SCREW JACK Russian patent published in 2006 - IPC B66F3/08 B60S9/06 

FIELD: mechanical engineering; transport engineering.

SUBSTANCE: invention relates to load-lifting devices with speed-changing gear trains, and it can be used for lifting vehicles. Proposed screw jack has lead screw connected with output shaft of two-speed reduction gear with speed change clutch. According to invention, reduction gear is made in form of differential planetary gear train and two worm pairs whose worms can be connected with input shaft of two-speed reduction gear. First central wheel of differential planetary gear train is connected with screw, and second one, with wheel of second worm pair for rotation in opposite direction relative to first one, and carrier is coupled with wheel of first worm pair. Worm of first worm pair is installed for axial displacement and is connected with clutch member, and clutch second member is installed on input shaft of two-speed reduction gear.

EFFECT: increased load-lifting capacity without increasing motor power owing to reduction of lead screw.

2 dwg