Abstract: A body support assembly includes a seat assembly and backrest assembly supported by a tilt control assembly. Methods of using and assembling the body support assembly are provided.

Abstract: A seatback assembly includes a pair of lateral seatback assembly frame members and a moveable thoracic back support defining a support surface operably coupled with an upper thoracic support bracket. An attachment assembly operably couples the thoracic back support to the upper thoracic support bracket, and includes a pair of mounting lugs disposed on either of one of the upper thoracic support bracket or the moveable thoracic back support, and a pair of mounting bosses disposed on the other of the upper thoracic support bracket or the thoracic back support. The seatback assembly is assembled by aligning the pair of mounting lugs with the pair of mounting bosses as the moveable thoracic back support is horizontally positioned above the lower seatback insert, whereby the pair of mounting lugs are received within the pair of mounting bosses, and vertically lowering the moveable thoracic back support relative the lower seatback insert.

Abstract: An energy absorbing backshell including a non-metallic core, a non-metallic casing surrounding the non-metallic core, a tube on the top surface of the non-metallic core and non-metallic casing.

Abstract: A seating device and seating device backrest are described. The seating device and backrest have a seat portion dimensioned for an occupant; a support arm coupled to seat portion proximate a first end of the support arm; a mounting receptacle coupled to the support arm proximate a second end of the support arm, wherein the mounting receptacle is configured to accept a substantially convex body, and wherein the support arm is configured to position the mounting receptacle at an angle such that the convex body makes focal contact at an seat occupant's optimally concave lumbar/thoracic spinal regions.

Abstract: A mounting clamp assembly that provides at least one support point for a wheelchair back mounting assembly, the mounting clamp assembly includes a clamp block and threaded clamp fastener extending through the clamp block and engaging a support by which the mounting clamp can be secured to a wheelchair cane; the mounting clamp assembly can be easily disassembled and adjusted to accommodate upright frame members of various diameters without the use of a tool.

Abstract: A portable seating apparatus and method for easy assembly/disassembly of the same is described. The apparatus is designed for easy display of theme based design components which may be easily changed with minimal effort and complication. The assembly includes standing and swing type embodiments. The apparatus comprises seat, side support, and back rest components. The seat component generally comprises one or more substantially horizontal seat members and a front frontboard member to be removably attached with the front of the seat component. Right and left side support components include integral seat support, arm rest and back rest support portions. The backrest component includes at least one backboard member.

Abstract: Described is a passenger seat that includes a seat bottom assembly (201) with a forward edge and a rear edge and a seat back assembly (101) extending up from the rear edge of the seat bottom assembly (201). The seat back assembly (101) may include a frame (103), a plurality of panels (104-107) within a perimeter of the frame (103), and at least one attachment member (161) configured to attach the plurality of panels (104-107) to the frame (103). The seat bottom assembly (201) may include a frame (203) and a plurality of panels (204,205,206) within a perimeter of the frame (103).

Abstract: A universal upper back support primarily for piano and organ benches has been created, and is easily attached to any wooden bench used for instrument playing. The back support contains a cushion which is positioned at the correct angle by two vertical side pieces for engagement with the musician's upper back, and allows free movement of the arms, hips, and legs in any direction without any hindrances while the musician plays a selected instrument. The vertical side pieces may each optionally have a lower front indentation to allow easy opening of the hinged top seat of a music bench having an interior storage space, and the back support can be alternatively made with a manual adjustment mechanism that allows finger-activated vertical height adjustment of its cushion in selected pre-drilled holes. The back support can be provided with an installation template for ease of user installation.

Abstract: An adjustment apparatus for a wheelchair back that can be used with various backs, that can be adjusted in a plurality of ways using a single adjustment point, and that can be adjusted without the use of tools. In another aspect, includes a support mechanism for mounting an adjustment apparatus for a wheelchair back that can be engaged using gravity, that provides at least one support point, and that can be utilized without the use of tools. Still another aspect of the wheelchair back assembly includes a mounting clamp that is simple in construction, that provides at least one support point, and that can be easily disassembled and adjusted to accommodate upright frame members of various diameters without the use of a tool.

Abstract: A lumbar support on a chair comprises a lumbar support body in which a vertical width gradually becomes smaller from right and left ends to the middle; four mounting portions spaced apart from each other vertically on the lumbar support body and moving vertically along a guide on each of the pair of side frame rods and an operating member connected to each of the mounting portions on the lower edge.

