Ratchet wrench

A ratchet wrench includes a ratchet wheel received in a handle and having an insertion hole. The ratchet wheel further includes an outer periphery having a toothed portion and a lower section below the toothed portion. The lower section includes an annular engagement groove and a cutout intercommunicating the annular engagement groove with the insertion hole. A clip includes a notch and has a diameter slightly smaller than a spacing between upper and lower wall faces of the annular engagement groove and larger than a depth of the annular engagement groove. The clip is not on the same plane when placed flat. The maximum width between an upper edge and a lower edge of the clip is slightly larger than the spacing between the upper and lower wall faces of the annular engagement groove. The clip includes an engagement section received in the cutout and extending into the insertion hole.

BACKGROUND OF THE INVENTION

The present invention relates to a ratchet wrench and, more particularly, to a ratchet wrench with improved assembly stability.

A type of conventional wrench includes a handle, a ratchet wheel, and a direction switching device. The ratchet wrench is mounted on the handle and can be controlled by the direction switching device to rotate in a clockwise direction or a counterclockwise direction. An insertion hole is defined in a center of the ratchet wheel for coupling with a tool, such as a bit, an extension rod, or the like. A magnet is mounted in the insertion hole for attracting the tool to prevent the tool from falling. However, the magnet has a low strength and is, thus, apt to damage or break when subjected to a large external force.

To avoid the above disadvantages, a clip has been proposed to replace the magnet. In an example shown inFIG. 8, a ratchet wrench includes a handle1′, a ratchet wheel2′, a direction switching device3′, and a clip4′. A through-hole11′ is defined in an end of the handle1′, extends from a top side through a bottom side of the end of the handle1′, and receives the ratchet wheel11′. A compartment12′ is defined in a sidewall of the through-hole11′ and receives the direction switching device3′. The ratchet wheel2′ is substantially cylindrical and includes an outer periphery having a plurality of teeth21′. The ratchet wheel2′ further includes an annular stop edge22′ above the teeth21′. The diameter of the stop edge22′ is larger than the diameter of the through-hole11′. The stop edge22′ abuts the top side of the handle1′. The stop edge22′ includes an insertion hole23′ in a center thereof. The ratchet wheel2′ further includes a lower portion having two cutouts24′. The direction switching device3′ is mounted in the compartment12′ and includes a pawl31′, a control button32′, a spring33′, and a pressing block34′. The pawl31′ meshes with the teeth21′ of the ratchet wheel2′. The control button32′ controls the pressing block34′ to press against the pawl31′ to thereby change the angular engagement relationship between the pawl31′ and the ratchet wheel2′, such that the ratchet wheel2′ can rotate in the clockwise direction or the counterclockwise direction. Two sides of the clip4′ are inserted in the cutouts24′ and can engage with an outer periphery of a tool5′ inserted into the insertion hole23′.

However, a large spacing X could exist between the clip4′ and the upper and lower wall faces of the cutouts24′ due to different manufacturing quality and manufacturing tolerances, such that the clip4′ could move relative to the ratchet wheel2′ in the vertical direction and, thus, cause movement of the tool5′ in the vertical direction, leading to unstable engagement between the tool5′ and the ratchet wheel2′. As a result, a bolt or a socket engaged with a front end of the tool5′ moves in the vertical direction, resulting in unstable engagement and inconvenience to operation. Furthermore, the stop edge22′ integrally formed on the top of the ratchet wheel2′ has a fixed shape and has the same color as the ratchet wheel2′, failing to provide an indicating function by the color or shape.

BRIEF SUMMARY OF THE INVENTION

An objective of the present invention is to provide a ratchet wrench with improved assembly stability.

Another objective of the present invention is to provide a ratchet wrench with improved indicating function.

