Hydraulic leveler with exhaust only height control valve

Claim 2

A combination hydraulic shock absorber and leveler unit comprising: a pressure cylinder, piston means located within said cylinder for opposite reciprocation therein, a hollow piston rod connected to said piston having one end thereof extending outwardly of said oil-filled pressure cylinder, means for sealing the outwardly extending end of said piston rod to prevent leakage of fluid from said pressure cylinder, a cap member connected to the outwardly extending end of said piston rod movable therewith, means carried by said movable cap member including an inner and an outer cylinder joined to form a sealed space therebetween, bladder means located within said space for separating said space into a radially inwardly located charged gas chamber and a radially outwardly located rod displacement chamber, first passage means for receiving fluid pumped from an external hydraulic source and for directing pumped fluid into said radially outwardly located rod displacement chamber to vary the pressure in said gas chamber, second passage means in said end cap member for directing pressurized fluid from said first passage means into said hollow piston rod thence to said pressure cylinder to produce an increase force on said piston rod to cause it to move exteriorly of said pressure cylinder, means including the interior of said hollow rod and said first and second passage means serving to communicate said rod displacement chamber with said pressure cylinder to accommodate for changes of rod displacement within said pressure cylinder due to rod movements of said piston rod into and out of said pressure cylinder, valve means in said piston means for producing damping of piston rod movement into and out of said pressure cylinder, means forming a low pressure chamber having an outlet adapted to be connected to an external hydraulic sump, and means responsive to a predetermined movement of said piston rod with respect to said pressure cylinder for communicating said second passage means with said outlet for directly bypassing fluid pumped to said first passage means back to a hydraulic sump to control the outward extension of said piston rod with respect to said pressure cylinder for maintaining a predetermined height relationship in a vehicle leveling system.

Claim 3

A combination shock absorber and leveler unit comprising: a pressure cylinder having an end closure on one end thereof, rod guide means in the opposite end of said pressure cylinder, a piston member supported within said pressure cylinder for opposite reciprocation therein dividing said pressure cylinder into an upper and lower compartment, a first pair of valves in said piston communicating said upper and lower compartments for regulating fluid flow therethrough to damp relative reciprocating movement of said piston with respect to said pressure cylinder, a hollow piston rod having one end thereof connected to said piston and the opposite end thereof extending through said rod guide means in supported relationship therewith to a point exteriorly of said pressure cylinder, a second pair of valves in said piston to accommodate rod volume changes in said pressure cylinder, one of said second pair of valves returning flow from said hollow rod to said lower compartment on rebound movement of said rod, the other of said second pair of valves communicating said upper and lower compartments on compression movement of said rod, seal means in engagement with the outer periphery of said piston rod for sealing the outer periphery of it to prevent the escape of fluid from said pressure cylinder, a cap member connectd to the exteriorly located end of said piston rod member, a dust shield having one end thereof connected in sealed relationship with said cap member depending therefrom in spaced telescoping relationship with said pressure cylinder, an inner cylinder having one end connected to said cap member located between said dust shield and said pressure cylinder, said inner cylinder having opposite ends joined to said dust shield to define a compartment movable with said cap member, a diaphragm located within said compartment separating it into a radially inwardly located gaS chamber and an oil-filled, radially outwardly located rod displacement chamber, passage means for directing oil into said pressure cylinder and said rod displacement chamber to compress gas in said gas chamber and to produce a resultant force on said piston rod to cause it to move exteriorly of said pressure chamber, said passage means serving to direct oil from said second pair of valves and said pressure cylinder into and out of said rod displacement chamber in response to ordinary road movement of said piston rod into and out of said pressure cylinder, means forming an exhaust space on the exterior of said pressure cylinder, exhaust valve means responsive to a predetermined extension of said piston rod outwardly of said pressure cylinder to communicate said pressure cylinder with said exhaust space, and outlet means from said exhaust space for directing oil therefrom to an external sump during an exhaust phase of operation.

