Seat lifting devices

Abstract

Seat lifting devices disposed between a seat support for supporting a seat cushion and a seat mount for mounting the seat support in order to vertically adjust the seat cushion are taught that comprise a first linking mechanism movably interconnecting the seat support and the seat mount. The first linking mechanism comprises first and second linking arms that are respectively pivotally connected to the seat mount and the seat support via pivot axes. One of the pivot axes of the second linking arm comprises a movable pivot axis that is arranged and constructed to move along the second linking arm and to engage the second linking arm, so that substantial length of the second linking arm can be changed when the movable pivot axis moves along the second linking arm.

Description

[0001] This application claims priority to Japanese Patent Application Serial Number 2002-150970, the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to seat vertical devices or seat lifting devices for adjusting height of a seat cushion of a vehicle seat.

[0004] 2. Description of the Related Art

[0005] A seat vertical device or seat lifting device for adjusting height of a seat cushion of a vehicle seat is taught, for example, by U.S. Pat. No. 6,347,778 and Japanese Laid-Open Patent Publication No. 2001-163091.

[0006] Typically, a vehicle seat comprises a seat back and a seat cushion. The seat back and the seat cushion are respectively supported by a seat back frame and a cushion frame. The cushion frame includes a pair of opposing elongated plate-shaped members or frame elements. The cushion frame thus constructed is seated on a seat slide device that are disposed on a vehicle floor. The seat slide device has a pair of slide rail assemblies that are arranged in parallel each other. The slide rail assemblies are positioned such that the distance therebetween is substantially identical to the distance between the frame elements of the cushion frame. Each of the slide rail assemblies includes an upper rail and a lower rail. The lower rail is affixed to the vehicle floor. The upper rail slidably engages the affixed lower rail.

[0007] In the known art described in U.S. Pat. No. 6,347,778, each of the frame elements of the cushion frame is linked to the upper rail of the slide rail assembly via front and rear linking mechanisms, which mechanisms constitute a seat lifting device. The front and rear linking mechanisms respectively include a front bracket and a rear bracket that are upwardly projected from the upper rail. The front linking mechanism further includes a front arm, which arm is pivotally attached to the frame element and the front bracket via pivot pins. Similarly, the rear linking mechanism further includes a rear arm, which arm is pivotally attached to the frame element and the rear bracket via pivot pins.

[0008] Further, the seat lifting device includes a drive mechanism, which drive mechanism also constitutes the seat lifting device. The drive mechanism includes a lever, an intermediate bracket upwardly project from the upper rail and a linking rod. The lever is pivotally attached to the intermediate bracket in its middle portion. One end of the linking rod is pivotally connected to the rear arm. Also, the other end of the linking rod is pivotally connected to an upper end of the lever. Further, a nut is rotatably attached to a lower end of the lever. This nut threadably engages a threaded shaft that is driven or rotated by a drive means or motor. Therefore, when the threaded shaft is rotated by the motor, the nut moves along the threaded shaft, thereby pivoting the lever around the intermediate bracket. As a result, the linking rod connected to the lever moves back and forth, thereby pivoting the rear arm. Thus, the flame element can be lifted, so that the height of the vehicle seat cushion can be adjusted.

[0009] In the known seat lifting device, the rear arm is formed with a laterally elongated slot (first slot) and a vertically elongated arcuate slot (second slot) having a plurality of concave portions arranged therealong. On the other hand, the rear arm is provided with a pivot pin that is received in the first slot and a locking pin that is received in the second slot.

[0010] According to the known seat lifting device, when an excessive forward and upward force is applied to the cushion frame via a seatbelt that is attached thereto, each of the frame elements of the cushion frame may be pulled forwardly and upwardly and moves in this direction. As a result, the rear arm rotates around the pivot pin. However, because the pivot pin is received within the elongated slot, the rear arm forwardly is shifted, thereby engaging the locking pin with one of the concave portions of the second slot. Thus, the seat lifting device is locked, thereby preventing the frame element from further moving forwardly and upwardly. As a result, the rear arm can be effectively prevented from further rotating around the pivot pin. Therefore, the drive mechanism that is linked to the rear arm can be effectively prevented from being subjected to an undesirable large force.

