| 摘要 |
<p>A control mechanism for controlling the reciprocating movement of a pusher for a picture-holder in a transparency projector of the type in which a rotating shaft serves to reciprocate the pusher during the course of a 360 DEG rotation of the shaft. A continuously rotating electric motor drives the shaft through two gear stages and a coupling member effects the coupling of the motor to the shaft first, through the first stage and then through the second stage.</p> |
