Air-suspension system for motor vehicles

Claim 2

An air-suspension system for motor vehicles, including a lowpressure tank, a high-pressure tank, means providing communication between the tanks, a comPressor by which compressed air is supplied from the low-pressure tank to the high-pressure tank, and a pneumatic means for communication with the low- and high-pressure tanks, the high-pressure tank supplying the compressed air to the pneumatic means as required, which then utilizes the elasticity of the compressed air confined therein as the energy medium and thereafter feed the air back to the lowpressure tank, and a pressure-sensitive means operably related to the low- and high-pressure tanks and the compressor, the pressure-sensitive means being operable in response to a difference between the pressure of the high-pressure tank and the low-pressure tank when the pressure difference becomes lower than a predetermined level to operate the compressor to pump compressed air from the low-pressure tank to the high-pressure tank and upon the pressure difference between the high-pressure tank and the low-pressure tank being restored to the predetermined level stops the operation of the compressor.

Claim 3

The air-suspension system as claimed in claim 1 in which said means for air replenishment comprises first changeover valve means installed between said low-pressure tank and said inlet valve of said compressor, second changeover valve means installed between said discharge valve of said compressor and said high-pressure tank, electromagnet means energized upon operation of said second pressure-sensitive means so as to cause said first and said second changeover valve means to simultaneously modify their respective passageways, a relay to which electric current is made to flow upon operation of said second pressure-sensitive means, and a switch disposed between a power supply and a motor adapted to drive said compressor, said switch being closed by said relay upon flow of current thereto.

Claim 4

The air-suspension system as claimed in claim 2 in which said means for air replenishment further comprises an alarm lamp which lights up upon operation of said second pressure-sensitive means thereby to indicate the start of an air replenishing operation.

Claim 5

An air-suspension system for motor vehicles, including a low-pressure tank, a high-pressure tank, means providing communication between the tanks, a compressor by which compressed air is supplied from the low-pressure tank to the high-pressure tank, a pneumatic means for communication with the tanks, the high-pressure tank supplying the compressed air to the pneumatic means as required, which then utilizes the elasticity of the compressed air confined therein as the energy medium and thereafter feeds the air back to the low-pressure tank, a first pressure-sensitive means operably related to the tanks and the compressor, the first pressure-sensitive means being responsive to change in the difference between the pressure of the high-pressure tank and the low-pressure tank in such a manner that the operation of the compressor is stopped thereby when the difference reaches a prescribed level, second pressure-sensitive means responsive to change in the pressure of said low-pressure tank in such a manner that the operation of said compressor which has been stopped by said first pressure-sensitive means is restarted thereby upon reduction in the pressure of said low-pressure tank to a prescribed level, and means for air replenishment becoming operative simultaneously with the operation of said second pressure-sensitive means so as to change the communication of an inlet valve of said compressor over to an atmospheric air intake from said low-pressure tank and the communication of a discharge valve thereof over to said low-pressure tank from said high-pressure tank.

Claim 6

An air-suspension system for motor vehicles, including a low-pressure tank, a high-pressure tank, means providing communication between the tanks, a compressor by which compressed air is supplied from the low-pressure tank to the high-pressure tank, a pneumatic means for communication with the tanks, the high-pressure tank supplying the compressed air to the pneumatic means as required, which then utilizes the elasticity of the compressed air confined therein as the energy medium and thereafter feeds the air back to the low-pressure tank, a first pressure-sensitive means operably related to the tanks and the compressor, the first pressure-sensitive means being responsive to change in the difference between the pressure of the high-pressure tank and the low-pressure tank in such a manner that the operation of the compressor is stopped thereby when the difference reaches a prescribed level, second pressure-sensitive means responsive to change in the pressure of said low-pressure tank in such a manner that the operation of said compressor which has been stopped by said first pressure-sensitive means is restarted thereby upon reduction in the pressure of said low-pressure tank to a prescribed level, and means for air replenishment becoming operative simultaneously with the operation of said second pressure-sensitive means so as to change the communication of an inlet valve of said compressor over to an atmospheric air intake from said low-pressure tank and the communication of a discharge valve thereof over to said low-pressure tank from said high-pressure tank.