Abstract: A body support assembly includes a moveable body support member coupled to a deflectable suspension material. Methods of using and assembling the body support assembly are provided.

Abstract: A structure for adjusting a support force of a lumbar pillow includes: a back hugger body, a lumbar pillow, an elastic support, and a support adjustment mechanism; wherein a bottom of the back hugger body is hinged to a top of the lumbar pillow, and a back of the back hugger body is provided with a connection arm; one end of the elastic support is connected to a back of the lumbar pillow, and the other end of the elastic support is connected to a front side of the connection arm; and the support adjustment mechanism includes a slide block and a drive assembly connected to the slide block, wherein the slide block is slidably connected between the elastic support and the connection arm and is abutted against a back of the elastic support.

Abstract: A home or office chair is disclosed having a flexible mesh back rest and a full lumbar back support including upper and lower lumbar supports that are located one above the other at the back of the chair to press against the outside of the mesh back rest. The upper and lower lumbar supports are connected to the back of the chair by a bolt so as to move back and forth in first and opposite directions in response to a user seated in the chair moving his back against and away from the flexible mesh back rest. The upper and lower lumbar supports of the full lumbar back support apply continuous pressure through the mesh back rest to provide support for upper and lower lumbar areas of the user's back regardless of whether the user's back is at rest or pressing against the mesh back rest.

Abstract: A system is disclosed. The system includes a passenger seat. The passenger seat includes a seatback comprising one or more guide tracks and a headrest configured to couple to the seatback. The headrest includes a head portion and a lumbar portion. The lumbar portion is configured to separate from the head portion and translate to a lumbar portion of the seatback. The lumbar portion includes one or more brackets configured to slide along the one or more guide tracks. The passenger seat further includes a translation assembly mechanically coupled to the seatback and the lumbar portion. The translation assembly includes a cable coupled to the one or more brackets, wherein a movement of the cable corresponds to a translation of the lumbar portion. The translation assembly further includes a cable route. The translation assembly further includes one or more pulleys configured to guide the cable through the cable route.

Abstract: An aircraft seat (10) comprising: a seat base (12) having a base support surface (22); an outer backrest (14) mounted to and extending upwardly from the seat base (12); an inner backrest (16) mounted to the outer backrest (14) and/or the seat base (12), the inner backrest (16) having a torso support surface (20) extending between a top end (26) and a bottom end (28) of the inner backrest (16) and being displaceable between a first position and a second position, wherein: when the inner backrest (16) is in the first position: the top end (26) of the inner backrest (16) is located adjacent to the outer backrest (14) and the bottom end (28) of the inner backrest (16) is located adjacent to the base support surface (22) of the seat base (12); and when the inner backrest (16) is in the second position: the top end (26) of the inner backrest (16) is located adjacent to the outer backrest (14) and the bottom end (28) of the inner backrest (16) is located adjacent to the base support surface (22) of the seat base (12

Abstract: A rotatable chair back includes a lower section attachable to a chair seat, a flexible Y-shaped upper section for supporting a chair back frame, and two rigid supports extending substantially vertically into and between the upper section and the lower section. In use, the substantially vertical supports each serve as an axis of rotation about which the upper section may rotate relative to the lower section.

Abstract: A head support apparatus provides support to a persons head while the person is seated. In some embodiments, A seat strap passes around the seat back of a seat and is adjusted tightly enough to maintain itself in position. A support strap attaches in a least one place to the seat strap at the back side of the seat back. The support strap passes up over the top of the seat back and presents a sling at the front side of the seat back to support a user's head. The seat strap, support strap, and sling are adjustable. In other embodiments, a sling has spring powered reels associated with each end. A strap extends from each reel. Each strap has a coupler at its exposed end which may connect directly to a seat. Some embodiments include a seat having complementary couplers complementary to the couplers on the straps.

Abstract: An adjustable motor vehicle seat includes a main part, an attachment which is movable relative to the main part, and a guide element which includes a receiving portion configured for receiving the main part or the attachment at least in part and having a surface which has at least one portion shaped spherically. The guide element is mounted in a bearing point of at least one of the main part and of the attachment, said bearing point having a cross section which at least in one portion is circular.

