Abstract: A mechanical drive arrangement for a cinematograph projector. A double-sided tooth drive belt passes, in succession, over a motor driven, film take-up sprocket, idler sprocket, intermittent drive sprocket, film feed sprocket and shutter drive sprocket. The intermittent drive sprocket and intermittent motion film sprocket are mounted on a rotatable disc. The axis of rotation of the disc coincides with the circumference of the intermittent drive sprocket at the point where the plane through the axes of both mounted sprockets cuts the region of engagement of the drive belt around that circumference. In consequence, rotation of the disc moves the film anchor point, on the intermittent motion film sprocket, with only slight rotation of the shutter drive. Thereby, ghosting is avoided when racking.

Abstract: Film tensioning and controlling transport mechanism for a cinematograph film projector. The film take-up mechanism has a torque motor drive separate from the projector mechanism drive motor. The torque motor is energised first to tension film before the projector drive motor is energised. The torque motor is first energised with a series temperature-sensitive resistor so that torque, and film-tension, increases before the projector mechanism starts up. Film between the projector mechanism and the take-up spool is formed into a loop over a movable roller, which is spring-tensioned in the loop-lenghtening direction but is restrained by a dashpot in the loop-shortening direction. Film-tension reduces the loop length, but the projector drive motor is energised before the whole loop is taken up.

Abstract: A composite projector gate, aperture and light dowser assembly for a cinematograph film projector. The film guide surface through the gate area is curved convex towards the light source, film being held to curved marginal guides by flexible bands anchored before the gate, in the direction of film motion. A quick-release anchor is provided to retain the tension springs. The projection aperture comprises a removable plate in front of which, towards the light source, are spaced-apart heat screens with a horizontally-moving light-dowser blade therebetween in a space in which is provided forced air ventilation.