Abstract: The structure for mounting a seating body according to the present invention includes a seating body mounting portion, a leg mounting portion and a screw. The seating body mounting portion is provided to a back surface of a seating face of a seating body, and has a screw hole. The leg mounting portion is provided to a leg member, and includes a through-bore formed thereon into which a screw shaft can be inserted. The screw fixes the seating body mounting portion and the leg mounting portion. The seating body mounting portion contacts the leg mounting portion on a first region in which the screw hole is formed and on a second region which is spaced from the first region via a groove.

Abstract: A support mechanism (20) for mounting a wheelchair back to a wheelchair post including at least one generally horizontally extending support pin (30), the support mechanism (20) comprising a hanger arm (24) having a downwardly opening hook (26) defining an upper support point and a self-locking latch (34) pivotally mounting to the hanger arm (24), the latch defining a locking notch (40) and a stop notch (42), the latch (34) being pivotal between a locked position in which the latch locking notch (40) and the hook (26) define a substantially closed hole around the support pin (30) and an unlocked position in which the pin (30) is seated in the stop notch (42) such that the latch (34) is secured open so the hanger arm hook (26) can be connected to or removed from the wheelchair post support pin (30); the latch (34) is shaped and weighted such that the latch can be moved to the locked position under the force of gravity.

Abstract: A vehicle seat assembly including at least a component of the seat assembled made of closed-cell foam and having an integral exterior surface. The component may include a backrest, headrest, seat cushion or a component thereof such as an armrest. A method of forming a seat assembly including a first seat component and a second seat component wherein at least one of the first and the second components are made of closed-cell foam.

Abstract: A backrest for a wheelchair includes an adjustable cushion support, a backrest frame, and attachment members. The adjustable cushion support supports a backrest cushion, and substantially defines plane P1. The backrest frame holds the cushion support and has two substantially parallel side posts substantially defining a plane P2. The attachment members attach the cushion support to the backrest frame. The cushion support comprises two side bars and a plurality of transversally extending and vertically spaced apart flexible straps. Each strap is length adjustable. The cushion support comprises at least two connecting plates. Each plate being integral with one of the side bars and being provided with at least two parallel adjustment slots. The slots define an angle ?, with said plane P1 of the adjustable support cushion. The attachment members are slidably mounted on the slots, enabling depth, width and angular adjustment of the cushion support on the backrest frame.

Abstract: A vehicle seating assembly having a seat back including a polymeric body portion defining a forward support frame having a plurality of forwardly extending connection pins on a front surface thereof. A flexible comfort carrier is disposed on the polymeric body portion and includes a plurality of slots configured to receive the plurality of forwardly extending connection pins. A seat includes a seat pan that is rotatable over a seat bin between open and closed positions. The seat pan includes a forward upwardly-rounded hump configured to lessen the potential of a passenger to slide forward in the seat. The seat pan includes a storage compartment on an underside thereof that includes a latchable lid.

Abstract: A support frame removably engageable with a wheelchair using no fasteners or tool-requiring engagement components. The support frame is slidably engaged and disengaged to the wheelchair by vertical translation. In an engaged position the weight of the support frame and anything attached thereto is born entirely by the rigid frame of the wheelchair through a positioning of support members of the frame in a frictional engagement atop the push handles of the wheelchair. So engaged, the support frame allows for easy transfer to other wheelchairs or easy removal and engagement from a collapsible wheelchair prior to or after transport of the wheelchair in a car or vehicle.

Abstract: In a seat backboard, a backboard section is formed with a size that enables it to pass through between left and right side frames of a seatback frame. Coupling fixing sections are also provided at the two seat width direction sides of the backboard section, the coupling fixing sections engaging with the front side of the side frames and supported by the side frames. The seat backboard can thereby be attached to the seatback frame from the seat front side, and the degrees of freedom for design can be increased. The seat backboard is also provided with a cover anchor section to which outer periphery anchor portions provided to a seat cover are anchored.

