GB2498465A

GB2498465A - Seat with belt force limitation device

Info

Publication number: GB2498465A
Application number: GB1302350.2A
Authority: GB
Inventors: Naveen Kumar
Original assignee: Daimler AG
Current assignee: Mercedes Benz Group AG
Priority date: 2013-02-08
Filing date: 2013-02-08
Publication date: 2013-07-17
Also published as: GB201302350D0

Abstract

Child seat device or seat apparatus, also claimed, for a vehicle, comprising a seat and at least one belt force limitation device 32. The device limits a force exerted by a safety belt 26 upon a passenger in an accident to a predeterminable threshold value. The device 32 comprises at least two holding portions 46a, 46b, separated from each other at least partially by at least one wall 48a, 48b, and at least one guide element 50 for guiding the safety belt 26. The guide element 50 is held to the seat in the first holding portion 46a. Due to a force exerted by the belt 26 upon the guide element 50 during an accident, the wall 48a, 48b deforms and the guide element is movable from the first into the second holding portion 46b, and is at least temporarily held there. The device 32 further comprises at least one guide 44 separated from the holding portions 45a-c, at least one second guide 52 element spaced from the first guide element 50 and movable along the guide 44, and at least one link element 54 connecting the guide elements 50, 52 and pivotally holding them on the seat about a common pivot axis 56.

Description

tM:;: INTELLECTUAL S... * PROPERTY OFFICE Application No. tJB1302350.2 RTM Date:7 June 2013 The following terms are registered trademarks and should be read as such wherever they occur in this document:

ISOFIX

Intellectual Properly Office is an operaling name of Ihe Patent Office www.ipo.gov.uk Child Seat Device for a Vehicle The invention relates to a child seat device for a vehicle, in particular a motor vehicle, according to the preamble of patent claim 1 as well as a seat apparatus according to the preamble of patent claim 5.

Such a child seat device for a vehicle can be gathered as known from DE 10 2005 039 711 B4. The child seat device comprises a child seat and a belt force limitation device, by means of which a force exerted by at least one safety belt for restraining a seat passenger of the child seat upon the seat passenger in the event of an accident is limitable to a predeterminable threshold value. The child seat in this setup further comprises a belt system of its own, which is independent of the belt system of the vehicle and comprises the safety belt.

A child seat device can also be found in GB 1214804 A. The belt force limitation device comprises at least two holding portions separated from each other at least partially by at least one wall. The belt force limitation device further comprises at least one guide element for guiding the safety belt, wherein, the at least one guide element in a first of the holding portions is held to the child seat, dye to a force exerted by the safety belt upon the guide element in the event of the accident with deformation, in particular failure, of the wall is movable from the first to the second holding portion, and at least temporarily is to be held in the second holding portion to the child seat.

It is the object of the present invention to further develop a child seat device for a vehicle of the aforementioned kind such that the seat occupant of the child seat can be restrained in a particularly advantageous way.

This object is achieved by a child seat device for a vehicle having the features of patent claim 1. Advantageous embodiments with expedient and non-trivial further developments of the invention are indicated in the other patent claims.

In order to create a child seat device for a vehicle, in particular a motor vehicle, of the kind indicated in the preamble of patent claim 1, which allows for a particularly advantageous restraining of a seat passenger of the child seat, the belt force limitation device comprises according to the present invention at least one guide separated from the holding portions.

The belt force limitation device further comprises at least one second guide element which is spaced away from the first guide element and which is movable along the guide.

Moreover, the belt force limitation device comprises at least one link element by means of which the guide elements are connected to each other. Further, by means of the link element the guide elements are pivotably held on the child seat about a common pivot axis.

