GB2368272A

GB2368272A - Weight responsive child safety seat

Info

Publication number: GB2368272A
Application number: GB0025901A
Authority: GB
Inventors: Per-Olaf Svensson
Original assignee: Autoliv Development AB
Current assignee: Autoliv Development AB
Priority date: 2000-10-23
Filing date: 2000-10-23
Publication date: 2002-05-01
Anticipated expiration: 2020-10-23
Also published as: GB2368272B; GB0025901D0

Abstract

A child safety-seat is provided for use in a motor vehicle which is adapted to be used with children of different sizes. The child safety seat comprises a child supporting squab (6) which is mounted on a parallel arm linkage (25, 33) to be moveable relative to the rest of the seat. Springs (28, 36) bias the squab upwardly. The seat is responsive to the weight of the child, to effect movement of the child supporting squab relative to the rest of the seat. Thus the child is positioned appropriately to wear a fixed safety-belt. Movement of squab 6 is preferably dampened by damper 30 and squab 6 may be locked in a forward position (Fig.1).

Description

DESCRIPTION OF INVENTION "IMPROVEMENTS IN OR RELATING TO A CHILD SAFETY SEAT" THE PRESENT INVENTION relates to a child safety seat and more particularly relates to a child safety seat for use in a motor vehicle such as a motor car.

It has been proposed previously to provide various types of child safety seat within a motor vehicle, such as a car. Some prior proposed child safety seats are in the form of safety seats which can be releasably mounted within the motor vehicle, and other child safety seats are in the form of safety seats which are permanently mounted within the vehicle but which can be moved between stowed and operative conditions. Typically such a safety seat may be integrated within the back seat structure of the motor vehicle.

A child safety seat of the type generally discussed above is intended to accommodate a child over a substantial period of its growth and development and thus a typical seat may be adapted to be occupied by a child of any age within a range of, typically, 18 months to ten years.

In order to retain a child securely within a safety seat it is necessary for the safety belt utilised to adopt a particular"geometry"with regard to the torso of the child. Ideally the safety belt used to restrain the child within the seat should extend across the chest of the child at an appropriate height. If the safety belt extends across the chest at too high a level there is a risk that part of the safety belt will pass across the thorax or throat of the child, which may lead to the child being injured in an accident situation. If the safety belt passes across the child at too low a level there is a risk that, in an accident situation, the child will be thrown forwardly and will"roll"out of the safety seat over the safety belt. A child, between the age of three years and ten years may increase substantially in size and thus it is important that a child safety seat should provide the correct seat belt geometry for children of different sizes.

The present invention seeks to provide an improved child safety seat.

According to this invention there is provided a child safety seat for use in a motor vehicle and adapted to be used with children of different sizes, the child safety seat comprising a child supporting squab, the child supporting squab being moveable relative to the rest of the seat, means being provided to sense a parameter of a child occupying the seat and to effect movement of the child supporting squab in dependence upon the sensed parameter.

Preferably, the sensed parameter is the weight of the occupant of the seat.

Conveniently, the child supporting squab is mounted for movement relative to an underlying support, resilient means being provided to bias the child supporting squab upwardly, and to permit downward movement of the squab in dependence upon the weight of a child sitting on the squab, the resilient means thus constituting the means responsive to a parameter of the child.

Advantageously, the child supporting squab is mounted to the underlying support by means of a parallel arm linkage, comprising a forward pair of parallel arms and a rearward paid of parallel arms, the resilient means comprising at least one compression spring. The resilient means may comprise said one compression spring, which is associated with the forward pair of parallel arms and a second compression spring associated with the rearward pair of parallel arms.

Preferably, a damper is provided to damp movement of the child supporting squab relative to the underlying support.

Conveniently the seat may form an integral part of the rear seat of a motor vehicle, the child supporting squab being moveable between an elevated position in which it overlies a rear portion of the squab unit of the seat and a stowed position in which it constitutes the forward part of the squab unit of the rear seat.

