23-02-2017, 11:01 AM
Geneva drive or maltese cross is an indexing mechanism that converts continuous motion into intermittent motion. By means of this mechanism, the rotational movement of the drive wheel is converted into intermittent rotational movement of the pinion. The film passed over the pinion. Due to intermittent motion, the film advanced frame by frame in front of the lens for 1 / 24th second at the 48 Hz frequency.
The Geneva wheel is used in cinema film projectors to pass the film in one frame at a time. This is a mechanism for intermittent motion. The lower wheel drives the upper wheel. The rotational movement of the lower wheel is continuous, but the top wheel only rotates intermittently . Four revolutions of the lower wheel are needed to produce a revolution of the upper wheel. The drive pin on the bottom wheel engages the grooves of the Geneva wheel and rotates enough so that it is in position when the pin rotates again.
The Geneva wheel is used in cinema film projectors to pass the film in one frame at a time. This is a mechanism for intermittent motion. The lower wheel drives the upper wheel. The rotational movement of the lower wheel is continuous, but the top wheel only rotates intermittently . Four revolutions of the lower wheel are needed to produce a revolution of the upper wheel. The drive pin on the bottom wheel engages the grooves of the Geneva wheel and rotates enough so that it is in position when the pin rotates again.