One-way ratchet tool

1. A tool comprising:

a shank including a first end and a second end;

a driving device mounted on the first end of the shank and including a first ratcheting mechanism having a compartment and a plurality of first unsymmetrical teeth in the compartment and including a second ratcheting mechanism rotatably received in the compartment and having a plurality of second unsymmetrical teeth engaged with the plurality of first teeth, with the compartment extending in a longitudinal direction of the first ratcheting mechanism and including a first compartment and a second compartment connected to and in communication with the first compartment, with the first compartment having a larger diametrical length than that of the second compartment, with the compartment further including a first joining section interconnecting respective inner peripheries of the first and second compartments, and with the plurality of first teeth disposed on the first joining section, with the first ratcheting mechanism being rotatable relative to the second ratcheting mechanism in a single direction, with the second ratcheting mechanism including a channel extending therein, a first body section received in the second compartment, a second body section received in the first compartment and a third body section extended from the second body section and received in the first compartment, with the first body section having a first outer diametrical length, with the second body section having a second outer diametrical length greater than the first outer diametrical length, with the third body section including a third outer diametrical length less than the second outer diametrical length of the second body section, with the second ratcheting mechanism further including a second joining section interconnecting respective outer peripheries of the first and second body sections, with the plurality of second teeth disposed on the second joining section;

a driving head having a shape corresponding to that of the channel and moveably received in the channel between two releasably fixed positions, with the driving head including a first lock and a second lock, with the first lock retained in a first aperture on the second ratcheting mechanism and the second lock exposed outside the second ratcheting mechanism when the driving head is at one fixed position, and with the second lock retained in a second aperture on the second ratcheting mechanism and the first lock exposed outside the second ratcheting mechanism when the driving head is at another fixed position;

a channel extending in a longitudinal direction of the second ratcheting mechanism and through the first, second, and third body sections, with the first aperture extending through the first body section and in communication with the channel, and with the second aperture extending through the third body section and in communication with the channel; and

an elastic member retained by an end cap and the second ratcheting mechanism for biasing the plurality of second teeth to engage with the plurality of first teeth;

wherein the driving head is switchable between a first mode with the driving head adapted to turn an element in a first direction and a second mode with the tool adapted to enable the driving member to turn the element in a second direction opposite to the first direction; and

wherein the driving head includes a corner interconnecting two peripheral sides thereof and a slot extending in a longitudinal direction of the corner and inset in the corner, wherein the second ratcheting mechanism includes a stopper received in an orifice which extends through the second ratcheting mechanism and is in communication with the channel, and with the stopper including a first end retained by an inner peripheral side of the bearing and a second end disposed in the channel and retained in the slot of the driving head.

2. The tool as claimed in claim 1 wherein the second body section includes a flange formed on the outer periphery thereof, and wherein the first and second ratcheting mechanisms include a bearing disposed therebetween and retained by the flange.

3. The tool as claimed in claim 1 wherein the channel has a shape corresponding to that of the driving head.

4. The tool as claimed in claim 1 wherein the slot has a proximal end and a distal end separated by a first distance, and wherein the first and second locks are separated by a second distance greater than the first distance.

5. The tool as claimed in claim 1 wherein the orifice extends through the second body section of the second ratcheting mechanism.

6. A tool comprising:

a shank including a first end and a second end;

a driving device mounted on the first end of the shank and including a first ratcheting mechanism having a compartment and a plurality of first unsymmetrical teeth in the compartment and including a second ratcheting mechanism rotatably received in the compartment and having a plurality of second unsymmetrical teeth engaged with the plurality of first teeth, with the first ratcheting mechanism being rotatable relative to the second ratcheting mechanism in a single direction, with the second ratcheting mechanism including a channel extending therein;

a driving head having a shape corresponding to that of the channel and moveably received in the channel between two releasably fixed positions, with the driving head including a first lock and a second lock, with the first lock retained in a first aperture on the second ratcheting mechanism and the second lock exposed outside the second ratcheting mechanism when the driving head is at one fixed position, and with the second lock retained in a second aperture on the second ratcheting mechanism and the first lock exposed outside the second ratcheting mechanism when the driving head is at another fixed position; and

an elastic member retained by an end cap and the second ratcheting mechanism for biasing the plurality of second teeth to engage with the plurality of first teeth;

wherein the driving head is switchable between a first mode with the driving head adapted to turn an element in a first direction and a second mode with the tool adapted to enable the driving member to turn the element in a second direction opposite to the first direction; and

wherein the first ratcheting mechanism includes a notch in the first compartment, wherein the end cap includes a periphery tight-fitted in the notch and an inner edge tight-fitted with the second ratcheting mechanism.

7. The tool as claimed in claim 6 wherein the first end of the shank includes two lugs separated by a space, wherein the driving device is pivotally clamped between the lugs within the space, wherein each lug includes a through hole and a pivot pin installed in the through hole, and wherein the first ratcheting mechanism includes an outer periphery having two peripheral surfaces opposed to each other and two cavities disposed on the two peripheral surfaces pivotally receiving the two pivot pins respectively.

8. The tool as claimed in claim 7 wherein the driving device is positioned at a selected pivoting position, wherein one of the two lugs and the first ratcheting mechanism includes a detent disposed thereon, and wherein another of the two lugs and the first ratcheting mechanism includes a plurality of recess on the outer periphery with which the detent is selectively engaged.

9. The tool as claimed in claim 8 wherein the plurality of recesses are radially disposed.

10. The tool as claimed in claim 8 wherein the detent includes an elastic element and a locking member biasably moved by the elastic element.

11. The tool as claimed in claim 6 wherein each of the first and second locks includes a resilient member and a retainer biasably moved by the resilient member to engage in the first and second apertures respectively.

12. The tool as claimed in claim 6 wherein the second end of the shank includes a hole adapted for receiving a driving tool, and wherein the shank is adapted to be used as a lever to drive the driving tool.