first side 18 of driving portion 11. Further, bridge 16 forms a sidewall delimiting second compartment 14.

[0024] According to the preferred form shown, a drive member 20 is rotatably received in first compartment 13. Drive member 20 includes a driving section 21 in a central portion thereof for directly or indirectly engaging with a fastener to be loosened or tightened. According to the most preferred form shown, driving section 21 includes a through-hole having a polygonal inner periphery for engaging and driving a fastener. Other forms of driving section 21 would be within the skill of the art. Drive member 20 further includes a plurality of teeth 22 in an outer periphery thereof. An annular groove 23 is formed in an end of the outer periphery of drive member 20. A retainer ring 24 in the most preferred form shown as a C-clip is partially received in annular groove 23 of drive member 20 and partially received in annular groove 131 of body 10, allowing rotation of drive member 20 relative to body 10 while retaining drive member 20 in first compartment 13.

[0025] According to the preferred form shown, first and second pawls 30 are slideably received in two ends of second compartment 14. Each of first and second pawls 30 includes an inner face 36 facing teeth 22 of drive member 20. Inner face 36 of each of first and second pawls 30 includes a plurality of teeth 31 releasably engaged with teeth 22 of drive member 20. Each of first and second pawls 30 further includes a top face 37 transverse to inner face 36. Top face 37 includes a recessed portion 33. According to the most preferred form shown, a coupling portion 32 in the preferred form shown as a peg is formed on an inner end of recessed portion 33 of top face 37 of each of first and second pawls 30. Each of first and second pawls 30 further includes an end face 38 transverse to top face 37 and to inner face 36. End faces 38 face each other and each has a receptacle 34. An elastic element 35 in the most preferred form shown as a spring is attached between first and second pawls 30 and includes two ends received in receptacles 34. Elastic element 35 biases first and second pawls 30 away from each other to engage teeth 31 of first and second pawls 30 with teeth 22 of drive member 20.

[0026] According to the preferred form shown, a control member 40 is pivotably mounted in third compartment 15 and seals second and third compartments 14 and 15 after assembly. Control member 40 includes first and second faces 50 and 52. A control section 42 in the most preferred form shown as a recessed portion is formed in second side 52. The recessed portion includes first and second outer corners 48. Control member 40 further includes a coupling hole 41 in second face 52. According to the most preferred form shown, a stub 56 is formed on second face 52 and includes coupling hole 41 in the form of a screw hole. Stub 56 is pivotably received in first enlarged portion 58 of fixing hole 151. A pivot 47 in the most preferred form shown as a screw is extended through fixing hole 151 into coupling hole 41 of control member 40 with a head 66 of pivot 47 received in second enlarged portion 62 of fixing hole 15. Thus, control member 40 is pivotable relative to body 10 about a pivot axis defined by pivot 47. Second face 52 of control member 40 further includes first, second, and third positioning holes 43, 44, and 45 corresponding to first, second, and third operative positions of control member 40. An angle between a first line L₁ passing through first outer corner 48 and the pivot axis and a second line L₂ passing through second outer corner 48 and the pivot axis is not greater than 70°. In another preferred form shown in FIG. 8, the angle is not greater than 100°. A positioning device 17 is provided to position control member 40 in one of the first, second, and third operative positions. Positioning device 17 is received in receiving hole 152 and includes a positioning member 172 in the most preferred form shown as a ball and an elastic element 171 in the most preferred form shown as a spring. Elastic element 171 biases positioning member 172 into one of first, second, and third positioning holes 43, 44, and 45 to retain control member 40 in one of the first, second, and third operative positions. Other forms of positioning device 17 would be within the skill of the art. According to the most preferred form shown, control member 40 further includes a manually operable thumb piece 46 to allow easy pivotal movement.

[0027] Now that the basic construction of the ratchet wrench of the preferred teachings of the present invention has been explained, the operation and some of the advantages of the ratchet wrench can be set forth and appreciated. In particular, for the sake of explanation, it will be assumed that control member 40 is initially in the second operative position (FIG. 5) intermediate the first and third operative positions. Positioning member 172 is received in second positioning hole 44 of control member 40. Coupling portions 32 of first and second pawls 30 are located between first and second outer corners 48, with first outer corner 48 in contact with coupling portion 32 of first pawl 30 and with second outer corner 48 in contact with coupling portion 32 of second pawl 30. Furthermore, teeth 31 of each of first and second pawls 30 are engaged with teeth 22 of drive member 20, allowing the drive member 20 to rotate in either of clockwise and counterclockwise directions to drive a fastener in the same direction. Free rotation of drive member 20 in a reverse direction without driving the fastener is not allowed. Namely, rotation of drive member 20 in a reverse direction drives the fastener in the reverse direction.

