Abstract:
A seat apparatus is provided for a vehicle comprising a first mechanism for moving a seat horizontally relative to the floor of the vehicle and a second mechanism movably mounted to the first mechanism for moving the seat vertically relative to the floor of the vehicle. The second mechanism includes at least one link and a motor drive assembly operatively associated with the link to move the seat vertically. The seat apparatus further includes a third mechanism for moving a seat belt to adjust for vertical and horizontal movement of the seat in order to insure that the seat belt will remain stationary relative to an occupant seated on the seat. The third mechanism is responsive to the motor drive assembly for moving the seat belt simultaneously with vertical movement of the seat.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to a seat belt for a seat in a moving vehicle and more particularly to a mechanism for a seat belt which allows the seat belt to raise and lower with the occupant as the seat is adjusted vertically. 
     BACKGROUND OF THE INVENTION 
     There are many variations in vehicle occupant restraint systems. In one such vehicle restraint system, a seat belt is used which consists of a lap belt and a shoulder belt that merge at a clasp structured to releasably engage a manual buckle mechanism or assembly. The buckle is typically attached to the underbody of the vehicle to function as an anchor when the occupant restraint system is in use. The buckle is normally positioned at or near the seat cushion or pan on the inboard side of the seat for easy accessibility when joining or disjoining the seat belt and buckle assembly. 
     In many of the vehicles designed today, the occupant is provided with a power seat adjustment feature, which allows the occupant to adjust the seat both horizontally and vertically to position or orient the occupant in a comfortable position. However, as the seat rises a distance vertically, the seat belt cannot accommodate the change in vertical distance. Consequently, the lap belt begins to tighten or pinch the occupant which makes it uncomfortable. This problem is not limited to the seat belt described above. 
     The prior art has attempted to address this concern. One example of a mechanism used to accommodate vertical and horizontal seat movement is shown in U.S. Pat. No. 3,977,725. While such a mechanism may accomplish the desired task, it was designed for a suspension seat for a truck wherein the seat experiences large vertical travel. For this reason, the mechanisms for supporting/moving the seat and for adjusting the seat belt employ an elaborate and sizable set of components. However, in vehicles with limited seat space and motion such as automobiles, these components are neither acceptable nor required. Space is a greater concern for those vehicles that employ power seat adjustment components. 
     Now, for those vehicles that do provide such power seat adjustment features, there does not exist a simple and space saving design for seat belt adjustment components that will function simultaneously with the power seat adjustment components. It follows that there does not exist a design for seat belt adjustment that minimizes or even eliminates damage to the power seat adjustment components resulting from a crash load. 
     It would therefore be desirable for a vehicle to employ a mechanism that allows the seat belt to raise and lower with the occupant as the seat is adjusted vertically which overcomes the drawbacks of the prior art described above. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a mechanism for a seat belt that allows the seat belt to raise and lower with the occupant as the seat is adjusted vertically that overcomes the disadvantages of the prior art. 
     Another object of the present invention is to provide a mechanism for a seat belt that allows the seat belt to raise and lower with the occupant as the seat is adjusted vertically which uses fewer components so that the mechanism fits within a confined space in an automobile. 
     Another object of the present invention is to provide a mechanism for a seat belt that allows the seat belt to raise and lower with the occupant as the seat is adjusted vertically which reduces or eliminates damage to power seat adjustment components as a result of a crash load. 
     These objects and other objects are accomplished by the present invention described in the following detailed description of the preferred embodiment, taken generally with the Figures. 
     Generally, however, the present invention provides a seat apparatus for a vehicle comprising a first mechanism for moving a seat horizontally relative to the floor of the vehicle and a second mechanism movably mounted to the first mechanism for moving the seat vertically relative to the floor of the vehicle. The second mechanism includes at least one link for supporting the seat and a motor drive assembly operatively associated with the link to move the seat vertically. The seat apparatus further includes a third mechanism for moving a seat belt to adjust for vertical movement of the seat in order to insure that the seat belt will remain stationary relative to an occupant seated on the seat. The third mechanism is responsive to the motor drive assembly for moving the seat belt simultaneously with vertical movement of the seat. 