Abstract: A vehicle has a seat on which a passenger sits, wherein the seat is bench-shaped and has a sitting portion, a backrest portion, and a supporting portion which supports the sitting portion and the backrest portion, wherein at least one of the sitting portion and the backrest portion is detachable from the supporting portion, wherein when the sitting portion is detachable, the sitting portion has a plurality of sitting regions which are arranged side by side in the right-left direction and have different thicknesses in the up-down direction, and wherein when the backrest portion is detachable, the backrest portion has a plurality of backrest regions which are arranged side by side in the right-left direction and have different thicknesses in the front-rear direction.

Abstract: A transformable sporting chair system which can be transformed from a working seat for use in the outdoors, to a transportable configuration for carrying the chair to or from an outdoor location. The chair features a frame which can be nearly entirely disassembled and reassembled into the working or transport configuration. The chair includes a holding element for holding tools or equipment, such as a hunting bow. The chair may also be strapped to a tree using ratchet straps.

Abstract: The invention relates to seating furniture comprising two frames arranged at a distance to each other on a support, between which frames a seat part and a backrest part can be mounted, and the frames have one upper frame part and a lower frame part each which mechanically immobilize the seat part and the backrest part a the sides thereof. The upper frame part and the lower frame part are clamping elements that can be braced with each other. At least one clamping element has a laterally extending recess on each edge which recess forms a frame groove in which a respective engaging element provided on the edges of the seat part and of the backrest part can be mounted by way of a frictional connection to the upper frame part and the lower frame part. The recess has an undercut portion which forms a stop for holding the clamped engaging element by a form fit.

Abstract: A vehicle seatback including a seatback frame provided with a pair of seatback side frame portions and a seatback upper frame portion that connects together upper end portions of the pair of seatback upper frame portions along the seat width direction, and a support member attached to the seatback frame. The support member is provided with a lower neck bearing portion covering the seatback upper frame portion, and a shoulder bearing portion disposed further towards the front than the seatback upper frame portion in the seat front-rear direction. When a load of a specific value or greater acts on the occupant towards the rear in the seat front-rear direction, the shoulder regions of the occupant are pressed against the shoulder bearing portion, suppressing movement of the occupant towards the rear in the seat front-rear direction.

Abstract: A collapsible chair configured for compact storage is disclosed.

Abstract: A convenient telescopic folding chair includes a front foot, back cushion, rear foot, seat cushion, and telescopic rods arranged between the rear foot and the seat cushion. The front foot pivots on the rear foot by connecting components. The back cushion is inserted into two ends of the front foot. The rear foot connects the seat cushion through two telescopic rods arranged to two ends of the rear foot. The seat cushion is further connected to the front foot through connecting components. The seat cushion includes a tube frame and a cushion. The cushion is fixed to the frame will two plugs formed to two lateral sides of the cushion inserting into two ends of the frame so as to form a convenient, space-saving, light and fine folding chair.

Abstract: A vehicle seat comprising a supporting structure and a first and a second contoured panel fitted to the supporting structure and respectively defining the seat portion and the backrest of the seat. The supporting structure comprises a first and a second lateral supporting member extending along opposite sides of the seat and joined to one another by a cross-member extending along the join between the seat portion and the backrest. The first and the second panel are covered with respective flexible cover sheets that are fixed securely to the supporting structure.

Abstract: A chair may include a seat, a chair back and a frame that may be connected to the seat and/or chair back. The chair back and the frame may include engaging portions and/or receiving portions that may be sized and configured to contact, abut, engage and/or interlock with each other to connect the chair back to the frame. The engaging portions and/or receiving portions may be sized and configured to connect the chair back to the frame using a friction, interference and/or snap fit.

Abstract: A vehicle seat is provided. The vehicle seat includes: a planar elastic body that has a frame body provided in a periphery of the planar elastic body, the planar elastic body stretched to the frame body; a cushion member disposed around the planar elastic body; and a backbone member, wherein a supporting surface configured to support a seated person is formed by the planar elastic body and the cushion member, the planar elastic body is assembled to the seat by fixing the frame body to the backbone member, and the cushion member is disposed to be overlaid on the periphery of the planar elastic body at a supporting surface side, the cushion member is covered by a skin material that is attached on the planar elastic body at the supporting surface side.

Abstract: An engaging structure has a first engaging portion and a second engaging portion provided on at least one portion from among a first attaching portion and a second attaching portion, and an engagable portion provided on another portion that is different from the one portion. The first attaching portion is overlapped with the second attaching portion such that the first engaging portion abuts against a first edge of the other portion and the second engaging portion abuts against a second edge of the other portion that is different from the first edge. A support member is engaged with a frame member by one of the first engaging portion or the second engaging portion being hooked onto the engagable portion.