The guide elements are connected to each other so that they can move simultaneously in the case of an accident. When an accident occurs, for instance in the case of a frontal crash of the vehicle into another party involved in the accident, an acceleration of the seat passenger occurs in the longitudinal direction of the vehicle towards the front, wherein the seat passenger is restrained by the safety belt. In this connection a force is exerted by the seat passenger upon the safety belt. From this a reaction force results, the reaction force being exerted by the safety belt upon the seat passenger. The load acting upon the safety belt due to the accident is transferred to the guide elements which, as a consequence of * the load, move simultaneously about the common pivot axis. S. S

* In this context the first guide element with deformation, in particular with failure, of the wall moves from the first into the second holding portion. This is accompanied by the movement of the second guide element along the guide. The first guide element being guided by the second guide element via the link element bears at least indirectly against the wall. Hereby a deformation of the wall allows for a controlled increase of the length of the safety belt as a consequence of the accident. Thereby the force acting upon the seat passenger, in particular in the area of his chest, can be kept to a minimum, If the force acting upon the wall exceeds a predeterminable force level, the wall deforms and might even fail for instance by breaking in such a way that the first guide element due to the loads acting upon the first guide element is moved into the second holding portion.

In this connection, then the same process may possibly occur again. Through deformation and maybe failure of the wall energy resulting from the accident can be absorbed so that the force acting upon the seat passenger can be kept particularly low by the belt force limitation device.

The force being exerted by the safety belt upon the passenger may further be adjusted by adjusting the friction between the second guide element and at least one wall constraining the guide. In this connection it is possible that an inner circumference of the guide across the whole extension of the guide may be equal to an outer circumference of the second guide element so that the second guide element can move very smoothly along the guide and thus guide the first guide element from the first holding portion to the second holding portion.

Moreover, the installation space required by the belt force limitation device can be kept to a minimum, because the first and the second guide element move rotationally about the pivot axis. A translational movement of the guide elements is not envisaged so that the guide elements can move in a very space-efficient way, simultaneously allowing for an effective load limitation. * * . * .

In particular, the child seat device can be capable of being arranged on a seat of a vehicle and of being fixed to the seat, for example, by means of a seat belt of the seat and/or by means of an ISOFIX attachment device. The ISOFIX attachment device is also known under the name of LATCH, under the name of LUAS, under the name of Canfix or under the name of UCSSS: Further, the ISOFIX attachment device is standardised according to ISO 13216. By using a ISOFIX attachment device, the child seat can be attached to and * detached from the seat without using any tool.

The invention also relates to seat apparatus for a vehicle, in particular a motor vehicle, of the kind indicated in the preamble of patent claim 5. According to the invention, the the belt force limitation device comprises at least one guide separated from the holding portions, at least one second guide element which is spaced away from the first guide element and movable along the guide and at least one link element by means of which the guide elements are connected to each other and by means of which the guide elements are pivotably held on the seat element about a common pivot axis.

Advantageous embodiments of the child seat device according to the invention are to be regarded as advantageous embodiments of the seat apparatus according to the invention and vice versa.

The idea behind both the child seat device and the seat apparatus is to use the described belt force limitation device which allows for a particularly advantageous restraining of a respective seat passenger, wherein forces being exerted upon the seat passenger can be kept to a minimum. The seat apparatus according, for example, can be configured as a drivers seat or a passenger seat or a rear seat of a vehicle. This means that the described belt force limitation device be used for child seats as well as for driver's seats or passenger seats or rear seats or the like.

Further advantages features and details of the invention derive from the following description of preferred embodiments and from the drawing. The features and combinations of features set out in the description and the features and combinations of features set out in the description of figures and/or displayed alone in the figures below can be used not only in the respectively indicated combination, but also in other combinations or alone without leaving the scope of the invention.

The drawing shows in: Fig. 1 a schematic front view of a child seat device comprising a child seat and two belt force limitation devices which each comprise two guide elements * * in the form of rods and at least one link element by means of which the rods are connected to each other and pivotably held on the child seat about a pivot axis; Fig. 2 a schematic side view of the child seat device; *. .

