Hydraulic suspension unit

A hydraulic suspension unit comprising:

• first and second members arranged in telescoping relation with one another for relative movement along a longitudinal axis of said suspension unit with changes in force on said suspension unit compressing and extending said suspension unit within an extension limit of the suspension unit;
• means containing a hydraulic liquid, said containing means including a first chamber containing hydraulic liquid in compressive force transmitting relation between said first and second members without resisting extension of said suspension unit to said extension limit by external forces on said suspension unit, the volume of said first chamber being decreased and increased with relative movement of said first and second members toward and away from one another along said longitudinal axis, respectively and said containing means further including a reservoir containing hydraulic liquid and passage means connecting said first chamber and said reservoir to permit the flow of hydraulic liquid between said first chamber and said reservoir, said reservoir including a movable wall which can be moved back and forth to increase and decrease the volume of said reservoir as a function of the volume of the hydraulic liquid flowing to and from said reservoir, respectively;
• spring means for resiliently biasing said movable wall against the hydraulic liquid in said reservoir with a force which is a function of the amount of movement of said spring means and in turn the position of said movable wall and volume of said reservoir, said spring means storing energy upon movement of said movable wall increasing the volume of said reservoir with the flow of hydraulic liquid to said reservoir, and said spring means releasing said stored energy upon movement of said movable wall decreasing the volume of said reservoir with the flow of hydraulic liquid from said reservoir to said first chamber;
• compression damping means for damping the flow of hydraulic liquid from said first chamber to said reservoir when said suspension unit is compressed to cause relative movement of said first and second members towards one another alone said longitudinal axis decreasing the volume of said first chamber;
• and
• rebound damping means for only affecting the rebound velocity of the initially compressed suspension unit when such velocity is due to the force imparted by the spring means when it is returning stored energy after some initial compression, said rebound damping means damping the flow of hydraulic liquid to said first chamber resulting from said spring means releasing energy stored therein by moving said movable wall to decrease the volume of said reservoir and flow hydraulic fluid from said reservoir to said first chamber for extending said suspension unit, while said rebound damping means and said suspension unit at the same time not resisting relative movement of said first and second members away from one another for extending said suspension unit to said extension limit of said suspension unit by external forces on said suspension unit;
• wherein said rebound damping means includes a rebound damping valve which is movable in response to pressure of said hydraulic liquid thereon for opening and closing said passage means for controlling the flow of hydraulic liquid through said passage means from said reservoir to said first chamber during release of stored energy from said spring means, and further comprising means for adjustably, resiliently biasing the rebound damping valve in a position closing said passage means for controlling the hydraulic liquid pressure necessary for moving said rebound damping valve to open said passage means permitting the flow of hydraulic liquid from said reservoir to said first chamber and the release of stored energy of said spring means,
• wherein said rebound damping valve is in the form of a poppet valve, and wherein said means for adjustably, resiliently biasing includes a coil spring and externally accessible means for adjusting a preload on said coil spring resiliently biasing the poppet valve in a position closing said passage means.

A hydraulic suspension unit comprising:

• first and second members arranged in telescoping relation with one another for relative movement along a longitudinal axis of said suspension unit with changes in force on said suspension unit compressing and extending said suspension unit;
• means containing a hydraulic liquid, said containing means including a first chamber containing hydraulic liquid in force transmitting relation between said first and second members, the volume of said first chamber being decreased and increased with relative movement of said first and second members toward and away from one another along said longitudinal axis, respectively, and said containing means further including a reservoir containing hydraulic liquid and passage means connecting said first chamber and said reservoir to permit the flow of hydraulic liquid between said first chamber and said reservoir, said reservoir including a movable wall which can be moved back and forth to increase and decrease the volume of said reservoir as a function of the volume of the hydraulic liquid flowing to and from said reservoir, respectively;
• spring means for resiliently biasing said movable wall against the hydraulic liquid in said reservoir with a force which is a function of the amount of movement of said spring means and in turn the position of said movable wall and volume of said reservoir, said spring means storing energy upon movement of said movable wall increasing the volume of said reservoir with the flow of hydraulic liquid to said reservoir, and said spring means releasing said stored energy upon movement of said movable wall decreasing the volume of said reservoir with the flow of hydraulic liquid from said reservoir to said first chamber;
• compression damping means for damping the flow of hydraulic liquid from said first chamber to said reservoir when said suspension unit is compressed to cause relative movement of said first and second members towards one another along said longitudinal axis decreasing the volume of said first chamber;
• rebound damping means for damping the flow of hydraulic liquid to said first chamber resulting from said spring means releasing energy stored therein by moving said movable wall to decrease the volume of said reservoir and flow hydraulic fluid from said reservoir to said first chamber for extending said suspension unit;
• wherein said movable wall is in the form of a flexible diaphragm mounted for movement within said suspension unit, said reservoir being located on one side of said flexible diaphragm and said spring means being provided on an opposite side of said flexible diaphragm for resiliently biasing said flexible diaphragm against hydraulic liquid in said reservoir, and wherein said flexible diaphragm is arranged to be in a torus shape when at the extremes of its travel, a disc of a stiff material being provided at the center of said flexible diaphragm for locally stiffening said center of said diaphragm.