[0028] When the control member 40 is moved from the second operative position to the third operative position (FIG. 6), second outer corner 48 of control member 40 engages with and moves coupling portion 32 of second pawl 30. Thus, second pawl 30 is moved away from drive member 20. As a result, teeth 31 of second pawl 30 are disengaged from teeth 22 of drive member 20. Teeth 31 of first pawl 30 are still engaged with teeth 22 of drive member 20, for first outer corner 48 moves away form coupling portion 32 of first pawl 30 in a direction without actuating coupling portion 32 of first pawl 30. Positioning member 172 is received in third positioning hole 45 of control member 40. In this state, drive member 20 can rotate in the counterclockwise direction to drive the fastener in the counterclockwise direction. Furthermore, drive member 20 can rotate freely in the clockwise direction without driving the fastener.

[0029] When the control member 40 is pivoted from the second operative position to the first operative position (FIG. 7), first outer corner 48 of control member 40 engages with and moves coupling portion 32 of first pawl 30. Thus, first pawl 30 is moved away from drive member 20. As a result, teeth 31 of first pawl 30 are disengaged from teeth 22 of drive member 20. Teeth 31 of second pawl 30 are still engaged with teeth 22 of drive member 20, for second outer corner 48 moves away from coupling portion 32 of second pawl 30 in a direction without actuating coupling portion 32 of second pawl 30. Positioning member 172 is received in first positioning hole 43 of control member 40. In this state, drive member 20 can rotate in the clockwise direction to drive the fastener in the clockwise direction. Furthermore, drive member 20 can rotate freely in the counterclockwise direction without driving the fastener.

[0030] Since the angle between the first and second lines L₁ and L₂ is not greater than 100° and since first and second outer corners 48 are in contact with coupling portions 32 of first and second pawls 30, idle travel during movement of control member 40 between the first, second, and third operative positions is minimized. Furthermore, switching of control member 40 between the first, second, and third operative positions can be rapidly achieved through small angular travel of control member 40. Further, the ratchet wrench according to the preferred teachings of the present invention can be utilized to perform slight tightness adjustment of the fastener when control member 40 is in the second operative position.

[0031] Now that the basic teachings of the present invention have been explained, many extensions and variations will be obvious to one having ordinary skill in the art. For example, thumb piece 46 can be omitted, and control member 40 can include a frictional outer periphery to allow easy manual operation to pivot control member 40 between the first, second, and third operative positions. Other arrangements allowing pivotal movement of control member 40 would be within the skill of the art. Drive member 20 can be of other forms. In a modified example shown in FIG. 9, drive member 20' also includes a plurality of teeth 22' and an annular groove 23' in an outer periphery thereof. A retainer ring 24' in the form of a C-clip is mounted in annular groove 23' of drive member 20' and annular groove 131 of body 10 to allow rotation of drive member 20' in first compartment 13. Furthermore, drive member 20' includes a drive section 21' outside of driving portion 11 of body 10. Drive section 21' is in the form of a drive column having square cross sections. Drive section 21' includes a spring-biased coupler 25' for releasable coupling with a socket. In another modified example shown in FIG. 10, drive member 20" also includes a plurality of teeth 22" and an annular groove 23" in an outer periphery thereof. A retainer ring 24" in the form of a C-clip is mounted in annular groove 23" of drive member 20" and annular groove 131 of body 10 to allow rotation of drive member 20" in first compartment 13. Furthermore, drive member 20" includes a drive section 21" outside of driving portion 11 of body 10. Drive section 21" is in the form of a drive column having square cross sections. Drive section 21" includes a spring-biased quick-release coupler 25" allowing releasable coupling with a socket. Other forms of drive member 20, 20', 20" would be within the skill of the art. Furthermore, driving portion 11 of body 10 can be of other forms without adversely affecting the function of rotatably receiving drive member 20, 20', 20", examples of which are shown in FIGS. 9 and 10. Recessed portion 33 of top face 37 of each of first and second pawls 30 can be omitted if desired, so that coupling portions 32 in the form of pegs are directly formed on top faces 37. Further, the pegs can have other forms including but not limited to square, rectangular, and irregular shapes. Further, each coupling portion 32 can have other forms such as a recess in an outer face of each of first and second pawls 30 opposite to inner face 36.

[0032] Thus since the invention disclosed herein may be embodied in other specific forms without departing from the spirit or general characteristics thereof, some of which forms have been indicated, the embodiments described herein are to be considered in all respects illustrative and not restrictive. The scope of the invention is to be indicated by the appended claims, rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.

