GB895768A - Spring motor for motion picture cameras - Google Patents

Abstract

895,768. Spring motors. FOSTER, E. E. May 2, 1958, No. 46413/58. Divided out of 894,505. Class 10. [Also in Group XX] The coils of a driving spring in a motion picture camera are arranged to be wound S-faahion between two spindles or sleeves, to which the ends of the spring ribbon are attached. The principle of action is described in Specification 894,505. As shown in Figs. 1 and 3, the spring ribbon 71 can be manually wound on to sleeve 75, where it is in the strained state, by a pivotable crank handle 78 having an opening 77 adapted to receive a straight-sided reduced portion 76 of a shaft 58 fast with sleeve 75. Shaft 58 carries a toothed wheel 57 for transmitting the drive, when the spring runs down, via pinion 59 and toothed wheel 61 fast therewith to a pinion 62 couplable (by means not shown) to a one-way clutch for driving via bevel gears 65, 66 the shutter disc 54. Overwinding of the spring is prevented by the entry into a notch 73 in the sleeve 74, when this is no longer covered by the spring, of hook 83 of a bell-crank lever 80, the other end of which acts as a footage indicator, moving past window 84 when the lever 80 is pivoted by winding-up of the spring on to sleeve 74. The one-way clutch shown in Fig. 5 comprises a spring 89 the free end 90 of which can engage a notch 91 in a member 63 fast with pinion 62 when the latter rotates anticlockwise. Pinion 62 is rigid with a shaft carrying a wheel from which drive is imparted to one of the film spools in a container 55 via a pair of spring discs acting as a slipping clutch.