Claim 4

A combination shock absorber and leveler unit comprising: a pressure cylinder having an end closure on one end thereof, rod guide means in the opposite end of said pressure cylinder, a piston member supported within said pressure cylinder for opposite reciprocation therein dividing said pressure cylinder into an upper and lower compartment, a first pair of valves in said piston communicating said upper and lower compartments for regulating fluid flow therethrough to damp relative reciprocating movement of said piston with respect to said pressure cylinder, a hollow piston rod having one end thereof connected to said piston and the opposite end thereof extending through said rod guide means in supported relationship therewith to a point exteriorly of said pressure cylinder, a second pair of valves in said piston to accommodate rod volume changes in said pressure cylinder, one of said second pair of valves returning flow from said hollow rod to said lower compartment on rebound movement of said rod, the other of said second pair of valves communicating said upper and lower compartments on compression movement of said rod, seal means in engagement with the outer periphery of said piston rod for sealing the outer periphery of it to prevent the escape of fluid from said pressure cylinder, a cap member connectd to the exteriorly located end of said piston rod member, a dust shield having one end thereof connected in sealed relationship with said cap member depending therefrom in spaced telescoping relationship with said pressure cylinder, an inner cylinder having one end connected to said cap member located between said dust shield and said pressure cylinder, said inner cylinder having opposite ends joined to said dust shield to define a compartment movable with said cap member, a diaphragm located within said compartment separating it into a radially inwardly located gaS chamber and an oil-filled, radially outwardly located rod displacement chamber, passage means for directing oil into said pressure cylinder and said rod displacement chamber to compress gas in said gas chamber and to produce a resultant force on said piston rod to cause it to move exteriorly of said pressure chamber, said passage means serving to direct oil from said second pair of valves and said pressure cylinder into and out of said rod displacement chamber in response to ordinary road movement of said piston rod into and out of said pressure cylinder, means forming an exhaust space on the exterior of said pressure cylinder, exhaust valve means responsive to a predetermined extension of said piston rod outwardly of said pressure cylinder to communicate said pressure cylinder with said exhaust space, and outlet means from said exhaust space for directing oil therefrom to an external sump during an exhaust phase of operation.

Claim 5

A combination shock absorber and vehicle leveler unit comprising: a pressure cylinder having a bottom end closure, a rod guide member in the opposite end of said pressure cylinder means including a seal cavity member on said rod guide member, valved piston means supported within said pressure cylinder for opposite reciprocation therein, means on said valved piston means for separating said cylinder into first and second chambers, a hollow piston rod member having one end thereof connected to said valved piston means and the opposite end thereof extending outwardly through said rod guide member and said seal cavity member, seal means within said cavity member engaging said rod to seal the outer periphery thereof to close the upper end of said pressure cylinder, a low pressure tube arranged concentrically of and radially outwardly of said pressure cylinder having the opposite ends thereof sealingly connected to said seal cavity member and said end closure respectively, valve means in said valved piston means operative to produce damping of movement of said piston rod into and out of said pressure cylinder, a cap member connected to said outer end of said piston rod and movable therewith, an outer cylinder on said cap member depending therefrom in spaced telescoping relationship with said low pressure tube, an inner cylindrical member connected to said cap member having one end thereof sealed to said cap member and the opposite end thereof sealed to said outer cylinder to form a space therebetween, means including a flexible sleeve bladder to separate said space into a gas chamber and an oil-filled rod displacement chamber, first passage means in said end cap communicating with said hollow rod and adapted to be connected to an external fluid source for pumping liquid into said hollow rod, second passage means in said end cap communicated with said first passage means and with said rod displacement chamber for directing oil pumped from said first passage means into said rod displacement chamber to compress gas in said gas chamber thereby to increase the internal pressure within said hollow rod and said pressure cylinder to produce an increased outward force on said hollow piston rod, said first and second passage means serving to direct rod displaced oil into and out of said rod displacement chamber in response to road travel movements of said rod to accommodate for changes of rod displacement within said pressure cylinder, and means located interiorly of said pressure cylinder responsive to a predetermined movement of said hollow rod exteriorly of said pressure cylinder to communicate said first passage means with said oil-filled low pressure chamber, and an outlet from said low pressure chamber adapted to be connected to an external hydraulic sump.

