Adjustable shock absorber

Claim 2

In an adjustable fluid energy absorber, comprising in combination: housing means including a central tubular housing member and a pair of end members positioned adjacent opposite ends of said central tubular housing member; sleeve means disposed in said housing member to form a first fluid chamber within the interior of said sleeve means and a second fluid chamber between said sleeve means and said tubular housing member; ram means slidably disposed on said housing means for receiving a shock load thereon, said ram means including a piston slidably disposed within one of said fluid chambers and a piston rod connected to said piston and extending outwardly from one end of said housing means; said sleeve means including a first sleeve member having a plurality of circular openings extending radially therethrough to permit fluid communication between said first and second chambers; said plurality of said circular openings being arranged in a plurality of substantially parallel rows which extend substantially axially of said first sleeve member, said plurality of parallel rows being spaced from one another circumferentially of said first sleeve member, each of said rows being formed by a different number of circular openings, the circular openings all being of substantially the same diameter and being substantially uniformly axially spaced apart, and the individual openings of the adjacent rows being substantially directly aligned with one another in the circumferentially extending direction of said first sleeve member; and control means for varying the effective flow area of the plurality of openings formed in said first sleeve member for selectively varying the energy dissipation characteristics of said energy absorber, said control means including a second sleeve member disposed substantially adjacent and in concentric, rotatable relationship with said first sleeve member, said second sleeve member having opening means extending radially therethrough, said opening means being of narrow circumferential extent but being elongated axially of said second sleeve member and positionable to at least partially overlap the circular openings of a selected one of the rows of openings formed in said first sleeve member, the remaining rows of openings formed in said first sleeve member being effectively closed by said second sleeve member; and adjustment means, including a movable adjustment member positioned externally of said housing means, operatively interconnected to one of said sleeve members for permitting relative rotational movement between said sleeve members for permitting said opening means to be selectively positioned in overlapping relationship with any of said rows of circular openings formed in said first sleeve member for permitting the energy dissipation characteristics of said absorber to be selectively varied.

Claim 3

An energy absorber according to claim 1, wherein said opening means as formed in said second sleeve member includes a plurality of circular openings extending radially through said second sleeve member and disposed within a single substantially axially extending row.

Claim 4

An energy absorber according to claim 2, wherein the openings as formed in said first sleeve member are of variable cross-sectional area as they extend radially through said first sleeve member, each of the openings formed in said first sleeve member having a first minimum cross-sectional area for controlling the quantity of fluid flowing therethrough, each of said openings in said first sleeve member also having a second cross-sectional area adjacent the radially outer end thereof, said second cross-sectional area being substantially larger than said first cross-sectional area, and the openings as formed in said second sleeve member each being of a third cross-sectional area which is grEater than said first cross-sectional area but substantially less than said second cross-sectional area whereby flow through the openings in said first and second sleeve members is controlled by said first cross-sectional area, and the adjacent rows of openings in said first sleeve member being positioned closely adjacent one another so that the openings in said second sleeve member can partially overlap the radially outer ends of the openings of two rows as formed in said first sleeve member.

Claim 5

In an adjustable fluid energy absorber, the combination of: housing means including a central tubular housing member and a pair of end members positioned adjacent opposite ends of said central tubular housing member; sleeve means disposed in said housing member so as to form a first fluid chamber within the interior of said sleeve means and a second fluid chamber between said sleeve means and said tubular housing member; ram means slidably disposed on said housing means for receiving a shock load thereon, said ram means including a piston slidably disposed within one of said fluid chambers and a piston rod connected to said piston and extending outwardly from one end of said housing means; said sleeve means including a first sleeve member having first opening means extending radially therethrough to permit fluid communication between said first and second chambers, whereby movement of said piston axially of said one chamber causes fluid to flow from said one chamber through said opening means into said other chamber; and control means for varying the effective flow area defined by said opening means to selectively vary the energy dissipation characteristics of said energy absorber, comprising the improvement wherein said control means includes means for selectively varying the effective length of said flow area of said first opening means in the axially extending direction of said first sleeve member while maintaining the effective flow area substantially constant per unit distance of displacement of said piston in said axial direction, whereby said control means is effective to enable the axial stopping of said ram means to be selectively varied; said control means including a second sleeve member disposed substantially adjacent and in concentric, rotatable relationship with said first sleeve member, said second sleeve member having second opening means extending radially therethrough, said second opening means being positioned to partially overlap said first opening means; one of said opening means extending over a substantial circumferential extent of its respective sleeve member with the axial length of said one opening means progressively increasing as said one opening means extends circumferentially through an angle defined between two extremes, and the other opening means extending axially through a distance at least equal to the maxium axial extent of said one opening means and extending circumferentially of said last-mentioned sleeve member through an angle substantially less than said one opening means, whereby said other opening means overlaps only a small fraction of the circumferential extent of said one opening means, the axial length of the overlapped area of said first and second opening means being dependent upon the circumferential position of said other opening means relative to said one opening means; said one opening means including a plurality of openings extending radially through the respective sleeve member to permit fluid communication between said first and second chambers, said plurality of openings being arranged in a plurality of substantially parallel rows which extend substantially axially of said respective sleeve member, said plurality of parallel rows being spaced from one another circumferentially of said respective sleeve member, each of said rows being formed by a different number of openings, the openings all being of substantially the same cross-sectional area and being substantially uniformly Axially spaced apart, and the individual openings of the adjacent rows being substantially directly aligned with one another in the circumferentially extending direction of said respective sleeve member.

