Seat integrated seat belt system

Abstract: A three point seat belt system (20) includes a belt (25) having one end affixed to the seat (26,27) and an opposite end mounted to a retractor secured to the seat (28,29). A seat belt tongue (32) is mounted to the belt (25) intermediate the belt ends and is releasably lockable with a belt buckle (33) on the opposite side of the seat thereby pulling one portion of the belt across the passenger lap and another portion of the belt across the passenger upper torso. The belt extends through a guide (30) located at the top of the seat (31). A seat tether includes a second belt (50) having one end (51) attached to the seat at the location of the guide (30) and a second end (52) mounted to a second retractor (53) located beneath the seat. The second retractor is operable to limit motion of the seat thereby minimizing the impact of vehicle motion on the first belt securing the passenger to the seat.

Description: BACKGROUND OF THE INVENTION Field of the Invention: This invention is in the field of seat belt systems. Description of the Prior Art: Seat belt systems are available combining a lap belt and upper torso belt. Typically, a single belt having its opposite ends mounted to a pair of retractors has a seat belt tongue mounted to the belt intermediate the belt ends. The tongue may then be swung across the person and engaged with a buckle affixed to the seat thereby positioning one portion of the belt across the lap and another portion of the belt across the upper torso. Instead of mounting both ends of the belt to a pair of retractors, some systems have only one end of the belt mounted to a retractor whereas the opposite end of the belt is affixed to the vehicle. Two such systems are disclosed in DE-A-34 29 426 and DE-A-36 13 830 . Rough riding equipment, such as trucks, provide special problems in relationship to seat belt systems. Slack inducing mechanisms are typically required to isolate the driver from belt pressure created by retractor lock up. Certain slack inducing mechanisms do not automatically provide for constant belt tensioning and constant belt pressure applied to the driver. The system disclosed herein reduces or eliminates the discomfort from belt pressure and cinching without the use of slack inducing mechanisms. In a known automobile seat with an integrated safety belt system (DE-A-38 13 557), all coupling points of both the safety belt system and the seat holding element are attached directly to the seat. The attachment of these safety systems to the seat requires reinforcement of the vehicle floor and seat in order to reduce the motion between the seat and vehicle which occurs during a crash. Such modifications are costly and require more expensive seats. Disclosed herein is a tether system which minimizes such relative motion while allowing for use of relatively inexpensive seats and elimination of any additional strengthening or rigidizing of the vehicle floor. SUMMARY OF THE INVENTION One embodiment of the present invention is a tether for holding a vehicle passenger seat with a back portion with belt guide comprising a tether assembly mountable to a vehicle and a passenger seat therein, said tether assembly including an extendable and retractable web extending between said passenger seat and said vehicle with said tether assembly being operable via said web to allow relative motion between said passenger seat and said vehicle during passenger adjustment but limiting relative motion during emergency stops, said tether assembly including a retractor mounted to said vehicle with said web extendable and retractable from said retractor, characterized by the fact that said web includes an outer end portion fixedly secured to said belt guide on said back portion of said passenger seat, said tether assembly including a web guide positioned above said retractor and behind said back portion, said web guide operable to guide said web upwardly from said retractor and forwardly toward said belt guide on said back portion to tether a passenger in said seat. It is an object of the present invention to provide an integrated seat belt system which reduces or eliminates the discomfort from belt pressure and cinching without the use of slack inducing mechanisms. A further object of the present invention is to provide a vehicle passenger restraint system to minimize belt movement normally resulting from normal vehicle motion. A further object of the present invention is to provide a tether for holding a vehicle passenger seat to insure constant seat belt pressure relative to the passenger. Related objects and advantages of the present invention will be apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a vehicle seat and associated seat belt system incorporating the present invention. FIG. 2 is the same view as FIG. 1 only showing a person occupying the seat. FIG. 3 is an enlarged top view of the seat of FIG. 1. FIG. 4 is an enlarged, fragmentary, cross-sectional view taken along the line 4-4 of FIG. 3 and viewed fragmentary, in the direction of the arrows. FIG. 5 is an enlarged, cross-sectional view taken along the line 5-5 of FIG. 3 and viewed in the direction of the arrows. FIG. 6 is a side view of an alternate guide for the seat tether. FIG. 7 is a fragmentary enlarged