S * St

FigS 3 a schematic back view of the child seat device; Fig. 4 a schematic and perspective view of one of the belt force limitation devices; Fig. 5 part of a schematic and perspective back view of the child seat device; Fig. 6 part of a schematic exploded view of the child seat device; and Fig. 7 a schematic perspective view of one of the belt force limitation devices covered by a housing.

Fig. 1 shows in a schematic front view a child seat device 10 comprising a child seat 12.

The child seat 12 is commonly also referred to as booster seat. As can be seen from an overall view of figs. ito 3, the child seat 12 comprises a seat part 14, a backrest part 16 coupled to the seat part 14, arm rests 18 and a headrest 20 coupled to the backrest part 16. In figs. ito 3 a dummy 22 is shown, the dummy 22 illustrating a child as an occupant of the child seat device 10.

The child seat device 10 also comprises a restraint system designated as a whole with reference 24. The restraint system 24 has two safety belts 26, 27 for restraining a seat passenger of the child seat 12. The restraint system 24 having the safety belts 26, 27 is a four-point safety belt system comprising a coupling device 28 for coupling and decoupling the safety belts 26.27. Alternatively, the restraint system 24 can also be configured as a five-point safety belt system, wherein the five-point safety belt system comprises a third safety belt not shown in figs. ito 3, the third safety belt on the one side is attached to the seat part 14, extending through legs 30 of the occupant and being capable of being coupled to the safety belts 26 by means of the coupling device 28.

As can be seen from figs. 2 and 3, the restraint system 24 also comprises two belt force limitation devices 32 and 34, which are arranged on a backside 36 of the backrest part 16, the backside 36 facing away from the occupant of the child seat device 10. The belt force limitation device 32 is assigned to the safety belt 26, whereas the belt force limitation device 34 is assigned to the safety belt 27. The belt force limitation devices 32, 34 respectively serve for limiting a force exerted by the safety belts 26, 27 respectively ::". upon the seat passenger in the event of an accident, for example in the event of a frontal crash of a vehicle with the child seat device 10. By means of the belt force limitation devices 32, 34 the force exerted by the safety belts 26, 27 upon the occupant can be limited to a predeterminable threshold value.

For this purpose, as can be seen from figs. 4 to 7, the belt force limitation devices 32, 34 respectively comprise a first supporting element in the form of a first disc 38 and a second supporting element in the form of a second disc 40. The discs 38, 40 are spaced away from each other in the transverse direction of the vehicle and in the transverse direction of the child seat device 10. The discs 38, 40 each comprise a first guide 42. The discs 38, each comprise a second guide 44.

As can be seen from fig. 4, the second guide 44 is at least substantially circular. The first guide 42 has three holding portions 46a-c which are separated from each other partially by respective walls 48a-d of the respective disc 38, 40. As can be seen from fig. 4, the corresponding walls 48a and 48b of the first guide 42 are spaced away from each other at a predeterminable first distance P. The corresponding walls 48c and 48d are spaced away from each other at a predeterminable second distance 0. Thus1 the first guide 42 is a slot whose inner circumference or whose inner diameter in the area of the corresponding walls 48a and 48b and of the corresponding walls 48c and 48d respectively is smaller than in the area of the holding portions 46a-c.

In the respective area of the holding portions 46a-c, the inner circumference or the inner diameter of the first guide 42 is at least substantially adjusted to the outer circumference or the outer diameter of a first guide element in the form of a first rod 50 of the belt force limitation device 32, 34 respectively. The first rod 50 has an outer contour in the form of a straight circular cylinder which engages partially in the corresponding first guide 42. The respective belt force limitation device 32, 34 respectively comprises also a second guide element in the form of a second rod 52. The second rod 52 has an outer contour in the form of a straight circular cylinder which also engages partially in the corresponding second guide 44. The second guide element in the form of the second rod 52 is spaced away from the first rod 50 and movable along the second guide 44.