A ratchet wrench according to the present invention includes a handle having top and bottom sides and a hollow portion extending from the top side through the bottom side. The handle further includes a compartment in a side of the hollow portion. A ratchet wheel unit includes a ratchet wheel and a clip. The ratchet wheel is substantially cylindrical and is received in the hollow portion of the handle. The ratchet wheel is rotatable relative to the handle. The ratchet wheel includes a central portion having an insertion hole. The insertion hole is circular in cross section in an upper portion and non-circular in cross section in a lower portion. The ratchet wheel further includes an outer periphery having an intermediate portion with a toothed portion. The outer periphery of the ratchet wheel further includes a lower section below the toothed portion. The lower section includes an annular engagement groove extending towards the insertion hole and having upper and lower wall faces. The lower section further includes a cutout intercommunicating the annular engagement groove with the insertion hole. The bottom side of the handle is located between the annular engagement groove and the top side of the handle. The clip is made of a flexible material and is annular. The clip includes a notch and has a diameter slightly smaller than a spacing between the upper and lower wall faces of the annular engagement groove and larger than a depth of the annular engagement groove. The clip is not on the same plane when placed flat. The clip includes a maximum width between an upper edge thereof and a lower edge thereof. The maximum width is slightly larger than the spacing between the upper and lower wall faces of the annular engagement groove. The clip includes an engagement section. The engagement section is received in the cutout and extends into the insertion hole when the clip is engaged and positioned in the annular engagement groove. A direction switching unit is mounted in the compartment of the handle. The direction switching unit is operable to control the ratchet wheel to rotate in a clockwise direction or a counterclockwise direction.

In an example, the notch is defined between the two ends of the clip, and the two ends of the clip are not located on the same plane.

The cutout of the ratchet wheel can be rectilinear. The annular engagement groove can be arcuate in the remaining portion thereof other than the cutout. The engagement section of the clip is rectilinear and has a length larger than a length of the cutout. The clip can further includes two arcuate sections. The notch is defined between the two arcuate sections. Each of the two arcuate sections is connected to one of two ends of the engagement section via a recessed portion. Each recessed portion is adapted to permit insertion of a tool.

The compartment of the handle can include a lower opening in a lower end thereof. The ratchet wheel unit can further include a lower cap mounted below the hollow portion of the handle. The lower cap includes a through-hole through which the lower section of the ratchet wheel extends. The lower cap further includes a covering portion covering the lower opening of the compartment. The lower cap includes a bottom face located above the annular engagement groove. The clip abuts the bottom face of the lower cap.

The handle can further include an upper annular wall extending from an upper end of an inner periphery of the hollow portion towards a center of the hollow portion. The upper annular wall includes a through-hole in a central portion thereof. The toothed portion of the ratchet wheel has a diameter larger than a diameter of the through-hole of the upper annular wall of the handle. The ratchet wheel unit can further include a rotational cap. The ratchet wheel can further include an upper section above the toothed portion. The upper section has a diameter slightly smaller than the diameter of the through-hole of the upper annular wall of the handle. The upper section of the ratchet wheel further includes a top extending above the upper annular wall. The top of the upper section has an annular inwardly extending retaining edge and an abutment side. The rotational cap is annular and is mounted around the top of the ratchet wheel. The rotational cap has an outer diameter larger than the diameter of the through-hole of the handle. The rotational cap further includes a coupling hole in a central portion thereof. The coupling hole includes an inner periphery having an engagement member engaged with the annular inwardly extending retaining edge of the ratchet wheel. The inner periphery of the coupling hole of the rotational cap further includes a stop side. The upper section of the ratchet wheel is received in the coupling hole of the rotational cap. The stop side of the rotational cap abuts against the abutment side of the upper section of the ratchet wheel for driving the ratchet wheel to rotate.

The rotational cap can be made of a plastic material.

The abutment side of the upper section of the ratchet wheel and the stop side of the rotational cap can be rectilinear.

DETAILED DESCRIPTION OF THE INVENTION

With reference toFIGS. 1-7, a ratchet wrench according to the preset invention includes a handle1, a ratchet wheel unit2, and a direction switching unit3. The handle1includes top and bottom sides and a hollow portion11extending from the top side through the bottom side. The handle1further includes an upper annular wall12extending from an upper end of an inner periphery of the hollow portion11towards a center of the hollow portion11. The upper annular wall12includes a through-hole13in a central portion thereof. The handle1further includes a compartment14in a side of the hollow portion11. The compartment14includes a lower opening141in a lower end thereof.