rear view of the seat of FIG. 1. DESCRIPTION OF THE PREFERRED EMBODIMENT For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. Referring now more particularly to FIGS. 1 and 2, there is shown the seat integrated seat belt system 20 incorporating the present invention. The seat includes a seat cushion 21 upon which passenger 22 sits also being supported by back support 23. Cushion 21 and back support 23 are mounted atop frame 24 which may be horizontally and vertically moved. System 20 includes a seat belt 25 having a first end 26 securely anchored by fastening device 27 to frame 24. The opposite end 28 of the belt is mounted and wound on a spindle rotatably mounted within a conventional emergency locking retractor 29. Belt 25 extends freely through a guide 30 fixedly mounted to the top portion 31 of seat back support 23. The belt extends through a conventional seat belt buckle tongue 32 which may be pulled across passenger 22 to lockingly engage a conventional seat belt buckle 33 fixedly secured to frame 24. Thus, belt 25 has a lap portion 45 extending across the lap of passenger 22 and an upper torso portion 34 extending across the chest of the passenger. Anchor plate 35 (FIG. 4) is fixedly secured by conventional fastening devices 36 to the back surface of the top 31 of back support 23. A D-loop guide 37 (FIG. 5) is mounted to plate 35 by means of a fastener 38. The fastener may take the form of a bolt and nut combination. Further, the fastener may be designed to allow guide 37 to pivot about the longitudinal axis of the bolt. Guide 37 includes a slot 39 through which belt 25 freely extends. Buckle tongue 32 has a pair of spaced apart slots 40 and 41 separated by wall 42. Belt 25 extends outwardly through slot 40 and then back through slot 41 allowing the buckle tongue to be adjusted along the length of the belt for sizing of the belt portion 45 extending across the lap of the occupant. The tongue has a distal end 43 with an aperture 44 to lockingly engage a conventional seat belt buckle 33 mounted to the seat on the side opposite of the location of the opposite ends 26 and 28 of the belt. A seat tether is provided to reduce the motion of the seat and seat belt normally resulting from vehicle motion. The tether includes a belt 50 (FIG. 1) having an outer end 51 fixedly attached to anchor plate 35 and an opposite end 52 mounted to and wound upon a spindle rotatably mounted within a conventional emergency locking retractor 53 mounted to the floor 94 of the vehicle beneath seat frame 24. A guide 54 is fixedly mounted to the vehicle thereby guiding the belt vertically upward from the retractor and then through the guide with the belt then extending horizontally to the top 31 of the seat. End 51 of belt 50 is fixedly secured to belt plate 95 (FIG. 4) in turn mounted by fastener 38 to plate 35. Thus, the distal end of belt 50 is attached to the back support 23 of the seat at the location of the mounting of the first belt guide 37. The tether system minimizes motion of the seat normally resulting from vehicle motion and, therefore, reduces motion of belt 25. Tether guide 54 (FIG. 1) is fixedly mounted to the vehicle by fastener 60 and has an outwardly projecting wall 61 with a an aperture provided therein through which belt 50 extends freely. An adjustable belt guide may be utilized in lieu of the fixed guide 54. A variety of adjustable belt guides are commercially available with one such guide shown in FIG. 6. Guide 62 includes a frame 63 fixedly secured to the vehicle with frame 63 having a pair of tracks upon which is slidably mounted slide 64. A push button control 65 is mounted to slide 64 to allow for the vertical adjustment and positioning of guide 66 fixedly mounted to slide 64 by fastener 67. Aperture 67 is formed on the outwardly projecting portion of guide 66 with the belt extending freely through aperture 67. One such guide is disclosed in US-A-4,652,012 with is incorporated herein by reference. Both guides 54 and 62 may be mounted to the B-pillar of the vehicle. The seat shown in FIG. 1 is supported upon either an air or mechanical suspension allowing for adjustable, vertical movement. Seat frame 24 includes a horizontally extending wall 70 upon which the seat cushion and back support are mounted. The frame includes a pair of depending side walls 71 (FIG. 7) and 72 having inwardly turned flanges 73 and 74. A pair of upper tracks 75 and 76 are fixedly fastened to wall 70 and depend therefrom being located opposite from and aligned with a second pair of tracks 77 and 78 fixedly mounted atop base plate 99. Tracks 75 and 76 include downwardly opening grooves 79 and 80 opposed to and aligned with a pair of upwardly extending grooves 81 and 82 formed in tracks 77 and 78. Bearings 83 and 84 are located within grooves 79 through 82 allowing frame 70 to move horizontally relative to base plate 99. A load support pin or bolt 83 extends through an aperture of wall 70, and then through a slot formed in base plate 99 and is affixed thereto by nut 84. Thus, as wall 70 moves horizontally with fastener 83, base plate 79 remains stationary allowing pin 83 to move within the slot formed in plate 99. Base plate 99 is mounted atop a pair of scissor links 85 and 86 having their top ends pivotally mounted to plate 99 and the bottom