초록 ▼

A lift axle suspension system for use on a vehicle having a chassis. The lift axle suspension system includes an axle assembly that is operably coupled to the vehicle chassis with a support arm assembly. A support biasing member is located between the axle assembly and the vehicle chassis for transf

A lift axle suspension system for use on a vehicle having a chassis. The lift axle suspension system includes an axle assembly that is operably coupled to the vehicle chassis with a support arm assembly. A support biasing member is located between the axle assembly and the vehicle chassis for transferring loads between the axle assembly and the vehicle chassis. A lift spring member is also provided. The lift spring member is an air spring member and has one end that is pivotally mounted. Extension of the lift spring member lifts the axle assembly from a use position where the wheels attached to the axle assembly are engageable with a road surface to a storage position where the wheels attached to the axle assembly are not engaged with the road surface.

대표청구항 ▼

What is claimed is: 1. A suspension system comprising: a vehicle chassis; an axle assembly; a support arm assembly operably coupling said axle assembly to said vehicle chassis wherein said axle assembly is vertically moveable relative to said vehicle chassis; a support biasing member operably dispo

What is claimed is: 1. A suspension system comprising: a vehicle chassis; an axle assembly; a support arm assembly operably coupling said axle assembly to said vehicle chassis wherein said axle assembly is vertically moveable relative to said vehicle chassis; a support biasing member operably disposed between said axle assembly and said vehicle chassis; a lift spring member wherein: (a) said lift spring member is an air spring that defines a central axis and has opposing first and second ends; (b) each of said first and second lift spring ends are operably coupled to said suspension system wherein extension of said lift spring member vertically displaces said axle assembly relative to said vehicle chassis; and (c) said first lift spring end is pivotally mounted about a pivot axis and wherein said central axis intersects said pivot axis; a first pivot stop and a second pivot stop; wherein said first lift spring end is adapted to abut said pivot stops upon rotation thereof about said pivot axis; wherein said first lift spring end is freely pivotable about said pivot axis except that, upon rotation thereof, said first lift spring end abuts said first or second pivot stop, whereby said first and second pivot stops operably limit rotation of said first lift spring end about said pivot axis to a predefined angular range between said pivot stops; a longitudinally extending structural member mounted on said vehicle chassis and having a bushing mounted on a distal end thereof; a pivot pin extending through said bushing and pivotally mounting said first lift spring end on said bushing and thereby defining said pivot axis; and wherein said first and second pivot stops are defined by plate members fixed to said structural member proximate said distal end thereof and lying in a plane oriented substantially perpendicular to said pivot axis. 2. The suspension system of claim 1 wherein said central axis intersects said pivot axis at an angle of approximately 90 degrees. 3. The suspension system of claim 1 wherein said pivot axis is fixed relative to said vehicle chassis. 4. The suspension system of claim 1 wherein said second lift spring end is non-pivotally fixed relative to a portion of said support arm assembly. 5. The suspension system of claim 1 wherein said vehicle chassis comprises first and second downwardly extending hangers and a cross member extending between said hangers; wherein said suspension system further comprises a second support arm assembly vertically coupling said axle assembly to said vehicle chassis, said support arm assembly being coupled to said first hanger and said second support arm assembly being coupled to said second hanger; and wherein said longitudinally extending structural member is mounted on said cross member. 6. The suspension system of claim 5 further comprising a second lift spring member, said second lift spring member being an air spring defining a second central axis, said second lift spring member having opposing third and fourth lift spring ends, each of said third and fourth lift spring ends being operably coupled to said suspension system wherein extension of said second lift spring vertically displaces said axle assembly relative to said vehicle chassis and wherein said third lift spring end is pivotally mounted to said cross member and is pivotal about a second pivot axis, said second pivot axis and said second central axis intersecting at an angle of approximately 90 degrees. 7. The suspension system of claim 1 further comprising a pivot mount secured to said first lift spring end, said pivot mount having a generally U-shaped configuration with a pair of side walls and a central web extending therebetween, said pivot axis extending between said sidewalls and intersecting said sidewalls at a substantially perpendicular axis, said first and second pivot stops being engageable with said central web on opposite sides of said pivot axis to thereby limit rotation of said first lift spring end. 8. A lift axle suspension assembly for a vehicle having a chassis, said lift axle suspension assembly comprising: an axle assembly; a pair of support arms operably coupling said axle assembly to the vehicle chassis wherein said axle assembly is moveable relative to the vehicle chassis between a storage position and a use position; a support biasing member operably disposed between said axle assembly and the vehicle chassis; a lift spring member wherein: (a) said lift spring member is an air spring that defines a central axis and has opposing first and second ends; (b) said lift spring member is operably disposed between said axle assembly and the vehicle chassis wherein extension of the lift spring member moves the axle assembly from the use position to the storage position; and (c) said first lift spring end is pivotal about a pivot axis and wherein said central axis intersects said pivot axis; a first pivot stop and a second pivot stop; wherein said first lift spring end is adapted to abut said pivot stops upon rotation thereof about said pivot axis; and, wherein said first lift spring end is freely pivotable about said pivot axis except that, upon rotation thereof, said first lift spring end abuts said first or second pivot stop, whereby said first and second pivot stops operably limit rotation of said first lift spring end about said pivot axis to a predefined angular range between said pivot stops; wherein said pair of support arms includes an upper support arm having opposite ends respectively pivotally connected to said vehicle chassis and said axle assembly and a lower support arm having opposite ends respectively pivotally connected to said vehicle chassis and said axle assembly, whereby said pair of support arms defines a parallelogram linkage; and wherein said pivot axis is fixed relative to said vehicle chassis and said second lift spring end is non-pivotally fixed to said upper support arm by a rigid member extending laterally from said upper support arm. 9. The lift axle suspension assembly of claim 8 wherein said central axis intersects said pivot axis at an angle of approximately 90 degrees. 