[0011] As will be recognized, if the seat lifting device is not locked when the excessive forward and upward force is applied to the cushion frame, the frame element cannot be prevented from moving forwardly and upwardly. Therefore, the rear arm can freely rotate around the pivot pin. As a result, a considerable force may be applied to the drive mechanism linked to the rear arm. Such a force may exert undesirable effects on the drive mechanism.

SUMMARY OF THE INVENTION

[0012] It is, accordingly, one object of the present teachings to provide improved seat lifting devices for adjusting height of a seat cushion of a vehicle seat.

[0013] For example, in one aspect of the present teachings, seat lifting devices disposed between a seat support for supporting a seat cushion and a seat mount for mounting the seat support in order to vertically adjust the seat cushion are taught that comprises a first linking mechanism movably interconnecting the seat support and the seat mount. The first linking mechanism comprises first and second linking arms that are respectively pivotally connected to the seat mount and the seat support via pivot axes. One of the pivot axes of the second linking arm comprises a movable pivot axis that is arranged and constructed to move along the second linking arm and to engage the second linking arm, so that substantial length of the second linking arm can be changed when the movable pivot axis moves along the second linking arm.

[0014] In such seat lifting devices, the movable pivot axis engages the second linking arm. Therefore, even if an excessive forward force is applied to the seat support, the first linking mechanism may reliably be immobilized, thereby locking the seat lifting device. As a result, the seat support may substantially be prevented from moving.

[0015] Other objects, features and advantage of the present invention will be ready understood after reading the following detailed description together with the accompanying drawings and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG. 1 is a side view illustrating a vehicle seat having a seat lifting device according to a first embodiment of the present teachings, in which the vehicle seat is adjusted to a lowered position;

[0017] FIG. 2 is a side view illustrating the vehicle seat, in which the vehicle seat is adjusted to a lifted position;

[0018] FIG. 3 is an exploded partially perspective view of the seat lifting device disposed on a upper rail of a seat slide device;

[0019] FIG. 4 is a side view similar to FIG. 1, which view illustrates a vehicle seat having a seat lifting device according to a second embodiment of the present teachings; and

[0020] FIG. 5 is an exploded partially perspective view of the seat lifting device disposed on a upper rail of a seat slide device; and

[0021] FIG. 6 is a side view similar to FIG. 1, which view illustrates a vehicle seat having a seat lifting device according to a third embodiment of the present teachings.

DETAILED DESCRIPTION OF THE INVENTION

[0022] In one embodiment of the present teachings, seat lifting devices disposed between a cushion frame for supporting a seat cushion and a seat slide device for mounting the cushion frame in order to vertically adjust the seat cushion may comprises a rear linking mechanism movably interconnecting the cushion frame and the seat slide device. The rear linking mechanism comprises first and second linking arms that are respectively pivotally connected to the seat slide device and the cushion frame via pivot axes. One of the pivot axes of the second linking arm comprises a movable pivot axis that is arranged and constructed to move along the second linking arm and to engage the second linking arm, so that substantial length of the second linking arm can be changed when the movable pivot axis moves along the second linking arm.

[0023] Optionally, the second linking arm may comprise a threaded shaft that is pivotally connected to the seat slide device and the cushion frame and a gear assembly that engages the threaded shaft. Preferably, the gear assembly may be arranged and constructed to move along the threaded shaft. Preferably, the movable pivot axis may be mechanically connected to the gear assembly, so as to move along the threaded shaft when the gear assembly moves along the threaded shaft.

[0024] Optionally, the seat lifting devices may further comprise a second linking mechanism movably interconnecting the cushion frame and the seat slide device. The second linking mechanism may comprise an elongated guide slot formed in the seat slide device and a guide pin attached to the cushion frame. The guide pin may slidably engage the guide slot.

[0025] Further, the seat lifting devices may further comprises an actuator. The actuator may preferably be arranged and constructed to drive the gear assembly, thereby relatively moving the gear assembly and the movable pivot axis attached thereto along the threaded shaft.

[0026] Optionally, the first and second linking arms may preferably be connected to the cushion frame via a common pivot axis. Further, the first and second linking arms may respectively be connected to the seat slide device via first and second pivot axes. The second pivot axis may preferably be positioned behind the first pivot axis.