Abstract: An adjustable motor vehicle seat includes a main part, an attachment which is movable relative to the main part, and at least two guide elements. Each guide element has a surface which is spherical in at least one portion, and a receiving portion configured for receiving the main part or the attachment at least in part. The guide elements are mounted in a bearing point of at least one of the main part and the attachment and arranged one behind the other with respect to a direction of translation of the attachment relative to the main part.

Abstract: A chair waist backrest height adjusting device includes a chair backrest bracket above the backrest, a worm rotated by turning the adjusting rod to slightly lower position, a first gear that is engaged with it and a second gear that is coaxially rotated with the first gear, and the chair backrest bracket under the backrest is provided with a waist backrest that can be slid up and down. The back of the waist backrest is provided with a tooth-row that is engaged with the second gear, so that the seated person on the chair can stretch out one or two hands to the adjustment rod for the forward or reverse turning operation, and the waist backrest can easily drive the waist backrest up and down, further the waist backrest is more easily adjusted, and there will be no displacement in the adjusted waist backrest.

Abstract: It is provided an adjusting device of a lumbar support or a side-bolster adjuster for changing the contour or position of a seat element of a vehicle seat supporting a body part of a seat user, with at least one driving device comprising a spindle drive and at least one adjustable support element for changing the contour or position of the seat element, wherein the spindle drive comprises a spindle extending along a spindle axis, which on a fastening part of the lumbar support or the side-bolster adjuster mounted in the vehicle seat is floatingly mounted at a spindle end via a spindle holder such that at this spindle end the spindle is displaceable along at least one spatial direction extending transversely to the spindle axis.

Abstract: The present invention relates to a vehicle sheet with a seat back which is provided with a urethane pad covered with a trim cover, and a pressing unit on the reverse side of the urethane pad covered with the trim cover, the pressing unit being formed with a shaft extending laterally and a pair of pressure portions arranged in the vertical direction with respect to the shaft to support both the upper and lower sides of the urethane pad by detecting the intermediate position of turning movement of the pressing unit by means of a turning movement detection unit and stopping the turning movement of the pressing unit, or is configured to press forward the upper side of the urethane pad using the upper pressure portion or the lower side of the urethane pad using the lower pressure portion by turning the laterally-extending shaft of the pressing unit.

Abstract: An arrangement having at least one resting unit (B; Hyx) each having a lying/sitting surface (B1) and an actuator (A; A1 . . . ), configured to act on the lying/sitting surface, to adjust a height and/or firmness profile (V1, . . . ). An input value (KG), which corresponds to the standard size of an article of clothing representing a given person in a clothing size system is specified via at least one input unit (EE). A control device (S) derives a control signal (SL) from the input value and outputs the control signal to the actuator, so that the actuator autonomously presets a height/firmness profile, which is adapted to physical body parameters of the person represented by the clothing size, in the lying/sitting surface. A data network (DNi) enables the control unit to output control signals (SLyx) to the actuator of a resting unit (Hyx) selected for the person in such an arrangement.

Abstract: A chair back assembly includes a frame assembly including a pair of slots extending through the frame assembly, a first location positioned between the pair of slots, and a pair of second locations located outward of an outer periphery of the frame assembly, and a vertically adjustable lumbar assembly configured to support a lumbar area of a seated user and including a central portion and a pair of end portions slidably engaging the central portion, the central portion located in the first location and the end portions located in the second locations, wherein the pair of end portion are slidably moveable within the slots between a first position and a second position that is different than the first position.

Abstract: A vehicle seat provided with a seat cushion and a seat back, wherein the seat back is provided with: a urethane pad in which the surface is covered by a trim cover; and a pressure means in which a laterally extending shaft and a pair of pressing parts in the vertical direction relative to the shaft are formed on the reverse side of the urethane pad toward the side covered by the trim cover, and a configuration is adopted such that the shaft extending in the lateral direction of the pressure means rotates or swings, thereby causing the upper-side pressing part among the upper and lower pair of pressing parts to press the upper side of the urethane pad forward and the lower-side pressing part to press the lower side of the urethane pad forward.

