GB2086711A - Passive safety belt system - Google Patents

Abstract

A passive restraint system for use with a motor vehicle having a front hinged door consists of a safety belt having a lap strap 14 and diagonal strap 16 connected to respective anchorages 22 and 24 inboard of the seat. A common strap 20 is led on to an inertia reel which is mounted in the adjacent door via a guide member 46 which is secured to a traveller 44 on a track 38. The track 38 has a first section 40 running upwardly and forwardly from the bottom rear corner of the door and a second section 42 running horizontally towards the front of the door. A limit means is provided on the common strap so as to be brought into contact with the runner as the door is opened and thereafter drive the runner forwardly along the track. <IMAGE>

Description

SPECIFICATION Passive safety belt system This invention relates to a passive safety belt system for a motor vehicle of the type in which the belt is moved away from the body of the user when the corresponding vehicle door is opened.

It is an object of the present invention to provide a system of the foregoing type in which the power used to move the safety belt is derived from the opening and closing movement of the vehicle door.

According to the invention, a motor vehicle has a front-hinged door and an adjacent seat provided with a safety belt system comprising a shoulder strap, a lap strap and a common strap interconnected at an interconnection point to form a three-point safety belt, the free ends of the lap and shoulder straps being connected to anchorage means at a location on the vehicle inboard of and adjacent to the bottom of the back of the seat and a point above the anchorage means for the lap strap respectively, and the common strap being led on to an inertia reel via first guide means secured to the door in proximity to the bottom rear corner thereof, the safety belt system further comprising a track extending forwardly from the point on the door in proximity to the first guide means and having a runner movable therealong, second guide means mounted on the runner and having the common strap slidable therethrough between the interconnection point and the first guide means and limit means for limiting movement of the common strap through the second guide means in the direction away from the reel, whereby, when the door is opened, the limit means causes the runner to be pulled forwardly along the track and, when the door is closed, the runner moves towards the first guide means.

Preferably the track extends upwardly towards an intermediate point between the front and back edges of the door and then horizontally towards the front edge thereof.

In one form of the invention, the limit means comprises a further flexible element joining the interconnection point and the second guide means.

In another form of the invention, the limit means comprises a stop on the common strap which cannot pass through the second guide means In yet another form of the invention, the common strap is threaded through third guide means at the interconnection point and its end secured to the runner so that the common strap itself serves as the limit means. With this arrangement, the limit set by the limit means is not predetermined, being dependant on the balance of the gravity forces on the runner relative to the force exerted on the common strap by the retractor spring of the inertia reel.

Three embodiments of the invention will now be described by way of example, with reference to the accompanying drawings in which: Figures 1 and 2 are perspective views of the interior of a motor car fitted with a safety belt system in accordance with the invention, with the door adjacent to the seat provided with the safety belt system closed and open respectively; and Figures 3, 4 and 5 are perspective views illustrating three alternative forms of limit means in accordance with the invention which can be used with the safety belt system shown in Figs. 1 and 2.

Figs. 1 and 2 show the driver's seat 10 of a motor car 1 2 in accordance with the invention. A safety belt for the driver consists of a single length of webbing, forming the lap element 14 and shoulder element 1 6 which runs freely through a flattened ring 18 connected to one end of another length of web bing forming the common element 20 of the safety belt. The free ends of the lap and shoulder elements 14 and 1 6 are connected to respective anchorages 22 and 24. The anchorage 22 is mounted on the transmission tunnel 26 of the car 1 2 while the anchorage 24 is mounted on a transverse bar 28 which extends across the vehicle immediately behind the seats. In a two-seater sports car, this bar may conveniently form the support for a parcels shelf (not shown).The shoulder element 1 6 is led from the anchorage 24 through a guide 30 mounted on the side of the head restraint 32 of the seat 10.

The free end of the common element 20 is attached to an inertia reel 33 (Fig. 3) mounted within the door 34 which is adjacent to the seat 10, the common element 20 emerging through a guide 36 adjacent to the bottom rear corner thereof. A track 38 is mounted on the inside face of the door 34. A diagonal portion 40 of the track extends from adjacent to the guide 36 forwardly and upwardly to an intermediate point along the top edge of the door, immediately below the window where it curves into a horizontal portion 42 which extends to the front top corner of the door. A runner 44 is mounted on the track 38 so as to be slidable therealong but captive thereon. A guide member 46 is pivotally coupled to the runner 44 and has the common element 20 of the safety belt threaded therethrough as it runs from the ring 1 8 to the guide 36.