[0027] Preferably, the first linking mechanism may be positioned adjacent to a seatbelt connecting position on the seat support.

[0028] Two detailed representative embodiments of the present teachings will now be described in further detail with reference to FIGS. 1 to 5.

[0029] First Detailed Representative Embodiment

[0030] The first detailed representative embodiment will now be described with reference to FIGS. 1 to 3.

[0031] As shown in FIGS. 1 and 2, a vehicle seat 1 of this embodiment generally comprises a seat back 4 and a seat cushion 10. The seat back 4 and the seat cushion 10 are respectively supported by a seat back frame 2 and a cushion frame (i.e., seat support) 8. Typically, the cushion frame 8 includes a pair of opposing elongated plate-shaped members or frame elements 12 (one of which is shown) and a connector member (not shown). Each of the frame elements 12 has a front portion 12a and a rear portion 12b. The rear portions 12b of the frame elements 12 are interconnected by the connector member, thereby defining the cushion frame 8 as a unit. In addition, a seatbelt 18 may preferably connected to the frame elements 12 via seatbelt connectors (not shown) that are positioned adjacent to the rear portions 12b.

[0032] The cushion frame 8 thus constructed is seated on a pair of slide rail assemblies 3 (one of which is shown) of a seat slide device (i.e., seat mount) that are disposed in parallel on a vehicle floor (not shown). The slide rail assemblies 3 may be positioned such that the distance therebetween is substantially identical to the distance between the frame elements 12 of the cushion frame 8. Each of the slide rail assemblies 3 may include an upper rail 16 and a lower rail 14. The lower rail 14 may be affixed to the vehicle floor. The upper rail 16 slidably engages the affixed lower rail 14. In addition, the frame elements 12 of the cushion frame 8 are linked to the upper rails 16 via a pair of first or rear linking mechanisms 30 (one of which is shown) and a pair of second or front linking mechanisms 20 (one of which is shown), which mechanisms constitute a seat lifting device. Thus, the cushion frame 8 may preferably be operatively connected to the slide rail assemblies 16.

[0033] The cushion frame 8 can be moved back and forth by sliding the upper rail 16 back and forth along the lower rail 14. Therefore, the longitudinal position of the seat cushion 10 can be adjusted by sliding the upper rail 16 along the lower rail 14. In addition, the cushion frame 8 can be moved up and down by operating the seat lifting device. Therefore, the vertical position of the seat cushion 8 can be adjusted by operating the seat lifting device.

[0034] As shown in FIGS. 1 to 3, each of the front linking mechanisms 20 of the seat lifting device may preferably include a guide bracket 22 that is fixed to an upper surface 16a of the upper rail 16. The guide bracket 22 is formed with an elongated arcuate guide slot 22a that is vertically extended and fowardly curved with respect to the upper rail 16. Further, the front linking mechanism 20 may include a guide pin 24 that is attached to the front portion 12a of the frame element 12. The guide pin 24 slidably engages the guide slot 22a such that the front portion 12a of the frame element 12 can move vertically and longitudinally with respect to the upper rail 16 along an arcuate path that is defined by the guide slot 22a.

[0035] As best shown in FIG. 3, each of the rear linking mechanisms 30 of the seat lifting device may include a plate-shaped linking arm (i.e., first linking arm) 36. Further, the rear linking mechanism 30 may preferably include a first or pivot bracket 32 and a second or support bracket 34 that are fixed to the upper surface 16a of the upper rail 16. An upper end of the linking arm 36 is pivotally connected to the rear portion 12b of the frame element 12 via a pivot axis or pivot pin 38 such that the arm 36 can pivot back and forth around the pivot pin 38. A lower end of the linking arm 36 is pivotally connected to the support bracket 34 via a first pivot axis or pivot pin 39 such that the arm 36 can pivot back and forth around the pivot pin 39.

[0036] Also, the rear linking mechanism 30 may preferably include a retainer 48 that is fixedly connected to the rear portion 12b of the frame element 12 by appropriate fixing means. In this embodiment, the retainer 48 is fixed to the frame element rear portion 12b by engaging apertures 48a formed in the retainer 48 with fixture pins 52 provided to the rear portion 12b and then caulking the fixture pins 52 or attaching E-rings (not shown) to the fixture pins 52.

