Device for adjusting the height of a vehicle

Abstract

The present invention is a system for adjusting the height of vehicles. The vehicle is supported by a hollow cylinder and a piston having an undersized piston skirt is mounted on the suspension system's coil spring, and sealingly slidable within the cylinder bore. When a fluid is introduced into the expandable pressure space between the piston and the cylinder top, the piston and cylinder are forced apart, raising the vehicle. The undersized piston skirt can extend beyond the end of the cylinder, allowing the piston a greater travel length within the cylinder bore. The invention may be operated manually by a vehicle driver through push buttons, which can be the vehicle's existing cruise control buttons. Alternatively, the system can be automated using a control unit to automatically adjust ground clearance to avoid collision with obstacles in the vehicle's path. In another embodiment, the lift system, or any lift system, is prevented from activating, and deactivates (if previously activated) if the vehicle is travelling at excessive speed.

I claim: 
     
         1 . A device for a vehicle with an underbody having a ground clearance, said vehicle having a lift s stem that can controllably lift and lower the underbody to achieve a desired ground clearance, a ground clearance sensor that senses the ground clearance in the vehicle's path, and a vehicle speed sensor that senses excessive speed of the vehicle, comprising:
 a control unit adapted to be operably connected to the lift system, the ground clearance sensor and the vehicle speed sensor,   wherein the control unit controls the lift system to automatically lift the underbody when the ground clearance sensor senses the ground clearance in the vehicle's path to be less than the desired ground clearance; and   wherein the control unit controls the lift system to automatically lower the underbody when the ground clearance sensor senses the ground clearance in the vehicle's path is greater than the desired ground clearance;   wherein the control unit prevents activation of the lift system and lifting of the underbody if the speed sensor senses excessive speed while the underbody is in a lowered position; and   wherein the control unit deactivates lifting of the underbody by the lift system and lowers the underbody if the speed sensor senses excessive speed while the underbody in a raised position.   
     
     
         2 . A device according to  claim 1 , wherein the control unit is operably connectable to switches, whereby said lift system can also be activated manually to lift the underbody and deactivated manually to lower the underbody. 
     
     
         3 . A device according to  claim 2 , wherein if the switches are used to activate the lift system and lift the underbody the control unit does not deactivate the lift system to automatically lower the underbody until the switches are used to deactivate the lift system. 
     
     
         4 . A device according to  claim 2  wherein the switches can toggle between a manual only mode and a full automatic mode. 
     
     
         5 . A device according to  claim 4 , wherein the switches can prevent activation of the lift system to raise the underbody. 
     
     
         6 . A device according to  claim 4 , wherein the switches can prevent deactivation of the lift system to lower the underbody. 
     
     
         7 . A device according to  claim 1 , wherein the control unit checks, a set time after the control unit controls the lift system to automatically lift the underbody, whether the ground clearance sensor senses the ground clearance in the vehicle's path is greater than the desired ground clearance and, if so, the lift system automatically lowers the underbody. 
     
     
         8 . A device according to  claim 1 , wherein the control unit operably connectable to switches that allow the desired ground clearance to be selected. 
     
     
         9 . A device according to  claim 1 , wherein the control unit is operably connectable to switches that allow the excessive speed to be selected. 
     
     
         10 . A device according to  claim 2 , wherein the switches are original equipment manufacturer cruise control buttons, whereby the lift system can be activated manually without the driver needing to take eyes off the road. 
     
     
         11 . A device according to  claim 2 , wherein the switches can prevent activation of the lift system to raise the underbody. 
     
     
         12 . A device according to  claim 2 , wherein the switches can prevent deactivation of the lift system to lower the underbody. 
     
     
         13 . A process for automatically adjusting ground clearance of a vehicle with underbody, said vehicle having a lift system that can controllably lift and lower the underbody to achieve a desired ground clearance, a ground clearance sensor, and a speed sensor, comprising:
 operably connecting a control unit to said lift system, said ground clearance sensor and said speed sensor;   wherein, in response to the ground clearance sensor sensing a ground clearance in the vehicle's path to be less than the desired ground clearance, the control unit causes the lift system to automatically lift the underbody; and   wherein, in response to the ground clearance sensor sensing a ground clearance in the vehicle's path to be more than the desired ground clearance, the control unit causes the lift system to automatically lower the underbody;   wherein, in response to the vehicle speed sensor sensing excessive speed of the vehicle while the underbody is in a lowered position, the control unit prevents activation of the lift system and lifting of the underbody; and   wherein, in response to the vehicle speed sensor sensing excessive speed of the vehicle while the underbody is in a raised position, the control unit causes the lift system to automatically deactivate lifting of the underbody by the lift system and lowers the underbody.   
     
     
         14 . A process according to  claim 13 , wherein said operably connecting step is performed with a control unit that deactivates lifting of the underbody by the lift system after a set time, if the ground clearance sensor senses the ground clearance in the vehicle's path is greater than the desired ground clearance. 
     
     
         15 . A process according to  claim 13 , further comprising:
 controllably connecting the control unit to cruise controls for the vehicle, whereby the lift system can be activated manually without the driver needing to take eyes off the road.