A hydraulic suspension unit comprising:

• first and second members arranged in telescoping relation with one another for relative movement along a longitudinal axis of said suspension unit with changes in force on said suspension unit compressing and extending said suspension unit within an extension limit of the suspension unit;
• means containing a hydraulic liquid, said containing means including a first chamber containing hydraulic liquid in compressive force transmitting relation between said first and second members without resisting extension of said suspension unit to said extension limit by external forces on said suspension unit, the volume of said first chamber being decreased and increased with relative movement of said first and second members toward and away from one another along said longitudinal axis, respectively and said containing means further including a reservoir containing hydraulic liquid and passage means connecting said first chamber and said reservoir to permit the flow of hydraulic liquid between said first chamber and said reservoir, said reservoir including a movable wall which can be moved back and forth to increase and decrease the volume of said reservoir as a function of the volume of the hydraulic liquid flowing to and from said reservoir, respectively;
• spring means for resiliently biasing said movable wall against the hydraulic liquid in said reservoir with a force which is a function of the amount of movement of said spring means and in turn the position of said movable wall and volume of said reservoir, said spring means storing energy upon movement of said movable wall increasing the volume of said reservoir with the flow of hydraulic liquid to said reservoir, and said spring means releasing said stored energy upon movement of said movable wall decreasing the volume of said reservoir with the flow of hydraulic liquid from said reservoir to said first chamber;
• compression damping means for damping the flow of hydraulic liquid from said first chamber to said reservoir when said suspension unit is compressed to cause relative movement of said first and second members towards one another along said longitudinal axis decreasing the volume of said first chamber;
• and
• rebound damping means for only affecting the rebound velocity of the initially compressed suspension unit when such velocity is due to the force imparted by the spring means when it is returning stored energy after some initial compression, said rebound damping means damping the flow of hydraulic liquid to said first chamber resulting from said spring means releasing energy stored therein by moving said movable wall to decrease the volume of said reservoir and flow hydraulic fluid from said reservoir to said first chamber for extending said suspension unit, while said rebound damping means and said suspension unit at the same time not resisting relative movement of said first and second members away from one another for extending said suspension unit to said extension limit of said suspension unit by external forces on said suspension unit, and further comprising auxiliary spring means acting to cause relative movement along said longitudinal axis along said first and second members to extend said suspension unit without resistance from said rebound damping means, and wherein said auxiliary spring means is external to said telescoping first and second members.

A hydraulic suspension unit comprising:

• first and second members arranged in telescoping relation with one another for relative movement along a longitudinal axis of said suspension unit with changes in force on said suspension unit compressing and extending said suspension unit within an extension limit of the suspension unit;
• means containing a hydraulic liquid, said containing means including a first chamber containing hydraulic liquid in compressive force transmitting relation between said first and second members without resisting extension of said suspension unit to said extension limit by external forces on said suspension unit, the volume of said first chamber being decreased and increased with relative movement of said first and second members toward and away from one another along said longitudinal axis, respectively, and said containing means further including a reservoir containing hydraulic liquid and passage means connecting said first chamber and said reservoir to permit the flow of hydraulic liquid between said first chamber and said reservoir, said reservoir including a movable wall which can be moved back and forth to increase and decrease the volume of said reservoir as a function of the volume of the hydraulic liquid flowing to and from said reservoir, respectively;
• spring means for resiliently biasing said movable wall against the hydraulic liquid in said reservoir with a force which is a function of the amount of movement of said spring means and in turn the position of said movable wall and volume of said reservoir, said spring means storing energy upon movement of said movable wall increasing the volume of said reservoir with the flow of hydraulic liquid to said reservoir, and said spring means releasing said stored energy upon movement of said movable wall decreasing the volume of said reservoir with the flow of hydraulic liquid from said reservoir to said first chamber;
• compression damping means for damping the flow of hydraulic liquid from said first chamber to said reservoir when said suspension unit is compressed to cause relative movement of said first and second members towards one another along said longitudinal axis decreasing the volume of said first chamber;
• and
• rebound damping means for only affecting the rebound velocity of the initially compressed suspension unit when such velocity is due to the force imparted by the spring means when it is returning stored energy after some initial compression, said rebound damping means damping the flow of hydraulic liquid to said first chamber resulting from said spring means releasing energy stored therein by moving said movable wall to decrease the volume of said reservoir and flow hydraulic fluid from said reservoir to said first chamber for extending said suspension unit, while said rebound damping means and said suspension unit at the same time not resisting relative movement of said first and second members away from one another for extending said suspension unit to said extension limit of said suspension unit by external forces on said suspension unit,
• wherein said containing means further comprises an additional reservoir containing hydraulic liquid and additional passage means connecting said first chamber and said additional reservoir to permit the flow of hydraulic liquid between said first chamber and said additional reservoir, said additional reservoir including an additional movable wall which can be moved back and forth to increase and decrease the volume of said additional reservoir as a function of the volume of the hydraulic liquid flowing to and from said additional reservoir, respectively, and additional spring means for resiliently biasing said additional movable wall against the hydraulic liquid in said additional reservoir with a force which is a function of the amount of movement of said additional spring means and in turn the position of said additional movable wall and volume of said additional reservoir.