Abstract: A seat assembly includes a molded plastic shell and an embedded frame. The seat assembly can include a seat bottom and a seat back which are connected by a curved backstop. The curve of the backstop is dictated by the embedded frame. The seat assembly can be part of a modular chair system, in which the seat assembly can be attached to a chair base, without or without optional arms. The seat assembly can be transferred between a low density stacking chair base and a high density stacking chair base without modification of the seat assembly. The arms can be attached to the chair base without modification of the chair base. A method for attaching a seat assembly to a chair base is also provided.

Abstract: A backrest for supporting the back of a seated person, intended and adapted to form part of an article of seating furniture, such as a wheelchair, has the feature that the backrest consists of two parts, that is: a lower backrest part for supporting the sacral-lumbar part of the back of a seated person, and an upper backrest part for supporting the lumbar-thoracic part of the back of a seated person; both backrest parts can be moved independently of each other relative to the carrier; and a carrier therefor which has three degrees of freedom in a vertical plane, perpendicularly of the main plane of the backrests, relative to the frame tube, i.e. two degrees of freedom of translation corresponding to height and depth, and one degree of freedom of rotation around a horizontal rotation axis.

Abstract: A chair includes a base, a seat board, a frame unit, a backrest and two armrests. The base has a cylinder, legs, and casters. The seat board is connected to the top of the base and a support frame is connected to the base so as to be connected with the frame unit. The backrest and the two armrests are detachably connected to the frame unit. The backrest and the two armrests are made by durable Nylon so as to have proper curvatures that meet ergonomic requirements. The material of the backrest and the armrests can be detached and/or replaced.

Abstract: An adjustment apparatus (100) for a wheelchair back that can be used with various backs, that can be adjusted in a plurality of ways using a single adjustment point (104), and that can be adjusted without the use of tools. In another aspect, includes a support mechanism (200) for mounting an adjustment apparatus (100) for a wheelchair back that can be engaged using gravity, that provides at least one support point, and that can be utilized without the use of tools. Still another aspect of the wheelchair back assembly includes a mounting clamp (300) that is simple in construction, that provides at least one support point, and that can be easily disassembled and adjusted to accommodate upright frame members of various diameters without the use of a tool.

Abstract: A back support is pivotally oriented to locate a pivot point relative to posterior superior iliac spines of a seated user, such that when an upper portion of the back support contacts the upper torso of the user and moves to a desired angular orientation to balance the upper torso over the pelvic area, the back support transfers support to the posterior superior iliac spines to maintain the pelvic skeletal structure in alignment. A lower portion of the back support angularly contacts, supports and confines gluteal and buttocks tissue of the user independently of the degree of pivotal orientation of the upper portion.

Abstract: A child seat has a seat base with a seating surface, a front edge, and a back end. A back support surface of the child seat is generally inclined relative to the seating surface. A seat bight is formed at the juncture between the seating surface and the back support surface. The seat bight is adjustable between a first bight position spaced a first distance from the front edge of the seat base and a second bight position spaced a second distance from the front edge of the seat base. The second distance is less than the first distance. A seat back insert can be provided that is attachable to the seat base in one or more insert positions defining one or more of the bight positions. The insert can create the back support surface at one or more position relative to the front edge. The seat base can also have a back wall creating the back support surface further from the front edge when the insert is removed.

Abstract: A child car seat subframe that is easily disassembled into component sections for washing within a residential-sized dishwasher. The car seat subframe can be disassembled by hand, and each individual component is capable of fitting in a residential-sized dishwasher individually and collectively. The component sections are attached by a combination of registration tabs and slots, and held tightly together by fasteners, or attached by a combination of tongue and groove joints. Hanging devices, such as hooks, may be formed on one side of each component section to facilitate hanging on racks in a dishwasher. The car seat subframe back panel and side panels are disassembled into a plurality of segments for easily fitting in a dishwasher.

Abstract: The back of a wheelchair user is independently supported along and about three mutually perpendicular axes. Two elongated adjustment arms are pivotally connected to extension arms which telescope into opposite ends of a hollow connecting tube. The support positions along and about the three axes is achieved by pivoting the arms and the connected relationships of a back shell and cushion to the connecting tube, while the adjustment arms remain pivotally connected to the wheelchair and the extension arms are telescopically retained in the connecting tube.

