Vehicle suspension apparatus

Claim 2

Vehicle suspension apparatus comprising: a plurality of springs in series for supporting the sprung mass of a vehicle on the unsprung mass thereof; and means responsive to static deflection of at least one of said springs from a predetermined minimum length resulting from increases in static load on said series of springs to restore said one spring to said predetermined minimum length and increase the spring rate of said series of springs.

Claim 3

Vehicle suspension apparatus as claimed in claim 1, wherein said one spring is mounted between a pair of relatively movable members, and said means comprises static displacement-resisting means engaged between said pair of relatively movable members.

Claim 4

Vehicle suspension apparatus as claimed in claim 2 wherein said static displacement resisting means includes an extensible and contractable pressure chamber containing a compressible pneumatic fluid, and means for introducing an incompressible hydraulic fluid into said pressure chamber to reduce the volume available to the compressible fluid when the pressure chamber contracts from a selected minimum size.

Claim 5

Vehicle suspension apparatus as claimed in claim 3 wherein said pressure chamber is defined by a cylinder member and a piston member telescopically received in said cylinder member, said piston and cylinder members expanding and contracting in accordance with expansion and contraction of said one spring.

Claim 6

Vehicle suspension apparatus as claimed in claim 4 wherein said means for introducing an incompressible hydraulic fluid into said pressure chamber includes a pressurized accumulator chamber.

Claim 7

Vehicle suspension apparatus comprising: a plurality of springs in series for supporting the sprung mass of a vehicle in the unsprung mass thereof; static displacement-resisting means for increasing the spring rate of the series of springs in response to increases in static load on the series of springs; said static displacement-resisting means being responsive to static deflection of at least one spring of the series from a predetermined minimum length to restore said one spring to said predetermined minimum length and provide increased resistance to subsequent deflection of said one spring from said minimum length until the static load on the series is reduced; said static displacement-resisting means including an extensible and contractable pressure chamber containing a compressible pneumatic fluid, and means for introducing an incompressible hydraulic fluid into said pressure chamber to reduce the volume available to the compressible fluid when the pressure chamber contracts from a selected minimum size; a cylinder member and a piston member telescopically received in said cylinder member to define said pressure chamber, said piston and cylinder members expanding and contracting in accordance with expansion and contraction of said one spring; said means for introducing an incompressible hydraulic fluid into said pressure chamber including a pressurized accumulator chamber; and a control member operable in response to contraction of said pressure chamber to provide communication between said accumulator chamber and said pressure chamber.

Claim 8

Vehicle suspension apparatus comprising: a plurality of springs in series for supporting the sprung mass of a vehicle in the unsprung mass thereof; static displacement-resisting means for increasing the spring rate of the series of springs in response to increases in static load on the series of springs; said static displacement-resisting means being responsive to static deflection of at least one spring of the series from a predetermined minimum length to restore said one spring to said predetermined minimum length and provide increased resistance to subsequent deflection of said one spring from said minimum length until the static load on the series is reduced; said static displacement-resisting means including an extensible and contractable pressure chamber containing a compressible pneumatic fluid, and means for introducing an incompressible hydraulic fluid into said pressure chamber to reduce the volume available to the compressible fluid when the pressure chamber contracts from a selected minimum size; a cylinder member and a piston member telescopically received in said cylinder member to define said pressure chamber, said piston and cylinder members expanding and contracting in accordance with expansion and contraction of said one spring; said means for introducing an incompressible hydraulic fluid into said pressure chamber including a pressurized accumulator chamber; and a control member operable in response to contraction of said pressure chamber to provide communication between said accumulator chamber and said pressure chamber.

Claim 9

Vehicle suspension apparatus as claimed in claim 6, further including a reservoir for said hydraulic fluid, said control member being operable in response to dynamic reciprocation between said piston and cylinder members to transfer hydraulic fluid from said reservoir to said accumulator chamber.

Claim 10

Vehicle suspension apparatus as claimed in claim 7 further including a check valve controlled intake tube communicating with said reservoir and slidably engaged with said control member for conducting hydraulic fluid from the reservoir in response to movement of said control member in one direction relative to said intake tube.

