A known ratchet wrench, such as that described in the patent numbered TWI529034, is primarily a wrench body provided with a drive ratchet wheel, a ratchet block and a knob, where the knob is rotatably disposed on the body. A spring is provided between the knob and the ratchet block to normally abut the ratchet block towards the drive ratchet wheel so as to limit the direction of rotation of the drive ratchet wheel. For example, when the knob is toggled to the left, the knob will move the ratchet block to the left, such that the teeth of the ratchet block are engaged with the drive ratchet wheel, and when the drive ratchet wheel is desired to be rotated in the clockwise direction, as the left half of the ratchet block is wedged between the wrench body and the drive ratchet wheel, the drive ratchet wheel is unable to rotate clockwise and instead can only rotate in an anticlockwise direction to achieve an idling effect, and vice versa.
However, the known ratchet wrench harbours the following problem: for example, when the knob is toggled to the left and the drive ratchet wheel is desired to rotate in an anticlockwise direction, if the ratchet block or drive ratchet wheel is manufactured with excessively large dimensional tolerance, the teeth on the right half of the ratchet block become stuck in the drive ratchet wheel so that the drive ratchet wheel cannot be smoothly rotated anticlockwise. This in turn will prevent the knob from being smoothly toggled from left to right, not only impacting on working efficiency, but also damaging the ratchet wrench. However, if the ratchet block or drive wheel is manufactured with reduced dimensional tolerance to avoid this problem, the costs of manufacturing the known ratchet wrench will rise considerably, which is a shortcoming in need of improvement.
Accordingly, there is a need to provide a novel and improved ratchet wrench to solve the above-mentioned problem.
USPTO Backgrounds
USPTO Backgrounds