     The present invention also provides a seat apparatus for a vehicle comprising a first mechanism for moving a seat horizontally relative to the floor of the vehicle. The mechanism includes first and second lower tracks mounted to the floor of the vehicle and first and second upper tracks movably carried on the first and second tracks, respectively. The seat apparatus also comprises a second mechanism movably mounted to the first and second upper tracks for moving the seat vertically relative to the floor of the vehicle. The second mechanism includes (1) a pair of lift links for lifting the seat and (2) a drive motor assembly operatively associated with the lift links for causing the pair of lift links to move the seat generally vertically. The seat apparatus further comprises a third mechanism for moving a seat belt to adjust for vertical movement of the seat in order to insure that the seat belt will remain stationary relative to an occupant seated on the seat, of the third mechanism including (1) a first seat belt link pivotably attached to the first upper track and (2) a motor drive assembly operatively associated with the first seat belt link to cause said seat belt link to pivot. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the figures, like reference numerals are used to denote like components and 
     FIG. 1 is a perspective view of a seat apparatus incorporating one embodiment of the mechanism for moving a seat belt in accordance with the present invention; 
     FIG. 2 is a rear view of the seat apparatus shown in FIG. 1 taken along lines  2 — 2 ; 
     FIG. 3A is a sectional view of the seat apparatus shown in FIG. 1 taken along lines  3 A— 3 A; 
     FIG. 3B is a view of the seat apparatus shown in FIG. 3A when the seat belt has been adjusted; 
     FIG. 4 is a side view of the seat apparatus in FIG. 1 showing a stop feature; 
     FIG. 5 is an exploded view of the stop feature shown in FIG. 4; 
     FIG. 6A is a side sectional view of a knee joint link when the seat belt is in a resting position; 
     FIG. 6B is a cross sectional view of a knee joint link in FIG. 6A acting as a stop, thereby limiting further movement of the buckle; and 
     FIG. 7 is a perspective view of the seat apparatus of FIG. 1 incorporating an alleviate embodiment of the mechanism for moving a seat belt in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Proceeding now to a description of the preferred embodiment, FIGS. 1 and 2 illustrate a vehicle seat apparatus  10  in which a seat  12  is installed on seat support brackets  14 , 16 . As will be discussed in detail below, seat support brackets  14 , 16  are attached to (vertical) lift links  18 , 20  and lift links  22 , 24  for raising and lowering support brackets  14 , 16 , respectively. Seat apparatus  10  includes a mechanism  26  for moving seat  12  horizontally. Mechanism  26  includes a pair of opposing parallel lower tracks  28 , 30  securely mounted (by bolts) to the floor of a vehicle, and a pair of opposing upper tracks  32 , 34  mounted to slide within the lower tracks  28 , 30 . In the preferred embodiment shown, lower track  28  and upper track  30  are positioned on the outboard side and lower track  30  and upper track  34  are positioned on the inboard side of the vehicle. 
     Seat apparatus  10  also includes a horizontal motor drive assembly  36  (also shown in FIG. 7 described below) consisting of a drive motor  38  and a drive bar  40  which has ends that extend away from the drive motor  38 , towards opposing upper  32 , 34  and lower tracks  28 , 30 . Motor drive assembly  36  further includes two horizontal gear boxes  42 , 44  integrally formed with the ends of drive bar  40 . It is seen in a cut away portion of an end of drive bar  40  that there is a motor screw  46  which interacts with the components inside horizontal gear boxes  42 , 44 . It is further seen from a cut away view of upper track  34 , motor drive assembly  36  further includes drive screw  48  and horizontal drive nut  50  threaded on drive screw  48  and bolted on a bottom wall thereof to lower track  30 . (Note that motor drive assembly  36  also includes an identical drive screw and drive nut on the outboard side, associated with horizontal gear box  42  and upper track  32 , which function the same as drive screw  48  and drive nut  50  on the inboard side. However, these components are not shown.) Horizontal gear box  44  is mounted to upper track  34  by way of a pin  52  which extends through a portion of gear box  44  into corresponding holes (no shown) in upper track  34 . Gear boxes  42 , 44  therefore simultaneously move with upper tracks  32 , 34  along lower tracks  28 , 30 . 
     Horizontal drive assembly  36  is controlled by control apparatus  54  which includes among other components including a switch (not shown). The switch is preferably mounted to the door of the vehicle. In operation, when the occupant wishes to move his/her seat forward, the occupant typically depresses the switch, and control box  54  activates motor  38  which causes gear boxes  42 , 44  to rotate drive screws  48  (and opposing drive screw not shown). Upper tracks  32 , 34  thus move horizontally as desired, along with (1) gear boxes  42 , 44  attached thereto and (2) drive motor  38 . 
     The seat apparatus  10  also includes front mechanism  56  and a rear mechanism  58  movably mounted to upper tracks  32 , 34  for moving seat  12  vertically relative to the floor of the vehicle. The front mechanism  56  and rear mechanism  58  are controlled by control box  54  which includes two switches (not shown) preferably located on the door of a vehicle. However, mechanisms  56 , 58  may alternatively be controlled by another control box. In this embodiment, mechanisms  56  and  58  are activated and controlled separately by two separate switches. Therefore, mechanisms  56 ,  58  move independently from one another, in response to the switches, should the occupant wish to raise or lower either the front or rear of seat  12 . 
