Hydropneumatic energy absorbing unit

Claim 2

In a hydropneumatic energy absorbing unit including a cylinder tube subassembly having a piston tube subassembly disposed thereon for relative telescopic bodily movement between An extended condition and a collapsed condition and a gas piston slidably disposed on said piston tube subassembly and defining therein a gas chamber filled with a gas under pressure, the combination comprising, a valve element disposed on said piston tube subassembly and cooperating with said cylinder tube subassembly in defining a primary chamber for a working fluid and with said gas piston in defining a secondary chamber for said working fluid, resilient means on said piston tube subassembly biasing said valve element toward a planar configuration, means defining a flow aperture in said valve element adapted for permitting flow of said working fluid between said primary and said secondary chambers during relative telescopic collapse and extension of said piston tube subassembly, an adjusting member disposed on said piston tube subassembly with a boss portion thereof projecting into said aperture and cooperating with the latter in defining a throttling orifice for said working fluid for effecting primary and secondary energy absorption during relative telescopic collapse and extension of said piston tube subassembly respectively, said throttling orifice creating a pressure differential across said valve element to deflect the latter from a closed position corresponding to the planar configuration of said valve element wherein the cross-sectional area of said orifice is minimum to an open position wherein the cross-sectional area exceeds the minimum in response to increasing pressure in said primary chamber so that the crosssectional area of said throttling orifice is directly proportional to the pressure in said primary chamber, and means on said adjusting member and said piston tube subassembly adapting the former for bodily movement relative to the latter between a plurality of positions wherein said boss portion projects progressively further into said flow aperture.

Claim 3

In a hydropneumatic energy absorbing unit including a cylinder tube subassembly having a piston tube subassembly disposed thereon for relative telescopic bodily movement between an extended condition and a collapsed condition and a gas piston slidably disposed on said piston tube subassembly and defining therein a gas chamber filled with a gas under pressure, the combination comprising, a flexible valve disc disposed on said piston tube subassembly and cooperating with said cylinder tube subassembly in defining a primary chamber for a working fluid and with said gas piston in defining a secondary chamber for said working fluid, said valve disc being self-biased toward a planar configuration, means defining a centrally located circular flow aperture in said valve disc adapted for permitting flow of said working fluid between said primary and said secondary chambers during relative telescopic collapse and extension of said piston tube subassembly, an adjusting member disposed on said piston tube subassembly with a cylindrical boss portion thereof projecting into said aperture and cooperating with the latter in defining an annular throttling orifice for said working fluid for effecting primary and secondary energy absorption during relative telescopic collapse and extension of said piston tube subassembly respectively, said annular throttling orifice creating a pressure differential across said valve disc to deflect the latter from a closed position corresponding to the planar configuration of said valve disc wherein the cross-sectional area of said annular orifice is minimum to an open position wherein the cross-sectional area exceeds the minimum in response to increasing pressure in said primary chamber so that the cross-sectional area of said annular throttling orifice is directly proportional to the pressure in said primary chamber, and means on said adjusting member and on said piston tube subassembly defining a threaded connection therebetween so that said adjusting member is bodily shiftable relative to said piston tube subassembly between a plurality of positions wherein said boss portion projecTs progressively further into said circular flow aperture in response to relative rotation between said adjusting member and said piston tube subassembly.

Claim 4

In a hydropneumatic energy absorbing unit including a cylinder tube subassembly having a piston tube subassembly disposed thereon for relative telescopic bodily movement between an extended condition and a collapsed condition and a gas piston slidably disposed on said piston tube subassembly and defining therein a gas chamber filled with a gas under pressure, the combination comprising, a flexible valve disc disposed on said piston tube subassembly and cooperating with said cylinder tube subassembly in defining a primary chamber for a working fluid and with said gas piston in defining a secondary chamber for said working fluid, said valve disc being self-biased toward a planar configuration, means defining a centrally located circular flow aperture in said valve disc adapted for permitting flow of said working fluid between said primary and said secondary chambers during relative telescopic collapse and extension of said piston tube subassembly, an adjusting member disposed on said piston tube subassembly with a cylindrical boss portion thereof projecting into said aperture and cooperating with the latter in defining an annular throttling orifice for said working fluid for effecting primary and secondary energy absorption during relative telescopic collapse and extension of said piston tube subassembly respectively, said annular throttling orifice creating a pressure differential across said valve disc to deflect the latter from a closed position corresponding to the planar configuration of said valve disc wherein the cross-sectional area of said annular orifice is minimum to an open position wherein the cross-sectional area exceeds the minimum in response to increasing pressure in said primary chamber so that the cross-sectional area of said annular throttling orifice is directly proportional to the pressure in said primary chamber, and means on said adjusting member and on said piston tube subassembly defining a threaded connection therebetween so that said adjusting member is bodily shiftable relative to said piston tube subassembly between a plurality of positions wherein said boss portion projecTs progressively further into said circular flow aperture in response to relative rotation between said adjusting member and said piston tube subassembly.

