Ratchet tool without drilling holes in an inside of the tool head

Information

  • Patent Grant
  • 6615693
  • Patent Number
    6,615,693
  • Date Filed
    Thursday, June 6, 2002
    22 years ago
  • Date Issued
    Tuesday, September 9, 2003
    20 years ago
  • Inventors
  • Examiners
    • Meislin; D. S.
    Agents
    • Baxley; Charles E.
Abstract
A ratchet tool includes a head with a hole and a driving member is rotatably received in the hole. A plurality of teeth are defined in an inside of the hole and a plurality of notches are defined in an outer periphery of the driving member. Each notch has a pawl received therein which is engaged with the teeth. A spring ring is mounted to the pawls and positions and pushes the pawls in the notches.
Description




FIELD OF THE INVENTION




The present invention relates to a ratchet tool that has a driving member rotatably received in the tool head and several pawls received in notches in the outside of the driving member so as to be engaged with the teeth in an inside of the tool head.




BACKGROUND OF THE INVENTION




A conventional ratchet tool generally includes a tool head and a hole is defined through the too head so that a driving member is rotatably received in the hole of the tool head. A recess is defined in an inside of the hole in the tool head so as to receive a pawl therein and the pawl is engaged with the teeth defined in an outside of the driving member. The pawl is biased by a spring so that when rotating the tool in one direction, the pawl is securely engaged with the driving member so as to tighten or loosen an object. On the other hand, when rotating the tool in the other direction, the pawl moves over the teeth of the driving member and the driving member is remained still. Although this arrangement is used for a long period of time, it requires a special tool and drill to make the recess in the inside of the hole of the tool head and the special tool and drill make the manufacturing of the ratchet tool become high.




The present invention intends to provide a ratchet tool that does not need to drill the recess in the inside of the hole of the tool head.




SUMMARY OF THE INVENTION




In accordance with one aspect of the present invention, there is provided a ratchet tool which comprises a tool head having a hole defined therethrough and teeth are defined in an inside of the hole. A driving member is rotatably received in the hole and has a plurality of are notches defined in an outer periphery of the driving member. Each notch comprises a short surface, a long surface and an arcuate surface which is connected between the short surface and the long surface.




Each notch has a pawl received therein which is an elongate member having engaging teeth defined in a first end thereof and a rounded convex extending from a second end of the pawl. The engaging teeth are engaged with the teeth in the inside of the hole. A short side and a long side are respectively connected to two sides of the rounded convex. The rounded convex is engaged with the arcuate surface of the notch corresponding thereto. The short side faces the short surface and the long side faces the long surface. A protrusion extends from one of a top and a bottom of each of the pawl.




A spring ring is mounted to the protrusions of each of the pawls and pushes the pawls toward the driving member.











The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.




BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is an exploded view to show the ratchet tool of the present invention;





FIG. 2

is a plan view to show the ratchet tool of the present invention;





FIG. 3

shows the pawl securely engaged with the teeth in the inside of the hole of the tool head when the tool is rotated in counter clockwise;





FIG. 4

shows the pawl is pushed away from the teeth in the inside of the hole of the tool head when the tool is rotated in clockwise;





FIG. 5

shows a cross sectional view of the the ratchet tool of the present invention, and





FIG. 6

is a cross sectional view to show another embodiment of the ratchet tool of the present invention.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT




Referring to

FIGS. 1

,


2


,


3


and


5


, the ratchet tool of the present invention comprises a tool head


2


having a hole


20


defined therethrough and teeth


21


are defined in an inside of the hole


20


. An aperture


201


defined by an inward flange extending from a bottom of the tool head


2


, and a groove


22


is defined in the inside of the hole


20


near the top of the tool head


2


. A driving member


3


is rotatably received in the hole


20


and has an engaged hole


31


defined therethrough which is engaged with an object to be tightened or loosened. A convex portion


30


extends from an end of the driving member


3


and is engaged with the aperture defined in a center of the flange


201


. A flange


300


extends outward from the other end of the driving member


3


and a groove


33


is defined in an outer periphery of the flange


300


. A retaining ring


7


is engaged in the groove


33


and the groove


22


to retain the driving member


3


in the hole


20


of the tool head


2


.




