ACTIVE SUSPENSION SYSTEM AND HYDRAULIC RAM THEREFOR
First Claim
1. An active suspension system for a vehicle including at least one fluid operated ram having a cylinder and a main piston mounted therein for reciprocating movement, control means for controlling an equilibrium position of the piston in the ram in response to lateral acceleration of the vehicle in order to counter the effects of body roll of the vehicle, the ram including shock absorbing means including upper and lower internal sealing members mounted within the main piston for permitting rapid movement of the piston from said equilibrium position when operating fluid in the ram is subjected to transient increases in pressure, wherein the main piston includes a main body, and upper and lower parts fitted to the main body, the upper internal sealing member fitted to rest in a sealing configuration against an inner surface of the upper part and being arranged such that an upper surface thereof is in direct communication with an upper working chamber above the main piston and a lower surface thereof is in direct communication with a lower working chamber below the main piston, the lower internal sealing member fitted to rest in a sealing configuration against an inner surface of the lower part and being arranged such that an upper surface thereof is in direct communication with the upper working chamber and a lower surface thereof is in direct communication with the lower working chamber, whereby a transient increase in pressure in the upper working chamber causes the upper internal sealing member to move away from said sealing configuration against the upper part to allow fluid to flow from the upper working chamber to the lower working chamber, and a transient increase in pressure in the lower working chamber causes the lower internal sealing member to move away from said sealing configuration against the lower part to allow fluid to flow from the lower working chamber to the upper working chamber.
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Accused Products
Abstract
An active suspension system for a vehicle including at least one fluid operated ram having a cylinder and a main piston mounted therein for reciprocating movement, control means for controlling an equilibrium position of the piston in the ram in response to lateral acceleration of the vehicle in order to counter the effects of body roll of the vehicle, and wherein the ram includes shock absorbing means for permitting rapid movement of the piston from the equilibrium position when operating fluid in the ram is subjected to transient increases in pressure.
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Citations
30 Claims
- 1. An active suspension system for a vehicle including at least one fluid operated ram having a cylinder and a main piston mounted therein for reciprocating movement, control means for controlling an equilibrium position of the piston in the ram in response to lateral acceleration of the vehicle in order to counter the effects of body roll of the vehicle, the ram including shock absorbing means including upper and lower internal sealing members mounted within the main piston for permitting rapid movement of the piston from said equilibrium position when operating fluid in the ram is subjected to transient increases in pressure, wherein the main piston includes a main body, and upper and lower parts fitted to the main body, the upper internal sealing member fitted to rest in a sealing configuration against an inner surface of the upper part and being arranged such that an upper surface thereof is in direct communication with an upper working chamber above the main piston and a lower surface thereof is in direct communication with a lower working chamber below the main piston, the lower internal sealing member fitted to rest in a sealing configuration against an inner surface of the lower part and being arranged such that an upper surface thereof is in direct communication with the upper working chamber and a lower surface thereof is in direct communication with the lower working chamber, whereby a transient increase in pressure in the upper working chamber causes the upper internal sealing member to move away from said sealing configuration against the upper part to allow fluid to flow from the upper working chamber to the lower working chamber, and a transient increase in pressure in the lower working chamber causes the lower internal sealing member to move away from said sealing configuration against the lower part to allow fluid to flow from the lower working chamber to the upper working chamber.
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6. (canceled)
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22-26. -26. (canceled)
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27. An hydraulic ram which can be used as an adjustable shock absorber, said ram having a cylinder, a main piston mounted on a piston rod and defining upper and lower working chambers in the cylinder;
- the ram including shock absorbing means including upper and lower internal sealing members mounted within the main piston for permitting rapid movement of the piston from said equilibrium position when operating fluid in the ram is subjected to transient increases in pressure, wherein the main piston includes a main body, and upper and lower parts fitted to the main body, the upper internal sealing member fitted to rest in a sealing configuration against an inner surface of the upper part and being arranged such that an upper surface thereof is in direct communication with the upper working chamber above the main piston and a lower surface thereof is in direct communication with the lower working chamber below the main piston, the lower internal sealing member fitted to rest in a sealing configuration against an inner surface of the lower part and being arranged such that an upper surface thereof is in direct communication with the upper working chamber and a lower surface thereof is in direct communication with the lower working chamber, and wherein a control fluid duct is provided in said piston rod in communication with passages in the main piston to provide fluid communication between said fluid control duct and upper and lower pressure relief pistons mounted within an internal cylinder of the main body to exert sealing force against the upper and lower sealing members, wherein the arrangement is such that hydraulic fluid supply means can be used to supply operating fluid at a high pressure and a low pressure to said upper and lower working chambers whereby the pressure difference across the main piston enables the ram to support a load and wherein the high pressure is, in use, applied to said control fluid duct so that the upper and lower sealing members are in a sealed configuration but, if a transient increase of fluid pressure is caused in the upper working chamber the upper internal sealing member is transiently displaced from said sealing configuration against the upper part to allow fluid to flow from the upper working chamber to the lower working chamber, and if a transient increase of fluid pressure is caused in the lower working chamber the lower internal sealing member is transiently displaced from said sealing configuration against the lower part to allow fluid to flow from the lower working chamber to the upper working chamber.
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28. (canceled)
Specification