WO2013061308A2

WO2013061308A2 - Child restraint system

Info

Publication number: WO2013061308A2
Application number: PCT/IB2012/055966
Authority: WO
Inventors: Christopher James Leatt; Pieter André KEEVY; Cornelis Uys DE JONGH; Willem Adolph LANDMAN; Tim WUCHER
Original assignee: Leatt Corporation
Priority date: 2011-10-27
Filing date: 2012-10-29
Publication date: 2013-05-02
Also published as: GB201118611D0; WO2013061308A3

Abstract

A personal restraint system (8) for a child or other occupant of a vehicle is provided, which includes a support (3, 4) that is attached to the vehicle, a seat (1) that supports the occupant, and a harness that holds the occupant in the seat person in the seat. The restraint system (8) includes one or more tethers (9) between the seat (1) and the support (3, 4), which remain taut before and during relative movement between the seat (1) and the support (3, 4). One or more compressible elements (6) of a crushable material, extend between the support (3, 4) and the seat (1) and are disposed about the tethers (9) to receive compressive loads during relative movement between the seat (1) and the support (3, 4). Tension release devices (12) are provided in one or more of the harness straps (10).

Description

CHILD RESTRAINT SYSTEM

FIELD OF THE INVENTION

This invention relates to restraint systems for occupants of vehicles and while it can also be used for adults in certain applications, it is described below with reference to its typical application as a child restraint system.

BACKGROUND TO THE INVENTION

Forces resulting from the rapid accelerations or deceleration of a vehicle during the impact of an accident are usually transferred to occupants of the vehicle and can lead to serious injuries. The occupied spaces of vehicle, including their seats, restraint systems and other objects with which occupants may interact during normal use of the vehicle or during impact (e.g. dashboards, internal door panels, etc.) are designed to receive adult occupants with relative comfort and to minimise the risk of injury, e.g. by restraining the occupants' bodies. However, even though the seats and restraint systems of vehicles are usually adjustable to compensate for variations in occupant sizes, they cannot be designed simultaneously to offer optimal restraint and protection to small occupants such as a young children and to full grown adults. As a result, additional restraint systems need to be fitted inside vehicles to

accommodate small occupants and to keep them safe.

Child restraint systems typically include a child seat that is mounted on top of a normal vehicle seat and that is attached fairly securely to prevent movement of the child seat relative to the vehicle seat. In some cases, the child restraint system includes a base that is securely attached to the vehicle seat and the child seat is fitted to the base - sometimes removably and sometimes with some degree of adjustment. The child restraint system further typically includes a harness system that holds the child in the seat. During a collision, such a child seat is exposed to the same forces of acceleration or deceleration as the vehicle, by virtue of its fixed attachment and owing to the harnesses, the child is held firmly to the child seat and is also exposed to these forces. There is typically some play between the

attachment of the child seat to the vehicle seat and between the child's body and the child seat, but this play typically results in higher instantaneous forces as the play is taken up rapidly during accidents.

The present invention seeks to provide a personal restraint system for an occupant of a vehicle, particularly for a small child, that reduces the forces to which the vehicle occupants' body is exposed during an accident.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention there is provided a personal restraint system for an occupant of a vehicle, said restraint system comprising:

a support with attachment means for attaching it to the vehicle (e.g. by attaching it to a vehicle seat);

a seat that is configured to support the occupant;

at least one harness that is attached to the seat and that is configured to extend around a part of the occupant's body, when seated, and to hold the occupant in the seat;

at least one tensile element extending between the seat and the support, allowing relative movement between the seat and the support; and

at least one compressible element extending between a part of the support and a part of the seat, being made of a material that is cruashable and being disposed about the tensile element to receive a compressive load during relative movement between the seat and the support and said tensile elemen being taut, at least before and during relative movement between the seat and the support.

The term "crushable" refers herein to materials that can withstand some

compression, but once a predetermined compression load on the material is exceeded, it compresses under further compressive loading - preferably, but not necessarily without an increase in resistance to compression. One suitable crushable material is polystyrene foam.

The term "taut" refers herein to to a condition in which a tensile element extends between the points between which it can bear a tensile load, without significant play or deflection, but not necessarily bering a tensile load.

The personal restraint system may include a plurality of the compressible elements.

The personal restraint system may include at least one tensile element extending between the seat and the support, allowing relative movement between the seat and the support. The tensile element may be a flexible element such as a tether, or may be a pivotable element such as a linkage.