     Front mechanism  56  includes a front motor drive assembly  60  and a front torsion bar  62  having opposite ends attached to upper tracks  32 , 34 . Torsion bar  62  is capable of rotating with respect to upper tracks  32 , 34 . Front mechanism  56  includes a pair of opposing front seat lift links  22 , 24  pivotably attached to brackets  14 , 16  via slave links  64 , 66  which are welded to torsion bar  62 . 
     Front motor drive assembly  60  includes a front vertical motor  68 , front vertical gear box  70  integrally formed to motor  68 , a drive screw  72  extending from gear box  70 , and front vertical drive nut  74  threaded on drive screw  72 . Front motor drive assembly  60  also includes front drive link  78  pivotably connected at one end thereof to front vertical drive nut  74  and secured (by weld) to the other end thereof to front torsion bar  62 , thereby coupling front drive nut  74  to front torsion bar  62 . In operation, a switch (not shown) electrically activates front vertical motor  68 . In response screw  72  is rotated to move front vertical drive nut  74  either forward or backward as desired, causing front drive link  78  to pivot and front torsion bar  62  to rotate. As a result, front seat lifts  22 , 24  pivot and move in an arcuate direction causing the front of the seat  12  to move vertically. 
     Front and rear mechanisms  56  and  58  use similar components which function similarly. Rear mechanism  58  includes a motor drive assembly  80 , rear torsion bar  82 , and a pair of opposing rear seat lift links  18 , 20 . Seat belt lift links  18 , 20  are each pivotably attached at one end thereof to brackets  14 , 16  and secured at the other end thereof to torsion bar  82 . Torsion bar  82  is attached at opposite ends thereof to the upper tracks  32 , 34  and capable of rotating with respect thereto. 
     Rear motor drive assembly  80  includes a rear vertical motor  84 , rear vertical gear box  86  integrally formed to the motor  84 , a drive screw  88  extending from gear box  86 , and rear vertical drive nut  90  threaded on screw  88 . Rear motor drive assembly  80  also includes rear drive link  92  pivotably attached to rear vertical drive nut  90  and secured (by weld) to rear torsion bar  82 , thereby coupling rear drive nut  90  to rear torsion bar  82 . In operation, a switch electrically activates rear vertical motor  84 . In response, screw  88  is rotated to move rear vertical drive nut  90  either forward or backward as desired, causing rear drive link  46  to pivot and rear torsion bar  82  to rotate. As a result, rear seat lifts  18 , 20  pivot and move in a generally arcuate direction, causing the rear brackets  14 , 16  and seat  12  supported thereon to move vertically. 
     The mechanisms  36  for moving seat  12  horizontally, mechanisms  56  and  58  for moving seat  12  vertically and the control apparatus&#39;, together are known as the power seat adjustment mechanisms. 
     Note that the apparatus  10  also includes a vertical drive bracket  94  which is mounted to upper track  32 . Front and rear gear boxes  70  and  86  are bolted to an end of vertical drive bracket  94 . Bracket  94  functions to support motor assemblies  60  and  80  during horizontal and vertical movement of seat apparatus  10 . Note that the particular design and components used for mechanisms  36  and  56 ,  58  described herein (for moving seat  12  horizontally and vertically) are identified as the preferred embodiment. Many different variations exist however for these mechanisms and their components. In addition, the seat apparatus  10  may be used in all types of vehicles such as trucks and automobiles. 
     Seat apparatus  10  also includes a mechanism  96  for moving a seat belt  98  to adjust for vertical movement of seat  12 . The mechanism  96  will ensure that seat belt  98  will remain stationary relative to an occupant seated on seat  12 . Mechanism  96  includes seat belt links  100 , 102  positioned on the outside of upper tracks  32 , 34  and slave links  104 , 106  positioned on the inside of upper tracks  32 , 34 . Seat belt links  100 , 102  and slave links  104 , 106 , respectively, are secured (by weld) at the ends thereof to drive rods  108 ,  110 . Rods  108 ,  110  each slidingly fit within members  112 , 114  of upper tracks  32 , 34 , respectively. Seat belt links  100 , 102  and slave links  104 , 106  are therefore said to be attached to upper tracks  32 , 34  and capable of pivoting or rotating with respect to upper tracks  32 , 34 . 