A hydraulic suspension unit comprising:

• first and second members arranged in telescoping relation with one another for relative movement along a longitudinal axis of said suspension unit with changes in force on said suspension unit compressing and extending said suspension unit within an extension limit of the suspension unit;
• means containing a hydraulic liquid, said containing means including a first chamber containing hydraulic liquid in compressive force transmitting relation between said first and second members without resisting extension of said suspension unit to said extension limit by external forces on said suspension unit, the volume of said first chamber being decreased and increased with relative movement of said first and second members toward and away from one another along said longitudinal axis, respectively, and said containing means further including a reservoir containing hydraulic liquid and passage means connecting said first chamber and said reservoir to permit the flow of hydraulic liquid between said first chamber and said reservoir, said reservoir including a movable wall which can be moved back and forth to increase and decrease the volume of said reservoir as a function of the volume of the hydraulic liquid flowing to and from said reservoir, respectively;
• spring means for resiliently biasing said movable wall against the hydraulic liquid in said reservoir with a force which is a function of the amount of movement of said spring means and in turn the position of said movable wall and volume of said reservoir, said sprint means storing energy upon movement of said movable wall increasing the volume of said reservoir with the flow of hydraulic liquid to said reservoir, and said spring means releasing said stored energy upon movement of said movable wall decreasing the volume of said reservoir with the flow of hydraulic liquid from said reservoir to said first chamber;
• compression damping means for damping the flow of hydraulic liquid from said first chamber to said reservoir when said suspension unit is compressed to cause relative movement of said first and second members towards one another along said longitudinal axis decreasing the volume of said first chamber;
• and
• rebound damping means for only affecting the rebound velocity of the initially compressed suspension unit when such velocity is due to the force imparted by the spring means when it is returning stored energy after some initial compression, said rebound damping means damping the flow of hydraulic liquid to said first chamber resulting from said spring means releasing energy stored therein by moving said movable wall to decrease the volume of said reservoir and flow hydraulic fluid from said reservoir to said first chamber for extending said suspension unit, while said rebound damping means and said suspension unit at the same time not resisting relative movement of said first and second members away from one another for extending said suspension unit to said extension limit of said suspension unit by external forces on said suspension unit,
• wherein said rebound damping means includes a rebound damping valve which is movable in response to pressure of said hydraulic liquid thereon for opening and closing said passage means for controlling the flow of hydraulic liquid through said passage means from said reservoir to said first chamber during release of stored energy from said spring means, and
• wherein said rebound damping valve is arranged for movement so as to displace hydraulic liquid on the first chamber side of the rebound damping valve during opening of said valve, the volume of said rebound damping valve and its linear travel during opening, being selected to provide displacement of a predetermined volume of hydraulic liquid and hence a predetermined expansion of said suspension unit during opening of said valve;
• and
• wherein said rebound damping valve is configured to require a predetermined linear travel before allowing any flow of hydraulic liquid past said rebound damping valve.

