Self-pumping vehicle height control assembly

Claim 2

In an automatic vehicle suspension leveling system of the type having fluid actuated lift units supplied with pressure fluid maintaining a constant suspension height between the sprung and unsprung masses as required by variance in vehicle load the improvement comprising; a pump housing including a cylinder, said housing being secured for movement with the sprung mass, a piston recipRocating within the cylinder, a piston rod secured to said piston and being movable with the unsprung mass, a pressure fluid discharge passage in fluid connection with an inner portion of said cylinder, an inlet passage connecting with an inner portion of said cylinder, a check valve assembly in said inlet passage preventing flow outwardly of said pump housing, a balanced control valve in fluid connection with said pressure fluid discharge passage, first means engaging said piston and said control valve biasing said balanced control valve closed while the fluid-actuated lift units are being supplied pressure fluid as said piston moves into said cylinder in response to road deflections, and second means biasing said balanced control valve open when said piston and said lift units are extended beyond a normal suspension height and said first means is ineffective to bias said control valve closed whereby pressure fluid reverse flows from said lift units through said pump housing until the normal suspension height is again obtained.

Claim 3

In an automotive vehicle suspension leveling system of the type having fluid-actuated lift units supplied with pressure fluid maintaining a constant suspension height between the vehicle sprung and unsprung masses in response to a vehicle load the improvement comprising; a pump housing including a cylinder, said housing being secured for movement with the sprung mass, a piston reciprocating within the cylinder, a piston rod secured to said piston and being movable with the unsprung mass, a pressure fluid discharge passage in connection with an inner portion of said cylinder, a reservoir secured to said pump housing, an inlet passage connecting said reservoir with an inner portion of said cylinder, a check valve in said inlet passage preventing flow outwardly of said pump housing into said reservoir, an exhaust passage in said pump housing connecting said discharge passage with said reservoir, a balanced control valve in fluid connection with fluid in said pressure fluid discharge passage controlling flow therethrough, first means engaging said piston and said control valve biasing said balanced control valve closed while the fluid-actuated lift units are being supplied pressure fluid as said piston reciprocates in said cylinder in response to normal road deflections, and second means biasing said balanced control valve open when said lift units and said piston are extended beyond a normal suspension height whereby pressure fluid reverse flows from said lift units through said pressure fluid discharge passage and said exhaust passage into said reservoir until the normal vehicle suspension height is again obtained.

Claim 4

In an automotive vehicle suspension leveling system of the type having fluid-actuated lift units supplied with pressure fluid maintaining a constant suspension height between the vehicle sprung and unsprung masses in response to a vehicle load the improvement comprising; a pump housing including a cylinder, said housing being secured for movement with the sprung mass, a piston reciprocating within the cylinder, a piston rod secured to said piston and being movable with the unsprung mass, a pressure fluid discharge passage in connection with an inner portion of said cylinder, a reservoir secured to said pump housing, an inlet passage connecting said reservoir with an inner portion of said cylinder, a check valve in said inlet passage preventing flow outwardly of said pump housing into said reservoir, an exhaust passage in said pump housing connecting said discharge passage with said reservoir, a balanced control valve in fluid connection with fluid in said pressure fluid discharge passage controlling flow therethrough, first means engaging said piston and said control valve biasing said balanced control valve closed while the fluid-actuated lift units are being supplied pressure fluid as said piston reciprocates in said cylinder in response to normal road deflections, and second means biasing said balanced control valve open when said lift units and said piston are extended beyond a normal suspension height whereby pressure fluid reverse flows from said lift units through said pressure fluid discharge passage and said exhaust passage into said reservoir until the normal vehicle suspension height is again obtained.