Abstract: A dismountable chair assembly includes a chair frame, back cushion, and seat cushion. The chair frame includes an H-shaped chair frame, two inverse L-shaped front chair feet, and a front transverse shaft. The back cushion is arranged to two upper shafts of the H-shaped chair frame. The lower sides of the two upper shafts are rear chair feet. A middle shaft serves to link the two inverse L-shaped chair feet and support the seat cushion. A bottom side of the seat cushion has a round skirt. Two columns are formed to a front side of the skirt. Two open holes are formed to a rear side of the skirt for being penetrated by the two inverse L-shaped front chair feet. Two rear sides of two inverse L-shaped front chair feet penetrating through the two open holes can be fixed to the middle shaft of the H-shaped chair frame by bolts.

Abstract: A folding or stacking chair has a seat and a backrest carried between opposite frame sides each with a backrest support, a front leg and a rear leg. One or both of the seat and the backrest has a continuous sheet of flexible and elastic knitted mesh or patterned open texture plastic held across and substantially covering an opening in an open-end hoop coupled between the frame sides. An open-end of the hoop faces in a front or a back orientation for the seat, or a top or a bottom orientation for the backrest, with sides of the hoop attached to the frame sides. The sheet of mesh or textured plastic has a finished edge spanning the open-end of the hoop.

Abstract: A chair assembly including a seat, a back and at least one arm that are detachably connected together without requiring the use of tools or special skill. The chair assembly can be advantageously shipped disassembled in a compact, space-efficient package to reduce shipping costs. A seat bracket affixed to the arm is slidably and removably received by a seat bracket receiver affixed to the seat, whereby the arm is detachably connected to the seat. A back bracket affixed to the back is slidably and removably received by a back bracket receiver at the arm, whereby the back is detachably connected to the arm. The back bracket includes a locking catch that is adapted to rotate into and out of locking engagement with one of a set of serrated edges from a locking plate of the back bracket receiver after the back bracket slides into removable receipt by the back bracket receiver.

Abstract: A support mechanism (20) for mounting a wheelchair back to a wheelchair post including at least one generally horizontally extending support pin (30), the support mechanism (20) comprising a hanger arm (24) having a downwardly opening hook (26) defining an upper support point and a self-locking latch (34) pivotally mounting to the hanger arm (24), the latch defining a locking notch (40) and a stop notch (42), the latch (34) being pivotal between a locked position in which the latch locking notch (40) and the hook (26) define a substantially closed hole around the support pin (30) and an unlocked position in which the pin (30) is seated in the stop notch (42) such that the latch (34) is secured open so the hanger arm hook (26) can be connected to or removed from the wheelchair post support pin (30); the latch (34) is shaped and weighted such that the latch can be moved to the locked position under the force of gravity.

Abstract: An assembling structure for a vehicle seat includes: an assembly frame having a frame shape and configured to be detachably attached to a seat main body of the vehicle seat, the seat main body having a backbone frame having a frame shape; a planar elastic body configured to elastically support a body of an occupant and is stretched on the assembly frame; an elastic latching unit configured to be detachably attached to a part of the backbone frame, the elastic latching unit formed on a part of a periphery of the assembly frame, wherein the assembly frame further includes a hook portion, the backbone frame further includes a portion to be hooked, and the planar elastic body is prevented from moving in an out-of-plane direction of the planar elastic body when the hook portion of the assembly frame is hooked on the portion to be hooked of the backbone frame.

Abstract: A vehicle seat includes a backrest connected to a sitting part by a backrest adjustment element. The adjustment element has a part that is connected to the backrest or to the sitting part. At least one means is formed, incorporated, shaped and/or arranged in the backrest, in the part and/or the seat part for securing the position of the part relative to the backrest and/or to the sitting part in at least one direction.

Abstract: A backrest of chair in which the lower part of a back frame can be concealed neatly by a stretching material. In the backrest device of a chair where a bag like stretching material (12) knitted or woven in the shape of mesh and opening downward is stretched across a back frame (11) formed by coupling the upper ends of right and left side frames (14a) directing the vertical direction by an upper frame (14b) directing the right and left direction, and coupling the lower ends of both the side frames (14a) by a lower frame (14c) which can be fixed to a backrest supporting rod (8) erected from the upper rear of the seat body of the chair, upper portion of the stretching material (12) is made air permeable, and at least a part at the lower portion of the stretching material (12) covering the lower frame (14c) is made non-translucent.