Turning to Fig. 3, it will be seen that the ring 1 8 has a central transverse bar 48 to which a flexible strap 50 is connected. The other end of the strap 50 is connected to the guide member 46.

In use, when the car door is closed, the runner 44 is located at the bottom of the track section 40, adjacent to the guide 36, the strap 50 is slack and the safety belt is in a configuration to be worn by an occupant of the seat 10, as shown in Fig. 1. When the door 34 is opened, as shown in Fig. 2, the strap 50 tightens and further opening of the door 34 causes the runner 44 to move up the diagonal track section 40 and on to the horizontal track section 42, thereby pulling more of the common element 20 off the inertia reel and moving the lap and shoulder elements 14 and 1 6 away from the body of an occupant of the seat 1 0. Further opening movement of the door 34 causes more of the common seat element 20 to be pulled off the inertia reel.If the seat occupant pushes the safety belt further away from him, the runner 44 moves further along the horizontal section 42 of the track 38. When the door closes, the retractor spring of the inertia reel causes the common element 20 to pull the slider 44 back down the track 38.

Turning to Fig. 4, the ring 1 8 with the cross bar 48 is replaced by a simple ring 60.

Instead of providing a separate strap 50, a stop 62 in the form of a pad of webbing which is too thick to go through the guide member 46, is sewn on to the common element 20 at a distance from the ring 60 equal to the length of the strap 50 of Fig. 3.

The slot of the guide 36 is made sufficiently wide to allow the stop 62 to be wound on to the inertia reel. When the door 34 is opened, more of the common element 20 is drawn off the inertia reel until the stop 62 abuts against the guide member 46. Further opening movement of the door 34 causes the slider 44 to move up diagonal section 40 of the track 38 as before.

Turning now to Fig. 5, the guide member 46 is replaced by a guide member 64 having an additional cross bar. The common element 20 is threaded through the ring 60 and its free end is fixed to the guide member 64.

With this arrangement, as the door is opened, the slider 44 immediately starts to move up the diagonal section 40 of the track 38, the precise relationship between the extent of upward movement and the opening of the door depending on the balance between the force exerted by the retractor spring of the inertia reel and the gravitational forces on the slider 44.

Claims (6)

1. A motor vehicle having a front-hinged door and an adjacent seat provided with a safety belt system comprising a shoulder strap, a lap strap and a common strap interconnected at an interconnection point to form a three-point safety belt, the free ends of the .lap and shoulder straps being connected to anchorage means at a location on the vehicle inboard of and adjacent to the bottom of the back of the seat and a point above the anchorage means for the lap strap respectively, and the common strap being led on to an inertia reel via first guide means secured to the door in proximity to the bottom rear corner thereof, the safety belt system further comprising a track extending forwardly from the point on the door in proximity to the first guide means and having a runner movable therealong, second guide means mounted on the runner and having the common strap slidable therethrough between the interconnection point and the first guide means and limit means for limiting movement of the common strap through the second guide means in the direction away from the reel whereby, when the door is opened, the limit means causes the runner to be pulled forwardly along the track and, when the door is closed, the runner moves towards the first guide means.

2. A motor vehicle according to claim 1, wherein the limit means comprises a further flexible element joining the interconnection point and the second guide means.

3. A motor vehicle according to claim 1, wherein the limit means comprises a stop on the common strap which cannot pass through the second guide means.

4. A vehicle according to claim 1, wherein the common strap is threaded through third guide means at the interconnection point and its end is secured to the runner, thereby serving as the limit means.

5. A motor vehicle according to any preceeding claim, wherein the track extends upwardly towards an intermediate point between the front and back edges of the door and then horizontally towards the front edges of the door.

6. A motor vehicle having a front hinged door and an adjacent seat provided with a safety belt system substantially as hereinbefore described with reference to the accompanying drawings.