Ratchet wrench with a reduced head

A ratchet wrench includes a connecting section between a head and a handle. The connecting section includes a vertical connecting portion integrally connected to a first side of the head. An extension extends outward from a section of an outer periphery of the head. A first compartment extends from the first side of the head through a second side of the head and rotatably receives a drive member. A second compartment is formed in a portion of the inner periphery of the first compartment aligned with the extension and receives two pawls releasably engaged with the drive member. The second compartment extends towards the extension. A first radius from the outer periphery of the head to a rotating axis defined by the head is smaller than a second radius from the extension to the rotating axis.

BACKGROUND OF THE INVENTION

The present invention relates to a ratchet wrench with a reduced head and, more particularly, to a ratchet wrench having a head that can be moved into a small, recessed environment for operation.

U.S. Pat. Ser. No. 7,093,520 discloses a gear wrench having a head formed with a receiving compartment for receiving a gear ring, a tail, and a neck between the head and the tail. The neck extends obliquely from the head towards the tail to form a height difference between the head and the tail. An indent and an aperture are provided between the neck and the head for mounting a direction switch. The indent allows access of the fingers of the user to the direction switch, such that the user can rotate the direction switch to change the driving direction of the ratchet wrench. In use, the obliquely extending neck allows the ratchet wrench to tighten or loosen a workpiece, such as a fastener, in a recessed environment. The maximal diameter of the head must be smaller than the space of the recessed environment. However, the head of the ratchet wrench can not enter the space if there are obstacles in the space. A solution to this problem is using an extension rod or extension socket to increase the working depth of the ratchet wrench to access the workpiece in the space. However, coupling of the extension rod or extension socket of a suitable length is troublesome and time-consuming. The weight of the extension rods or extension sockets cause a burden to the user in addition to troublesome handling and selection of the extension rod or extension socket of the desired size. Thus, the ratchet wrench of this type still has disadvantages.

Thus, a need exists for a novel ratchet wrench without the above disadvantages.

BRIEF SUMMARY OF THE INVENTION

The present invention solves this need and other problems in the field of convenient use of ratchet wrenches in a small space by providing, in a preferred aspect, a ratchet wrench including a body having a head, a handle, and a connecting section between the head and the handle. The head defines a rotating axis. The head is adapted to drive a workpiece to rotate. The head includes first and second sides spaced along the rotating axis. The first side has a spacing to the workpiece larger than the second side. The head further includes an outer periphery extending between the first and second sides and surrounding the rotating axis. The outer periphery includes an arcuate section. An extension extends outward from a section of the outer periphery outside of the arcuate section in a radial direction perpendicular to the rotating axis. The head further includes a first compartment extending from the first side through the second side of the head along the rotating axis. The first compartment has circular cross sections and includes an inner periphery. A second compartment is formed in a portion of the inner periphery of the first compartment aligned with the extension. The second compartment extends towards the extension. The connecting section includes a vertical connecting portion at an end thereof. The vertical connecting portion is integrally connected to the first side of the head. The other end of the connecting section is integrally connected to an end of the handle. A drive member is rotatably received in the first compartment of the head and is rotatable relative to the head about the rotating axis. A pawl device is mounted in the second compartment of the body. The pawl device is selectively engageable with the drive member in either of first and second engagement relations corresponding to two driving directions of the ratchet wrench driving the workpiece. A switch is pivotably mounted to the drive member and operatively connected to the pawl device in the second compartment. The switch includes a ring exposed outside of the first side of the head for manual operation to control the pawl device to be in one of the first and second engagement relations with the drive member.

Preferably, a positioning device is mounted between the switch and the vertical connecting portion of the connecting section. The ring includes first and second positioning portions. The positioning device is engaged with one of the first and second positioning portions to retain the ring, maintaining the pawl device in one of the first and second engagement relations with the drive member.

Preferably, the vertical connecting portion includes a receptacle extending in a radial direction perpendicular to the rotating axis. The positioning device includes an elastic element received in the receptacle and a positioning member between the elastic element and the switch. The positioning member is biased by the elastic element to engage with one of the first and second positioning portions.

Preferably, the drive member includes first and second ends spaced along the rotating axis. An axle is formed on the first end of the drive member. The switch includes an axle hole receiving the axle. The switch and the drive member are pivotable relative to each other.

