# US 12,759,367 B1 · Position dependent damper > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,759,367 B1 - Document ID: US12759367B1 - Status: Granted - Kind: B1 - Application number: 19/252,774 - Filed: 2025-06-27 - Granted: 2026-10-13 - Earliest claimed: 2012-03-26 - Assignees: Oshkosh Defense, LLC - Applicants: Oshkosh Defense, LLC - Inventors: Erik S. Ellifson; Patrick S. Dillman; Jason J. Zuleger; Aaron J. Rositch; Robert K. Sollenskog - Web page: https://patentgrep.com/patent/US12759367B1 ## CPC - B60G 17/08: Characteristics of fluid dampers (adjusting fluid dampers in general F16F9/44 - F16F9/53) - B60G 11/265: {hydraulic springs} - B60G 13/08: hydraulic - B60G 21/073: between wheels on the same axle but on different sides of the vehicle, i.e. the left and right wheel suspensions being interconnected - F16F 9/19: with a single cylinder {and of single-tube type} - F16F 9/28: with two parallel cylinders and with the two pistons or plungers connected together - F16F 9/346: Throttling passages in the form of slots arranged in cylinder walls - F16F 9/48: Arrangements for providing different damping effects at different parts of the stroke ({F16F9/346, F16F9/516} , F16F9/53 take precedence) - B60G 2202/24: Fluid damper - B60G 2500/10: Damping action or damper - F16F 9/185: {Bitubular units (where compression of gas leads to a clear spring action F16F9/062)} - B60G: VEHICLE SUSPENSION ARRANGEMENTS (air-cushion vehicles B60V; {cycle suspensions B62K25/00}) - F16F: SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION ## Abstract A damper assembly includes a housing including a wall defining a first aperture fluidly coupled to a second aperture, a first tubular member coupled to the housing, a second tubular member extending between the wall and the first tubular member, a first plunger coupled to the second tubular member and in sliding engagement with an inner surface of the wall and an outer surface of the first tubular member, a third member extending within the first tubular member, and a second plunger coupled to the third member and in sliding engagement with an inner surface of the first tubular member. ## Claims ### Claim 1 A damper assembly, comprising: a body portion comprising a housing including a wall defining a first aperture and coupled to a second aperture; a rod portion extending within the body portion; a first plunger in sliding engagement with an inner surface of the body portion and coupled to the rod portion; and a second plunger in sliding engagement with an inner surface of the rod portion, the second plunger coupled to the rod portion; wherein the damper assembly is configured to provide a damping force that varies based on a longitudinal position of the first plunger. ### Claim 2 (depends on 1) The damper assembly of claim 1, wherein the body portion comprises an outer chamber and an inner chamber, and wherein the first plunger is in sliding engagement with the housing within the outer chamber, and the second plunger is positioned within the inner chamber. ### Claim 3 (depends on 1) The damper assembly of claim 1, wherein the body portion comprises a first tubular member coupled within the housing, the first tubular member separating the housing into an inner chamber within the first tubular member and an outer chamber between the first tubular member and the wall of the housing. ### Claim 4 (depends on 1) The damper assembly of claim 1, wherein the body portion comprises a first tubular member coupled within the housing, and wherein the rod portion comprises a second tubular member extending between the first tubular member and the housing. ### Claim 5 (depends on 1) The damper assembly of claim 1, wherein the body portion comprises an outer chamber and an inner chamber, and wherein the rod portion comprises a first tubular member extending within the outer chamber, the first plunger coupled to the first tubular member. ### Claim 6 (depends on 1) The damper assembly of claim 1, wherein the body portion comprises an outer chamber and an inner chamber, and wherein the rod portion comprises a first tubular member extending within the outer chamber and a second tubular member extending within the inner chamber, the second plunger coupled to the second tubular member. ### Claim 7 (depends on 1) The damper assembly of claim 1, wherein the body portion comprises a first tubular member coupled within the housing, the first tubular member separating the housing into an inner chamber within the first tubular member and an outer chamber between the first tubular member and the wall of the housing, the first tubular member defining a third aperture fluidly coupling the inner chamber and the outer chamber. ### Claim 8 (depends on 1) The damper assembly of claim 1, wherein the body portion comprises a first tubular member coupled within the housing, and wherein a first chamber is at least partially defined by the inner surface of the wall, an outer surface of the first tubular member, and a first surface of the first plunger, and wherein a second chamber is at least partially defined by the inner surface of the wall, an outer surface of the rod portion, and a second surface of the first plunger. ### Claim 9 (depends on 8) The damper assembly of claim 8, wherein, in a first position of the first plunger, the first aperture is in direct fluid communication with the first chamber and the second aperture is in direct fluid communication with the second chamber, and wherein, in a second position of the first plunger, the first aperture and the second aperture are both in direct fluid communication with the second chamber. ### Claim 10 (depends on 1) The damper assembly of claim 1, wherein the body portion comprises a first tubular member coupled within the housing, and wherein the rod portion comprises a second tubular member extending between the first tubular member and the housing and a third tubular member extending within the first tubular member. ### Claim 11 (depends on 1) The damper assembly of claim 1, wherein the body portion and the rod portion share a common central axis. ### Claim 12 (depends on 1) The damper assembly of claim 1, wherein the body portion and the rod portion are both coupled to a cap. ### Claim 13 A damper assembly, comprising: a housing including a wall that defines an inner volume, a plurality of apertures offset relative to one another, and a first flow path between at least two apertures of the plurality of apertures; a piston slidably coupled to the housing and separating the inner volume into a first chamber and a second chamber; and a second flow path between at least two apertures of the plurality of apertures; wherein, in a first position of the piston, the first flow path is activated providing flow between the first chamber and the second chamber; wherein, in a second position of the piston, the first flow path is deactivated; wherein, in both the first position and the second position of the piston, the second flow path is activated providing flow between the first chamber and the second chamber; and wherein, in a third position of the piston, both the first flow path and the second flow path are deactivated. ### Claim 14 (depends on 13) The damper assembly of claim 13, wherein the first flow path is between a first aperture and the second aperture, and a second flow path is between a third aperture and a fourth aperture, the third aperture positioned between the first aperture and the second aperture. ### Claim 15 (depends on 14) The damper assembly of claim 14, further comprising: a first conduit extending outside of the inner volume and fluidly coupling the first aperture and the second aperture; and a second conduit extending outside of the inner volume and fluidly coupling the third aperture and the fourth aperture. ### Claim 16 A damper assembly, comprising: a housing defining at least three first apertures that are part of a first flow path and at least three second apertures that are part of a second flow path; and a piston extending within the housing and slidingly engaged to a surface of the housing; wherein the damper assembly is configured to provide a damping force that varies based on a longitudinal position of the piston relative to the housing. ### Claim 17 (depends on 16) The damper assembly of claim 16, further comprising a tubular member extending within the housing, wherein a plunger is positioned within the tubular member. ### Claim 18 (depends on 16) The damper assembly of claim 16, further comprising a tubular member extending within the housing, wherein the piston is coupled to the tubular member.