The personal restraint system may include a plurality of the compressible elements disposed about the tensile element.

The personal restraint system may include at least one guide that is configured to guide relative movement between the seat and the support along a predetermined movement path, e.g. to allow adjustment of the seat position and/or to guide movement of the seat during an accident to ensure that the movement is transferred to the support as a compressive load via the compressible element.

The support may include a primary support element such as a frame that is attachable to the vehicle, and an adjustable support element such as a base that can move relative to the primary support, with the compressible elements extending between the seat and the adjustable support element.

The seat or the support may include a protuberance that extends into one or more of the compressible elements.

The harness may include at least one strap comprising two parts that are connected to a frame of a tension release device, with a cushion provided between at least one end of the strap and the frame and the tension release device may include a pin that is attached to the frame, with the cusion extending at least between the pin and a part of the frame, the pin being configured to collapse when a predetermined tensile load is exerted on the pin by the strap. The cushion may be of a non-newtonian material.

According to another aspect of the present invention there is provided a personal restraint system for an occupant of a vehicle, said restraint system comprising:

a support with attachment means for attaching it to the vehicle;

a seat that is configured to support the occupant; and

wherein the harness includes at least one strap comprising two parts that are connected to a frame of a tension release device, with a cushion provided between at least one end of the strap and the frame.

The tension release device may include a pin that is attached to the frame, with the cusion extending at least between the pin and a part of the frame, the pin being configured to collapse when a predetermined tensile load is exerted on the pin by the strap. The cushion may be of a non-newtonian material.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, and to show how the same may be carried into effect, the invention will now be described by way of non-limiting example, with reference to the accompanying drawings in which:

Figure 1 is a schematic side view of a personal restraint system according to the present invention;

Figure 2 is a schematic front view of a support of the personal restraint system of Figure 1 ;

Figure 3 is a schematic front view of the support of Figure 2, with a seat of the restraint system shown semi-transparently superimposed on the support and showing a harness of the personal restraint system;

Figures 4 and 5 are schematic side views of the restraint system of Figure 1 , showing the seat in relatively upright and reclined positions, respectively;

Figures 6 and 7 are schematic side views of the restraint system of Figure 1 , before and after rapid rearward acceleration, respectively;

Figure 8 is a three dimensional view of a tension release device of the harness of

Figure 3; and

Figure 9 is a side view of the tension release device of Figure 8. DETAILED DESCRIPTION OF THE DRAWINGS

Referring to the drawings, a personal restraint system according to the present invention is identified generally be reference number 8 and while some embodiments of the present invention can be used for adults; the system 8 is described herein below as a child restraint system ("CRS").

The CRS 8 includes a support comprising a primary support element in the form of a support frame 3 that is attachable to a vehicle and an adjustable support element in the form of a base 4. The frame 3 has attachment means for attaching it to a vehicle - typically for attaching it to a vehicle seat with straps, clips, or the like, and while this attachment is typically not rigid, it should preferably keep relative movement between the vehicle seat and the frame to a minimum.

A seat 1 with an adjustable lateral headrests 2 of the CRS 8, is supported on the frame 3 and base 4 by four compressible elements 6 extending between the seat and the base and is held in position by tensile elements in the form of tethers 9 extending between the seat and a pivot point 5 on the base. The seat 1 is a "floating seat" in the sense that it is not fixedly held in position relative to the base 4, per se. Instead, the tethers 9 allow the seat 1 to pivot relative to the base 4 about the pivot point 5, but in order to pivot so; the seat has to compress one or more of the compressible elements 6. The compressible elements 6 are spaced about the pivot point 5 - each in a "corner region" of the seat, so that the seat can pivot forwards, backwards or sideways. In other embodiments of the invention, the compressible elements may be disposed about the pivot point 5 in any other configuration in which it can receive a compressive load when the seat 1 is moved relative to the base 4. Instead of tethers 9, the CRS 8 can include linkages, or the like - which would perform the same function. The tethers 9 (or linkages) are taut during normal use of the CRS 8.