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described, by way of example, with reference to the accompanying drawings in which FIGURE 1 is a diagrammatic side view of part of a rear seat of a motor vehicle provided with an integrated child's safety seat in accordance with the invention, showing the seat in one condition with the child safety seat stowed, FIGURE 2 is a view corresponding to Figure 1 showing the child safety seat in the operative condition, FIGURE 3 is an enlarged view of part of the seat as shown in Figure 2, FIGURE 4 is a view corresponding to Figure 3 showing that part of the seat in an alternative condition, FIGURE 5 is a view of the child safety seat of Figures 1 to 4 occupied by a dummy corresponding to a three year old child, FIGURE 6 is a view corresponding to Figure 5 showing the seat occupied by a dummy corresponding to a six year old child and FIGURE 7 is a view corresponding to Figure 6 showing the seat occupied by a dummy corresponding to a ten year old child.

Referring initially to Figure 1 of the accompanying drawings a vehicle seat 1 is provided, the seat having a squab structure 2 and a backrest 3, the seat being associated with a conventional safety belt 4 which is of the lap-anddiagonal form.

The squab section 2 of the seat is divided into two regions, a fixed rear region 5 and a moveable front region 6. The front region 6, as will become clear from the following description, can be moved from a stowed position, as shown in Figure 1, in which the rear region 5 and the front region 6 together form a conventional squab, to an operative condition, as shown in Figure 2, in which the front region 6 forms the squab of a child seat.

Figure 3 illustrates the structure of the front part 6 of the squab section 2 of the seat.

Referring to Figure 3 of the accompanying drawings, a mounting plate 10 is provided adapted to be secured to a frame underlying the squab section 2 of the seat. The mounting plate 10 is provided with two upwardly directed lugs 11 each of which supports, by means of a respective pivot pin 12, an arcuate arm 13. The arms 13 may pivot about the axis defined by the pivot pins 12. Each arm 13 is of arcuate form and terminates with a further pivot pin 14. The arm is provided with a catch, shown schematically as catch 15 which co-operates with a latch, shown schematically as latch 16 provided on the mounting plate 10. The latch 16 may be actuated by means of a Bowden cable 17. The catch serves to retain the arcuate ann 13 in the operative position illustrated in Figure 3.

The pivot pin 14 supports a mounting tray 20. The forward edge of the mounting tray 20 is pivotally mounted for pivotal movement about the axis defined by the pivot pins 14. The mounting tray extends, in the position illustrated, generally rearwardly from the pivot pins 14 in a substantially horizontal direction. The mounting tray is located above the rear part 5 of the squab unit of the seat.

A locking detent 21 is provided at the forward edge of the tray 20 in the region of the pivot pin 14 for a purpose which will be described hereinafter. The main, horizontal extending portion of the mounting tray 20 is provided with aligned pairs of upstanding lugs 22,23. The first pair of aligned lugs 22, located forwardly on the mounting tray 20, are provided with aligned pivot pins 24 which support a first pair of linear links 25, the upper ends of the links 25 being pivotally connected by pivots 26 to a child supporting squab 27 which actually constitutes a principal element of the front portion 6 of the squab section 2 of the seat 1 as shown in Figure 1. The upper surface of the child supporting squab will be padded and upholstered. The linear link 25 as shown in Figure 3 is inclined slightly forwardly. A compression spring 28 is provided extending between the mounting tray 20 and the child supporting squab 27 in the region of the links 25, the axis of the compression spring being inclined slightly rearwardly relative to the axis of the links 25.

At least one of the links 25 is provided with a projecting finger or tab 28 which extends from the link and which is connected to a drive rod 29 which extends to a damper 30 which may, for example, be a hydraulic damper. The damper 30 is connected to the mounting tray 20 by means of a lug 31.