ends pivotally mounted to housing 87 mounted fixedly atop floor 94. A conventional air or mechanical suspension 88 is mounted to housing 87 having a top end affixed to base plate 99, and being operable to move the base plate and accompanying seat frame 24 and seat upwardly or downwardly. A shock absorber may also be located between base plate 99 and housing 87. Base plate 99 is normally spaced apart and above flanges 73 and 74 which may contact plate 79 during a crash thereby limiting motion of the seat frame and seat relative to the floor. A tether cable 90 is attached to and extends between floor 94 and base plate 79 providing a further motion limitation of the seat during a crash. Retractor 29 is mounted atop and to seat frame 24 which extends rearwardly of back support 23. Likewise, the opposite end 26 of the belt is secured to the seat frame. As a result, belt 25 moves as an integral portion of the seat whenever the seat is adjusted vertically or horizontally, thus maintaining constant pressure on the occupant. Likewise, retractor 53 mounted to the vehicle floor is operable to play out or retract belt 50 depending upon the vertical or horizontal controlled motion of the seat which occurs, for example, during seat adjustment. During an emergency such as a crash, retractor 53 is operable to lock thereby applying holding force to the top end of the back portion of the seat minimizing seat motion and belt motion. During such an emergency, retractor 29 will likewise lock thereby preventing outward play of belt 25 and insuring the occupant is securely held to the seat. Notably, the restraining force exerted by belt 50 and retractor 53 relative to the seat is independent of any pressure applied to the occupant by belt 25 during emergency stops. Retractors 29 and 53 are inertia retractors and are commercially available. Such an inertia locking retractor is disclosed in US-A-4,506,844 which is herewith incorporated by reference. The sensitivity of the emergency locking retractor 29 does not cause excessive lock up from the normal horizontal and vertical motion controlled by the occupant. That is, the retractor is operable only to lock the belt during emergency stops. Buckle 33 being affixed to frame 24 moves as a unit with belt 25 during seat motion providing for the integral relationship between the belt system and seat. Emergency locking retractor 53 is positioned low in the vehicle cab to minimize motion of belt 50 and reduce lock up in rough ride conditions. As such, retractor 53 is located lower in elevation than seat frame 24. Many advantages result from the present invention. Typically, in order to anchor conventional seats to a vehicle, various portions of the vehicle must be strengthened. By utilizing retractor 53 and belt 50, the retractor and guide 54 may be mounted to the normal columns or strong areas of the vehicle eliminating the necessity for further reinforcement. Further, since the tether is attached to the location of the upper guide for belt 25, the upper torso is being tethered allowing for use of relatively inexpensive or unreinforced seats.

Claims: A tether for holding a vehicle passenger seat with a back portion (23) with belt guide (30) comprising: a tether assembly mountable to a vehicle and a passenger seat therein, said tether assembly including an extendable and retractable web (50) extending between said passenger seat and said vehicle with said tether assembly being operable via said web (50) to allow relative motion between said passenger seat and said vehicle during passenger adjustment but limiting relative motion during emergency stops, said tether assembly including a retractor (53) mounted to said vehicle with said web (50) extendable and retractable from said retractor (53), characterized by the fact that said web (50) includes an outer end portion (51) fixedly secured to said belt guide (30) on said back portion (23) of said passenger seat, said tether assembly including a web guide (54) positioned above said retractor (53) and behind said back portion (23), said web guide (54) operable to guide said web (50) upwardly from said retractor (53) and forwardly toward said belt guide (30) on said back portion (23) to tether a passenger in said seat. The tether of claim 1 wherein: said tether assembly includes an emergency locking retractor (53) mounted to said vehicle with said web (50) extendable and retractable from said emergency locking retractor (53), said web (50) includes an outer end portion (51) secured to said back portion (23) of said passenger seat. The tether of claim 1 wherein: said tether assembly includes a belt mount (95) mounted to an anchor plate (35) affixed to said back portion (23) of said passenger seat, said plate extends outwardly of said seat with said outer end portion (51) attached thereto. The tether of claim 1 wherein: said web guide (66) is movably mounted to said vehicle to allow for adjustment of said web (50) relative to said belt guide (30).

Inventors: CLIFTON WILLIAM L III, HOMEIER RONALD F, LORTZ ALLAN R, WILLIAMS JEFFREY L, CLIFTON, WILLIAM L., III, HOMEIER, RONALD F., LORTZ, ALLAN R., WILLIAMS, JEFFREY L.
Applicants: INDIANA MILLS & MFG, INDIANA MILLS & MANUFACTURING, INC.
Application year: 1991
Main classification: B60R22
IPC codes: B60R22, B60N2