In the present case, the second guide 44 has an inner circumference or an inner diameter 2.! which is constant across the complete extension of the second guide 44. Moreover, the inner circumference of the second guide 44 is at least substantially adjusted to an outer circumference or an outer diameter of the second rod 52. That means that the inner circumference or the inner diameter of the second guide 44 is at least substantially equal * to the outer circumference or the outer diameter of the second rod 52. Hence, the second rod 52 can slide through the corresponding slot in the form of the second guide 44 which is a guide along which the second rod 52 is movable.

The respective belt force limitation device 32, 34 also has link elements 54 by means of which the guide elements in the form of the rods 50, 52 are connected to each other.

Further, the rods 50, 52 are pivotably held on the discs 38, 40 by means of the link elements 54 about a common pivot axis 56. An angular orientation of the rods 50, 52 is illustrated in fig. 4 by a directional arrow 58.

The discs 38, 40 are mounted on respective attachment brackets 60 which are attached to the backside 36 of the backrest part 16. For this purpose, the discs 38,40 have through openings 62 which correspond with screw bolts 64 mounted on the respective * I. attachment bracket 60. The screw bolts 64 can be inserted through the through openings 62 whereupon corresponding nuts are screwed and tightened on the screw bolts 64.

Thus, the attachment brackets 60 are mounted on the backside 36 of the seat part 16 by screwing them to the backrest part 16.

Moreover, the belt force limitation device 32, 34 comprises a fastening element 67 which is attached to the second rod 52. By means of the fastening element 67 the respective safety belt 26, 27 is connected to the second rod 52.

The rods 50, 52 are advantageously made of high-strength steel whereas the discs 38, 40 are preferably made of a plastic material, Thereby, the discs 38, 40 can be deformed in a very advantageous way when the rods 50, 52 move along the respective guide 42, 44.

In the event of an accident, for example in the event of a frontal crash of the vehicle into another party involved in the accident, the dummy 22 or the occupant of the child seat device 10 is accelerated in the longitudinal direction of the vehicle towards the front. This results in a forward loading phase of the dummy 22 or the occupant. This means the dummy 22 or the occupant moves in the longitudinal direction of the vehicle towards the front. Thereby, reaction forces are exerted upon the safety belts 26, 27. These reaction forces are transferred to the second rod 52 and via the link element 54 to the first rod 50.

2_i This results in a torque acting about the pivot axis 56, the torque being illustrated in fig. 4 by directional arrows 66.

The rod 50 can bear against the walls 48a and 48b so that the rods 50, 52 are supported against the rotational movement about the pivot axis 56 by the walls 48a and 48b. If the torque or the loads acting upon the rods 50, 52 due to the accident exceed a predeterminable force level, the wall 48a and/or the wall 48b is deformed by the rod 50, whereby energy is absorbed, i.e. energy resulting from the accident is transformed into deformation energy. With deformation or even with failure of the wall 48a and/or of the wall 48b, the rod 50 can move along the first guide 42 from the holding portion 56a to the holding portion 56b and at least temporarily is held in the holding portion 56b adjacent to the holding portion 56a.

Then the rod 50 can bear against the walls 58c and 58d. If the loads resulting from the accident and acting upon the rods 50, 52 exceed a predeterminable force level, a further movement of the rod 50 as described above can occur, but now from the holding portion 46b to theholding portion 46c with deformation or even failure of the wall 48c and/or of the wall 48d. During the accident energy absorption is realized by the deformation or failure of the guide 42, the deformation or failure being caused by the rod 50 moving along the first guide 42. Different load limiting types, i.e. constant, progressive and degressive, can be achieved by varying the widths of the first guide 42 in the area of the respective corresponding walls 48a-d, that means by varying the distances P and 0.

During the movement along the guide 42, the first rod 50 is guided by the second rod 52 via the link elements 54. By means of friction between the second rod 52 and at least one wall constraining the second guide 44 energy can be absorbed, too.