     As described, the ends of seat belt links  100 , 102  are pivotably attached to upper tracks  32 , 34 . At the other end of seat belt links  100 , 102 , there are seat belt components attached thereto. On the outboard side, clasp  116  is pivotably attached to seat belt link  100 . A buckle  118  and strap  120  are attached to seat belt link  102  on the inboard side of the vehicle. Mechanism  96  also includes drive links  122 , 124  welded at one end thereof to rear torsion bar  82  and follower links  126 , 128  pivotably attached at the ends thereof to slave links  104 , 106  and drive links  122 , 124 , respectively. 
     In operation, an occupant activates a switch to power the rear vertical seat adjustment components. In particular, rear drive motor  84  causes rear drive nut  90  to extend (or retract) outwardly toward the rear. Rear drive link  92  causes torsion bar  82  to rotate with respect to upper tracks  32 , 34 . Hence lift links  18 , 20  rotate causing seat brackets  14 , 16  to rise vertically. Now, as torsion bar  82  rotates, drive links  122 , 124  simultaneously rotate, pulling follower links  126 , 128  toward the rear of the vehicle. Follower links  126 , 128  consequently pull on slave links  104 , 106  and cause them to rotate, driving drive seat belt links  100 , 102  to pivot or rotate clockwise. Consequently, the seat belt attachments (clasp  116 , buckle  118 , strap  120 ) rise (i.e., move upwardly and forwardly) which provides a small amount of slack in the belt across the occupant as the seat vertically rises. FIG. 3A shows seat  12  and belt link  100  in one position and FIG. 3B shows seat  12  and belt link  100  in a second raised (adjusted) position. Although not shown in FIGS. 3A and 3B, seat belt link  102  moves similarly and simultaneously with seat belt link  100 . 
     As seen in the Figures, the preferred mechanism  96  shown includes the same linking components (follower link, drive link, slave link etc.) on the outboard side as on the inboard side of the vehicle. These components function together in response to rear motor  84 , torsion bar  82 , etc. to adjust the seat belt on both sides of the occupant. Alternatively however, the mechanism for moving the seat belt to adjust for vertical seat movement may merely include components on one of the sides of the vehicle to achieve the desired belt adjustment. 
     In FIG. 7 for example, there is shown an alternate embodiment for the seat belt linking components in FIG.  1 . The seat belt linking components on the inboard side of the vehicle have been removed. In place of such components, there is shown a strap  130  pivotably attached at one end thereof to the outside of upper track  34  and a buckle  132  at the other end thereof. In this FIG. 7, note that on the inboard side of a vehicle there is neither any seat belt drive link on the outside of upper track  34  nor any seat belt driving linkages (follower link, slave link, drive link) on the inside of upper track  34 . Strap  130  cannot be moved to elevate and adjust the belt as seat  12  moves vertically. Strap  130  is merely adapted to pivot with respect to upper track  34 . The mechanism  96  however includes the same linking components (seat belt drive link  122 , follower link  126 , slave link  104 ) on the outboard side of the vehicle so that mechanism  96  may continue to perform the desired function of adjusting the seat belt to provide slack to the belt across the occupant as he/she moves vertically (as in FIG. 
     FIGS. 4 and 5 illustrate an additional feature to seat apparatus  10  shown in FIG. 1. A stop  140  is shown which is attached to the upper track  34 . Stop  140  functions to stop the movement of seat belt link  102  from rotating past a desired point during a load from a crash. Stop  140  extends outwardly in the path of seat belt link  102  to perform the desired function. Another option is shown in FIGS. 6A and 6B. Knee joint link  142  is shown which functions as the seat belt link  102 . Knee joint link  142  is pivotably attached to the inside and outside of upper track  34 . As the knee joint link  142  rotates forward the knee joint link  142  contacts the top of upper track  34  thereby stopping the forward movement of link  142 . Stop  140  and knee joint link  142  shown in FIGS. 4-6 may be employed to satisfy vehicle law or original equipment manufacturer (“OEM”) requirements for the resulting excursion seen by the rotating seat belt link. 
     Although the seat apparatus  10  described herein applies to the driver side of a vehicle, it may be designed in a similar configuration for any location in a vehicle including the passenger side. For the apparatus  10  located on the passenger side, a seat apparatus  10  would look as if it appeared in a mirror. The strap and attached buckle would be positioned on the inboard side and the seat belt would be positioned on the outboard side of a vehicle. The mechanism for moving a seat belt to adjust for vertical movement of a seat includes the same components as that mechanism that performs the same function of apparatus  10  on the driver side of a vehicle. The same components would appear in reverse at they would appear in a mirror. 
     While the present invention has been described and illustrated in connection with the embodiments and components described above, it is not to be limited to those descriptions but is to be limited solely by the scope of the claims which follow.