# US 2014/0360353 A1 · Vibration damper with a hydraulic end stop > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0360353 A1 - Document ID: US20140360353A1 - Status: Published application - Kind: A1 - Application number: 14/366,953 - Filed: 2012-11-21 - Published: 2014-12-11 - Earliest claimed: 2011-12-20 - Assignees: ZF Friedrichshafen AG - Inventors: Helmut Baalmann; Stefan Schmitt; Peter Schmitt - Web page: https://patentgrep.com/patent/US20140360353A1 ## CPC - F15B 15/24: for restricting the stroke - F16F 9/49: Stops limiting fluid passage, e.g. hydraulic stops {or elastomeric elements inside the cylinder which contribute to changes in fluid damping (fluid-actuated displacement devices with means for accelerating or decelerating the stroke F15B15/22)} - F15B 15/222: {having a piston with a piston extension or piston recess which throttles the main fluid outlet as the piston approaches its end position} - F16J 15/16: between relatively-moving surfaces (F16J15/50, F16J15/52 take precedence; bellows pistons F16J3/06; piston-rings or ring sealings of similar construction F16J9/00) - F15B: SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR - F16F: SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION - F16J: PISTONS {(specially adapted for dampers F16F9/32)}; CYLINDERS; SEALINGS ## Abstract The vibration damper including a hydraulic end stop that has a sealing ring which is arranged between the end stop ring and the closure element, is supported axially on one side at the end stop ring, engages radially around the piston rod, is mounted in a sliding manner at the piston rod, and with its outer circumferential surface radially contacts the inner wall of the control space, wherein the sealing ring has at least one radial throttle groove which takes effect when the end stop with the sealing ring moves into the control space and ensures a defined flow of damping medium between the control chamber and the first working space, and wherein the sealing ring has a plurality of spring tongues which are supported at a supporting surface on the piston rod side. ## Claims ### Claim at position 1 1-16. (canceled) ### Claim 17 A vibration damper (1) with a hydraulic end stop (2) comprising: a cylinder (3) radially limiting a cylinder space (31) filled with damping medium; a piston rod guide (51) axially limiting the cylinder space (31) on at least one side; a piston rod (4) having a supporting surface (42) and axially guided within the cylinder space (31) and penetrating the piston rod guide (51), the piston rod (4) connected to a piston (6) which divides the cylinder space (31) into a first working space (31a) arranged between the piston (6) and the piston rod guide (51) and a second working space (31b) arranged on the opposite side of the piston (6); a control space (71) formed at one end of the cylinder (3), the control space being bounded by an inner wall; wherein the hydraulic end stop (2) comprises an end stop ring (8), axially secured to the piston rod (4) and engaging radially around the piston rod (4), and wherein the hydraulic end stop (2) penetrates into the control space (71) in the end stroke region of the piston and axially limits the control space (71) on one side such that a control chamber (71a) is formed inside the control space (71), the control chamber (71a) having a volume and being axially limited by the closure element (5) on the one side and by the hydraulic end stop (2) on the other side; the volume of the control chamber (71a) being alterable depending on the axial position of the hydraulic end stop (2) in the control space (71); the hydraulic end stop (2) further comprising a sealing ring (9) that is arranged between the end stop ring (8) and the piston rod guide (51), that is supported axially on one side at the end stop ring (8), that engages radially around the piston rod (4), that is mounted in a sliding manner at the piston rod (4), wherein the sealing ring has an outer circumferential surface (91) radially contacting the inner wall of the control space (71); wherein the sealing ring (9) comprises at least one radial throttle groove (92) which ensures a defined flow of damping medium between the control chamber (71a) and the first working space (31a) when the hydraulic end stop (2) with the sealing ring (9) moves into the control space (71); and wherein the sealing ring (9) comprises a plurality of spring tongues (93) which are supported at the supporting surface (42) of the piston rod. ### Claim 18 (depends on 17) The vibration damper (1) with a hydraulic end stop (2) according to claim 17, wherein the sealing ring (9) has at least one cutout (94) formed at the radially inner surface thereof, and wherein the cutout (94) is dimensioned so as to extend axially over the entire height of the sealing ring (9). ### Claim 19 (depends on 17) The vibration damper (1) with a hydraulic end stop (2) according claim 17, wherein the sealing ring (9) comprises a throttle groove (92) and wherein the cutout (94) is connected to the throttle groove (92). ### Claim 20 (depends on 17) The vibration damper (1) with a hydraulic end stop (2) according to claim 17, wherein the supporting surface (42) is constructed as an annular groove (43). ### Claim 21 (depends on 20) The vibration damper (1) with a hydraulic end stop (2) according to claim 20, wherein the spring tongues (93) have a height and the annular groove (43) has an axial extension, and wherein the axial extension of the annular groove (43) is greater than the height of the spring tongues (93). ### Claim 22 (depends on 17) The vibration damper (1) with a hydraulic end stop (2) according to claim 17, wherein the sealing ring (9) has at least one outer bevel (95). ### Claim 23 (depends on 22) The vibration damper (1) with a hydraulic end stop (2) according to claim 22, wherein the outer bevel (95) of the sealing ring (9) is formed at the side remote of the end stop ring (8) in the installed condition. ### Claim 24 (depends on 17) The vibration damper (1) with a hydraulic end stop (2) according to claim 17, wherein the sealing ring (9) comprises an engagement formation (100) with locking tongues (101; 102) formed thereon. ### Claim 25 (depends on 17) The vibration damper (1) with a hydraulic end stop (2) according to claim 17, wherein the sealing ring (9) is formed from a plastic having resilient characteristics. ### Claim 26 (depends on 17) The vibration damper (1) with a hydraulic end stop (2) according to claim 17, additionally comprising a control tube (7), and wherein the control space (71) is limited radially by the control tube (7). ### Claim 27 (depends on 26) The vibration damper (1) with a hydraulic end stop (2) according to claim 26, wherein the control tube (7) comprises a fastening portion (72) at the end of the control tube (7) facing the piston rod guide (5) in the installed position. ### Claim 28 (depends on 27) The vibration damper (1) with a hydraulic end stop (2) according to claim 27, wherein the fastening portion (72) has a greater diameter than the diameter of the rest of the control tube (7). ### Claim 29 (depends on 27) The vibration damper (1) with a hydraulic end stop (2) according claim 27, wherein the fastening portion (72) comprises locking notches (103). ### Claim 30 (depends on 29) The vibration damper (1) with a hydraulic end stop (2) according to claim 29, wherein the control tube (7) further comprises a fastening portion (72) and locking notches (103) constructed to enter into a locking formation (104) with a further structural component part of the vibration damper (1) in the fastening portion (72) of the control tube (7). ### Claim 31 (depends on 26) The vibration damper (1) with a hydraulic end stop (2) according claim 26, wherein the control tube (7) has an inner bevel (73) at its end remote of the fastening portion (72). ### Claim 32 (depends on 26) The vibration damper (1) with a hydraulic end stop (2) according claim 26, wherein the control tube (7) comprises at least one axial bypass groove (74).