# US 8,739,683 B2 · Gas spring piston with partial bellows support feature and gas spring assembly including same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,739,683 B2 - Document ID: US8739683B2 - Status: Granted - Kind: B2 - Application number: 13/466,534 - Filed: 2012-05-08 - Published: 2012-08-30 - Granted: 2014-06-03 - Earliest claimed: 2008-07-02 - Assignees: Firestone Industrial Products Company, LLC - Applicants: Stephen R. Egolf; Andrew Grabarz; Stephen C. Street; Pradipta N. Moulik - Inventors: Stephen R. Egolf; Andrew Grabarz; Stephen C. Street; Pradipta N. Moulik - Web page: https://patentgrep.com/patent/US8739683B2 ## CPC - F16F 9/057: {characterised by the piston} - F16F: SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION ## Abstract A piston for use in forming a gas spring assembly includes a longitudinally extending axis, a first end wall extending approximately transverse to the axis, and an outer side wall extending longitudinally from adjacent the first end wall. The outer side wall includes a first side wall portion that forms a fully circumferential outer surface and a second side wall portion that forms a partially circumferential outer surface that extends longitudinally beyond the fully circumferential outer surface. A gas spring assembly including such a piston is also included. ## Claims ### Claim 1 A gas spring assembly comprising: a flexible sleeve including a sleeve wall extending between longitudinally-spaced sleeve ends and having a longitudinal axis extending therebetween, said sleeve wall extending circumferentially about said axis to at least partially define a spring chamber; an end member secured along one of said ends of said flexible sleeve such that a substantially fluid-tight seal is formed with said sleeve wall; and, a piston secured on the other of said ends of said flexible sleeve such that a substantially fluid-tight seal is formed with said sleeve wall, said piston including a first end wall abuttingly engaging said sleeve wall and an outer side wall extending transverse to said first end wall and suitable for rolling a lobe of said sleeve wall therealong, said outer side wall including: a first side wall portion at least partially defining a fully circumferential support area for abuttingly engaging said flexible sleeve; a second side wall portion extending longitudinally from said first side wall portion in a direction away from said first end wall, said second side wall portion defining a first partially circumferential support area that extends around less than the full circumference of said piston; and, a third side wall portion extending longitudinally from said first side wall portion in a direction away from said first end wall, said third side wall portion disposed in circumferentially spaced relation to said second side wall portion and defining a third partially circumferential support area that extends around less than the full circumference of said piston; said first and second partially circumferential support areas being dimensioned to abuttingly engage corresponding circumferential portions of said flexible sleeve upon longitudinal displacement of said lobe of said sleeve wall beyond said fully circumferential support area. ### Claim 2 (depends on 1) A gas spring assembly according to claim 1, wherein said first end wall is approximately planar. ### Claim 3 (depends on 1) A gas spring assembly according to claim 1, wherein said outer side wall includes a distal edge disposed opposite said first end wall, and said distal edge being at least partially defined by a distal extent of said first side wall portion and said a distal extent of said second side wall portion such that said distal edge has a non-planar profile. ### Claim 4 (depends on 3) A gas spring assembly according to claim 3, wherein said third side wall portion has a distal extent disposed said second longitudinal distance from said first end wall, said distal edge of said outer side wall is at least partially defined by said distal extent of said first side wall portion, said distal extent of said second side wall portion and said distal extent of said third side wall portion with said distal extents of said second and third side wall portions and said distal extent of said first side wall portion being interconnected such that said distal edge of said outer side wall extends substantially continuously about said outer side wall. ### Claim 5 (depends on 1) A gas spring assembly according to claim 1, wherein said piston includes an inner side wall disposed in radially-inwardly spaced relation to said outer side wall such that an outer chamber is at least partially defined therebetween. ### Claim 6 (depends on 5) A gas spring assembly according to claim 5, wherein said piston includes first and second support walls extending from said inner side wall to said outer side wall such that said inner and outer side walls are interconnected thereby, said first and second support walls being disposed in spaced relation to one another such that said outer chamber is at least partially divided by said first and second support walls. ### Claim 7 (depends on 5) A gas spring assembly according to claim 5, wherein said piston extends longitudinally between opposing first and second ends, and said inner side wall at least partially defines an inner chamber having an open end disposed toward one of said first and second ends of said piston. ### Claim 8 (depends on 1) A gas spring assembly according to claim 1, wherein said outer side wall includes a distal edge disposed in spaced relation to said first end wall, and said piston includes a second end wall disposed opposite said first end wall along said second end, said second end wall being substantially planar and adapted to abuttingly engage an associated structural component such that said distal edge of said outer side wall is supported in spaced relation to the associated structural component. ### Claim 9 (depends on 8) A gas spring assembly according to claim 8, wherein said piston includes at least one securement feature accessible from along said second end and operative to at least partially secure said piston along the associated structural component. ### Claim 10 (depends on 9) A gas spring assembly according to claim 9 further comprising an external mounting bracket adapted to cooperatively align with said at least one securement feature for securing said piston on the associated structural component. ### Claim 11 A piston for use in forming an associated gas