Claim 6

A combination shock absorber and vehicle leveler unit comprising: a pressure cylinder having a bottom end closure, a rod guide member in the opposite end of said pressure cylinder means including a seal cavity member on said rod guide member, valved piston means supported within said pressure cylinder for opposite reciprocation therein, means on said valved piston means for separating said cylinder into first and second chambers, a hollow piston rod member having one end thereof connected to said valved piston means and the opposite end thereof extending outwardly through said rod guide member and said seal cavity member, seal means within said cavity member engaging said rod to seal the outer periphery thereof to close the upper end of said pressure cylinder, a low pressure tube arranged concentrically of and radially outwardly of said pressure cylinder having the opposite ends thereof sealingly connected to said seal cavity member and said end closure respectively, valve means in said valved piston means operative to produce damping of movement of said piston rod into and out of said pressure cylinder, a cap member connected to said outer end of said piston rod and movable therewith, an outer cylinder on said cap member depending therefrom in spaced telescoping relationship with said low pressure tube, an inner cylindrical member connected to said cap member having one end thereof sealed to said cap member and the opposite end thereof sealed to said outer cylinder to form a space therebetween, means including a flexible sleeve bladder to separate said space into a gas chamber and an oil-filled rod displacement chamber, first passage means in said end cap communicating with said hollow rod and adapted to be connected to an external fluid source for pumping liquid into said hollow rod, second passage means in said end cap communicated with said first passage means and with said rod displacement chamber for directing oil pumped from said first passage means into said rod displacement chamber to compress gas in said gas chamber thereby to increase the internal pressure within said hollow rod and said pressure cylinder to produce an increased outward force on said hollow piston rod, said first and second passage means serving to direct rod displaced oil into and out of said rod displacement chamber in response to road travel movements of said rod to accommodate for changes of rod displacement within said pressure cylinder, and means located interiorly of said pressure cylinder responsive to a predetermined movement of said hollow rod exteriorly of said pressure cylinder to communicate said first passage means with said oil-filled low pressure chamber, and an outlet from said low pressure chamber adapted to be connected to an external hydraulic sump.

Claim 7

A combination shock absorber and leveler unit comprising: a pressure cylinder having an end closure member on one end thereof, rod guide means in the opposite end of said pressure cylinder, a piston supported within said pressure cylinder for opposite reciprocation therein dividing said prEssure cylinder into an upper and lower compartment, valve means in said piston communicating said upper and lower compartments for regulating fluid flow therethrough for damping relatively reciprocating movement of said piston with respect to said pressure cylinder, a piston rod having one end thereof connected to said piston and the opposite end thereof extending through said rod guide means in supported relationship therewith hence exteriorly of said pressure cylinder, seal means in engagement with the outer periphery of said piston rod for sealing the outer periphery thereof to prevent the escape of fluid from said pressure cylinder, a cap member connected to the exteriorly located end of said piston rod member, a dust shield having one end thereof connected in sealed relationship with said cap member depending therefrom in spaced telescoping relationship with said pressure cylinder, an inner cylinder carried by said cap member located between said dust shield and said pressure cylinder to define a compartment movable with said cap member, a diaphragm located within said space separating it into a gas chamber and an oil-filled rod displacement chamber, passage means for directing oil from an external source into said pressure cylinder and said rod displacement chamber to compress gas in said gas chamber and to produce a resultant force on said piston rod to cause it to move exteriorly of said pressure chamber, said passage means serving to direct oil from said pressure cylinder into and out of said rod displacement chamber in response to ordinary road movement of said piston rod into and out of said pressure cylinder, means forming a low pressure chamber having an outlet adapted to be connected to an external hydraulic sump, exhaust valve means including a bleed port located intermediate the ends of said pressure cylinder, a valve sleeve slidably supported inside of said pressure cylinder and movable with respect to said bleed port for opening and closing said bleed port, a spring located within said pressure cylinder having one end thereof connected to said rod guide means and the opposite end thereof connected to said valve sleeve for normally positioning it in overlying relationship with said port during normal shock absorber operation, said piston being moved upon a predetermined movement of said piston rod outwardly of said pressure cylinder into engagement with said sleeve to move it out of overlying relationship with said bleed port causing discharge of oil pumped into said pressure cylinder into said low pressure chamber thence through said outlet port for return to a hydraulic sump.