[0037] Further, the fixing means of the retainer 48 is not limited to this embodiment. For example, the retainer 48 can be fixed to the frame element rear portion 12b by utilizing apertures (not shown) formed in the retainer 48 and the rear portion 12b and bolts (not shown) and nuts (not shown).

[0038] As best shown in FIG. 3, the seat lifting device may further include a pair of drive mechanisms 40 (one of which is shown). Each of the drive mechanisms 40 may preferably includes a drive source assembly that comprises a gear box 44 and an actuator or motor 42. The gear box 44 and the motor 42 may preferably be vertically positioned. The motor 42 is combined to the gear box 44 such that a drive gear (not shown) received in the gear box 44 is driven when the motor 42 is driven. In addition, the gear box 44 has a threaded shaft (i.e., second linking arm) 46 extending therethrough. As will be appreciated, the threaded shaft 46 threadably engages the drive gear received in the gear box 44 such that the gear box 44 moves along the threaded shaft 46 when the motor 42 is forwardly or reversely driven.

[0039] As shown in FIG. 3, the gear box 44 is movably or rotatably connected to the retainer 48 via a pivot axis or pivot pin 50. Therefore, the pivot pin 50 can move along the threaded shaft 46 when the gear box 44 moves along the threaded shaft 46. Further, the pivot pin 50 may preferably be aligned with the pivot pin 38 of the linking arm 36. As a result, the gear box 44 and the upper end of the linking arm 36 are connected to the rear portion 12b of the frame element 12 via a common pivot axis. Further, the threaded shaft 46 has an aperture 46a that is formed in its rear end. The rear end of the threaded shaft 46 is pivotally connected to the support bracket 34 via a second pivot axis or pivot pin 54 received in the aperture 46a such that the threaded shaft 46 can pivot back and forth around the pivot pin 54. As will be appreciated, the gear box 44 and the threaded shaft 46 may function as a part of the rear linking mechanism 30. In other words, the gear box 44 and the threaded shaft 46 may preferably constitute both of the drive mechanism 40 and the rear linking mechanism 30.

[0040] Further, the pivot pins 38 and 50 is not limited to this embodiment. For example, the pivot pin 38 can be extended along a longitudinal axis thereof, so that the gear box 44 can be pivotally connected to the retainer 48 via an extended end of the pivot pin 38. According to this construction, the pivot pin 50 can be omitted.

[0041] According to the seat lifting device of this embodiment, when each of the drive mechanisms 40 is actuated, the front and rear linking mechanisms 20 and 30 of the seat lifting device are operated, thereby changing height of the seat cushion 10. That is, when the motor 42 of the drive mechanism 40 is driven forwardly or reversely, the gear box 44 moves forwardly or backwardly along the threaded shaft 46, thereby changing substantial length of the threaded shaft 46. As a result, the pivot pins 38 and 50 of the rear linking mechanisms 30 moves vertically and longitudinally relative to the upper rail 16 while the linking arm 36 and the threaded shaft 46 respectively pivotally rotate around the pivot pin 39 and the pivot pin 54. At this time, the guide pin 24 of the front linking mechanism 20 synchronously moves along the guide slot 22a of the guide bracket 22. Consequently, the front and rear linking mechanisms 20 and 30 simultaneously rise or fall down. Therefore, the frame elements 12 linked to the linking mechanisms 20 and 30 are shifted upwardly or downwardly. Thus, the seat cushion 10 may preferably be continuously vertically adjusted, so as to have various vertical positions (e.g., a lowered position (FIG. 1) and a lifted position (FIG. 2)).

[0042] According to the seat lifting device of this embodiment, when an excessive forward force is applied to the cushion frame 8 via the seatbelt 18 that is attached thereto, each of the frame elements 12 of the cushion frame 8 is pulled forwardly and upwardly. As a result, the front and rear linking mechanisms 20 and 30 that is linked to the frame element 12 are pulled in this direction. However, because the drive gear received in the gear box 44 threadably engages the threaded shaft 46, the rear linking mechanism 30 may preferably be immobilized, thereby locking the seat lifting device. As a result, the frame element 12 may be substantially prevented from moving forwardly and upwardly. That is, the seat cushion 10 may be prevented from moving forwardly and upwardly. Therefore, the drive mechanism 40, for example, may be prevented from being applied with a considerable large force.

