A vehicle lift includes a hydraulic cylinder having a component that rotates as the cylinder lengthens and shortens. A sensor measures the rotation or rotational position of the rotating component, and the sensor's output is used by a controller to control the vehicle lift. In some embodiments, the vehicle lift includes a scissor or parallelogram mechanism, while others are column lifts. In some embodiments, the controller uses the sensor's output to manage the limits of travel of the vehicle lift, and in others, the controller uses it to coordinate lift operations with other lifts.

A vehicle lift includes a hydraulic cylinder having a component that rotates as the cylinder lengthens and shortens. A sensor measures the rotation or rotational position of the rotating component, and the sensor's output is used by a controller to control the vehicle lift. In some embodiments, the vehicle lift includes a scissor or parallelogram mechanism, while others are column lifts. In some embodiments, the controller uses the sensor's output to manage the limits of travel of the vehicle lift, and in others, the controller uses it to coordinate lift operations with other lifts.

The independent hydraulic jack system uses four independent jacks strategically mounted on the four corners of the bottom of a vehicle. Each of the jacks is connected via hydraulic hoses to a central hydraulic pump, also mountable on the bottom of the vehicle. The hydraulic pump can raise or lower any of the four jacks without affecting the other three. This hydraulic pump is controlled by a user-operated remote control whereby the user can directly adjust the height of the four jacks. The control also has a locking feature whereby the jacks will not alter their height until the control is unlocked. As a safety precaution, the pump cannot be utilized unless the vehicle brakes are applied.

The independent hydraulic jack system uses four independent jacks strategically mounted on the four corners of the bottom of a vehicle. Each of the jacks is connected via hydraulic hoses to a central hydraulic pump, also mountable on the bottom of the vehicle. The hydraulic pump can raise or lower any of the four jacks without affecting the other three. This hydraulic pump is controlled by a user-operated remote control whereby the user can directly adjust the height of the four jacks. The control also has a locking feature whereby the jacks will not alter their height until the control is unlocked. As a safety precaution, the pump cannot be utilized unless the vehicle brakes are applied.

A lifting device with a head cavity in the lifting member shaped to accept a removable lifting head. The head cavity in the lifting device—e.g., the piston of a bottle jack—may be provided with threads, or may have the threads removed. A yoke fitted on the lifting head provides registration, horizontal restraint, or both against a lifted object, component, or surface to prevent sliding off the lifting head while in use. In a smooth-walled-shaft embodiment, a set of risers (spacers, adjusters, trims, or shims) serves to adjust an extension height of the shaft, elevating the lifting head with respect to the piston prior to beginning to lift the hydraulic piston.

A lifting device with a head cavity in the lifting member shaped to accept a removable lifting head. The head cavity in the lifting device—e.g., the piston of a bottle jack—may be provided with threads, or may have the threads removed. A yoke fitted on the lifting head provides registration, horizontal restraint, or both against a lifted object, component, or surface to prevent sliding off the lifting head while in use. In a smooth-walled-shaft embodiment, a set of risers (spacers, adjusters, trims, or shims) serves to adjust an extension height of the shaft, elevating the lifting head with respect to the piston prior to beginning to lift the hydraulic piston.

Provided is a jack device rendering an operation of changing the posture of a jack cylinder easy without using a device that actively changes the posture. The jack device includes an arm, a jack body including the jack cylinder, and a reaction-force application unit supported by the arm. The reaction-force application unit makes a reaction-force moment act on the jack body in all postures from the upright posture to the storage posture in response to a force applied from the jack body. The reaction-force application unit makes a reaction-force moment greater than a self-weight moment act on the jack body in the storage posture and makes a reaction-force moment smaller than the self-weight moment act on the jack body in the upright posture.

Provided is a jack device rendering an operation of changing the posture of a jack cylinder easy without using a device that actively changes the posture. The jack device includes an arm, a jack body including the jack cylinder, and a reaction-force application unit supported by the arm. The reaction-force application unit makes a reaction-force moment act on the jack body in all postures from the upright posture to the storage posture in response to a force applied from the jack body. The reaction-force application unit makes a reaction-force moment greater than a self-weight moment act on the jack body in the storage posture and makes a reaction-force moment smaller than the self-weight moment act on the jack body in the upright posture.

A jack with a double high-pressure structure is provided, including a base, a pump body installed on the base, an oil cylinder, an oil drain valve, and a safety valve. The base is provided with a low-pressure check valve and a high-pressure check valve A. It is characterized in that a high-pressure check valve B is also installed on the base. The present invention can improve the safety performance during use and prolong the service life.

A jack with a double high-pressure structure is provided, including a base, a pump body installed on the base, an oil cylinder, an oil drain valve, and a safety valve. The base is provided with a low-pressure check valve and a high-pressure check valve A. It is characterized in that a high-pressure check valve B is also installed on the base. The present invention can improve the safety performance during use and prolong the service life.