In a lightweight, wheeled vehicle where rider weight is a relatively large percentage of total sprung weight of said vehicle, said vehicle including a vehicle body, a vehicle wheel and a hydraulic suspension unit for supporting weight of said vehicle in relation to said wheel, the improvement comprising said hydraulic suspension unit comprising:

• first and second members arranged in telescoping relation with one another for relative movement along a longitudinal axis of said suspension unit with changes in force on said suspension unit compressing and extending said suspension unit within an extension limit of the suspension unit;
• means containing a hydraulic liquid, said containing means including a first chamber containing hydraulic liquid in compressive force transmitting relation between said first and second members without resisting extension of said suspension unit to said extension limit by external forces on said suspension unit, the volume of said first chamber being decreased and increased with relative movement of said first and second members toward and away from one another along said longitudinal axis, respectively, and said containing means further including a reservoir containing hydraulic liquid and passage means connecting said first chamber and said reservoir to permit the flow of hydraulic liquid between said first chamber and said reservoir, said reservoir including a movable wall which can be moved back and forth to increase and decrease the volume of said reservoir as a function of the volume of the hydraulic liquid flowing to and from said reservoir, respectively;
• spring means for resiliently biasing said movable wall against the hydraulic liquid in said reservoir with a force which is a function of the amount of movement of said spring means and in turn the position of said movable wall and volume of said reservoir, said spring means storing energy upon movement of said movable wall increasing the volume of said reservoir with the flow of hydraulic liquid to said reservoir, and said spring means releasing said stored energy upon movement of said movable wall decreasing the volume of said reservoir with the flow of hydraulic liquid from said reservoir to said first chamber;
• compression damping means for damping the flow of hydraulic liquid from said first chamber to said reservoir when said suspension unit is compressed to cause relative movement of said first and second members towards one another along said longitudinal axis decreasing the volume of said first chamber;
• and
• rebound damping means for only affecting the rebound velocity of the initially compressed suspension unit when such velocity is due to the force imparted by the spring means when it is returning stored energy after some initial compression, said rebound damping means damping the flow of hydraulic liquid to said first chamber resulting from said spring means releasing energy stored therein by moving said movable wall to decrease the volume of said reservoir and flow hydraulic fluid from said reservoir to said first chamber for extending said suspension unit, while said rebound damping means and said suspension unit at the same time not resisting relative movement of said first and second members away from one another for extending said suspension unit to said extension limit of the suspension unit by external forces on said suspension unit;
• and
• externally accessible means for independently adjusting each of a spring characteristic of said spring means and an amount of rebound damping provided by said rebound damping means.

A hydraulic suspension unit comprising:

• first and second members arranged in telescoping relation with one another for relative movement along a longitudinal axis of said suspension unit with changes in force on said suspension unit compressing and extending said suspension unit within an extension limit of the suspension unit;
• means containing a hydraulic liquid, said containing means including a first chamber containing hydraulic liquid in compressive force transmitting relation between said first and second members without resisting extension of said suspension unit to said extension limit by external forces on said suspension unit, the volume of said first chamber being decreased and increased with relative movement of said first and second members toward and away from one another along said longitudinal axis, respectively, and said containing means further including a reservoir containing hydraulic liquid and passage means connecting said first chamber and said reservoir to permit the flow of hydraulic liquid between said first chamber and said reservoir, said reservoir including a movable wall which can be moved back and forth to increase and decrease the volume of said reservoir as a function of the volume of the hydraulic liquid flowing to and from said reservoir, respectively;
• spring means for resiliently biasing said movable wall against the hydraulic liquid in said reservoir with a force which is a function of the amount of movement of said spring means and in turn the position of said movable wall and volume of said reservoir, said spring means storing energy upon movement of said movable wall increasing the volume of said reservoir with the flow of hydraulic liquid to said reservoir, and said spring means releasing said stored energy upon movement of said movable wall decreasing the volume of said reservoir with the flow of hydraulic liquid from said reservoir to said first chamber;
• compression damping means for damping the flow of hydraulic liquid from said first chamber to paid reservoir when said suspension unit is compressed to cause relative movement of said first and second members towards one another along said longitudinal axis decreasing the volume of said first chamber;
• rebound damping means for only affecting the rebound velocity of the initially compressed suspension unit when such velocity is due to the force imparted by the spring means when it is returning stored energy after some initial compression, said rebound damping means damping the flow of hydraulic liquid to said first chamber resulting from said spring means releasing energy stored therein by moving said movable wall to decrease the volume of said reservoir and flow hydraulic fluid from said reservoir to said first chamber for extending said suspension unit, while said rebound damping means and said suspension unit at the same time not resisting relative movement of said first and second members away from one another for extending said suspension unit to said extension limit of the suspension unit by external force on said suspension unit;
• wherein said compression damping means includes a compression damping valve which is movable in response to pressure of said hydraulic liquid thereon for opening and closing said passage means for controlling the flow of hydraulic liquid through said passage means from said first chamber to said reservoir during compression of said suspension unit, and further comprising means for adjustably biasing the compression damping valve in a position closing said passage means for controlling the hydraulic liquid pressure and hence compressive force on the suspension unit necessary for moving said compression damping valve to open said passage means permitting the flow of hydraulic liquid from said first chamber to said reservoir and the compression of said suspension unit;
• and wherein said means for adjustably biasing the compression damping valve also simultaneously adjustably limits the maximum flow area for hydraulic liquid flowing from said first chamber to said reservoir when said compression damping valve is open for controlling a maximum speed of compression of said suspension unit.