[0043] In this embodiment, the seat lifting device is always locked unless the drive mechanisms 40 is actuated. As a result, even if the excessive forward force is applied to the cushion frame 8, the frame element 12 can be maintained in place without moving forwardly and upwardly. Therefore, the drive mechanism 40 can be reliably prevented from being applied with such a considerable force.

[0044] Further, in this embodiment, the gear box 44 and the threaded shaft 46 of the drive mechanism 40 constitute a part of the rear linking mechanism 30. Therefore, the seat lifting device can be simplified.

[0045] Further, the seat lifting device is not limited to the representative embodiment. For example, the front linking mechanism 20 may include a linking arm that is pivotally connected to the front portion 12a of the frame element 12 and the upper rail 16. Moreover, the front linking mechanism 20 may include a pair of linking arms that are pivotally connected to the frame element front portion 12a and the upper rail 16.

[0046] Second Detailed Representative Embodiment

[0047] The second detailed representative embodiment will now described with reference to FIGS. 4 and 5. Because the second embodiment relates to the first embodiment, only constructions and elements that are different from the first embodiment will be explained in detail. Elements that are the same in the first embodiment will be identified by the same reference numerals and detailed description of such elements will be omitted.

[0048] In this embodiment, the seat lifting device may further include a pair of drive mechanisms 140 (one of which is shown). Each of the drive mechanisms 140 may preferably includes a drive source assembly that comprises a gear box 144 and a motor 142. As best shown in FIG. 5, unlike the first embodiment, the gear box 144 and the motor 142 may preferably be laterally or horizontally positioned.

[0049] Third Detailed Representative Embodiment

[0050] The third detailed representative embodiment will now described with reference to FIG. 6. Because the third embodiment relates to the first and second embodiments, only constructions and elements that are different from the first and second embodiments will be explained in detail. Elements that are the same in the first and second embodiments will be identified by the same reference numerals and detailed description of such elements will be omitted.

[0051] In this embodiment, the seat lifting device may further include a pair of drive mechanisms 240 (one of which is shown). Each of the drive mechanisms 240 may preferably includes a drive source assembly that comprises a gear box 244 and a motor 242. As shown in FIG. 6, unlike the first and second embodiments, the motor 242 is separate from the gear box 244. That is, the motor 242 is positioned in the front portion 12a of the frame element 12 and fixed thereto. The motor 242 thus positioned is coupled to the gear box 244 via a power transmitting member 243, such as a rotating cable or a rotating shaft, such that a drive gear (not shown) received in the gear box 244 is driven when the motor 242 is driven.

[0052] Representative examples of the present teachings have been described in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Only the claims define the scope of the claimed invention. Therefore, combinations of features and steps disclosed in the foregoing detail description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe detailed representative examples of the invention. Moreover, the various features taught in this specification may be combined in ways that are not specifically enumerated in order to obtain additional useful embodiments of the present teachings.

Claims

1. A seat lifting device disposed between a seat support for supporting a seat cushion and a seat mount for mounting the seat support in order to vertically adjust the seat cushion, comprising: a first linking mechanism movably interconnecting the seat support and the seat mount, the first linking mechanism comprising first and second linking arms that are respectively pivotally connected to the seat mount and the seat support via pivot axes, wherein one of the pivot axes of the second linking arm comprises a movable pivot axis that is arranged and constructed to move along the second linking arm and to engage the second linking arm, so that substantial length of the second linking arm can be changed when the movable pivot axis moves along the second linking arm.

2. A seat lifting device as defined in claim 1, wherein the second linking arm comprises a threaded shaft that is pivotally connected to the seat mount and the seat support and a gear assembly having a nut that engages the threaded shaft, the gear assembly is arranged and constructed to move along the threaded shaft, and wherein the movable pivot axis is mechanically connected to the gear assembly, so as to move along the threaded shaft when the gear assembly moves along the threaded shaft.

