A jack assembly is shown and describe. The jack assembly may include a first tube having first and second end portions and a central portion between the first and second end portions, and a second tube positioned within the first tube and movable with respect to the first tube. The jack assembly may also include an expanded portion on the first tube, the expanded portion having a larger inner diameter than an inner diameter of the central portion, and a bushing attached to the expanded portion, where the bushing generally prevents contact between the first and second tubes.

A jack assembly is shown and describe. The jack assembly may include a first tube having first and second end portions and a central portion between the first and second end portions, and a second tube positioned within the first tube and movable with respect to the first tube. The jack assembly may also include an expanded portion on the first tube, the expanded portion having a larger inner diameter than an inner diameter of the central portion, and a bushing attached to the expanded portion, where the bushing generally prevents contact between the first and second tubes.

A transmission device for lifting a sickbed contains a first casing, a second casing, a power input assembly, a power output assembly, and multiple screw elements. The first casing includes a first rotatable connection portion, a second rotatable connection portion, a first space, and multiple locking orifices. The second casing includes a third rotatable connection portion, a fourth rotatable connection portion, a second space, and multiple coupling orifices. The power input assembly includes an input shaft and a first bevel gear. The power output assembly includes an output shaft and a second bevel gear. The multiple screw elements are inserted through the multiple coupling orifices of the second casing to screw with the multiple locking orifices of the first casing.

A transmission device for lifting a sickbed contains a first casing, a second casing, a power input assembly, a power output assembly, and multiple screw elements. The first casing includes a first rotatable connection portion, a second rotatable connection portion, a first space, and multiple locking orifices. The second casing includes a third rotatable connection portion, a fourth rotatable connection portion, a second space, and multiple coupling orifices. The power input assembly includes an input shaft and a first bevel gear. The power output assembly includes an output shaft and a second bevel gear. The multiple screw elements are inserted through the multiple coupling orifices of the second casing to screw with the multiple locking orifices of the first casing.

A jack assembly including a telescopic column driven via a gear box, wherein: the gear box is coupled to a rotary input of a drive mechanism that extends and retracts the column; the gear box has only a single input gear and a single output gear that is coupled to the drive mechanism; and the input gear has a connector adapted to be engaged and driven by a portable, hand-held power tool. The invention also relates to a jack assembly with a gear box for use as a jockey wheel for attachment to a towed vehicle, to raise and lower a draw bar of the vehicle.

A jack assembly including a telescopic column driven via a gear box, wherein: the gear box is coupled to a rotary input of a drive mechanism that extends and retracts the column; the gear box has only a single input gear and a single output gear that is coupled to the drive mechanism; and the input gear has a connector adapted to be engaged and driven by a portable, hand-held power tool. The invention also relates to a jack assembly with a gear box for use as a jockey wheel for attachment to a towed vehicle, to raise and lower a draw bar of the vehicle.

A jack screw system having an upper, middle, and lower jack screw, each having corresponding jack screw teeth, for raising and lowering surfaces. The telescopic expansion of the jack screw system can be achieved using an engaging gear or belt. The jack screw system is generally used with furniture but may be used to raise any appropriate surface.

A jack screw system having an upper, middle, and lower jack screw, each having corresponding jack screw teeth, for raising and lowering surfaces. The telescopic expansion of the jack screw system can be achieved using an engaging gear or belt. The jack screw system is generally used with furniture but may be used to raise any appropriate surface.

A jack (1), which is extensible,comprising: a first tubular body (5), a second tubular body (30) slidably associated with the first tubular body (5) and movable along a predetermined longitudinal direction (A), a third tubular body (95) slidably associated with the second tubular body (30) and movable along the longitudinal direction (A), a base (115) for support associated with an end (105) of the third tubular body (95) distal from the second tubular body (30), characterized in that it comprises an automatic safety device (145) provided with a lockbolt (150) movable between a first position, wherein it allows relative sliding between the third tubular body (95) and the second tubular body (30), and a second position wherein it prevents the third tubular body (95) from sliding relative to the second tubular body (30).

A jack assembly including a telescopic column driven via a gear box, wherein: the gear box is coupled to a rotary input of a drive mechanism that extends and retracts the column; the gear box has only a single input gear and a single output gear that is coupled to the drive mechanism; and the input gear has a connector adapted to be engaged and driven by a portable, hand-held power tool. The invention also relates to a jack assembly with a gear box for use as a jockey wheel for attachment to a towed vehicle, to raise and lower a draw bar of the vehicle.