Each of the compressible elements 6 is made of a crushable material, such as polystyrene foam or the like, which is strong enough to withstand the compression loading exerted during normal use of the CRS 8, but which compresses (is

"crushed") once the compression loading exceeds a predetermined crushing threshold. The geometry of each of the compressible elements 6 is designed to cause them to be crushed in a desired manner. So, for instance, one or more of the compressible elements can be tapered so that the compressive stresses in narrower parts exceed the crushing threshold earlier than in wider areas and the tapered geometry of the compressible element causes it to be crushed more gradually while compression loads increase, rather than merely crushing it when a loading threshold has been reached. The geometry of the compressible elements 6 can thus be configured to offer an increased resistance to compression, while the compressible element is being crushed.

The floating seat 1 is configured to support a person or occupant such as a young child sitting in the seat and it includes a harness that is attached to the seat and that can extend around a part of the occupant's body, when seated in the seat. The harness preferably extends around any two or more of the occupant's shoulder, hips or groin region to hold the occupant in the seat - preferably with the least scope for relative movement of the occupant relative to the seat, that comfort will allow. In the illustrated example, the harness is a three point harness that is attached to the seat 1 above the occupant's shoulders and between the occupant's legs, with webbing or straps 10 extending from these attachment points to a buckle 12. A tension release device or breakaway clip 12 is provided in each of the harness' shoulder straps 10.

Each breakaway clip 12 consists of a metal frame 13 with a collapsible pin 14. The clip 12 is stitched into the harness strap 10 to form part of the harness itself. One side of the harness strap 10 is connected directly to the frame 13 on one side of the clip 12 and the other side of the strap is connected to the collapsible pin 14. A cushion 15 of collapsible material, e.g. visco-elastic or non-newtonian material, is provided between the collapsible pin 14 and the metal frame 13, with the side of the strap 10 that is connected to the collapsible pin extending around the pin 14, cushion 15 and part of the frame 13, as shown in Figures 8 and 9.

The seat 1 is guided to move relative to the frame 3 by guides 7 that are pivotally attached to the frame on either side and each of which receives a lateral

protuberance from the seat, in a longitudinal slot of the guide. The seat 1 can move relative to the frame 3, e.g. along a predetermined movement path while its protuberances slide along the longitudinal slots of the guides 7, but the range of relative movement between the seat and the frame is limited by the lengths of the guide slots.

The base 4, together with the compressible elements 6, seat 1 and tethers 9 can move relative to the frame 3, while being guided by the guides 7. Such movement could include moving the base 4 backwards relative to the frame 3 to tilt the seat 1 to an upright position as shown in Figure 4, or moving the base forwards relative to the frame to tilt the seat to a more reclined position as shown in Figure 5. This movement is only permitted temporarily, to make adjustments for comfort and the like, and the base 4 is locked relative to the frame 3 after such an adjustment has been made. (The tethers 9 have been omitted from Figures 4 and 5 purely for the sake of clarity.)

In use, an occupant sits in the seat 1 and is held generally firmly relative to the seat by the harness. During normal use, the seat 1 is supported above the base 4 by the compressible elements 6 and the compressive loads on the compressive elements are too low to deform them significantly. The condition of the CRS 8 during normal use is shown in Figure 6.

During rapid acceleration (which includes "deceleration" ), e.g. during an accident, the seat 1 moves relative to the base 4 while its movement is constrained by the tethers 9, which remain taut and bears a tensile load, without significant elongation, and is possibly also constrained by the guides 7. The relative movement of the seat 1 relative to the base 4 exerts a compressive load on one or more of the

compressible elements 6 that exceeds the crushing threshold of one or more of the compressible elements. The compressible element 6 is crushed by the movement of the seat 1 relative to the base 4 and while it is being crushed, it dissipates kinetic energy, reduces the maximum acceleration of the seat and thus reduces the forces experienced by the occupant during the acceleration.

Figure 7 shows the CRS 8 of Figure 6 after rapid rearward acceleration - as is typically experienced in a frontal collision. The rearward acceleration of the vehicle was transferred to the frame 3 and base 4 by the attachment between the vehicle and the base 3, but the inertia of the seat 1 caused it to pivot forward relative to the base - while constrained by the tethers 9 and guides 7, so that the front

compressible elements 6 were crushed and served to mitigate the forces

experienced by the occupant. The crushing of the front compressible elements 6 caused the seat 1 to pivot forwards and to separate from the rear compressible elements 6. Before the rapid acceleration, the tethers 9 were taut and the

compressible elements 6 were in contact with the base 4 and seat 1 without significant play. The crushed compressible elements 6 are easily identified after the rapid acceleration and need to be replaced after any incident that compressed it to the extent that there is play or free movement between the seat 1 and base 4.