The second pair of aligned lugs 23, provided at the rear of the mounting tray are provided with aligned pivot pins 32, which support a second pair of linear links 33, the upper end of each linear link 33 being connected, by means of a pivot 34, to a rear part of the child supporting squab 27. The rear links 33 are inclined forwardly and thus are parallel with the forward links 25. A further compression spring 36 is provided extending between the mounting tray 20 and the child supporting squab 27 in alignment with the rear links 33.

The axis of the spring 36 is substantially parallel with the axis of the spring 28.

The child supporting squab 27 is provided with an actuating button 37 provided towards the forward edge of the child supporting squab 27. The button 37 is adapted to actuate the Bowden cable 17 which releases the latch 16. The button 37 can also be actuated to release a retainer which is adapted to engage the detent 21 provided on support tray 20.

It is to be appreciated that the described child supporting squab 27 is illustrated in Figure 3 in the operative position. It is to be understood that if the actuating button 37 is actuated the catch 15 may be released by the latch 16 and the entire child supporting squab may be pivoted forwardly, with the arcuate arms 13 pivoting about the pivot axis defined by the pivot pins 12 and with the child supporting squab pivoting about the pivot axis 14. The arrangement may then occupy the position as shown in Figure 4. It will be appreciated that with a slight further movement the illustrated components will be in such a position that the child supporting squab 27 again constitutes the front section 6 of the squab unit 2 of the seat. It has, of course, been known previously to provide a child supporting squab which can move pivotally, in this way, between an operative position and a stowed position, and vice versa.

In the described embodiment of the invention the child supporting squab 27 is mounted on the support tray by means of a parallel arm linkage constituted by the arms 25 and 33, and is biased upwardly by means of the compression springs 28 and 36. When the arrangement is to be in the stowed condition shown in Figure 1 manual pressure is applied to the child supporting squab 27 thus compressing the springs 28 and 36 until a catch actuated by the button 37 engages the detent 21 provided on the support tray 20 thus retaining the child supporting squab 27 in a predetermined position relative to the support tray 20. However, when the child safety seat is to be used by a child, the components are moved to the position illustrating in Figure 3 and the retainer operated by the button 37 is released so that the child supporting squab 27 is moved to an elevated position relative to the support tray 20 by the springs 28 and 36.

The springs 28 and 36 have a selected strength so that the child supporting squab 27 moves downwardly, on the parallel arm linkage 25,33 in dependence upon the weight of a child sitting on the squab.

It has been appreciated by the present invention that if a fixed safety belt is utilised with a child safety seat, in order to ensure that the safety belt has the desired geometry when used by any particular child, the position of the torso of the child in the seat, relative to the belt, should be adjusted vertically in dependence upon the height of the child. Thus a tall child should sit lower down, so that the shoulder of the child is substantially at a predetermined position in the seat with the safety belt passing over the shoulder of the child.

A shorter child should sit higher up in the seat so that the safety belt passes, in a desired manner, over the shoulder of the child.

It has also been appreciated by the present invention that the height of a child is closely related to the weight of a child and thus, in the described embodiment of the invention, the child supporting squab of the safety seat is adapted to move substantially vertically in response to the sensed weight of the child. In the described embodiment this is achieved in a elegant manner by utilising the parallel linkage constituted by the links 25,33, which permits the upward and downward movement of the child supporting squab 27 relative to the support tray 20, and the compression springs 28,36 which provide a resilient upward bias to the child supporting squab 27, that bias being selected so that the child supporting squab 27 will move downwardly by an appropriate distance for every predetermined increment in the weight of the child.

In order to facilitate an understanding of the operation of the seat references now made to Figure 5 which illustrates the seat of the invention in use with a dummy representing a three year old child. The dummy 40 shown in position on the seat, and it can be seen that the safety belt 4 passes over the top of the backrest 3 of the seat extending diagonally across the seat, as is conventional. It can be seen that the child supporting squab 27 is in a elevated position. The head of the dummy is well within the area defined by the headrest forming an integral part of the back 3 of the seat, and safety belt 4 passes over the shoulder of the dummy 40 in a desired manner. The safety belt does not cross the neck of the dummy but is in an appropriate position.