Abstract: A lumbar support of a chair includes a crossbar member and a first flex member. The crossbar member has a first end and a second end. The first flex member includes a first front portion coupled to the first end, a first back portion coupled to the chair, and a first web portion interconnecting the first front portion and the first back portion. The crossbar member supports a back of a user and the first flex member flexes upon engagement of the crossbar member by the back of the user.

Abstract: The invention relates to a lumbar support (1) for a chair with a backrest comprising backrest carriers (7) which are pivotable independently of each other, wherein the lumbar support comprises support regions (10a, 10b) which are each mounted on a spring element (2). The spring action of each spring element (2) is individually adjustable. In this arrangement, the spring elements (2) are arranged on a carrier (5), which can be articulated to the backrest carriers (7) of the backrest of the chair, which are pivotable independently of each other. The invention further relates to a chair with a backrest, which is formed from backrest carriers (7) which are pivotable independently of each other and which also comprises the aforementioned lumbar support (1). In this case, the lumbar support (1) is articulated to the backrest carriers (7) which are pivotable independently of each other.

Abstract: A vehicle seating assembly has a seat having a lower seat and a seatback extending upwardly from the lower seat. The seatback has a lower stationary seatback base portion having a seatback frame assembly, and an upper movable seatback hood module vertically adjustable relative the lower stationary portion. The upper movable seatback hood module has an upper seatback slide bracket, and a plurality of rail guides slidably engaging a rail. An electric motor drive unit engages a driven member to vertically adjust the upper movable seatback hood module relative the lower stationary portion when the electric motor drive unit is actuated.

Abstract: A seat assembly including a seat, a support plate configured to pivot with respect to the seat, a slide plate slidably mounted to the support plate, and a pivot arm positioned between the support plate and the slide plate and connected to the slide plate and the seat. When the support plate is pivotally adjusted with respect to the seat, the pivot arm causes the slide plate to slide along the support plate.

Abstract: An office chair including a chair back assembly that is independently adjustable to adjust the vertical height of the chair back and to provide lumbar support. The chair back assembly includes a flexible back shell that is movable vertically along a back support yoke. The vertical movement of the flexible back shell adjusts the vertical height of the chair back assembly relative to the seat. The chair back assembly further includes a lumbar adjustment mechanism having an adjustment cable connected to a bottom end of the flexible back shell. Operation of the lumbar adjustment mechanism moves the bottom end of the flexible back shell vertically within a pair of spaced lower movement slots. The movement of the bottom end of the flexible back shell increases the amount that the flexible back shell protrudes from the back support yoke, thereby increasing the lumbar support.

Abstract: A thoracic support assembly for a seat back of a seat assembly. The thoracic support assembly may include a cover and a thoracic support pad. The thoracic support pad may be movable with respect to the cover and may be configured to support at least a portion of a thoracic region of a user's spine.

Abstract: A method for assembling a chair component assembly includes providing a back support component adapted to support a portion of a seated user, providing a lumbar support assembly adapted to support the lumbar area of a seated user, providing a cover having an aesthetic outer surface and including a first pocket defining a first interior space therein, and a flap member having a first side edge attached to the first pocket and a second side edge, positioning the lumbar support assembly proximate the first pocket, folding the flap over the lumbar support assembly, and securing the second side edge of the flap to form a second pocket defining a second interior space within which the lumbar support assembly is located.

Abstract: A fiber-reinforced resin structure having a hole into which a connector that connects to another member is inserted, wherein a bearing strength at a part of an inside surface of the hole on which a load from the connector acts, represented by a stress at which displacement of the part of the inside surface of the hole starts increasing even without the load acting on the part of the inside surface of the hole from the connector increasing, is less than a breaking strength of a fiber-reinforced resin constituting that part of the structure.

Abstract: A lumbar support device includes: a seat back frame; a warped plate supported by the seat back frame to press a back of a seated person; and a reinforcing plate that reinforces the warped plate, the reinforcing plate being able to curve together with the warped plate. The warped plate includes a holder that holds a first end portion of the reinforcing plate, and a non-interference portion that allows movement of the reinforcing plate relative to the warped plate.

Abstract: A chair component assembly includes a back support component adapted to support a portion of a seated user, a lumbar support assembly adapted to support the lumbar area of a seated user, wherein the lumbar support is vertically adjustable, and a cover having an aesthetic outer surface and including a first pocket that receives the back support component therein, and a second pocket that receives the lumbar support assembly such that the lumbar support is vertically adjustable with the second pocket.

