Ratchet Wheel Mounting Arrangement of a Wrench

The present invention relates to a ratchet socket wrench, and more particularly, to an improved wheel mounting arrangement of a ratchet socket wrench which is easy to manufacture, and can be rapidly installed.

A variety of ratchet socket wrenches for turning hexagon head bolts and hexagon nuts has appeared on the market. FIGS. 1 to 3 show a ratchet wheel mounting arrangement of a ratchet socket wrench according to the prior art, wherein a ratchet wheel is mounted within a box end at one end of the wrench and secured in place by a C-shaped clamp and a cover plate. A spring is mounted in the box end. A toothed arch block is mounted within the box end is and forced by the spring into engagement with the ratchet wheel to limit rotary motion of the ratchet wheel inside the box end to one direction. The ratchet wheel has an annular groove around the periphery, and a plurality of teeth equiangularly spaced around the annular groove. The toothed arch block is mounted in a recessed hole inside the box end of the wrench, having a projecting rod raised from a back side thereof. The spring is mounted inside the recessed hole in the box end of the wrench and connected between the projecting rod of the toothed arch block and inside wall of the recessed hole. Because the teeth of the ratchet wheel are formed at the annular groove around the periphery (see FIGS. 16 to 18), the fabrication process of the ratchet wheel is complicated. The processing process of the recessed hole in the box end of the wrench is also complicated (see FIG. 11). Furthermore, the tooth arch block tends to be forced away from the spring. FIGS. 5 and 6 show another ratchet wheel mounting arrangement according to the prior art. This arrangement has the same drawbacks.

The present invention has been accomplished to provide a ratchet wheel mounting arrangement for a ratchet socket wrench which eliminates the aforesaid drawbacks. According to one aspect of the present invention, the box end of the wrench has a smoothly arched notch axially extended to the topmost edge of the inside wall thereof for receiving the toothed arch block, and a blind hole in the smoothly arched notch for receiving the spring, permitting the toothed arch block to be forced by the spring into positive engagement with the ratchet wheel. According to another aspect of the present invention, the teeth of the ratchet wheel are arranged around the peripheral wall thereof, and the height of teeth on the toothed front side of the toothed arch block is approximately equal to that of the teeth on the ratchet wheel.

FIG. 1 is a top view in section of a ratchet wheel mounting arrangement of a ratchet socket wrench according to the prior art.

FIG. 2 is a side view in section of the ratchet wheel mounting arrangement shown in FIG. 1.

FIG. 3 is an exploded view of the arrangement shown in FIG. 1.

FIG. 4 is a perspective view of the tooth arch block shown in FIG. 3.

FIG. 5 is a top plan view of another ratchet wheel mounting arrangement according to the prior art.

FIG. 6 is an exploded view of the ratchet wheel mounting arrangement shown in FIG. 5.

FIG. 7 is a perspective view of a wrench constructed according to the present invention.

FIG. 8 is an exploded view in an enlarged scale of the ratchet wheel mounting arrangement of the wrench shown in FIG. 7.

FIG. 9 is a sectional view of the ratchet wheel mounting arrangement according to the present invention, showing the ratchet wheel turned forward and force into engagement with the toothed arch block.

FIG. 10 is a sectional view in an enlarged scale of a part of the ratchet wheel mounting arrangement according to the present invention, showing the ratchet wheel turned backwards and disengaged from the toothed arch block.

FIG. 11 is a sectional view of a part of FIG. 10, showing the spring mounted in the blind hole and connected to the toothed arch block.

FIG. 12 shows the processing of the recessed hole on the inside wall of the box end of the wrench according to the prior art.

FIG. 13 shows the processing of the smoothly arched notch on the inside wall of the box end of the wrench according to the present invention.

FIG. 14 is an exploded view of the ratchet wheel and the toothed arch block according to the present invention.

FIG. 15 shows the toothed arch block meshed with the ratchet wheel according to the present invention.

FIG. 16 is an exploded view of the ratchet wheel and the toothed arch block according to the prior art.

FIG. 17 is a side view in section showing an abnormal engagement between the toothed arch block and the ratchet wheel according to the prior art.

FIG. 18 is a side view in section showing the toothed arch block engaged with the ratchet wheel according to the prior art.

Referring to FIG. 7, according to the present invention, a ratchet wrench 1 is shown having a handle section and an open end type head at one end of the handle section and a box-type end 10 at the other end. The box-type end 10 includes a circular peripheral wall defining a chamber therein for receiving a rachet wheel 11 therein. Referring to FIGS. 7 to 11, the ratchet wheel 11 is mounted within the inner surface of the box end 10 and secured in place by a C-shaped clamp 14. The box end 10 includes cover plate 15, a spring 13 mounted in the box end 10, the spring 13 having a first end and a second end and a toothed arch block 12 mounted within the box end 10 and operatively associated with the ratchet wheel 11. The arch block 12 is a biased or forced by the spring 13 into engagement with the ratchet wheel 11 to limit rotary motion of the ratchet wheel 11 to one direction. The arch block 12 has a curved back side and a toothed front side and is biased by the first end of the spring 13 into engagement with the ratchet wheel 11 in a radial direction relative to the circular peripheral wall to limit rotary motion of the ratchet wheel 11 to one direction. The arch block 12 has a predetermined transverse width dimension. The box end 10 of the wrench 1 has a smoothly arched notch 101 smoothly curved inwardly at the smooth inside wall thereof and is axially extended to the topmost edge of the smooth inside wall. The arched notch 101 has a shape match with that of the curved back side of the toothed arch block 12. The arched notch 101 is abuttingly received in the toothed arched block 12. A blind hole 102 at the smoothly arched notch 101 is spaced from one end of the smoothly arched notch 101 at a distance approximately 1/4 of the width of the smoothly arched notch 101. The spring 13 has one end mounted in the blind hole 102, and an opposite end connected to one end of the toothed arch block 12. The toothed arch block 12 is mounted in the smoothly arched notch 101 inside the box end 10 and forced or biased by the spring 12 into engagement with the ratchet wheel 11 to limit the rotary motion of the ratchet wheel 11 in the box end 10 of the wrench 1 in one direction. A smoothly curved contact surface portion 121 disposed at the back side near one end remote from spring 13 and is forced into close contact with the surface of the smoothly arched notch 101. The opposite end of the toothed arch block 12 is biased by the smoothly arched notch 101 by the spring 13.

Referring to FIGS. 14 and 15, the height of teeth of the toothed arch block 12 is approximately equal to the height of teeth of the ratchet wheel 11. When the toothed arch block 12 and the ratchet wheel 11 are meshed together, the ratchet wheel 11 is positively stopped from a forward rotation relative to the toothed arch block 12, and thereby turns in a reverse direction relative to the toothed arch block 12 and the box end 10 of the wrench 1.