Claim 5

A self-pumping vehicle height control assembly of the type operable in response to road deflections to supply pressurized fluid to lift units operating in conjunction with primary coil suspension springs automatically maintaining the suspension height at a constant distance regardless of vehicle load comprising a pump housing including a cylinder, said housing being secured for movement with the vehicle sprung mass, a piston reciprocating within the cylinder, a piston rod secured to said piston and being movable with the vehicle unsprung mass, a pressure fluid discharge passage in said pump housing in fluid connection with an inner portion of said cylinder, a reservoir secured to said pump housing, an inlet passage connecting said reservoir with an inner portion of said cylinder, a check valve in said inlet passage preventing flow outwardly from said pump housing into said reservoir, an exhaust passage in said pump housing connecting said discharge passage with said reservoir, a balanced control valve in fluid connection with said pressure fluid discharge passage controlling flow through said exhaust passage, a first coil compression spring mounted in said piston and biasing said balanced control valve closed while the fluid actuated units are being supplied pressure fluid as said piston reciprocates in said cylinder in response to road deflections, a spring limiter member concentrically located within said first compression spring and being biased into engagement with said balanced control valve by said spring, and a second coil spring biasing said balanced control valve toward an open position and being located within a portion of said exhaust passage, said second spring being operative to open said balanced control valve when said lift units and said piston are extended beyond a normal suspension height removing the biasing force of said first spring from said control valve whereby pressure fluid reverse flows from said lift units through said pump housing into said reservoir until the normal suspension height is again obtained.

Claim 6

A self-pumping vehicle height control assembly of the type operable in response to road deflections to supply pressurized fluid to lift units operating in conjunction with primary coil suspension springs automatically maintaining the suspension height at a constant distance regardless of vehicle load comprising a pump housing including a cylinder, said housing being secured for movement with the vehicle sprung mass, a piston reciprocating within the cylinder, a piston rod secured to said piston and being movable with the vehicle unsprung mass, a pressure fluid discharge passage in said pump housing in fluid connection with an inner portion of said cylinder, a reservoir secured to said pump housing, an inlet passage connecting said reservoir with an inner portion of said cylinder, a check valve in said inlet passage preventing flow outwardly from said pump housing into said reservoir, an exhaust passage in said pump housing connecting said discharge passage with said reservoir, a balanced control valve in fluid connection with said pressure fluid discharge passage controlling flow through said exhaust passage, a first coil compression spring mounted in said piston and biasing said balanced control valve closed while the fluid actuated units are being supplied pressure fluid as said piston reciprocates in said cylinder in response to road deflections, a spring limiter member concentrically located within said first compression spring and being biased into engagement with said balanced control valve by said spring, and a second coil spring biasing said balanced control valve toward an open position and being located within a portion of said exhaust passage, said second spring being operative to open said balanced control valve when said lift units and said piston are extended beyond a normal suspension height removing the biasing force of said first spring from said control valve whereby pressure fluid reverse flows from said lift units through said pump housing into said reservoir until the normal suspension height is again obtained.

Claim 7

A self-pumping vehicle height control assembly as described in claim 3 wherein said spring limiter comprises a first sleeve having a first annular flange engaged by one end of said first compression spring, a second sleeve positioned for slidable movement over the exterior surface of said first sleeve and having a first annular flange engaged by the other end of said first coil compression spring, a second annular flange on said first sleeve positioned within said second sleeve, and a second annular flange on said second sleeve positioned exteriorly of said first sleeve and formed to engage the second flange of said first sleeve within the second sleeve thereby limiting expansive movement of the spring limiter assembly as the two sleeves are biased apart by said first coil compression spring.

