# US 2019/0167007 A1 · Compliant backrest > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0167007 A1 - Document ID: US20190167007A1 - Status: Published application - Kind: A1 - Application number: 16/208,206 - Filed: 2018-12-03 - Published: 2019-06-06 - Earliest claimed: 2017-12-05 - Assignees: Steelcase Inc. - Applicants: Steelcase Inc. - Inventors: Nickolaus William Charles Deevers; Kurt R. Heidmann; Pascal Rolf Hien; Jeffrey A. Hall; John Colasanti; Michael Yancharas - Web page: https://patentgrep.com/patent/US20190167007A1 ## CPC - A47C 7/44: with elastically-mounted frame - A47C 7/40: for the back - A47C 7/46: with special, e.g. adjustable {, lumbar region support} profile; "Ackerblom" profile chairs - A47C: CHAIRS; SOFAS; BEDS ## Abstract A backrest includes a frame having a pair of laterally spaced upright members connected with longitudinally spaced upper and lower members. A flexible shell has opposite sides coupled to the upright members and upper and lower portions coupled to the upper and lower members. The shell includes first and second slots extending longitudinally along opposite sides of the shell inboard of locations where the shell is connected to the upright members, and one or more third slots extending laterally along the lower portion of the shell above a location where the shell is connected to the lower member. Terminal ends of the one or more third slots are spaced apart from lower terminal ends of the first and second slots. In other embodiments, the shell is a three-dimensional molded component having a plurality of openings. In various embodiments, the slots and/or openings provide different levels of compliance to the backrest. ## Claims ### Claim 1 A backrest comprising: a peripheral frame defining a central opening and comprising a pair of laterally spaced upright members connected with longitudinally spaced upper and lower members; and a flexible shell comprising opposite sides coupled to the upright members and upper and lower portions coupled to the upper and lower members, wherein the shell comprises: first and second slots extending longitudinally along opposite sides of the shell inboard of locations where the shell is connected to the upright members; and one or more third slots extending laterally along the lower portion of the shell above a location where the shell is connected to the lower member, wherein terminal ends of the one or more third slots are spaced apart from lower terminal ends of the first and second slots, wherein the shell comprises first and second bridge portions defined between the terminal ends of the one or more third slot and the lower terminal ends of the first and second slots. ### Claim 2 (depends on 1) The backrest of claim 1 wherein the shell further comprises a plurality of openings arranged between the first and second slots and above the one or more third slots. ### Claim 3 (depends on 2) The backrest of claim 2 wherein the plurality of openings comprises a matrix of openings adapted to allow lateral expansion of the shell. ### Claim 4 (depends on 3) The backrest of claim 3 wherein the matrix of openings is adapted to provide longitudinal expansion of the shell. ### Claim 5 (depends on 2) The backrest of claim 2 wherein the plurality of openings comprise a plurality of first openings having a first shape and a plurality of second openings having a second shape different than the first shape, wherein the first and second openings are arranged in an alternating pattern in both a lateral direction and a longitudinal direction. ### Claim 6 (depends on 5) The backrest of claim 5 wherein the first shape is a laterally oriented dog-bone shape and the second shape is a longitudinally oriented dog-bone shape. ### Claim 7 (depends on 1) The backrest of claim 1 wherein the terminal ends of the one or more third slots are positioned below the lower terminal ends of the first and second slots. ### Claim 8 (depends on 7) The backrest of claim 7 wherein the lower terminal ends of the first and second slots extend laterally outwardly from the first and second slots. ### Claim 9 (depends on 7) The backrest of claim 7 wherein the one or more third slots have an intermediate portion with an upwardly oriented concave shape. ### Claim 10 (depends on 9) The backrest of claim 9 wherein the terminal ends of the one or more third slots each have a downwardly oriented concave shape. ### Claim 11 (depends on 2) The backrest of claim 2 wherein the shell comprises a ring-like peripheral edge portion surrounding the plurality of openings. ### Claim 12 (depends on 11) The backrest of claim 11 wherein the one or more third slots extend laterally along a bottom portion, and between opposite side portions, of the peripheral edge portion. ### Claim 13 (depends on 1) The backrest of claim 1 wherein the first and second slots each have a length greater than ⅓ of an overall length of the shell. ### Claim 14 (depends on 13) The backrest of claim 13 wherein at least ½ of the length of each of the first and second slots is disposed beneath a laterally extending centerline of the shell. ### Claim 15 (depends on 1) The backrest of claim 1 further comprising an auxiliary body support member having end portions engaging the shell at, and moveable along, the first and second slots, wherein the auxiliary body support member is moveable along a surface of the shell as the end portions are moveable along the first and second slots. ### Claim 16 (depends on 15) The backrest of claim 15 wherein the auxiliary body support member is disposed against and is moveable along a forwardly facing body support surface of the shell. ### Claim 17 (depends on 16) The backrest of claim 16 further comprising a cover disposed over the body support surface of the shell, wherein the auxiliary body support member is disposed between the cover and the shell. ### Claim 18 (depends on 2) The backrest of claim 2 wherein the shell comprises a molded component having a three-dimensional shape in a non-loaded configuration. ### Claim 19 (depends on 18) The backrest of claim 18 wherein the shell has a forwardly facing convex shape along a vertical centerline and a forwardly facing concave shape along a horizontal centerline in the non-loaded configuration. ### Claim 20 (depends on 18) The backrest of claim 18 wherein the shell has flush front and rear surfaces in an area defined by the plurality of openings. ### Claim 21 (depends on 20) The backrest of claim 20 wherein the shell material has a Young's Modulus E≥100,000 PSI. ### Claim 22 (depends on 20) The backrest of claim 20 wherein the shell has different thicknesses in different regions of the area defined by the plurality of openings. ### Claim 23 (depends on 1) The backrest of claim 1 wherein the opposite sides of the shell are non-rotationally fixed to the upright members. ### Claim 24 (depends on 23) The backrest of claim 23 wherein the upper and lower portions are non-rotationally fixed to the upper and lower members. ### Claim at position 25 25-38. (canceled) ### Claim 39 A backrest comprising: a peripheral frame defining a central opening and comprising a pair of laterally spaced upright members connected with longitudinally spaced upper and lower members; and a flexible shell comprising opposite sides coupled to the upright members and upper and lower portions coupled to the upper and lower members, wherein the shell comprises: first means for providing macro-compliance of the shell relative to the frame; and second means for providing micro-compliance of the shell of the frame relative to the frame. ### Claim 40 A backrest comprising: a frame comprising a pair of laterally spaced upright members; and a flexible shell comprising opposite sides coupled to the upright members, wherein the shell comprises: first and second slots extending longitudinally along opposite sides of the shell inboard of locations where the shell is connected to the upright members; and a plurality of openings arranged between the first and second slots, wherein the plurality of openings comprises a matrix of openings adapted to allow lateral expansion of the shell. ### Claim at position 28 41-42. (canceled) ### Claim 43 (depends on 40) The backrest of claim 40 wherein the frame comprises a lower member extending between and connecting the laterally spaced upright members, and wherein the flexible shell comprises a lower portion positioned below the plurality of openings and connected to the lower member, and wherein the shell further comprises one or more third slots extending laterally along the lower portion of the shell above a location where the shell is connected to the lower member and below the plurality of openings. ### Claim 44 (depends on 39) The backrest of claim 39 wherein the first means for providing macro-compliance comprises first and second slots extending longitudinally along opposite sides of the shell inboard of locations where the shell is connected to the upright members and wherein the second means for providing micro-compliance comprises a plurality of openings arranged between the first and second slots.