3. A seat lifting device disposed between a seat support for supporting a seat cushion and a seat mount for mounting the seat support in order to vertically adjust the seat cushion, comprising: a pair of first linking mechanisms movably interconnecting the seat support and the seat mount, at least one of the first linking mechanisms comprising first and second linking arms that are respectively pivotally connected to the seat mount and the seat support via pivot axes, wherein one of the pivot axes of the second linking arm comprises a movable pivot axis that is arranged and constructed to move along the second linking arm and to engage the second linking arm, so that substantial length of the second linking arm can be changed when the movable pivot axis moves along the second linking arm.

4. A seat lifting device as defined in claim 3, wherein the second linking arm comprises a threaded shaft that is pivotally connected to the seat mount and the seat support and a gear assembly having a nut that engages the threaded shaft, the gear assembly is arranged and constructed to move along the threaded shaft, and wherein the movable pivot axis is mechanically connected to the gear assembly, so as to move along the threaded shaft when the gear assembly moves along the threaded shaft.

5. A seat lifting device as defined in claim 4 further comprising a second linking mechanism movably interconnecting the seat support and the seat mount, wherein the second linking mechanism comprises an elongated guide slot formed in the seat mount and a guide pin attached to the seat support, and wherein the guide pin slidably engages the guide slot.

6. A seat lifting device as defined in claim 2 further comprising an actuator, wherein the actuator is arranged and constructed to drive the gear assembly, thereby moving the gear assembly and the movable pivot axis attached thereto along the threaded shaft.

7. A seat lifting device as defined in claim 4 further comprising an actuator, wherein the actuator is arranged and constructed to drive the gear assembly, thereby moving the gear assembly and the movable pivot axis attached thereto along the threaded shaft.

8. A seat lifting device as defined in claim 5 further comprising an actuator, wherein the actuator is arranged and constructed to drive the gear assembly, thereby moving the gear assembly and the movable pivot axis attached thereto along the threaded shaft.

9. A seat lifting device disposed between a seat support for supporting a seat cushion and a seat mount for mounting the seat support in order to vertically adjust the seat cushion, comprising: a pair of first linking mechanisms movably interconnecting the seat support and the seat mount, at least one of the first linking mechanisms comprising first and second linking arms that are respectively pivotally connected to the seat mount and the seat support via pivot axes; and a second linking mechanism movably interconnecting the seat support and the seat mount, the second linking mechanism comprising an elongated guide slot formed in the seat mount and a guide pin attached to the seat support, the guide pin slidably engaging the guide slot, wherein one of the pivot axes of the second linking arm comprises a movable pivot axis that is arranged and constructed to move along the second linking arm and to engage the second linking arm, so that substantial length of the second linking arm can be changed when the movable pivot axis moves along the second linking arm, wherein the second linking arm comprises a threaded shaft that is pivotally connected to the seat mount and the seat support and a gear assembly having a nut that engages the threaded shaft, the gear assembly is arranged and constructed to move along the threaded shaft, and wherein the movable pivot axis is mechanically connected to the gear assembly, so as to move along the threaded shaft when the gear assembly moves along the threaded shaft.

10. A seat lifting device as defined in claim 1, wherein the first and second linking arms are connected to the seat support via a common pivot axis, and wherein the first and second linking arms are respectively connected to the seat mount via first and second pivot axes, the second pivot axis is positioned behind the first pivot axis.

11. A seat lifting device as defined in claim 3, wherein the first and second linking arms are connected to the seat support via a common pivot axis, and wherein the first and second linking arms are respectively connected to the seat mount via first and second pivot axes, the second pivot axis is positioned behind the first pivot axis.

12. A seat lifting device as defined in claim 9, wherein the first and second linking arms are connected to the seat support via a common pivot axis, and wherein the first and second linking arms are respectively connected to the seat mount via first and second pivot axes, the second pivot axis is positioned behind the first pivot axis.

13. A seat lifting device as defined in claim 2, wherein the first linking mechanism is positioned adjacent to a seatbelt connecting position on the seat support.

14. A seat lifting device as defined in claim 4, wherein the first linking mechanism is positioned adjacent to a seatbelt connecting position on the seat support.

15. A seat lifting device as defined in claim 5, wherein the first linking mechanism is positioned adjacent to a seatbelt connecting position on the seat support.

16. A seat lifting device as defined in claim 9, wherein the first linking mechanism is positioned adjacent to a seatbelt connecting position on the seat support.