Preferably, the axle extends beyond the first side of the head. The axle includes an annular engagement groove. The axle hole of the switch includes an annular engagement groove. A retainer ring is engaged in the engagement grooves of the axle and the switch, preventing disengagement of the switch while allowing relative rotating movement between the switch and the drive member. The drive member includes a stepped portion on an outer periphery thereof. The stepped portion has an outer diameter larger than a diameter of the first compartment.

Preferably, the drive member includes an annular toothed portion between the first and second ends of the drive member. The toothed portion of the drive member is received in the first compartment of the body. The pawl device includes first and second pawls and an elastic element mounted between the first and second pawls. The elastic element biases the first and second pawls to press against two lateral walls of the second compartment. The first pawl includes a first toothed section facing the first compartment. The first toothed section is engageable with the toothed portion of the drive member under bias of the elastic element. The second pawl includes a second toothed section facing the first compartment. The second toothed section is engageable with the toothed portion of the drive member under the bias of the elastic element.

Preferably, the first pawl includes a first push face. The second pawl includes a second push face. The switch includes first and second actuating portions extending into the second compartment. The switch is pivotable in a first direction to cause the first actuating portion to press against the first push face, disengaging the first toothed section from the toothed portion of the drive member. On the other hand, the switch is pivotable in a second direction opposite to the first direction to cause the second actuating portion to press against the second push face, disengaging the second toothed section from the toothed portion of the drive member.

Preferably, the ring includes a lip extending perpendicularly from an inner face of the ring. The lip includes the first and second actuating portions. A notch is formed between the first and second actuating portions.

Preferably, the ring includes a third positioning portion between the first and second portions. When the first and second pawls are located in the notch, the first and second toothed sections of the first and second pawls are engaged with toothed portion of the drive member, and the positioning device is engaged with the third positioning portion, preventing the drive member from rotating relative to the head.

Preferably, the axle of the drive member has an outer diameter smaller than a diameter of the first compartment. The first and second actuating portions of the switch extend through the first compartment into the second compartment.

In an embodiment, the head further includes a control groove extending from the first side through the second compartment. The first and second actuating portions of the switch extend through the control groove into the second compartment. Preferably, the control groove is in communication with the first compartment. The control groove has a longitudinal axis coincident to the rotating axis. The control groove is annular, extends between the first side of the head and the first compartment and forms a ledge. The switch is hollow, and the first and second actuating portions are arcuate and movable in the control groove in a circumferential direction about the rotating axis.

The head includes a thickness between the first and second sides along the rotating axis. The vertical connecting portion includes a height along the rotating axis smaller than the thickness of the head. Preferably, the axle of the drive member has a protruding extent beyond the first side of the head along the rotating axis. The protruding extent is not larger than the height of the vertical connecting portion. The ring has an exposed extent outside of the first side of the head. The exposed extent is not larger than the height of the vertical connecting portion.

Preferably, the exposed extent of the ring is equal to the protruding extent of the axle.

Preferably, the exposed extent of the ring is equal to the height of the vertical connecting portion.

Preferably, the handle includes upper and lower faces. The upper face has a spacing to the workpiece larger than the lower face. In an embodiment, a spacing between the lower face of the handle and the second side of the head is larger than half of the thickness of the head. A spacing between the upper face of the handle and the first side of the head is larger than the height of the vertical connecting portion and smaller than the thickness of the head. Preferably, the spacing between the upper face of the handle and the first side of the head is equal to the height of the vertical connecting portion.

In another embodiment, the spacing between the lower face of the handle and the second side of the head is larger than a sum of the height of the vertical connecting portion and the thickness of the head.

Preferably, the other end of the connecting section opposite to the vertical connecting portion includes a bend integrally connected to the end of the handle. The connecting section has an inclined section intermediate the vertical connecting portion and the bend. The inclined section has increasing widths towards the vertical connecting portion and is at an angle of 75° to the handle.

Preferably, the head has a first radius from the outer periphery to the rotating axis. The head further has a second radius from the extension to the rotating axis. The first radius is smaller than the second radius. The vertical connecting portion includes an arcuate concave face facing the rotating axis. The arcuate concave face has a third radius to the rotating axis. The third radius is equal to the first radius.