Claim 5

In a hydropneumatic energy absorbing unit including a cylinder tube subassembly having a piston tube subassembly disposed thereon for relative telescopic bodily movement between an extended condition and a collapsed condition and a gas piston slidably disposed on said piston tube subassembly and defining therein a gas chamber filled with a gas under pressure, the combination comprising, a circular end cap having an annular ridge thereon and including a centrally located threaded bore and a plurality of passages, a flexible valve disc self-biased toward a planar configuration and having a centrally located circular aperture therein, means rigidly attaching said end cap to said piston tube subassembly with said valve disc captured between an annular surface portion of said piston tube subassembly and said annular ridge on said end cap so that said valve disc cooperates with said cylinder tube subassembly in defining a primary chamber for a working fluid and with said gas piston in defining a secondary chamber for said working fluid, said valve disc circular aperture permitting flow of said working fluid between said primary and said secondary chambers during relative telescopic collapse and extension of said piston tube subassembly, and an adjusting member including a cylindrical boss portion and a threaded stud adapted for reception in said threaded bore in said end cap thereby to support said adjusting member on said piston tube subassembly with said boss portion projecting into said circular aperture and cooperating with the latter in defining an annular throttling orifice for said working fluid for effecting primary and secondary energy absorption during relative telescopic collapse and extension of said piston tube subassembly respectively, said annular throttling orifice creating a pressure differential across said valve disc to deflect the latter from a closed position corresponding to the planar configuration of said valve disc wherein the cross-sectional area of said orifice is minimum to an open position wherein the cross-sectional area exceeds the minimum in response to increasing pressure in said primary chamber so that the cross-sectional area of said throttling orifice is directly proportional to the pressure in said primary chamber, and said adjusting member being bodily shiftable relative to said piston tube subassembly between a plurality of positions wherein said boss portion projects progressively further into said circular flow aperture.

Claim 6

In a hydropneumatic energy absorbing unit including a cylinder tube subassembly having a piston tube subassembly disposed thereon for relative telescopic bodily movement between an extended condition and a collapsed condition and a gas piston slidably disposed on said piston tube subassembly and defining therein a gas chamber filled with a gas under pressure, the combination comprising, a circular end cap having an annular ridge thereon and including a centrally located threaded bore and a plurality of passages, a flexible valve disc self-biased toward a planar configuration and having a centrally located circular aperture therein, means rigidly attaching said end cap to said piston tube subassembly with said valve disc captured between an annular surface portion of said piston tube subassembly and said annular ridge on said end cap so that said valve disc cooperates with said cylinder tube subassembly in defining a primary chamber for a working fluid and with said gas piston in defining a secondary chamber for said working fluid, said valve disc circular aperture permitting flow of said working fluid between said primary and said secondary chambers during relative telescopic collapse and extension of said piston tube subassembly, and an adjusting member including a cylindrical boss portion and a threaded stud adapted for reception in said threaded bore in said end cap thereby to support said adjusting member on said piston tube subassembly with said boss portion projecting into said circular aperture and cooperating with the latter in defining an annular throttling orifice for said working fluid for effecting primary and secondary energy absorption during relative telescopic collapse and extension of said piston tube subassembly respectively, said annular throttling orifice creating a pressure differential across said valve disc to deflect the latter from a closed position corresponding to the planar configuration of said valve disc wherein the cross-sectional area of said orifice is minimum to an open position wherein the cross-sectional area exceeds the minimum in response to increasing pressure in said primary chamber so that the cross-sectional area of said throttling orifice is directly proportional to the pressure in said primary chamber, and said adjusting member being bodily shiftable relative to said piston tube subassembly between a plurality of positions wherein said boss portion projects progressively further into said circular flow aperture.