Abstract: A variable lumbar support including a frame and a support extending between an upper end and a lower end wherein the support bracket includes a first longitudinal direction. A pad having a first surface is provided within the assembly. The first surface of the pad contacts the lumbar portion of the seat assembly. The pad is positioned between the lumbar portion and the seat back cushion. Upon a sliding movement of the lumbar member along the support while in contact with the pad, a curved surface of the pad is displaced in the first longitudinal direction and a second direction normal to the first direction. As the lumbar member contacts the curved areas of the pad, the foam is displaced and pushed towards (a bulge) the seat back cushion so that the user of the vehicle seat feels a fore-and-aft movement of the lumbar member.

Abstract: A variable lumbar support including a frame and a support extending between an upper end and a lower end wherein the support bracket includes a first longitudinal direction. A pad having a first surface is provided within the assembly. The first surface of the pad contacts the lumbar portion of the seat assembly. The pad is positioned between the lumbar portion and the seat back cushion. Upon a sliding movement of the lumbar member along the support while in contact with the pad, a curved surface of the pad is displaced in the first longitudinal direction and a second direction normal to the first direction. As the lumbar member contacts the curved areas of the pad, the foam is displaced and pushed towards (a bulge) the seat back cushion so that the user of the vehicle seat feels a fore-and-aft movement of the lumbar member.

Abstract: A lumbar support of a car seat according to the present invention includes: a support plate to support user's back and made of elastic material; a support frame to which the support plate is rotatably engaged; a slider member mounted on the support frame in a movable manner in a vertical direction; a vertically driving means to move the slider member on the support frame; a biasing force control means including an upper member moving together with the slider member, a lower member disposed below the upper member, a biasing member connecting the upper and lower members to each other and having a controllable biasing force acting on the support plate depending on a distance between the upper and lower members, and an actuating means to control the distance between the upper member and the lower member.

Abstract: An adjusting device for a lumbar support includes a pair of spaced guide members. A first adjusting member is coupled to the pair of guide members and displaceable along the pair of guide members and configured such that the lumbar support is adjusted when the first adjusting member is displaced. A second adjusting member is displaceable along the pair of guide members. A drive mechanism for effecting an adjustment of the lumbar support includes a motor provided on the first adjusting member so as to be displaceable along the guide members jointly with the first adjusting member.

Abstract: A variable lumbar support assembly for a seatback of a vehicle seat assembly includes a support bracket and a lumbar member. The support bracket has an upper end, an opposite lower end, and a pair of side rails extending between the upper end and the lower end. The support bracket has a curved central portion positioned between the upper and the lower end. The lumbar member is slidingly attached to the pair of side rails of the support bracket. The slidingly attachment of the lumbar member along the pair of slide rails provides both a vertical displacement and a fore and aft displacement of the lumbar member.

Abstract: A lumbar support seat is disclosed for supporting lumbar vertebra portion, which stably supports the lumbar vertebra portion and the pelvis portion so as to maintain proper posture and comfortable sitting. The lumbar support seat includes a seat main body having an upper central portion that is curvedly indented so as to correspond to the shape of pelvis portion; a lumbar supporting die including fixing frames fixed at the upper portion of the rear end of the seat main body, and a base plate for supporting lumbar vertebra portion. The pelvis portion is supported via the seat main body and the lumbar vertebra portion is stably supported via the lumbar supporting die. The lumbar support seat helps a user to sit with proper and comfortable posture.

Abstract: A folding chair is disclosed including a folding chair frame, support material, and a pillow that can move between raised and lowered positions relative to the folding chair frame.

Abstract: An orthopedic device for improving posture while sitting, having a foundation member including a front portion for upper legs and a bowl portion for lower pelvic area. The bowl portion has a central portion and an upwardly inclined lateral portion. The lateral portion and the front portion collectively surround the central portion. A channel attachment is connected with one or more pelvic crest portions. The channel attachment portion connects over a concave recessed portion. The central portion has plural regions of varying flexibility and the lateral portion has plural regions of varying flexibility.