Claim 11

Vehicle suspension apparatus as claimed in claim 8 further including a check valve controlled delivery passage in said control member for conduCting hydraulic fluid from said intake tube in response to movement of said control member in the other direction relative to said intake tube.

Claim 12

Vehicle suspension apparatus as claimed in claim 9 further including at least one port in said accumulator chamber for connecting the accumulator chamber with said delivery passage when the pressure chamber contracts.

Claim 13

Vehicle suspension apparatus as claimed in claim 10 further including at least one port providing communication between said delivery passage and said pressure chamber such that the accumulator chamber is connected with the pressure chamber when the delivery passage communicates the port in the wall of the accumulator chamber.

Claim 14

Vehicle suspension apparatus as claimed in claim 11 wherein the port in the wall of the accumulator is substantially larger than the port providing communication between the delivery passage and said pressure chamber whereby the greater portion of fluid delivered from said delivery passage during dynamic reciprocation between said piston and cylinder members will be delivered to the accumulator chamber.

Claim 15

Vehicle suspension apparatus as claimed in claim 11 further including an exhaust passage connecting said pressure chamber with said reservoir, a normally closed valve controlling said exhaust passage engageable by said control member in response to expansion of said pressure chamber beyond a maximum amount to connect said pressure chamber with said reservoir to relieve the pressure therein.

Claim 16

Vehicle suspension apparatus adapted to be interposed between a pair of relatively movable members for maintaining the relatively movable members at a preselected minimum spacing under static conditions, said suspension apparatus comprising: a spring engageable with the relatively movable members such that forces tending to move the relatively movable members toward each other will cause the spring to deflect; and hydropneumatic displacement resisting means engageable with the relatively movable members and responsive to static displacement of the members toward each other from the preselected minimum spacing to restore the preselected minimum spacing and the spring to a length corresponding to the minimum spacing, and at the same time provide increased resistance to subsequent movement of the members toward each other.

Claim 17

Vehicle suspension apparatus adapted to be interposed between a pair of relatively movable members for maintaining the relatively movable members at a preselected minimum spacing under static conditions, said suspension apparatus comprising: a spring engageable with the relatively movable members such that forces tending to move the relatively movable members toward each other will cause the spring to deflect; and hydropneumatic displacement resisting means engageable with the relatively movable members and responsive to static displacement of the members toward each other from the preselected minimum spacing to restore the preselected minimum spacing and the spring to a length corresponding to the minimum spacing, and at the same time provide increased resistance to subsequent movement of the members toward each other.

Claim 18

Vehicle suspension apparatus as defined in claim 14 wherein said hydropneumatic displacement-resisting means includes an extensible and contractable pressure chamber containing a compressible pneumatic fluid, and means for introducing an incompressible hydraulic fluid into said pressure chamber to reduce the volume available to the compressible fluid in response to contraction of said chamber from a predetermined size to thereby increase the pressure and extend the chamber.

Claim 19

Vehicle suspension apparatus as claimed in claim 15 wherein said displacement-resisting means includes a cylinder member engageable with one of the relatively movable members, and a piston member engageable with the other of the relatively movable members and telescopically received in said cylinder member to define said pressure chamber.

Claim 20

Vehicle suspension apparatus as claimed in claim 16 wherein said means for introducing an incompressible hydraulic fluid into said pressure chamber includes a pressurized accumulator chamber.

Claim 21

Vehicle suspension apparatus as claimed in claim 17 further including a control member operable in response to contraction of said pressure chamber to provide communication between said accumulator chamber and said pressure chamber.

Claim 22

Vehicle suspension apparatus as claimed in claim 18 wherein said displacement-resisting means further includes a reservoir for the hydraulic fluid, and wherein said control member is reciprocable in response to dynamic oscillation between said piston and cylinder members to transfer hydraulic fluid from said reservoir to said accumulator chamber.

Claim 23

A vehicle suspension apparatus as claimed in claim 19 Further including a check valve controlled intake tube connected with said reservoir and slidably engaged with said control member for conducting hydraulic fluid from the reservoir in response to movement of said control member in one direction relative to said intake tube.

Claim 24

Vehicle suspension apparatus as claimed in claim 20 further including a check valve controlled delivery passage in said control member for conducting hydraulic fluid from said intake tube in response to movement of said control member in the other direction relative to said intake tube.