The tethers 9 and the guides 7 serve to guide movement of the seat 1 along a predetermined movement path or one of a number of predetermined movement paths, relative to the base 4 during rapid acceleration, so that rapid acceleration in any direction will cause a compressive load on one or more of the compressible elements 6.

This harness configuration including the breakaway clips 12 allows the harness to function as normal, but adds a unique feature which is activated during rapid acceleration, particularly a high G type frontal impact. During a frontal impact the occupant's upper torso tends to move forward out of the seat 1 , but the harness restrains such a movement and holds the upper torso back. This creates tensile loads within the harness straps 10 and exerts compressive forces on the chest of the occupant. The breakaway clip 12 comes into play once a pre-determined tensile load limit within the harness strap 10 is reached, which causes the collapsible pin 14 to give way or collapse (e.g. by shearing off the frame or failing mechanically in any other suitable way) and the cushion 15 absorbs some of the tensile load in the strap , thereby relieving the compressive forces exerted on the occupant's chest. The load threshold for the pin 14 to give way or collapse, can be pre-set during manufacture of the CRS.

In another embodiment, the seat 1 and/or the support 3,4 may include a

protuberance such as an anchor formation, which extends into one or more of the compressible elements 6.

Claims

CLAIMS:

1 . A personal restraint system (8) for an occupant of a vehicle, said restraint system comprising:

a support (3,4) with attachment means for attaching it to the vehicle; a seat (1 ) that is configured to support the occupant;

at least one harness that is attached to the seat and that is configured to extend around a part of the occupant's body, when seated, and to hold the occupant in the seat; and

at least one tensile element (9) extending between the seat (1 ) and the support (3,4), allowing relative movement between the seat (1 ) and the support (3,4);

characterised in that said personal restraint system further includes at least one compressible element (6), extending between a part of the support (3,4) and a part of the seat (1 ), being made of a material that is crushable and being disposed about the tensile element (9) to receive compressive loads during relative movement between the seat (1 ) and the support (3,4), said tensile element (9) being taut, at least before and during the relative movement between the seat (1 ) and the support (3,4).

2. A personal restraint system (8) according to claim 1 , characterised in that said perspma; restraint system (8) includes a plurality of said compressible elements (6).

3. Apersonal restraint system (8) according to claim 1 or claim 2, characterised in that said personal restraint system (8) includes at least one guide (7) that is configured to guide the relative movement between the seat (1 ) and the support (3,4) along a predetermined movement path.

4. A personal restraint system (8) according to any one of the preceding claims, characterised in that the support includes a primary support element (3) that is attachable to the vehicle, and an adjustable support element (4) that can move relative to the primary support element (3), said compressible elements (6) extending between the seat (1 ) and the adjustable support element (4).

5. A personal restraint system (8) according to any one of the preceding claims, characterised in that said restraint system (8) includes a protuberance extending from at least one of the seat (1 ) and support (3,4) into at least one of said compressible elements (6).

6. A personal restraint system (8) according to any one of the preceding claims, characterised in that said harness includes at least one strap (10) comprising two parts that are connected to a frame (13) of a tension release device (12), with a cushion (15) provided between at least one end of the strap (10) and the frame (13).

7. A personal restraint system (8) according to claim 6, characterised in that said tension release device (12) includes a pin (14) that is attached to the frame (13), with the cusion (15) extending at least between the pin (14) and a part of the frame (13), said pin being configured to collapse when a predetermined tensile load is exerted on the pin (14) by the strap (10).

8. A personal restraint system (8) according to claim 6 or claim 7, characterised in that said cusion (15) is of a non-newtonian material.

9. A personal restraint system (8) for an occupant of a vehicle, said restraint system comprising:

a support (3,4) with attachment means for attaching it to the vehicle;

a seat (1 ) that is configured to support the occupant; and

characterised in that said harness includes at least one strap (10) comprising two parts that are connected to a frame (13) of a tension release device (12), with a cushion (15) provided between at least one end of the strap (10) and the frame (13).

10. A personal restraint system (8) according to claim 9, characterised in that said tension release device (12) includes a pin (14) that is attached to the frame (13), with the cusion (15) extending at least between the pin (14) and a part of the frame (13), said pin being configured to collapse when a predetermined tensile load is exerted on the pin (14) by the strap (10).

1 1 . A personal restraint system (8) according to claim 9 or claim 10,

characterised in that said cusion (15) is of a non-newtonian material.