A plurality of notches


32


are defined in an outer periphery of the driving member


3


and each notch


32


comprises a short surface


320


, a long surface


323


and an arcuate surface


321


which is connected between the short surface


320


and the long surface


323


. An annular groove


34


located below the flange


300


is defined in the outer periphery of the driving member


3


and communicates with the notches


32


.




Each notch


32


has a pawl


4


received therein which is an elongate member having engaging teeth


44


defined in a first end thereof and a rounded convex


42


extends from a second end of the pawl


4


. A protrusion


40


extends from one of a top and a bottom of each of the pawl


4


. The protrusion


40


has an engaging surface


400


defined in a vertical wall thereof and the engaging surface


400


faces the teeth


21


in the inside of the hole


20


of the tool head


2


. A spring ring


5


is engaged with the annular groove


34


and mounted to the protrusions


40


of each of the pawls


4


and pushes the pawls


4


toward the driving member


3


.




The engaging teeth


44


are engaged with the teeth


21


in the inside of the hole


20


. A short side


41


and a long side


43


are respectively connected to two sides of the rounded convex


42


which is engaged with the arcuate surface


231


of the notch


32


corresponding thereto. The short side


41


faces the short surface


320


and the long side


43


faces the long surface


323


.




A minimum distance between the rounded convex


42


and the engaging teeth


44


is longer than a minimum distance between the arcuate surface


321


of each of the notches


32


to the teeth


21


defined in an inside of the hole


20


.




As shown in

FIG. 3

, when rotating the tool counter clockwise, the teeth


21


push the pawls


4


and let the short side


41


securely match with the short surface


320


, and the driving member


3


is rotated with the tool because the pawls


4


push the driving member


3


to rotate. As shown in

FIG. 4

, when the tool is rotated in clockwise, the teeth


21


pushes the long side of each of the pawl


4


which is pivoted about axis of the rounded convex


42


and the teeth


21


move over the engaging teeth


44


of the pawls


4


. The ratchet tool has no recesses to be drilled in the inside of the hole


20


so that no special tools and drills are required and the manufacturing cost can be reduced.





FIG. 6

shows that the pawls


4


may have two protrusions


40


on the top and the bottom of each of the pawl


4


and two spring rings


5


are required to be mounted onto the protrusions


40


.




While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.



Claims
  • 1. A ratchet tool comprising:a tool head having a hole defined therethrough and teeth defined in an inside of the hole, a driving member rotatably received in the hole and a plurality of notches defined in an outer periphery of the driving member and each notch comprising a short surface, a long surface and an arcuate surface which is connected between the short surface and the long surface; each notch having a pawl received therein which is an elongate member having engaging teeth defined in a first end thereof and a rounded convex extending from a second end of the pawl, the engaging teeth engaged with the teeth in the inside of the hole, a short side and a long side respectively connected to two sides of the rounded convex, the rounded convex engaged with the arcuate surface of the notch corresponding thereto, the short side facing the short surface and the long side facing the long surface, a protrusion extending from one of a top and a bottom of each of the pawl, and a spring ring mounted to the protrusions of each of the pawls and pushing the pawls toward the driving member.
  • 2. The ratchet tool as claimed in claim 1, wherein an annular groove is defined in the outer periphery of the driving member and communicates with the notches, the spring ring engaged with the annular groove.
  • 3. The ratchet tool as claimed in claim 1, wherein a minimum distance between the rounded convex and the engaging teeth is longer than a minimum distance between the arcuate surface of each of the notches to the teeth defined in an inside of the hole.
  • 4. The ratchet tool as claimed in claim 1, wherein the protrusion has an engaging surface defined in a vertical wall thereof and the engaging surface faces the teeth in the inside of the hole of the tool head, an extension line extending from the engaging surface intersecting the long side of the pawl at an acute angle.
US Referenced Citations (7)
Number Name Date Kind
2407558 Kress Sep 1946 A
2744432 Rueb May 1956 A
2982161 Angquist et al. May 1961 A
3044591 Kilness Jul 1962 A
4574928 Norton Mar 1986 A
6357323 Chi et al. Mar 2002 B2
6530296 Liao Mar 2003 B1