| 摘要 |
A stepless ratchet one way clutch mechanism as applied to an improved screwdriver tool is disclosed. A wheel is rotationally fixed to a drive shaft. Two couplings are rotatably mounted about the drive shaft and extend away from the drive shaft. The wheel is between the couplings. A lever is pivotably attached to the couplings at a pivot pin between the couplings. The pivot pin is beyond the wheel outer diameter. When the lever is rotated in relation to the couplings an engaging edge of the lever presses the outer diameter surface of the wheel. The interface between the lever and wheel is of high friction. The interface has a "V" groove on one of the lever or wheel, and a "V" chamfer rib on the other of the lever or wheel. An elongated resilient spring biases the pivot pin either directly or through the lever or coupling to cause the lever to rotate in relation to the couplings. When the lever is held at a distal end while the pin is biased, the wheel is prevented from rotating in one or the other direction. The spring includes a "Z" shaped portion such that a slide switch causes a side to side bias on the spring.
|