Claim 25

A vehicle suspension unit as claimed in claim 21 further including a port in said accumulator chamber for connecting the accumulator chamber with said delivery passage when the pressure chamber contracts.

Claim 26

A vehicle suspension unit as claimed in claim 22 further including a port providing communication between said delivery passage and said pressure chamber such that the accumulator chamber is connected with the pressure chamber when the delivery passage communicates with the port in the wall of the accumulator chamber.

Claim 27

A vehicle suspension unit as claimed in claim 23 further including a normally closed outlet port in said pressure chamber, and means on said control member operable to open said outlet port and connect the pressure chamber with the reservoir when the pressure chamber expands to a predetermined size.

Claim 28

Vehicle suspension apparatus comprising: spring means for supporting the sprung mass of a vehicle in the unsprung mass thereof; and static displacement-resisting means responsive to static deflection of said spring means caused by an increase in the static load of said spring means to restore at least a portion of said spring means to a predetermined static length and provide increased resistance to subsequent deflection of said portion from said minimum length.

Claim 29

Vehicle suspension apparatus comprising: spring means for supporting the sprung mass of a vehicle in the unsprung mass thereof; and static displacement-resisting means responsive to static deflection of said spring means caused by an increase in the static load of said spring means to restore at least a portion of said spring means to a predetermined static length and provide increased resistance to subsequent deflection of said portion from said minimum length.

Claim 30

Vehicle suspension apparatus as claimed in claim 25 wherein said static displacement-resisting means includes an extensible and contractable pressure chamber containing a compressible pneumatic fluid, and means for introducing an incompressible hydraulic fluid into said pressure chamber to reduce the volume available to the compressible fluid when the pressure chamber contracts from a minimum selected size.

Claim 31

Vehicle suspension apparatus as claimed in claim 26 wherein said pressure chamber is defined by a cylinder member and a piston member telescopically received in said cylinder member, said piston and cylinder members expanding and contracting in accordance with expansion and contraction of said portion of said spring means.

Claim 32

Vehicle suspension apparatus as claimed in claim 27 wherein said means for introducing an incompressible hydraulic fluid into said pressure chamber includes a pressurized accumulator chamber.

Claim 33

Vehicle suspension apparatus as claimed in claim 28, further including a control member operable in response to contraction of said pressure chamber to provide communication between said accumulator chamber and said pressure chamber.

Claim 34

Vehicle suspension apparatus as claimed in claim 29 further including a reservoir for said hydraulic fluid, said control member being operable in response to reciprocation between said piston and cylinder members to transfer hydraulic fluid from said reservoir to said accumulator chamber.

Claim 35

Vehicle suspension apparatus comprising: means defining a pair of spring seat members movable relative to each other; a spring mounted between said seat members such that movement of said seat members toward each other compresses said spring; and hydropneumatic displacement-resisting means engaged with said seat members and operable in response to static displacement of said spring seat members toward each other from a predetermined minimum spacing to restore said seat members to said minimum spacing and said spring to a length corresponding thereto, and provide increased resistance to subsequent displacement of said seat members toward each other.

Claim 36

Vehicle suspension apparatus comprising: means defining a pair of spring seat members movable relative to each other; a spring mounted between said seat members such that movement of said seat members toward each other compresses said spring; and hydropneumatic displacement-resisting means engaged with said seat members and operable in response to static displacement of said spring seat members toward each other from a predetermined minimum spacing to restore said seat members to said minimum spacing and said spring to a length corresponding thereto, and provide increased resistance to subsequent displacement of said seat members toward each other.

Claim 37

Vehicle suspension apparatus as claimed in claim 31 further including means defining a third spring seat member movable relative to said pair of spring seat members, and a second spring mounted between one of said pair of spring seat members and said third spring seat member.

Claim 38

Vehicle suspension apparatus as claimed in claim 32 further including means defining a fourth spring seat member movable relative to said pair of spring seat members as well as said third spring seat member, and a third spring mounted between said third and fourth spring seat members.

Claim 39

Vehicle suspension apparatus including spring means and hydropneumatic means adapted to cooperatively resiliently resist relative movement between a pair of relatively movable members, said hydropneumatic means being operable in response to static load causing deflection of the spring means beyond a predetermined amount to remove the deflection of said spring in excess of the predetermined amount and at the same time provide increased resistance to deflection until the static load is reduced.

