An apparatus for pre-loading a mechanical constant-resistance single prop includes a rhombic stretchable bracket, a screw rod, a first cylindrical sleeve ring, and a second cylindrical sleeve ring. The screw rod is connected to two opposite apex corners of the rhombic stretchable bracket. A tail end of the screw rod is fixedly connected to one apex corner of the rhombic stretchable bracket. An end head of the screw rod passes through another apex corner of the rhombic stretchable bracket. The remaining two opposite apex corners of the rhombic stretchable bracket are respectively fixedly connected to edges of the first cylindrical sleeve ring and the second cylindrical sleeve ring through connecting rods. The screw rod is threadedly connected to the apex corner of the rhombic stretchable bracket through which the screw rod passes. A method for pre-loading a mechanical constant-resistance single prop is also provided.

An apparatus for pre-loading a mechanical constant-resistance single prop includes a rhombic stretchable bracket, a screw rod, a first cylindrical sleeve ring, and a second cylindrical sleeve ring. The screw rod is connected to two opposite apex corners of the rhombic stretchable bracket. A tail end of the screw rod is fixedly connected to one apex corner of the rhombic stretchable bracket. An end head of the screw rod passes through another apex corner of the rhombic stretchable bracket. The remaining two opposite apex corners of the rhombic stretchable bracket are respectively fixedly connected to edges of the first cylindrical sleeve ring and the second cylindrical sleeve ring through connecting rods. The screw rod is threadedly connected to the apex corner of the rhombic stretchable bracket through which the screw rod passes. A method for pre-loading a mechanical constant-resistance single prop is also provided.

A device comprising a main support an equipment support having a first position and a second position adjustable relative to the height of the main support. A first crank lever is mounted to the first bearing and rotatable about a first rotational axis via a first shaft. A connecting rod is connected to the first crank lever via a first joint and to the equipment support via a second joint. A guide is arranged such that the equipment support is displaceable while guided to remain parallel to the main support. The equipment support passes an upper dead center position when moving from a first to a second position by rotation of the first crank lever and, upon further rotation a stop element contacts a stop.

A device comprising a main support an equipment support having a first position and a second position adjustable relative to the height of the main support. A first crank lever is mounted to the first bearing and rotatable about a first rotational axis via a first shaft. A connecting rod is connected to the first crank lever via a first joint and to the equipment support via a second joint. A guide is arranged such that the equipment support is displaceable while guided to remain parallel to the main support. The equipment support passes an upper dead center position when moving from a first to a second position by rotation of the first crank lever and, upon further rotation a stop element contacts a stop.

Disclosed is a vehicle jack device. The vehicle jack device according to an exemplary embodiment of the present invention includes: a base portion in which an inserting hole into which a hinge shaft is inserted is formed and which is supported on a bottom side; a pair of lower arms of which a first portion is installed in the hinge shaft of the base portion in a rotatable way and in which a reinforcing rib is formed in a lengthwise direction; a pair of upper arms respectively installed in a second portion of the lower arm, and on which a reinforcing rib is formed in a lengthwise direction; a bracket member for fixing a first portion of the upper arm in a rotatable way; and a driver installed between the lower arm and the upper arm and providing a tucking driving force to the lower arm and the upper arm. Herein, multiple reinforcing ribs are formed with different heights in a lengthwise direction of the lower arm and wherein the upper arm, the base portion, the lower arm, the upper arm, and the bracket member are made of a plastic material.

A scissor jack comprises a bracket coupled to a first upper arm and a second upper arm; a load rest positioned above the bracket and pivotally connected to the bracket; an elastic element disposed between the load rest and the bracket; a base coupled to a first lower arm and a second lower arm; a first connector pivotally connected to the first upper arm and the first lower arm; a second connector pivotally connected to the second upper arm and the second lower arm; and a driving rod drivably connected to the first and second connectors.

A scissor jack comprises a bracket coupled to a first upper arm and a second upper arm; a load rest positioned above the bracket and pivotally connected to the bracket; an elastic element disposed between the load rest and the bracket; a base coupled to a first lower arm and a second lower arm; a first connector pivotally connected to the first upper arm and the first lower arm; a second connector pivotally connected to the second upper arm and the second lower arm; and a driving rod drivably connected to the first and second connectors.

A portable wheel lifting system to assist in the replacement of a wheel on a vehicle utilizing a portable outer housing, an inner lifting linkage system to hold a wheel or tire in place, and an electrical motor to vertically raise the lifting linkage system and thus the wheel to the desired location.

A system for a tire caddy and jack device to help a user easily perform tire changes on various-sized vehicles is disclosed. The Tire Caddy Jack is built using a base box supported by a plurality of casters that permits the entire Tire Caddy Jack to be moved easily around an automobile repair facility or garage. A scissor lift assembly is mounted in the center of the top surface of the base box. A scissor lift crank attaches to the scissor lift assembly that when turned will cause the scissor lift assembly to extend upwards, raising the tire and wheel above the ground. The tire and wheel rest upon rollers that are coupled to a pair of twin half roller arms mounted on top of the scissor lift assembly, permitting the tire and wheel to smoothly be raised and lowered to mount and unmount the tire and wheel onto a vehicle. The Tire Caddy Jack supports the tire and wheel while the mechanic removes or replaces the lug nuts or lug bolts that hold the tire and wheel on the vehicle.

A system for a tire caddy and jack device to help a user easily perform tire changes on various-sized vehicles is disclosed. The Tire Caddy Jack is built using a base box supported by a plurality of casters that permits the entire Tire Caddy Jack to be moved easily around an automobile repair facility or garage. A scissor lift assembly is mounted in the center of the top surface of the base box. A scissor lift crank attaches to the scissor lift assembly that when turned will cause the scissor lift assembly to extend upwards, raising the tire and wheel above the ground. The tire and wheel rest upon rollers that are coupled to a pair of twin half roller arms mounted on top of the scissor lift assembly, permitting the tire and wheel to smoothly be raised and lowered to mount and unmount the tire and wheel onto a vehicle. The Tire Caddy Jack supports the tire and wheel while the mechanic removes or replaces the lug nuts or lug bolts that hold the tire and wheel on the vehicle.