Remote control mechanisms

摘要

A remote control mechanism comprises a foot pedal 2 which is pivotable about an axis 3 to effect rotation of a quadrant gear 17 about the same axis. A pinion 19 meshes with the quadrant gear and is rotatably fast with a snail cam 20 which pivots about the pinion axis. The snail cam 20 has a continuously variable velocity ratio and has attached to it the core 4 of a cable 5 so that the core is translated within the cable casing 6 when the snail cam 20 is pivoted about the pinion axis in response to an operative pivotal movement of the foot pedal 2. Successive regions of the cam periphery 33 of the snail cam engage and pick up the cable core 4 as the snail cam is pivoted, the radius of pick-up decreasing as the snail cam is pivoted by the operative movement of the foot pedal 2. The cable core 4 operates an injection pump unit against a spring loading which increases the more the core is translated and the increasing velocity ratio of the snail cam 20 is matched to the increasing load on the cable core to give a substantially constant load feel on the foot pedal 2 throughout its range of travel.