| 摘要 |
PURPOSE:To prevent addenda from running aground when a rack and a pinion mesh with each other by installing a pin lower than the tooth depth of the rack in such a manner as to freely advance and retreat in the direction of the height in front of the forward end tooth of the rack, and urging the pin in the projecting direction through a resilient member. CONSTITUTION:When the tooth side of a tooth P1 of a pinion P and a pin 9 are brought into contact with each other by the relative approach of a rack R and a pinion P, the pinion P pressed by the pin 9 is rotated, the following tooth P2 of the pinion P pressed to the pin 9 is moved to such a position as to be meshed with the front tooth R1 of the rack R. Thus, the rack R and the pinion P smoothly mesh with each other to prevent the addenda from running aground. Further, when by the addendum of the tooth P1 of the pinion P and the forward end 9a of the pin 9 engage with each other by the relative approach of the rack R and the pinion P, the pin 9 is retreated into a guide hole 8 against the urging force of a spring 10 to rotate the pinion P, so that the tooth P is moved to such a position as to be meshed with the tooth R1. Accordingly, the rack R and the pinion P smoothly mesh with each other to prevent the addenda from running aground. |
