Drive transmission mechanism

摘要

A sliding coupling mounted between a pair of separately rotational members, including a pair of coiled springs, which realizes no rotational delay at time of reversing a rotational direction of one of the rotational members. Each coiled spring has a projecting part extending radially outwardly from one end thereof. The pair of coiled springs are fictionally mounted on an outer surface of one of the rotational members with the circular parts and the projecting parts of the coiled springs being overlapped with each other so that the winding directions of the coiled springs are opposite to each other. The other rotational member has an engaging groove with which the projecting parts of the coiled springs are engaged without a space between each projecting part and a surface forming the engaging groove of the rotational member in each rotational direction. When the rotational direction of the one rotational member is reversed, the rotational direction of the other rotational member is also reversed with no rotational delay.