Where used in the various figures of the drawings, the same numerals designate the same or similar parts. Furthermore, when the terms “first”, “second”, “lower”, “upper”, “top”, “inner”, “outer”, “side”, “end”, “portion”, “section”, “longitudinal”, “radial”, “circumferential”, “lateral”, “horizontal”, “vertical”, “annular”, “outward”, “spacing”, “clockwise”, “thickness”, “height”, 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 INVENTION

With reference toFIGS. 1-4, a ratchet wrench10of a first embodiment according to the present invention includes a body20, a drive member30, a pawl device40, and a switch50. Body20includes a head21, a handle23, and a connecting section22between head21and handle23. Head21defines a rotating axis X1. A user can operate body20by rotating handle23about rotating axis X1for driving a workpiece, such as a fastener, to rotate. Head21includes parallel, first and second sides211and212spaced along rotating axis X1. First side211has a spacing to the workpiece larger than second side212. Head21has a thickness T between first side211and second side212along rotating axis X1.

Head21further includes a control groove217extending from first side211through second compartment216. In this embodiment, control groove217is in communication with first compartment215and has a longitudinal axis coincident to rotating axis X1. Control groove217is annular, extends between first side211of the head21and first compartment215and forms a ledge219.

Head21further includes a first compartment215extending from first side211through second side212along rotating axis X1. First compartment215has circular cross sections. A second compartment216is formed in a portion of an inner periphery of first compartment215aligned with extension214. Second compartment216extends towards extension214and is crescent in cross section.

Head21further includes a control groove217extending from first side211through second compartment216. In this embodiment, control groove217is in communication with first compartment215and has a longitudinal axis coincident to rotating axis X1. Control groove217is annular and extends between first side211of the head21and first compartment215and forms a ledge219.

Connecting section22includes a vertical connecting portion221at an end thereof. Vertical connecting portion221is integrally connected to first side211of head21, such that head21has a small volume and occupies a small space. In this embodiment, vertical connecting portion221is integrally connected to a side of extension214opposite to second side212of head21. Thus, second radius R2of head21can be effectively reduced to reduce the size of head21. Vertical connecting portion221includes a height H along rotating axis X1smaller than thickness T of head21.

Vertical connecting portion221includes an arcuate concave face222facing rotating axis X1. Arcuate concave face222of vertical connecting portion221includes a receptacle223extending in a radial direction perpendicular to rotating axis X1. Arcuate concave face222has a third radius R3to rotating axis X1. Third radius R3is equal to first radius R1of outer periphery213of head21, as shown inFIG. 5. Thus, second radius R2of head21can be effectively reduced to reduce the size of head21.

The other end of connecting section22opposite to vertical connecting portion221includes a bend224integrally connected to the end of handle23. Connecting section22has an inclined section intermediate vertical connecting portion221and bend224. The inclined section has increasing widths towards vertical connecting portion221and is at an angle of in the order of 75° to handle23. Thus, connecting section22is substantially at 75° to head21.

Handle23includes upper and lower faces231and232. Upper face231has a spacing to the workpiece larger than lower face232. A spacing between lower face232of handle23and second side212of head21is larger than a sum of height H of vertical connecting portion221and thickness T of head21. This allows the small head21to extend into a small space for operation while the user grips handle23.

Drive member30is rotatably received in first compartment215of head21and rotatable relative to head21about rotating axis X1. Drive member30includes an annular toothed portion31between first and second ends of drive member30spaced along rotating axis X1. A driving portion32is formed on the second end of drive member30for driving the workpiece to rotate. In this embodiment, driving portion32extends beyond second side212of head21and includes a polygonal hole and a conical outer periphery. A stepped portion33is formed between driving portion32and toothed portion31and has an outer diameter larger than a diameter of first compartment215. Thus, stepped portion33can abut second side212of head21. An axle34is formed on the first end of drive member30and extends beyond first side211of head21. The protruding extent of axle34beyond first side211of head21along rotating axis X1is not larger than height H of vertical connecting portion221. Axle34includes an annular engagement groove341.

Pawl device40is mounted in second compartment216of body20and is selectively engageable with drive member30in either of first, second, and third engagement relations. The first and second engagement relations correspond to two driving directions of ratchet wrench10driving the workpiece. Drive member30can not rotate relative to head21when pawl device40is in the third engagement relation with drive member30.

Pawl device40includes first and second pawls41and42and an elastic element43mounted between first and second pawls41and42. Elastic element43biases first and second pawls41and42to press against two lateral walls of second compartment216. First pawl41includes a first toothed section411facing first compartment215. First toothed section411is engageable with toothed portion31of drive member30under the bias of elastic element43. First pawl41includes a first push face412corresponding to the position of control groove217. Second pawl42includes a second toothed section421facing first compartment215. Second toothed section421is engageable with toothed portion31of drive member30under the bias of elastic element43. Second pawl42includes a second push face422corresponding to the position of control groove217.