The ratchet wheel unit2includes a ratchet wheel21, a lower cap22, a clip23, and a rotational cap24. The ratchet wheel21is substantially cylindrical and is received in the hollow portion11of the handle1. The ratchet wheel21is rotatable relative to the handle1. The ratchet wheel21includes a central portion having an insertion hole211which extends in an axial direction and which is non-circular in cross section. The ratchet wheel21further includes an outer periphery having an intermediate portion with a toothed portion212. The toothed portion212has a diameter larger than a diameter of the through-hole13of the upper annular wall12of the handle1. The toothed portion212includes a plurality of teeth213extending in the vertical direction and arranged in a circumferential direction. The outer periphery of the ratchet wheel21further includes a lower section214below the toothed portion212. The lower section214includes an annular engagement groove215extending towards the insertion hole211and having upper and lower wall faces2151and2152. The lower section214further includes a cutout216intercommunicating the annular engagement groove215with the insertion hole211. The cutout216of the ratchet wheel21is rectilinear. The annular engagement groove215is arcuate in the remaining portion thereof other than the cutout216. The bottom side of the handle1is located between the annular engagement groove215and the top side of the handle1when the ratchet wheel21is mounted in the hollow portion11of the handle1. The ratchet wheel21further includes an upper section217above the toothed portion212. The upper section217has a diameter slightly smaller than the diameter of the through-hole13of the upper annular wall12of the handle1and extends through the through-hole13. The upper section217of the ratchet wheel21further includes a top extending above the upper annular wall12. The top of the upper section217has an annular inwardly extending retaining edge218and an abutment side219that is rectilinear.

The lower cap22is mounted below the hollow portion11of the handle1. The lower cap22includes a through-hole221through which the lower section214of the ratchet wheel21extends. The lower cap22further includes a covering portion222covering the lower opening141of the compartment14. A bottom face of the lower cap22is located above the annular engagement groove215when the lower cap22is mounted below the through-hole13of the handle1.

The clip23is made of a flexible material and is annular. The clip23includes a notch231and is substantially circular in cross section (seeFIGS. 1 and 2). The clip23has a diameter C slightly smaller than a spacing D between the upper and lower wall faces2151and2152of the annular engagement groove215and larger than a depth of the annular engagement groove215. The clip23is not on the same plane when placed flat. The clip23includes two ends between which the notch231is defined. Thus, the two ends of the clip23are not located on the same plane. The clip23includes a maximum width F between an upper edge thereof and a lower edge thereof. The maximum width F is slightly larger than the spacing D between the upper and lower wall faces2151and2152of the annular engagement groove215. In the form shown, the clip23includes an engagement section232. The engagement section232of the clip23is rectilinear and has a length larger than a length of the cutout216. The clip23further includes two arcuate sections233. The notch231is defined between the two arcuate sections233. Each of the two arcuate sections233is connected to one of two ends of the engagement section232via a recessed portion234. The recessed portions234are adapted to pear lit insertion of a tool with a pointed end.

The clip23can expand due to provision of the notch231and can be engaged in the annular engagement groove215of the ratchet wheel21. The engagement section232is received in the cutout216and extends into the insertion hole211when the clip23is engaged and positioned in the annular engagement groove215. An outer edge of each arcuate section233extends outside of the annular engagement groove215and abuts the bottom face of the lower cap22to prevent disengagement of the lower cap22. When the clip23is engaged in the annular engagement groove215, the upper edge and the lower edge of the clip23are compressed and respectively press against the upper wall face2151and the lower wall face2152of the annular engagement groove215(seeFIG. 3), providing a positioning effect under the returning force of the clip23due to the flexibility of the clip23.

