Abstract: A drive mechanism which is suitable for long strokes of motion (4 feet to over 100 feet) and is capable of carrying heavy loads (500 pounds to over 20,000 pounds) at very high speeds (over 5 feet per second) operates without substantial use of electronics or hydraulics. To produce these desirable characteristics a special index drive unit has two separate output drive gears (43, 45) which are driven by the same motor. The first output drive gear engages a first rack to produce rapid acceleration. The second output drive gear which is directly connected to the input drive shaft from the motor to the index drive unit then engages a second rack to produce high velocity movement. At the end of the desired movement the first gear engages a further rack to produce rapid deceleration of the load carrier of the drive mechanism.

Abstract: In an index drive system in which a cam follower is yoke mounted in a wheel for rotation with a shaft, to engage a cam plate, a cylindrical cam follower bearing surface or tire is trunion-mounted, with trunions projecting laterally from and beyond opposite sides of the cam follower bearing surface or tire and journalled in antifriction bearings supported by the wheel.