Switch50includes a ring52exposed outside of first side211of head21for manual operation. An outer periphery of ring52is aligned with outer periphery213of head21. Thus, the user can easily rotate ring52from outside. In this embodiment, ring52has a diameter larger than the diameter of first compartment215. Furthermore, a radius of ring52is smaller than first radius R1of outer periphery213of head21. Thus, when switch50is rotated relative to head21, ring52still remains in the extent of first radius R1of outer periphery213of head21. Namely, switch50does not extend beyond first radius R1. Thus, connecting section22of body20can be adjacent to rotating axis X1without being interfered by switch50, effectively reducing the radius of head21and reliably reducing the size of head21.

Switch50includes a ring52exposed outside of first side211of head21for manual operation. An outer periphery of ring52is aligned with outer periphery213of head21. Thus, the user can easily rotate ring52from outside. In this embodiment, ring52has a diameter larger than the diameter of first compartment215. Furthermore, a radius of ring52is smaller than first radius R1of outer periphery213of head21. Thus, when switch50is rotated relative to head21, ring52still remains in the extent of first radius R1of outer periphery213of head21. Namely, switch50does not extend beyond first radius R1. Thus, connecting section22of body20can be more adjacent to rotating axis X1without being interfered by switch50, effectively reducing the radius of head21and reliably reducing the size of head21.

Ring52has an exposed extent outside of first side211of head21. The exposed extent of ring52is not larger than height H of vertical connecting portion221of body20. Preferably, the exposed extent of ring52is equal to the protruding extent of axle34beyond first side211of head21. Thus, a top face of ring52is flush with a top face of axle34of drive member30. Thus, the top face of axle34is exposed and accessible to the user.

Switch50includes first and second actuating portions53and54extending into second compartment216. Switch50can be pivoted in a first direction to cause first actuating portion53to press against first push face412, disengaging first toothed section411from toothed portion31of drive member30, as shown inFIG. 6. Likewise, switch50can be pivoted in a second direction opposite to the first direction to cause second actuating portion54to press against second push face422, disengaging second toothed section421from toothed portion31of drive member30.

In this embodiment, first and second actuating portions53and54of switch50extend through control groove217into second compartment216. First and second actuating portions53and54are arcuate and movable in control groove217in the circumferential direction about rotating axis X1. First actuating portion53has a thickness along rotating axis X1larger than a height of first toothed section411of first pawl41along rotating axis X1. Thus, when first actuating portion53separates first pawl41from drive member30, first pawl41disengages from drive member30. Note that first pawl41presses against one of the two lateral walls of second compartment216under the bias of elastic element43. Thus, first and second pawls41and42provide reliable ratcheting effect. Likewise, second actuating portion54has a thickness along rotating axis X1larger than a height of second toothed section421of second pawl42along rotating axis X1. Thus, when second actuating portion54separates second pawl42from drive member30, second pawl42disengages from drive member30. Note that second pawl42presses against the other lateral wall of second compartment216under the bias of elastic element43. Thus, first and second pawls41and42provide reliable ratcheting effect.

In this embodiment, ring52includes an outer periphery having first and second positioning portions56and a third positioning portion56between first and second portions56. Ring52further includes a lip58extending perpendicularly from an inner face of ring52opposite to the top face of ring52. Lip58includes first and second actuating portions53and54. A notch55is formed between first and second actuating portions53and54. First and second toothed sections411and421of first and second pawls41and42engage with toothed portion31of drive member30when first and second pawls41and42are located in notch55, preventing drive member30from rotating relative to head21.

A positioning device60is mounted between switch50and vertical connecting portion221of connecting section22. When positioning device60is engaged with one of first and second positioning portions56and retains ring52, pawl device40is in one of the first and second engagement relations with drive member30, allowing rotation of drive member30relative to head21in one of two opposite directions corresponding to one of two driving directions of ratchet wrench10. On the other hand, when positioning device60is engaged with third positioning portion56and retains ring52, pawl device40is in the third engagement relation with drive member30, allowing joint rotation of drive member30and head21in either direction.

Since positioning device60is mounted to vertical connecting portion221that is integrally connected to first side211of head21, extension214of head21can be very short as long as the radial extent of extension214allows connecting section22to be close to drive member30. The radial dimension of head21can, thus, be effectively reduced to reduce the size of head21.