Abstract: Wheelchair seat back mounting hardware permits the seat back to be mounted on various wheelchairs. The mounting hardware may be in the form of two-point mounting hardware that connects the seat back to the wheelchair and permits the seat back height to be adjusted independently of the mounting hardware location on the wheelchair.

Abstract: A seat assembly for a vehicle includes a seat bottom and a seatback. The seatback includes a seatback frame and is selectively rotatable relative to the seat bottom from an upright position to a forward position. A seatbelt assembly includes a retractor coupled to the seatback frame and a belt selectively extendable from and retractable to the retractor. A first end of the belt is disposed in the retractor. A guide is coupled to the seatback frame and defines an orifice with the belt slideably extending through the orifice. The retractor and the guide are fixed relative to the seatback frame and the second end of the belt is fixed to the seatback frame. The retractor, the guide, and both ends of the belt rotate from the upright position to the forward position in response to a force exerted on the seatback frame during rapid deceleration of the seat assembly.

Abstract: A supportive back rest for attachment to an original equipment back rest of a wheelchair to enhance the supportive characteristics of the wheelchair back rest. The supportive back rest includes a cushion, a suspension element and a cover. The cushion and one side of the suspension element are positioned in the cover. An opposed side of the suspension element is exposed and defines a space between it and the cushion. The suspension element slips over the upper edge of the original equipment back rest of the wheelchair to suspend the supportive back rest in position behind a seated user. The suspension element can be attached to the cover or can be attached to the cushion by molding or through attachment anchors.

Abstract: A method for manufacturing a chair assembly (20) with a customized backrest (46) includes fabricating a standardized frame (22), preparing a contoured plywood blank (48) for the backrest (46), selecting a customized design for the backrest (46) and then converting the design for the backrest (46) into a readable format, loading the readable format for the backrest (46) design into a customized cutting apparatus, loading the blank (48) into the cutting apparatus, cutting the blank (48) in conformity with the selected backrest (46) design, removing the completed blank (48) from the cutting apparatus, mounting the backrest (46) onto the frame (22), and lastly, mounting a seat (36) onto the frame (22).

Abstract: A portable lift chair has a lightweight frame with a pair of cross members extending from opposing sides thereof from front to back in a substantially X-shaped configuration, with the cross members pivotally secured to one another and to the front portion of the frame by a pivoting linkage, a seat base, a pivotable bracket connecting the front portion of the seat base to the frame, a weight adjustable pressurized cylinder providing an upward bias to the rear portion of the seat base, a removable back rest, and a guide track with an actuator for moving the weight adjustment bracket from one anchor point to another as desired to achieve a predetermined pressure for the seat.

Abstract: A seat assembly including a base and backrest having integrally formed coupler sockets that each receives respective portions of at least one coupler that preferably is an elongate angled coupling tube that joins the base and backrest while serving as a frame. The base and backrest have mating surfaces that abut when assembled to the at least one coupler with one mating surface having a tongue that is received in a groove formed in the other mating surface helping to keep the coupler seated in at least one of the sockets. In a preferred embodiment, each socket includes an elongate channel. In a preferred embodiment, a pair of coupling tubes are used with mounting portions exposed to which seating hardware is attachable. Integrally formed sockets can also be provided for attachment of other features that include armrests and/or hip restraints.

Abstract: A combined backrest for a chair comprises a left side plastic fastener, a right side plastic fastener and at least one wooden rest board. The left side plastic fastener is fixedly connected to the left side rest staff. The right side plastic fastener is fixedly connected to the right side rest staff, and the left edge part and the right edge pad of the wooden rest board are fixedly connected to the left side plastic fastener and the right side plastic fastener, respectively.

Abstract: A frame structure of a seat back for a vehicle contains a seat back frame which includes a framework disposed endlessly along a peripheral edge of a panel frame in a plane form with a substantially rectangular shape, the framework including a steel tube portion with a closed rectangular cross-section into which a pressed member is formed by welding in accordance with a position where the seat back for the vehicle is fixed to a vehicle body, the steel tube portion contains a surface on which the seat back for the vehicle is fixed.