10. The suspension system of claim 8 further comprising first and second downwardly extending hangers secured to the vehicle chassis and a cross member extending between said hangers; wherein said suspension system further comprises a second pair of support arms operably coupling said axle assembly to the vehicle chassis, said pair of support arms being coupled to said first hanger and said second pair of support arms being coupled to the vehicle chassis through said second hanger; and wherein said first lift spring end is pivotally mounted on said cross member. 11. A suspension system comprising: a vehicle chassis including first and second longitudinal members, first and second hangers extending downwardly respectively from said first and second longitudinal members and a cross member extending between said first and second hangers; an axle assembly; a support arm assembly operably coupling said axle assembly to said vehicle chassis wherein said axle assembly is vertically moveable relative to said vehicle chassis; a support biasing member operably disposed between said axle assembly and said vehicle chassis; at least one lift spring member, said lift spring member being an air spring, said lift spring member having opposing first and second lift spring ends, said first lift spring end being pivotally mounted to said cross member, said second lift spring end being coupled to said support arm assembly wherein extension of said lift spring member vertically displaces said axle assembly; a first pivot stop and a second pivot stop, said first pivot stop being fixed relative to said vehicle chassis and limiting pivotal movement of said lift spring member in a first rotational direction, said second pivot stop being fixed relative to said vehicle chassis and limiting pivotal movement of said lift spring member in an opposite second rotational direction; a pivot mount secured to said first lift spring end, said pivot mount having a generally U-shaped configuration with a pair of side walls and a central web extending therebetween, said pivot axis extending between said sidewalls and intersecting said sidewalls at a substantially perpendicular axis, said first and second pivot stops being engageable with said central web on opposite sides of said pivot axis to thereby limit rotation of said first lift spring end: a structural member extending longitudinally from said cross member and having a bushing mounted on a distal end thereof: a pivot pin extending through said bushing and said side walls pivotally joining said lift spring member and said structural member and defining a pivot axis, said pivot axis intersecting a central axis defined by said lift spring member at an angle of approximately 90 degrees; and wherein said first and second pivot stops are defined by plate members fixed to said structural member proximate said distal end thereof and lying in a plane oriented substantially perpendicular to said pivot axis. 12. The suspension system of claim 11 wherein said second lift spring end is non-pivotally fixed relative to a portion of said support arm assembly. 13. The suspension system of claim 11 wherein said support arm assembly includes an upper support arm having opposite ends respectively pivotally connected to a first one of said hangers and said axle assembly; said support arm assembly further including a lower support arm having opposite ends respectively pivotally connected to said first hanger and said axle assembly, whereby said upper and lower support arms define a parallelogram linkage; said second lift spring end being non-pivotally fixed relative to said upper support arm. 14. The suspension system of claim 13 wherein said second lift spring end is non-pivotally fixed to said upper support arm by a rigid member extending laterally from said upper support arm. 15. A lift axle suspension assembly for a vehicle having a chassis, said lift axle suspension assembly comprising: an axle assembly; a support arm assembly operably coupling said axle assembly to the vehicle chassis wherein said axle assembly is vertically moveable relative to the vehicle chassis between an uppermost position and a lowermost position, said support arm assembly including an upper support arm having opposite ends respectively pivotally connected to said vehicle chassis and said axle assembly and a lower support arm having opposite ends respectively pivotally connected to said vehicle chassis and said axle assembly, whereby said pair of support arms define a parallelogram linkage; a support biasing member operably disposed between said axle assembly and the vehicle chassis; a lift spring member wherein: (a) said lift spring member is an air spring having opposing first and second ends and defining a central axis; (b) said first end of said lift spring member is pivotally mounted about a pivot axis; (c) said lift spring member is operably disposed between the vehicle chassis and one of said upper or lower support arms wherein extension of said lift spring member vertically displaces said axle assembly, said central axis having a first angular position relative to said pivot axis when said axle assembly is in said lowermost position and a second angular position relative to said pivot axis when said axle assembly is in said uppermost position, said first and second angular positions defining a first predefined angular range therebetween; and first and second pivot stops disposed proximate said first end of said lift spring member wherein said first pivot stop limits rotation of said lift spring member in a first rotational direction about said pivot axis and said second pivot stop limits rotation of said lift spring member in a second opposite rotational direction about said pivot axis whereby rotation of said lift spring member about said pivot axis is limited to a second predefined angular range between said first and second pivot stops, said second predefined angular range being larger than said first predefined angular range. 16. The lift axle suspension of claim 15 wherein said pivot axis is fixed relative to the vehicle chassis. 17. The lift axle suspension of claim 16 wherein said second end of said lift spring member is non-pivotally fixed relative to a portion of said support arm assembly. 18. The lift axle suspension of claim 15 further comprising a pivot mount secured to said first end of said lift spring member, said pivot mount having a generally U-shaped configuration with a pair of side walls and a central web extending therebetween, said pivot axis extending between said sidewalls and intersecting said sidewalls at a substantially perpendicular axis, said first and second pivot stops being engageable with said central web on opposite sides of said pivot axis to thereby limit rotation of said first end of said lift spring member. 19. The lift axle suspension of claim 18 further comprising: a structural member extending in a direction substantially perpendicular to said pivot axis and having a bushing mounted on a distal end thereof, said bushing being positioned concentric with said pivot axis; and a pivot pin extending through said bushing and said side walls pivotally joining said lift spring member and said structural member and defining said pivot axis. 20. The suspension system of claim 19 wherein said first and second pivot stops are defined by plate members fixed to said structural member proximate said distal end thereof and lying in a plane oriented substantially perpendicular to said pivot axis.