Abstract: A seating structure includes a backrest member having an upper edge, opposite side edges and a lower edge. The backrest member has a forwardly facing convex shape formed along a vertical centerline thereof between the upper and lower edges. The lower edge has a forwardly facing concave shape. The lower edge has outer portions positioned forwardly of an entirety of the upper edge.

Abstract: A lumbar support apparatus includes a curved plate which is provided to a seat-back frame so that the upper part of the curved plate is rotatable in the vertical direction, and which is deformable in the direction in which a seated person's lumbar spine is pressed; a curved-plate deformation-amount adjustment unit including a threaded rod having an external thread foamed on the peripheral surface thereof, and a nut member that is threadedly engaged with the external thread of the threaded rod and is attached to the lower part of the curved plate so as to be prohibited from rotating about a center axis and so as to be movable in the vertical direction; and a drive unit for rotatingly driving the threaded rod.

Abstract: Provided is a chair which comprises a lumbar support that is capable of comfortably supporting the lumbar region and that is capable of providing stable support with a side frame pole of a back frame. This invention comprises: a lumbar support main body (41) in which a lumbar support (10) that is provided on the chair has a top-to-bottom dimension that gradually becomes smaller from the left and right ends toward the center by having the lower edge of the center in the left/right direction curving upward in an arc shape; four attaching portions (42) which are provided on both sides of the lumbar support main body (41) so as to be separated in the vertical direction and which are movably supported in the vertical direction by guide portions that are provided on the left and right side frame poles (19) and that are directed vertically; and operating members (44) which are linked with the left and right lower attaching portions (42).

Abstract: A resilient leaning position-restoring device for a height-adjustable chair back of an office chair includes a back support unit, a height-adjustable chair back disposed on the back support unit, and a resilient leaning position-restoring device disposed between the back support unit and the chair back. The resilient leaning position-restoring device essentially includes a sliding element slidable along a slot disposed on the back support unit and being pulled downward by a spring. The upper end of the sliding element extends to form a resilient member of an inverted U shape. A lower end of the resilient member is coupled to the chair back. The resilient member maintains the predetermined resilience thereof for supporting the bottom of the chair back while height adjustment of the chair back is underway. The bottom of the chair back lends proper support to the sitter's waist, regardless of an adjusted position of the chair back.

Abstract: A lumbar support device includes: a seat back frame; a warped plate supported by the seat back frame to press a back of a seated person; and a reinforcing plate that reinforces the warped plate, the reinforcing plate being able to curve together with the warped plate. The warped plate includes a holder that holds a first end portion of the reinforcing plate, and a non-interference portion that allows movement of the reinforcing plate relative to the warped plate.

Abstract: An office chair includes a seat and a backrest that are pivotally connected together at a pivot axis such that the backrest can pivot with respect to the seat between an upright position and a reclining position. The seat is mounted on a base such that the seat can move with respect to a base, and the seat includes front and rear portions that can pivot with respect to one another. When the backrest is pivoted from the upright position to the reclining position, both of the seat and the pivot axis move forward with respect to said base, and the seat front portion flexes with respect to the seat rear portion such that the angle between said upward faces of said seat front portion and the seat rear portion increases. The backrest may also include an upper portion and a lower portion that can pivot with respect to one another. When the backrest is moved to the recline position, the angle between the forward faces of the upper and lower backrest portions decreases.

Abstract: A chair assembly includes a base structure, a seat support structure movably coupled to the base structure, an upwardly-extending back support structure movably coupled to the base structure, wherein the back support structure is adapted to move between an upright and reclined positions, wherein the back support structure is operably coupled to the seat support structure, a flexible shell structure defining a forwardly-facing surface forming a lumbar support, wherein the flexible shell is movably coupled to the seat support structure, and a resilient member generating a variable compressive force acting on the flexible shell structure in a manner that tends to cause a curvature of the back support structure to increase, and wherein the compressive force decreases as the back support structure moves from the upright position to the reclined position.