A hydraulic suspension unit comprising:

• first and second members arranged in telescoping relation with one another for relative movement along a longitudinal axis of said suspension unit with changes in force on said suspension unit compressing and extending said suspension unit within an extension limit of the suspension unit;
• means containing a hydraulic liquid, said containing means including a first chamber containing hydraulic liquid in compressive force transmitting relation between said first and second member without resisting extension of said suspension unit to said extension limit by external forces on said suspension unit, the volume of said first chamber being decreased and increased with relative movement of said first and second members toward and away from one another along said longitudinal axis, respectively, and said containing means further including a reservoir containing hydraulic liquid and passage means connecting said first chamber and said reservoir to permit the flow of hydraulic liquid between said first chamber and said reservoir, said reservoir including a movable wall which can be moved back and forth to increase and decrease the volume of said reservoir as a function of the volume of the hydraulic liquid flowing to and from said reservoir, respectively;
• spring means for resiliently biasing said movable wall against the hydraulic liquid in said reservoir with a force which is a function of the amount of movement of said spring means and in turn the position of said movable wall and volume of said reservoir, said spring means storing energy upon movement of said movable wall increasing the volume of said reservoir with the flow of hydraulic liquid to said reservoir, and said spring means releasing said stored energy upon movement of said movable wall decreasing the volume of said reservoir with the flow of hydraulic liquid from said reservoir to said first chamber;
• compression damping means for damping the flow of hydraulic liquid from said first chamber to said reservoir when said suspension unit is compressed to cause relative movement of said first and second members toward one another along said longitudinal axis decreasing the volume of said first chamber, said compression damping means including a compression damping valve which is movable in response to pressure of said hydraulic liquid thereon for opening and closing said passage means for controlling the flow of hydraulic liquid through said passage means from said first chafer to said reservoir during compression of said suspension unit, and means for adjustably biasing the compression damping valve in a position closing said passage means for controlling the hydraulic liquid pressure and hence compressive force on the suspension unit necessary for moving said compression damping valve to open said passage means permitting the flow of hydraulic liquid from said first chamber to said reservoir and the compression of said suspension unit;
• rebound damping means for only affecting the rebound velocity of the initially compressed suspension unit when such velocity is due to the force imparted by the spring means when it is returning stored energy after some initial compression, said rebound damping means damping the flow of hydraulic liquid to said first chamber resulting from said spring means releasing energy stored therein by moving said movable wall to decrease the volume of said reservoir and flow hydraulic fluid from said reservoir to said first chamber for extending said suspension unit, while said rebound damping means and said suspension unit at the same time not resisting relative movement of said first and second members away from one another for extending said suspension unit to said extension limit of the suspension unit by external forces on said suspension unit, said rebound damping means including a rebound damping valve which is movable in response to pressure of said hydraulic liquid thereon for opening and closing said passage means for controlling the hydraulic liquid through said passage means from said reservoir to said first chamber during release of stored energy from said spring means, and means for adjustably limiting the maximum flow area for hydraulic liquid flowing from said reservoir to said first chamber when said rebound damping valve is opened for controlling a maximum speed of expansion of said suspension unit due to release of stored energy from said spring means, and means for adjustably, resiliently biasing the rebound damping valve in a position closing said passage means for controlling the hydraulic liquid pressure necessary for moving said rebound damping valve to open said passage means permitting the flow of hydraulic liquid from said reservoir to said first chamber and the release of stored energy of said spring means;
• and
• wherein said means for adjustably limiting the maximum flow area for hydraulic liquid flowing from said first chamber to said reservoir when said compression damping valve is open for controlling a maximum speed compression of said suspension unit includes an additional valve located in said passage means upstream of said compression damping valve with respect to the flow of hydraulic liquid from said first chamber to said reservoir, and means for adjusting the extent which said additional valve restricts the flow of hydraulic liquid in said passage means during compression of said suspension unit.