Claim 40

Vehicle suspension apparatus including spring means and hydropneumatic means adapted to cooperatively resiliently resist relative movement between a pair of relatively movable members, said hydropneumatic means being operable in response to static load causing deflection of the spring means beyond a predetermined amount to remove the deflection of said spring in excess of the predetermined amount and at the same time provide increased resistance to deflection until the static load is reduced.

Claim 41

Vehicle suspension apparatus as claimed in claim 34 wherein said spring means comprises a coil spring and said hydropneumatic means is operable to maintain the coil spring at a preselected minimum length.

Claim 42

Vehicle suspension apparatus as claimed in claim 34 wherein said spring means comprises a plurality of springs in series.

Claim 43

Vehicle suspension apparatus comprising: a base member; a piston member; a cylindrical casing having one end secured to said piston member and its other end secured to said base member; a cylinder member telescopically receiving said piston member to define therewith an expansible and contractable pressure chamber; an inner sleeve member enclosed by said casing and having one end secured to said piston and its other end connected with said base member; a control member slidably received in said inner sleeve, said control member having a stem slidably projecting through said piston member and connected with the cylinder member; means defining a reservoir chamber in said base member; means defining an accumulator chamber in the space between said inner sleeve and said casing; and intake tube projecting from said reservoir chamber, said control member having a cylindrical opening slidably receiving said intake tube; means defining a space between the control member and said inner sleeve; a passage in said control member communicating with said space and said pressure chamber; a check valve controlling communication between said cylindrical opening and said passage; a check valve controlling communication between said reservoir and said intake tube; said check valves controlling flow such that expansion of said pressure chamber withdraws fluid from the reservoir into the intake tube and cylindrical opening, and contraction of the pressure chamber forces fluid from the cylindrical opening into said passage; at least one port in said inner sleeve for connecting said accumulator chamber with said passage when the pressure chamber contracts sufficiently to bring said port into registry with the reduced diameter portion of said control member; and normally closed exhaust valve means controlling communication between said pressure chamber and reservoir operable by said control member upon expansion of said pressure chamber to a predetermined size to connect the pressure chamber with the reservoir chamber.

Claim 44

Vehicle suspension apparatus comprising: a base member; a piston member; a cylindrical casing having one end secured to said piston member and its other end secured to said base member; a cylinder member telescopically receiving said piston member to define therewith an expansible and contractable pressure chamber; an inner sleeve member enclosed by said casing and having one end secured to said piston and its other end connected with said base member; a control member slidably received in said inner sleeve, said control member having a stem slidably projecting through said piston member and connected with the cylinder member; means defining a reservoir chamber in said base member; means defining an accumulator chamber in the space between said inner sleeve and said casing; and intake tube projecting from said reservoir chamber, said control member having a cylindrical opening slidably receiving said intake tube; means defining a space between the control member and said inner sleeve; a passage in said control member communicating with said space and said pressure chamber; a check valve controlling communication between said cylindrical opening and said passage; a check valve controlling communication between said reservoir and said intake tube; said check valves controlling flow such that expansion of said pressure chamber withdraws fluid from the reservoir into the intake tube and cylindrical opening, and contraction of the pressure chamber forces fluid from the cylindrical opening into said passage; at least one port in said inner sleeve for connecting said accumulator chamber with said passage when the pressure chamber contracts sufficiently to bring said port into registry with the reduced diameter portion of said control member; and normally closed exhaust valve means controlling communication between said pressure chamber and reservoir operable by said control member upon expansion of said pressure chamber to a predetermined size to connect the pressure chamber with the reservoir chamber.

Claim 45

Vehicle suspension apparatus as claimed in claim 37 wherein said base member includes a cylindrical skirt portion threadedly receiving said casing; and further including an annular plate member threadedly mounted in said skirt portion with a depending cylindrical extension coaxial with said inner sleeve, said intake tube extending into said cylindrical extension.

Claim 46

Vehicle suspension apparatus as claimed in claim 37 wherein said base member as a dished portion and said other end of said inner sleeve is mounted on said dished portion, and wherein a check valve fitting is mounted in saId dished portion and said intake tube projects from said check valve fitting.