| CPC B60S 9/08 (2013.01) [B60D 1/66 (2013.01)] | 20 Claims |

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1. A linear jack, comprising:
an outer tube defining a centerline axis;
a first rotating screw mounted to the outer tube and extending coaxially along the centerline axis;
a coarse nut threadedly coupled to the first rotating screw;
a first sleeve received at least partially into the outer tube, the first sleeve is configured to translate with respect to the outer tube between a first retracted position and a first extended position;
a second rotating screw in coaxial alignment with the first rotating screw, the second rotating screw is configured to rotate together with the first rotating screw; and
a second sleeve received at least partially into the first sleeve, the second sleeve is configured to translate with respect to the first sleeve between a second retracted position and a second extended position, and the second sleeve is threadedly coupled to the second rotating screw;
wherein the first sleeve is configured to translate with respect to the coarse nut between a first position, wherein the coarse nut is meshingly engaged with the first sleeve, and a second position, wherein the coarse nut is free to rotate together with the second rotating screw and the first rotating screw with respect to the first sleeve.
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