Claims

1. A ratchet wrench comprising:

a body including a driving portion and a handle interconnected to the driving portion, with the driving portion including a first compartment, a second compartment in communication with the first compartment, and a third compartment in communication with the second compartment;

a drive member rotatably received in the first compartment, with the drive member including a plurality of teeth in an outer periphery thereof;

first and second pawls slideably received in the second compartment, with each of the first and second pawls including an inner face facing the plurality of teeth of the drive member, with the inner face of each of the first and second pawls including a plurality of teeth releasably engaged with the plurality of teeth of the drive member, with a first elastic element being mounted between the first and second pawls to bias the first and second pawls away from each other to engage the plurality of teeth of the first and second pawls with the plurality of teeth of the drive member; and

a control member pivotably mounted in the third compartment and pivotable between first, second, and third operative positions about a pivot axis, with the second operative position intermediate the first and third operative positions, with the control member including a control section having first and second outer corners, with an angle between a first line (L₁) passing through the first outer corner and the pivot axis and a second line (L₂) passing through the second outer corner and the pivot axis is not greater than 100°,

wherein when the control member is in the first operative position, the plurality of teeth of the second pawl are engaged with the plurality of teeth of the drive member, the first outer corner of the control member is engaged with the first pawl to disengage the plurality of teeth of the first pawl from the plurality of teeth of the drive member, allowing the drive member to rotate in a first direction driving a fastener in the first direction, and allowing the drive member to rotate freely in a second direction reverse to the first direction without driving the fastener,
wherein when the control member is in the third operative position, the plurality of teeth of the first pawl are engaged with the plurality of teeth of the drive member, the second outer corner of the control member is engaged with the second pawl to disengage the plurality of teeth of the second pawl from the plurality of teeth of the drive member, allowing the drive member to rotate in the second direction driving the fastener in the second direction, and allowing the drive member to rotate freely in the first direction without driving the fastener, and
wherein when the control member is in the second operative position, the plurality of teeth of each of the first and second pawls are engaged with the plurality of teeth of the drive member, allowing the drive member to rotate in either of the first and second directions driving the fastener, and not allowing free rotation of the drive member in either of the first and second directions without driving the fastener.

2. The ratchet wrench as claimed in claim 1, with the driving portion including opposite first and second sides, with the second compartment formed between the first and second sides, with the third compartment extending from the first side toward and spaced from the second side of the driving portion, with the third compartment including a bottom wall, with a fixing hole extending from the bottom wall through the second side of the driving portion, with the control member including first and second faces, with the control member further including a coupling hole in the second face, with a pivot extending through the fixing hole into the coupling hole of the control member, with the pivot defining the pivot axis and allowing rotational movement of the control member about the pivot axis.

3. The ratchet wrench as claimed in claim 2, with the fixing hole including a first enlarged portion formed in the bottom wall of the third compartment and a main portion, with the control member including a stub formed on the second face and rotatably received in the first enlarged portion of the fixing hole, with the stub including the coupling hole, with the coupling hole being a screw hole, and with the pivot including a screw threadedly engaged with the screw hole.

4. The ratchet wrench as claimed in claim 3, with the fixing hole further including a second enlarged portion formed in the second side of the driving portion, with the main portion between the first and second enlarged portions, with the screw having a head received in the second enlarged portion.

5. The ratchet wrench as claimed in claim 2, with the bottom wall of the third compartment further including a receiving hole, with the second face of the control member further including first, second, and third positioning holes corresponding to the first, second, and third operative positions of the control member, with a positioning member and a second elastic element being received in the receiving hole, and with the second elastic element biasing the positioning member into one of the first, second, and third positioning holes to retain the control member in one of the first, second, and third operative positions.

6. The ratchet wrench as claimed in claim 5, with the second compartment intermediate the first and third compartments, with the third compartment being spaced from the first compartment by a bridge that is a part of the first side of the driving portion, and with the bridge forming a sidewall delimiting the second compartment.

7. The ratchet wrench as claimed in claim 1, with the first pawl including a first coupling portion, with the second pawl including a second coupling portion,
wherein when the control member is in the second operative position, the first and second coupling portions are located between the first and second outer corners, with the first outer corner in contact with the first coupling portion and with the second outer corner in contact with the second coupling portion,
wherein when the control member is in the first operative position, the first outer corner of the control member is engaged with the first coupling portion to disengage the plurality of teeth of the first pawl from the plurality of teeth of the drive member, and
wherein when the control member is in the third operative position, the second outer corner of the control member is engaged with the second coupling portion to disengage the plurality of teeth of the second pawl from the plurality of teeth of the drive member.

8. The ratchet wrench as claimed in claim 7, with each of the first and second pawls including a top face transverse to the inner face, with the top face having an inner end, with the first coupling portion including a first peg formed on the inner end of the top face of the first pawl, with the second coupling portion including a second peg formed on the inner end of the top face of the second pawl, with each of the first and second pawls including an end face transverse to the top face and to the inner face, with the end faces facing each other and each having a receptacle, and with the first elastic element including a spring having two ends received in the receptacles.

Drawing