manual screw jack,hand operated worm gear screw jack

manual screw jack,hand operated worm gear screw jack, also called hand operated worm gear screw jack or hand operated bevel gear jack. Which is ideal solutions for applications where electricity or power generators is inconvenient or dangerous, light weight, low duty cycle, low target cost and short travel length. 

manual screw jack,hand operated worm gear screw jack is composed of hand wheel or hand crank and a complete set worm gear screw jack with internal worm and worm gear sets, standard hand wheel or hand crank dimensions from 5" to 20" diameter, special hand wheel or hand crank dimensions required, please contact Jacton engineers. When hand operated worm gear acme screw jack, machine screw jack, which has intermittent precisely positioning and self-locking feature for no creeping down without brake mechanism or other locking systems. But hand operated worm gear ball screw jack, no self-locking feature, avoid ball screw back drive with attached load, which needs additional brake or locking mechanism to prevent it creep. 

All manual screw jack,hand operated worm gear screw jack has this disadvantage, slow travel speed, maximum 1.5mm travel length per full turn of hand wheel or hand crank. Hand operated bevel gear jack is ideal solution of slow travel speed with internal pairs spiral bevel gears, maximum up to 12mm travel length per full turn of hand wheel or hand crank.

For precise position display, a range of digital mechanical counters are available for matching with hand operated screw jacks. These digital mechanical counters measure the rotations of the input shaft and display corresponding position in a mecahncial counter window. The display value per input shaft revolution is variable and is achieved through a series of gear reductions configured to accommodate different worm gear screw jack ratios, screw pitch and travel lengths.