The rotational cap24is mounted around the top of the ratchet wheel21and can be made of a plastic material or any outer suitable material. The rotational cap24can have a desired color according to need. The rotational cap24is annular and has an outer diameter larger than the diameter of the through-hole13of the handle1. The rotational cap24further includes a coupling hole241in a central portion thereof. The upper section217of the ratchet wheel21is received in the coupling hole241of the rotational cap24. The coupling hole241includes an inner periphery having an engagement member242engaged with the annular inwardly extending retaining edge218of the ratchet wheel21. The inner periphery of the coupling hole241of the rotational cap24further includes a stop side243corresponding to the abutment side219of the upper section217. The stop side243of the rotational cap24is rectilinear. The rotational cap24further includes a plurality of slip-preventing teeth244on an outer periphery thereof.

The direction switching unit3is mounted in the compartment14of the handle1and is operable to control the ratchet wheel21to rotate in a clockwise direction or a counterclockwise direction. The direction switching unit3includes a pawl31, a control button32, a spring33, and a pressing block34. The pawl31includes a first side having a toothed section311meshed with the toothed portion212of the ratchet wheel21. The pawl31further includes a second side having a pressing face312. The control button32is operable to actuate the spring33and the pressing block34. The pressing block34includes an end pressing against the pressing face312of the pawl31. The control button32controls an extent of angular movement of the pawl31and controls a rotating direction of the ratchet wheel21. The structure of the direction switching unit3is conventional and, thus, not further described to avoid redundancy.

In assembly, the pawl31, the spring33, and the pressing block34of the direction switching unit3are inserted into the compartment14via the lower opening141. The ratchet wheel21is mounted into the hollow portion11from below. A portion of the upper section217of the ratchet wheel21extends upwards beyond the through-hole13. The coupling hole241of the rotational cap24is mounted around the upper section217of the ratchet wheel21. The stop side243of the rotational cap24abuts against the abutment side219of the upper section217of the ratchet wheel21. The engagement member242engages with the annular inwardly extending retaining edge218of the ratchet wheel21. Thus, the rotational cap24can rotate the ratchet wheel21and can prevent the ratchet wheel21from falling downwards. The lower cap22is mounted below the ratchet wheel21with the covering portion222covering the lower opening141of the compartment14. The clip23is engaged in the annular engagement groove215of the lower section214of the ratchet wheel21. Due to the non-plane design of the clip23, the clip23can be reliably positioned to the upper wall face2151and the lower wall face2152of the annular engagement groove215. The engagement section232is engaged in the cutout216. The recessed portions234are not located in the annular engagement groove215. A portion of the clip23extends outside of the annular engagement groove215and abuts the lower cap22to prevent disengagement of the lower cap22while a portion of the engagement section232is received in the insertion hole211.

With reference toFIG. 7, when a tool4in the form of a bit is inserted into the insertion hole211, the engagement section232of the clip23is engaged in grooves41of the tool4to position the tool4. Furthermore, the clip23is positioned by the annular engagement groove215without the risk of movement in the vertical direction, preventing vertical movement of the tool4relative to the ratchet wheel21and providing improved assembly stability and operational convenience. When it is desired to repair or replace elements of the ratchet wrench according to the present invention, the recessed portions234of the clip23permits insertion of a tool (not shown) with a pointed end to remove the clip23, permitting easy repair and maintenance.

The clip23according to the present invention provides both functions of positioning the tool4and preventing disengagement of the lower cap22. Furthermore, the rotational cap24according to the present invention can be made of a plastic material to provide a different color or a shape for indicating purposes, permitting easier visual identification.

When the diameter of the upper section217of the ratchet wheel21is larger than the diameter of the through-hole13, the ratchet wrench does not have to include the rotational cap24, and the ratchet wheel21is mounted from top. Furthermore, when the compartment14does not include the lower opening141, the direction switching unit3is mounted in the compartment14via the hollow portion11, and the ratchet wrench does not have to include the lower cap22. Furthermore, the direction switching unit3can be replaced by any equivalent mechanism.