Claim 8

A combination shock absorber and leveler unit comprising: a pressure cylinder having an end closure member on one end thereof, rod guide means in the opposite end of said pressure cylinder, a piston supported within said pressure cylinder for opposite reciprocation therein dividing said prEssure cylinder into an upper and lower compartment, valve means in said piston communicating said upper and lower compartments for regulating fluid flow therethrough for damping relatively reciprocating movement of said piston with respect to said pressure cylinder, a piston rod having one end thereof connected to said piston and the opposite end thereof extending through said rod guide means in supported relationship therewith hence exteriorly of said pressure cylinder, seal means in engagement with the outer periphery of said piston rod for sealing the outer periphery thereof to prevent the escape of fluid from said pressure cylinder, a cap member connected to the exteriorly located end of said piston rod member, a dust shield having one end thereof connected in sealed relationship with said cap member depending therefrom in spaced telescoping relationship with said pressure cylinder, an inner cylinder carried by said cap member located between said dust shield and said pressure cylinder to define a compartment movable with said cap member, a diaphragm located within said space separating it into a gas chamber and an oil-filled rod displacement chamber, passage means for directing oil from an external source into said pressure cylinder and said rod displacement chamber to compress gas in said gas chamber and to produce a resultant force on said piston rod to cause it to move exteriorly of said pressure chamber, said passage means serving to direct oil from said pressure cylinder into and out of said rod displacement chamber in response to ordinary road movement of said piston rod into and out of said pressure cylinder, means forming a low pressure chamber having an outlet adapted to be connected to an external hydraulic sump, exhaust valve means including a bleed port located intermediate the ends of said pressure cylinder, a valve sleeve slidably supported inside of said pressure cylinder and movable with respect to said bleed port for opening and closing said bleed port, a spring located within said pressure cylinder having one end thereof connected to said rod guide means and the opposite end thereof connected to said valve sleeve for normally positioning it in overlying relationship with said port during normal shock absorber operation, said piston being moved upon a predetermined movement of said piston rod outwardly of said pressure cylinder into engagement with said sleeve to move it out of overlying relationship with said bleed port causing discharge of oil pumped into said pressure cylinder into said low pressure chamber thence through said outlet port for return to a hydraulic sump.