Positioning device60includes an elastic element61received in receptacle223and a positioning member62between elastic element61and switch50. Positioning member62is biased by elastic element61to engage with one of first, second, and third positioning portions56. In this embodiment, positioning member62is in the form of a ball.

With reference toFIGS. 7 and 8, since the outer periphery of ring52is aligned with outer periphery213of head21, the user can easily rotate ring52from outside to change the rotating relation between drive member30and head21. Furthermore, since the radius of ring52is smaller than first radius R1of outer periphery213of head21, ring52remains in first radius R1of outer periphery213of head21while switch50rotates relative to head21. Thus, switch50does not extend beyond first radius R1, allowing connecting section22to be closer to rotating axis X1without being interfered by switch50, effectively reducing the radial dimension of head21and achieving reduction of the size of head21.

After switch50is rotated, positioning device60can be retained in one of first, second, and third positioning portions56to retain switch50in the desired location. Since positioning device60is mounted to vertical connecting portion221integrally connected to first side211of head21, extension214of head21can be very short as long as the radial extent of extension214allows connecting section22to be close to drive member30. Since vertical connecting portion221of connecting section22is close to first, second, and third positioning portions56of switch50, the radial dimension of head21can be effectively reduced to reduce the size of head21.

With reference toFIGS. 9 and 10, after switch50is positioned, second actuating portion54of switch50can push second push face422of second pawl42to disengage second pawl42from drive member30. Since the thickness of second actuating portion54is larger than the height of second toothed section421of second pawl42, second pawl42disengages from drive member30when second actuating portion54separates second pawl42from drive member30. Note that second pawl42presses against the other lateral wall of second compartment216under the bias of elastic element43. Thus, first and second pawls41and42provide reliable ratcheting effect. In the state shown inFIG. 10, drive member30can rotate in a clockwise direction relative to head21.

With reference toFIG. 11, compared to conventional ratchet wrenches, the radial dimension of head21is relatively small. Thus, ratchet wrench10can extend into smaller spaces for driving the workpieces in the smaller spaces to rotate, significantly eliminating hindrance by obstacles in the smaller spaces.

With reference toFIG. 12, since driving portion32extends beyond second side212of head21and includes a polygonal hole and a conical outer periphery, the ratchet wrench10is suitable to work in a countersink without an extension rod or extension socket, which is convenient to the user.

FIG. 13shows ratchet wrench10of a second embodiment. The difference between the first and second embodiments is that an inclined connecting portion and a head21are provided on each of two ends of handle23. Driving members30in heads21are of different sizes for driving workpieces of different sizes.

FIG. 14shows ratchet wrench10of a third embodiment substantially the same as the first embodiment except that the other end of handle23of the third embodiment has an open end24.

FIG. 15shows ratchet wrench10of a fourth embodiment substantially the same as the first embodiment except that the other end of handle23of the fourth embodiment has a grip25and that driving portion32of drive member30is in the form of a drive column having square cross sections.

FIGS. 16 and 17show ratchet wrench10of a fifth embodiment substantially the same as the first embodiment except that the diameter of axle34of drive member30of the fifth embodiment is smaller than the diameter of first compartment215, such that first and second actuating portions53and54of switch50directly extend through first compartment215into second compartment216for controlling the engagement relations between pawl device40and drive member30, further reducing the size of head21by reducing the radial dimension of head21.

FIG. 18shows ratchet wrench10of a sixth embodiment substantially the same as the first embodiment except that a spacing between lower face232of handle23and second side212of head21is larger than half of thickness T of head21in the sixth embodiment. Furthermore, the spacing between upper face231of handle23and first side211of head21is larger than height H of vertical connecting portion221and smaller than thickness T of head21. This allows the small head21to extend into smaller spaces for operation while reducing the radial dimension of head21. Preferably, the spacing between upper face231of handle23and first side211of head21is equal to height H of vertical connecting portion221.

The exposed extent of ring52outside of first side211of head21is equal to height H of vertical connecting portion221along rotating axis X1. Preferably, the spacing between upper face231of handle23and first side211of head21is equal to height H of vertical connecting portion221. Furthermore, the exposed extent of ring52outside of first side211of head21is equal to the protruding extent of axle34beyond first side211of head21. The top face of ring52is flush with the top face of axle34. Thus, the top face of axle34is exposed and accessible to the user.

If desired, switch50can include only first and second positioning portions56, such that pawl device40can be selectively engageable with drive member30in either of first and second engagement relations corresponding to two driving directions of ratchet wrench10driving the workpiece.