| 摘要 |
1,206,252. Cine-camera spool drive. AGFA-GEVAERT A.G. Feb.11, 1969 [Feb. 14, 1968; March 28, 1968], No.7243/69. Heading G2E. In a sub-standard cine camera a reciprocating film pull-down mechanism and a film take-up spool are driven by a common motor the spool driving means deriving its motion from a reciprocating member, which may be the pull-down mechanism itself, through a hairpin spring coupling which allows lost motion and avoids the necessity of using a frictional coupling. As shown, the reciprocating member is the pulldown mechanism and the spool driving means includes two intermeshing gearwheels, 12, 13 coupled to the take-up spool (not shown) and arranged to be alternately driven by an arm 14, having two pawls 14a, 14b, which arm is pivoted at one end of a first lever 15 pivoted at its other end about a pin 16 fixed to the camera. A second lever is also pivoted at pin 16 and is driven by a hairpin spring 18 engaging flaps 17b and connected directly to the film pull-down mechanism 8. Lever 15 has fixed pins 15a, 15b so that it may be rotated by lever 17 when arm 14c engages one of the pins. In operation, when the pull-down mechanism 8 begins its movement in one direction, one of the pawls 14a, 14b engages, while the other disengages one of the gearwheels 12, 13 owing to the pivoting movement of arm 14. When one of the fixed pins 15a, 15b is engaged by arm 14c the lever 15 rotates about pin 16 to advance the gearwheel engaged by a pawl. The other gearwheel is advanced similarly during the opposite movement of the pull-down mechanism 8. In a second embodiment Fig. 3 (not shown) the pawls 14a, 14b are individually pivotable as one arm of a two-armed lever (15) and are spring biased for engagement with gearwheel 12, 13. The lever 15 may be driven by another reciprocating member driven by motor 1. |