Claim 8

A self-pumping vehicle height control assembly of the type operable in response to road deflections to supply pressurized fluid to suspension lift units operating in conjunction with primary coil suspension springs to automatically maintain the suspension height at a constant distance regardless of vehicle load comprising a pump housing including a cylinder, said housing being secured for movement with the vehicle sprung mass, a piston reciprocating within the cylinder, a piston rod secured to said piston and being movable with the vehicle unsprung mass, a pressure fluid discharge passage in said pump housing in fluid connection with an inner portion of said cylinder, a reservoir secured to one end of the pump housing, an inlet passage connecting said reservoir with the inner portion of said cylinder, a check valve in said inlet passage preventing flow outwardly from said pump housing into said reservoir, an exhaust passage in said pump housing connecting said discharge passage with said reservoir, said pressure discharge passage connecting with said inlet passage, a check valve assembly positioned in said pressure discharge passage biased to a closed position to prevent reverse flow from said pressure discharge passage into said inlet passage, a bushing containing a metering orifice secured in said discharge passage metering the flow of pressurized fluid to said lift units, a balanced control valve in fluid connection with said pressure discharge passage controlling flow through said exhaust passage, a first coil compression spring biasing said balanced control valve closed while the fluid actuated lift units are being supplied pressure fluid as said piston reciprocates in said cylinder in response to road deflections, a spring limiter assembly concentrically located within said compression spring in being biased into engagement with said balanced control valve, said spring limiter assembly comprising a first sleeve telescopingly received within a second sleeve, annular flanges on the outer ends of said sleeves engaged by said spring whereby said spring tends to bias the respective sleeves apart, stop flanges on the inner ends of said sleeves engaging as said compression spring expands limiting the expansive movement thereof, an annular recess in the upper surface of said piston receiving and supporting a portion of said first coil compression spring and said second sleeve member, and a second coil spring biasing said balanced control valve toward an open position and being loCated within a portion of said exhaust passage, said second spring being operative to open said balanced control valve when said lift units are extended and said piston moves to an extended position within said cylinder whereupon said spring limiter assembly prevents further expansion of said first coil compression spring and said spring limiter assembly is moved out of engagement with said control valve, the opening of said balanced control valve allowing reverse flow from said lift units through said pump housing into said reservoir until said compression spring and limiter assembly again closes said control valve when the desired suspension height is obtained, said balanced control valve acting as a relief valve when excessive pressures occur in said pressure discharge passage and said lift units.

Claim 9

A self-pumping vehicle height control assembly of the type operable in response to road deflections to supply pressurized fluid to suspension lift units operating in conjunction with primary coil suspension springs to automatically maintain the suspension height at a constant distance regardless of vehicle load comprising a pump housing including a cylinder, said housing being secured for movement with the vehicle sprung mass, a piston reciprocating within the cylinder, a piston rod secured to said piston and being movable with the vehicle unsprung mass, a pressure fluid discharge passage in said pump housing in fluid connection with an inner portion of said cylinder, a reservoir secured to one end of the pump housing, an inlet passage connecting said reservoir with the inner portion of said cylinder, a check valve in said inlet passage preventing flow outwardly from said pump housing into said reservoir, an exhaust passage in said pump housing connecting said discharge passage with said reservoir, said pressure discharge passage connecting with said inlet passage, a check valve assembly positioned in said pressure discharge passage biased to a closed position to prevent reverse flow from said pressure discharge passage into said inlet passage, a bushing containing a metering orifice secured in said discharge passage metering the flow of pressurized fluid to said lift units, a balanced control valve in fluid connection with said pressure discharge passage controlling flow through said exhaust passage, a first coil compression spring biasing said balanced control valve closed while the fluid actuated lift units are being supplied pressure fluid as said piston reciprocates in said cylinder in response to road deflections, a spring limiter assembly concentrically located within said compression spring in being biased into engagement with said balanced control valve, said spring limiter assembly comprising a first sleeve telescopingly received within a second sleeve, annular flanges on the outer ends of said sleeves engaged by said spring whereby said spring tends to bias the respective sleeves apart, stop flanges on the inner ends of said sleeves engaging as said compression spring expands limiting the expansive movement thereof, an annular recess in the upper surface of said piston receiving and supporting a portion of said first coil compression spring and said second sleeve member, and a second coil spring biasing said balanced control valve toward an open position and being loCated within a portion of said exhaust passage, said second spring being operative to open said balanced control valve when said lift units are extended and said piston moves to an extended position within said cylinder whereupon said spring limiter assembly prevents further expansion of said first coil compression spring and said spring limiter assembly is moved out of engagement with said control valve, the opening of said balanced control valve allowing reverse flow from said lift units through said pump housing into said reservoir until said compression spring and limiter assembly again closes said control valve when the desired suspension height is obtained, said balanced control valve acting as a relief valve when excessive pressures occur in said pressure discharge passage and said lift units.