Figure 6 shows the seat occupied by a dummy corresponding to a six year old child. The six year old child is heavier than and taller than the three year old child. Because the six year old child is heavier, the child supporting squab 27 is depressed, against the resilient bias provided by the springs 28,36, relative to the position shown in Figure 5. The lower part of the torso of the dummy 41 shown in Figure 6 is thus at a lower level, but because the torso is longer (as the child has a greater height) the shoulder of the dummy is again at a position such that the safety belt 4 passes over the shoulder of the dummy with the desired geometry. The child supporting squab remains in this position, without"floating"up and down, because of the effect of the damper 30.

Referring finally to Figure 7, the seat is shown occupied by a dummy 42 corresponding to a ten year old child. Here the child supporting squab 27 is in a fully depressed condition, with the springs 28,36 being substantially completely compressed because the dummy 42 has a greater mass than that of the dummy 41. However, the length of the torso of the dummy 42 is greater than the length of the torso of the dummy 41 and thus, again, the safety belt 4 passes over the shoulder of the dummy with a desired geometry. Again the damper 30 prevents"floating".

It is thus to be appreciated that in the described embodiment of the invention the position of the child supporting squab 27 is adjusted in response to a sensed parameter of the occupant of the seat. In this case the sensed parameter is weight, but because weight is, at least to a first approximation, a good indicator of height, especially in connection with a child between the age of three to ten years, the overall effect is that the position of the occupant of the child safety seat relative to the fixed part of the seat, and thus relative to the safety belt, is such that the safety belt has a desired geometry with respect to the occupant of the seat.

Of course, other mechanisms may be utilised to adjust the position of the child supporting squab, but the presently described parallel linkage, and the associated springs, is preferred since it is straightforward to manufacture and provides the desired effect.

While the invention has been described with reference to an embodiment which is an integral child seat, the invention may also be embodied in a child safety seat of the type that is releasably mounted in a motor vehicle.

In the present specification"comprise"means"includes or consists of and"comprising"means"including or consisting of.

The features disclosed in the foregoing description, or the following Claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAIMS: 1. A child safety seat for use in a motor vehicle and adapted to be used with children of different sizes, the child safety seat comprising a child supporting squab, the child supporting squab being moveable relative to the rest of the seat, means being provided to sense a parameter of a child occupying the seat and to effect movement of the child supporting squab in dependence upon the sensed parameter.
2. A seat according to Claim 1 wherein the sensed parameter is the weight of the occupant of the seat.
3. A seat according to Claim 1 or 2 wherein the child supporting squab is mounted for movement relative to an underlying support, resilient means being provided to bias the child supporting squab upwardly, and to permit downward movement of the squab in dependence upon the weight of a child sitting on the squab, the resilient means thus constituting the means responsive to a parameter of the child.
4. A seat according to Claim 3 wherein the child supporting squab is mounted to the underlying support by means of a parallel arm linkage, comprising a forward pair of parallel arms and a rearward paid of parallel arms, the resilient means comprising at least one compression spring.
5. A seat according to Claim 4 wherein the resilient means comprise said one compression spring, which is associated with the forward pair of parallel arms and a second compression spring associated with the rearward pair of parallel arms comprising
6. A seat according to Claims 3 or 4 wherein a damper is provided to damp movement of the child supporting squab relative to the underlying support.
7. A seat according to any one of the preceding claims forming an integral part of the rear seat of a motor vehicle, the child supporting squab being moveable between an elevated position in which it overlies a rear portion of the squab unit of the seat and a stowed position in which it constitutes the forward part of the squab unit of the rear seat.
8. A child safety seat substantially as herein described with reference to and as shown in the accompanying drawings.
9. Any novel feature or combination of features disclosed herein.