Claim 9

A combination shock absorber and leveler unit comprising: a pressure cylinder having an end closure member on one end thereof, a rod guide means in the opposite end of said pressure cylinder, a piston supported within said pressure cylinder for opposite reciprocation therein dividing said pressure cylinder into an upper and lower compartment, valve means in said piston communicating said upper and lower compartments for regulating fluid flow therethrough and for damping relatively reciprocating movement of said piston with respect to said pressure cylinder, a hollow piston rod having one end thereof connected to said piston and the opposite end thereof extending through said rod guide means in supported relationship therewith hence exteriorly of said pressure cylinder, seal means in engagement with the outer periphery of said piston rod for sealing the outer periphery thereof to prevent the escape of fluid from said pressure cylinder, a cap member connected to the exteriorly located end of said piston rod member, a dust shield having one end thereof connected in sealed relationship with said cap member depending therefrom in spaced telescoping relationship with said pressure cylinder, an inner cylinder carried by said cap member located between said dust shield and said pressure cylinder to define a compartment movable with said cap member, a diaphragm located within said space separaTing it into a gas chamber and an oil-filled rod displacement chamber, passage means for directing oil from an external source into said pressure cylinder and said rod displacement chamber to compress gas in said gas chamber and to produce a resultant force on said piston rod to cause it to move exteriorly of said pressure chamber, said passage means serving to direct oil from said pressure cylinder into and out of said rod displacement chamber in response to ordinary road movement of said piston rod into and out of said pressure cylinder, means forming a low pressure chamber having an outlet adapted to be connected to an external hydraulic sump, exhaust valve means including a base valve having a movable valving element maintained normally closed interposed between said low pressure chamber and said pressure cylinder, an upstanding tube supported by said base valve member directed coaxially within said hollow piston rod, a sleeve telescoped over said tube, said sleeve having one end thereof connected to said piston in spaced relationship with said tube to form an enlarged clearance therebetween at said piston, and an open opposite end thereof in communication with the interior of said hollow piston, said tube including an enlarged diameter portion thereon having a bleed port therein, said enlarged portion engaging the inner diameter of said sleeve for normally closing communication between the interior of said hollow piston rod and said bleed port, said sleeve being movable upon a predetermined movement of said piston rod to locate said tube in an open communication with said interior of said piston rod through the enlarged clearance between said sleeve and said tube thereby causing liquid pumped to said piston rod to flow through the open end of said sleeve thence through said bleed port and said tube across said movable valving element into said low pressure chamber for exhaust through said outlet.

Claim 10

A combination shock absorber and leveler unit comprising: a pressure cylinder having an end closure member on one end thereof, a rod guide means in the opposite end of said pressure cylinder, a piston supported within said pressure cylinder for opposite reciprocation therein dividing said pressure cylinder into an upper and lower compartment, valve means in said piston communicating said upper and lower compartments for regulating fluid flow therethrough and for damping relatively reciprocating movement of said piston with respect to said pressure cylinder, a hollow piston rod having one end thereof connected to said piston and the opposite end thereof extending through said rod guide means in supported relationship therewith hence exteriorly of said pressure cylinder, seal means in engagement with the outer periphery of said piston rod for sealing the outer periphery thereof to prevent the escape of fluid from said pressure cylinder, a cap member connected to the exteriorly located end of said piston rod member, a dust shield having one end thereof connected in sealed relationship with said cap member depending therefrom in spaced telescoping relationship with said pressure cylinder, an inner cylinder carried by said cap member located between said dust shield and said pressure cylinder to define a compartment movable with said cap member, a diaphragm located within said space separaTing it into a gas chamber and an oil-filled rod displacement chamber, passage means for directing oil from an external source into said pressure cylinder and said rod displacement chamber to compress gas in said gas chamber and to produce a resultant force on said piston rod to cause it to move exteriorly of said pressure chamber, said passage means serving to direct oil from said pressure cylinder into and out of said rod displacement chamber in response to ordinary road movement of said piston rod into and out of said pressure cylinder, means forming a low pressure chamber having an outlet adapted to be connected to an external hydraulic sump, exhaust valve means including a base valve having a movable valving element maintained normally closed interposed between said low pressure chamber and said pressure cylinder, an upstanding tube supported by said base valve member directed coaxially within said hollow piston rod, a sleeve telescoped over said tube, said sleeve having one end thereof connected to said piston in spaced relationship with said tube to form an enlarged clearance therebetween at said piston, and an open opposite end thereof in communication with the interior of said hollow piston, said tube including an enlarged diameter portion thereon having a bleed port therein, said enlarged portion engaging the inner diameter of said sleeve for normally closing communication between the interior of said hollow piston rod and said bleed port, said sleeve being movable upon a predetermined movement of said piston rod to locate said tube in an open communication with said interior of said piston rod through the enlarged clearance between said sleeve and said tube thereby causing liquid pumped to said piston rod to flow through the open end of said sleeve thence through said bleed port and said tube across said movable valving element into said low pressure chamber for exhaust through said outlet.