spring assembly including an associated flexible sleeve, said piston comprising: a first end including a first end wall adapted to abuttingly engage the associated flexible sleeve of the associated gas spring assembly; an opposing second end including a second end wall adapted to abuttingly engage an associated structural component, said second end disposed in longitudinally-spaced relation to said first end such that a central axis extends therebetween; and, an outer side wall extending longitudinally along said piston and being suitable for rolling of an associated lobe of the associated flexible sleeve therealong, said outer side wall including: a first side wall portion at least partially defining a fully circumferential support area for abuttingly engaging said flexible sleeve, said first side wall portion having a distal extent disposed at a first longitudinal distance from said first end wall; a plurality of second side wall portions extending longitudinally from said first side wall portion in a direction away from said first end wall, said plurality of second side wall portions disposed in circumferentially spaced relation to one another and having a distal extent disposed at a second longitudinal distance from said first end wall, said second longitudinal distance being greater than said first longitudinal distance such that said plurality of second side wall portions extend longitudinally beyond said distal extent of said first side wall portion, and each of said plurality of second side wall portions defining a partially circumferential support area that extends around less than the full circumference of said piston, said plurality of second side wall portions being dimensioned to abuttingly engage a corresponding circumferential portion of the associated flexible sleeve upon longitudinal displacement of the associated lobe of the associated sleeve wall beyond said fully circumferential support area. ### Claim 12 (depends on 11) A piston according to claim 11, wherein said distal extent of said first side wall portion and said distal extent of said at least one second side wall portion together at least partially define a distal edge of said outer side wall with said distal edge having a non-planar profile. ### Claim 13 (depends on 11) A piston according to claim 11, wherein said distal extents of said plurality of second side wall portions and said distal extent of said first side wall portion are interconnected to at least partially define a distal edge that extends substantially continuously about said outer side wall. ### Claim 14 (depends on 13) A piston according to claim 13, wherein said plurality of second side wall portions each include first and second transition sections which are each curvilinear and approximately tangentially interconnect with said distal extents of said first and second side wall portions such that said distal edge of said outer side wall forms a single contoured surface. ### Claim 15 (depends on 11) A piston according to claim 11 further comprising an inner side wall extending longitudinally along said piston, said inner side wall disposed in radially-inwardly spaced relation to said outer side wall such that an outer chamber is at least partially defined therebetween. ### Claim 16 (depends on 15) A piston according to claim 15 further comprising a plurality of support walls extending between said inner and outer side walls thereby interconnecting said inner and outer support walls to one another, said plurality of support walls disposed in spaced relation to one another such said outer chamber is at least partially separated into a plurality of chamber portions. ### Claim 17 (depends on 11) A piston according to claim 11, wherein said outer side wall includes one or more of a substantially cylindrical wall section, a curvilinear wall section and a frustoconical wall section extending longitudinally therealong. ### Claim 18 (depends on 1) A gas spring assembly according to claim 1, wherein said second side wall portion extends circumferentially through an included angle having a value within a range of from approximately 10 degrees to approximately 170 degrees, and said third side wall portion extends circumferentially through an included angle having a value within a range of from approximately 10 degrees to approximately 170 degrees. ### Claim 19 (depends on 11) A piston according to claim 11, wherein said plurality of second side wall portions extend circumferentially through an included angle having a value within a range of from approximately 10 degrees to approximately 170 degrees. ### Claim 20 A gas spring assembly comprising: a flexible sleeve including a sleeve wall extending between longitudinally-spaced sleeve ends and having a longitudinal axis extending therebetween, said sleeve wall extending circumferentially about said axis to at least partially define a spring chamber; a first end member secured along one of said ends of said flexible sleeve such that a substantially fluid-tight seal is formed with said sleeve wall; and, a second end member secured on the other of said ends of said flexible sleeve such that a substantially fluid-tight seal is formed with said sleeve wall, said second end member including: a first end wall abuttingly engaging said sleeve wall; a first side wall portion extending transverse to said first end wall and suitable for rolling a lobe of said sleeve wall therealong, said first side wall portion at least partially defining a fully circumferential support area for abuttingly engaging said flexible sleeve, said first side wall portion having at least one distal extent disposed at a first longitudinal distance from said first end wall; and, a plurality of second side wall portions extending longitudinally from said first side wall portion in a direction away from said first end wall, said plurality of second side wall portions extend longitudinally beyond said distal extent of said first side wall portion, said plurality of second side wall portions disposed in circumferentially spaced relation to one another such that each of said plurality of second side wall portions defines a partially circumferential support area that extends around less than the full circumference of said second end member, said plurality of second side wall portions being dimensioned to abuttingly engage a corresponding circumferential portion of said flexible sleeve upon longitudinal displacement of said lobe of said flexible sleeve wall beyond said fully circumferential support area.