Claim 6

In an adjustable fluid energy absorber, the combination of: housing means including a central tubular housing member and a pair of end members positioned adjacent opposite ends of said central tubular housing member; sleeve means disposed in said housing member so as to form a first fluid chamber within the interior of said sleeve means and a second fluid chamber between said sleeve means and said tubular housing member; ram means slidably disposed on said housing means for receiving a shock load thereon, said ram means including a piston slidably disposed within one of said fluid chambers and a piston rod connected to said piston and extending outwardly from one end of said housing means; said sleeve means including a first sleeve member having first opening means extending radially therethrough to permit fluid communication between said first and second chambers, whereby movement of said piston axially of said one chamber causes fluid to flow from said one chamber through said opening means into said other chamber; and control means for varying the effective flow area defined by said opening means to selectively vary the energy dissipation characteristics of said energy absorber, comprising the improvement wherein said control means includes means for selectively varying the effective length of said flow area of said first opening means in the axially extending direction of said first sleeve member while maintaining the effective flow area substantially constant per unit distance of displacement of said piston in said axial direction, whereby said control means is effective to enable the axial stopping of said ram means to be selectively varied; said control means including a second sleeve member disposed substantially adjacent and in concentric, rotatable relationship with said first sleeve member, said second sleeve member having second opening means extending radially therethrough, said second opening means being positioned to partially overlap said first opening means; one of said opening means extending over a substantial circumferential extent of its respective sleeve member with the axial length of said one opening means progressively increasing as said one opening means extends circumferentially through an angle defined between two extremes, and the other opening means extending axially through a distance at least equal to the maxium axial extent of said one opening means and extending circumferentially of said last-mentioned sleeve member through an angle substantially less than said one opening means, whereby said other opening means overlaps only a small fraction of the circumferential extent of said one opening means, the axial length of the overlapped area of said first and second opening means being dependent upon the circumferential position of said other opening means relative to said one opening means; said one opening means including a plurality of openings extending radially through the respective sleeve member to permit fluid communication between said first and second chambers, said plurality of openings being arranged in a plurality of substantially parallel rows which extend substantially axially of said respective sleeve member, said plurality of parallel rows being spaced from one another circumferentially of said respective sleeve member, each of said rows being formed by a different number of openings, the openings all being of substantially the same cross-sectional area and being substantially uniformly Axially spaced apart, and the individual openings of the adjacent rows being substantially directly aligned with one another in the circumferentially extending direction of said respective sleeve member.

Claim 7

An energy absorber according to claim 4, wherein there are at least three of said parallel rows of openings extending axially of said respective sleeve member and spaced circumferentially thereof from one another, said three rows of openings being circumferentially adjacent one another and including a first row positioned on one side of a second row and a third row positioned on the opposite side of said second row from said first row, and said second row of openings containing therein a number of openings which is greater than the number of openings in said third row but is less than the number of openings in said first row.

Claim 8

An energy absorber according to claim 4, wherein said other opening means comprises a single row of substantially identical openings, said single row of openings extending axially of its respective sleeve member, said single row of openings containing therein a number of openings which is substantially the same as the number of openings contained in the longest row of openings associated with said one opening means.

Claim 9

An energy absorber according to claim 6, wherein the individual openings contained within each row associated with said one opening means each includes a flared conical portion adapted to communicate at the maximum diameter thereof with the openings associated with said single row.

Claim 10

An energy absorber according to claim 4, further including adjustment means operatively interconnected to said second sleeve member for permitting rotation thereof relative to said first sleeve member for permitting said second opening means to be selectively positioned in overlapping relationship with said first opening means for permitting the energy dissipation characteristics of said absorber to be selectively varied, said adjustment means including a manually rotatable adjustment member disposed directly adjacent the exterior axial end face of one of said end members and fixedly interconnected to the adjacent axial end of said second sleeve member for permitting relative rotation between said first and second sleeve members, said adjustment member being coaxial with and rotatably movable substantially about the longitudinal axis of said piston rod.