Abstract: A vehicle seat (10) includes an improved seat frame member (14) used as a seat back, a recliner mechanism connection (16) and a vehicle seat track actuator mechanism (18). The seat back frame member (14) includes a side frame member (30) having a side frame structural member (32) preferably made from a relatively high strength steel and a stiffening insert member (42) to provide strength and rigidity to the recliner mechanism connection (16) and to reduce the overall mass of the vehicle seat frame member and thereby the vehicle seat (10). The seat frame member (14) further includes a recliner mechanism (34) welded to the side frame structural member (32) preferably utilizing a shaped laser weld pattern (40). The vehicle seat track actuator mechanism (18) includes a bar (56), first and second pivot pins (62, 64) and connectors (70).

Abstract: An office chair (1) comprising a seat (2) and a backrest (3), wherein the backrest (3) includes a lumbar support (4), which is adjustable between an inactive position in which it follows the general shape of the backrest (3), and a fully active position in which it is curved outwards forwardly from the backrest (3) in order to support the lumbar back portion of a person seated on the seat (2) of the chair (1).

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 task chair with a chair base, a pivoting mechanism housing supported by the chair base, a non-pivoting seat bottom, and a pivoting seat back coupled to the pivoting mechanism housing. The seat bottom can have a rigid seat pan that underlies a flexible seat insert and a seat cushion. The seat pan, the seat insert, and the seat cushion can be matingly engaged. A seat back frame can retain a panel of elastomeric material, and lumbar supports can be slidably retained by the seat back frame. The lumbar supports can be flexible to adjust to contoured support rails and can be fixed at selected locations along the rails. The lumbar supports can have non-symmetrical, contoured surfaces and shapes and can be nondestructively removable and exchangeable. Adjustable arm structures with upper and lower arm members can be raised and lowered by operation of an actuation trigger.

Abstract: A combination includes front and rear frames each having a central hollow portion. The central hollow portion of the front frame includes two lateral sides each having a flexible plate with a plurality of vertically spaced positioning grooves. A guiding groove is defined in each of two lateral sides of the central hollow portion of the rear frame. A waistrest includes a support portion. A lug is formed on each of two sides of the support portion. A protrusion is formed on a rear face of each lug and is received in one of the guiding grooves of the rear frame. A positioning member is formed on the front face of each lug. Each flexible plate abuts the front face of one of the lugs. The positioning member of each lug of the waistrest is engaged in one of the positioning grooves of one of the flexible plates.

Abstract: An adjusting device for a lumbar support comprises a pair of spaced guide members, an adjusting member coupled to the pair of guide members, and a drive mechanism for effecting an adjustment of the lumbar support. The adjusting member is displaceable along the pair of guide members and configured such that the lumbar support is adjusted when the adjusting member is displaced. The drive mechanism comprises a motor, which is provided on the adjusting member so as to be displaceable along the guide members jointly with the adjusting member. The motor may be coupled to a shaft having a structured exterior surface, the drive mechanism being configured to effect a relative displacement between the adjusting member and the shaft.

Abstract: A pelvic support apparatus for a seat having a seat back and a seat pan includes a frame positioned within the seat back and a pelvic support member coupled with the frame adjacent a bottom of the seat back and a rear of the seat pan. The pelvic support member is movable between a first, retracted position, and a second, extended position that provides support to a pelvic area of a person seated in the seat. The pelvic support member has first and second lateral support portions operable to provide support to the pelvic area, each lateral support portion spaced from a central axis of the seat back.

Abstract: A folding chair is disclosed including a folding chair frame, support material, and a pillow that can move between raised and lowered positions relative to the folding chair frame.

Abstract: A four way lumbar support for an automobile seat includes a wire array, a fixed frame, and a basculating arm. When in its extended position, the basculating arm exerts pressure on the wire array thus providing lumbar support to the seat occupant at that point. A system of cables and sliding connections allows the basculating arm to slide along the fixed frame so that the lumbar support may be provided at different heights within the seat.

Abstract: An adjusting device for a lumbar support comprises a pair of spaced guide members, an adjusting member coupled to the pair of guide members, and a drive mechanism for effecting an adjustment of the lumbar support. The adjusting member is displaceable along the pair of guide members and configured such that the lumbar support is adjusted when the adjusting member is displaced. The drive mechanism comprises a motor, which is provided on the adjusting member so as to be displaceable along the guide members jointly with the adjusting member. The motor may be coupled to a shaft having a structured exterior surface, the drive mechanism being configured to effect a relative displacement between the adjusting member and the shaft.