GB1377928A - Camera shutter control system - Google Patents

Abstract

1377928 Cinematography BELL & HOWELL CO 11 April 1973 17353/73 Heading G2E A cine camera includes a motor driven rotary shutter 40 and a switch ( movable plate 60 and contact 62) which when closed by depressing trigger 30 energizes the shutter motor. When the trigger is released a device mounted on the shutter 40 ensures that the shutter stops with the film shielded by it. As shown depressing the trigger 30 raises the plate 60 to touch contact 62, the trigger being connected to the plate 60 through a linkage Fig. 2, which includes a spring 85 which positively urges the plate 60 into its raised and lowered positions. On releasing the trigger 30 the plate 60 will fall only if the sector 47 of the shutter 40 is located as in Fig 4. Otherwise tooth 66 will engage rim 46 and the switch will remain closed so permitting the shutter to rotate until the sector 47 arrives in the Fig. 4, position. The sector 47 is located wholly within the opaque sector 42 of the disc 40. Arm 70 pivoted on pin 71 and attached to tension spring 73 is used to absorb the momentum of the shutter 40. The shutter 40 rotates clockwise, as viewed in Fig.4. If the tooth 66 enters section 47 to the right of the arm 70 the shutter momentum is absorbed by the arm 70. If the tooth enters to the left then the momentum of the shutter 40 is sufficient for the tooth 66 to engage the bent end 48 of rim 46 and so lift up the plate 60 to close the switch. The shutter therefore completes a further revolution so that tooth 66 can re-enter the sector 47 to the right of the arm 70.