By assigning the belt force limitation device 32 to the safety belt 26 and the belt force limitation device 34 to the safety belt 27, a dual load limiter is realized, by means of which the occupant can be restrained particularly well, especially in the case of an offset deformable barrier loadcase, where there is a high influence of vehicle rotation, usually leading to high chest accelerations. By means of the belt force limitation devices 32, 34 loads resulting from an accident and acting upon the occupant and particularly on the chest of the occupant can be kept to a minimum. The belt force limitation devices 32, 34 also allow for realizing a variable load limiting for different sizes and weights of children ages 3 to 10 in a very easy and cost-efficient way.

In fig. 7 a housing 68 for covering the respective belt force limitation device 32, 34 can be discerned. As can be seen from fig. 3, the belt force limitation devices 32, 34 only require little installation space and have a very low weight. * * t

* :*.; The restraint system 24 also comprises a top tether 70 for restraining the headrest 20.

The top tether 70 is held on the headrest 20 and in the vertical direction of the child seat device 10 is spaced away from the belt force limitation devices 32, 34 upwards.

The top tether 70 has two belts 72, which on the one side are attached to the headrest 20 via consoles 74. The belts 72 on the other side are connected to a mounting element 76, by means of which the top tether 70 can -for example -be mounted on a corresponding mounting device of the vehicle. As can be seen from fig. 3, the belts 72 are extending crosswise. Said predeterminable threshold value, to which the force acting upon the occupant or the dummy is to be limited, can be adjusted as required by adjusting the distances P and Q respectively and/or the respective thickness of the walls 48a-d, the respective thickness to be adjusted extending in the longitudinal direction of extension of the first guide 42. The longitudinal direction of extension of the first guide 42 corresponds with the direction of movement, in which the rod 50 can move or moves in the case of an accident. *0 Ca

* .-. * * * * * * a. * * a * * e*_ * S* * * a.. ! . a e

Claims

<claim-text>Claims A child seat device (10) for a vehicle, comprising a child seat (12) and at least one belt force limitation device (32), by means of which a force exerted by at least one safety belt (26) for restraining a seat passenger (22) of the child seat (12) upon the seat passenger in the event of an accident is limitable to a predeterniinable threshold value, the belt force limitation (32) device comprising: -at least two holding portions (46a, 46b) separated from each other at least partially by at least one wall (48a, 48b) and -at least one guide element (50) for guiding the safety belt (26), wherein the at least one guide element (50) in a first of the holding portions (46a, 46b) is held to the child seat (12), due to a force exerted by the safety belt (26) upon the guide element (50) in the event of the accident with deformation of the wall (48a, 48b) * is movable from the first into the second holding portion (46b), and at least * temporarily is to be held in the second holding portion (46b) to the child seat (12), characterized in that the belt force limitation device (32) comprises: -at least one guide (44) separated from the holding portions (46a-c), -at least one second guide (52) element which is spaced away from the first guide element (50) and movable along the guide (44), and -at least one link element (54) by means of which the guide elements (50, 52) are connected to each other and by means of which the guide elements (50, 52) are pivotably held on the child seat (12) about a common pivot axis (56).</claim-text> <claim-text>2. The child seat device (10) according to claim 1, characterized in that at least one tether (70) for restraining the child seat (12), in particular for restraining a head rest (20) of the child seat (12), is held on the child seat (12), the tether (70) in the vertical direction of the child seat device (10) is spaced away from the belt force limitation device (32) upwards.</claim-text> <claim-text>3. The child seat device (10) according to any one of the preceding claims, characterized in that the at least one safety belt (26) is a first safety belt (26) of a four-point safety belt system (24) or a five-point safety belt system comprising the first safety belt (26) and a second safety belt (27) for restraining the seat passenger (22) in the event of the accident.</claim-text> <claim-text>4. The child seat device (10) according to claim 3, characterized in that the belt force limitation device (32) is assigned to the first safety belt (26), wherein an additional second belt force limitation (34) device is assigned to the second safety belt (27).5. A seat apparatus for a vehicle, comprising at least one seat element and at least one belt force limitation device (32), by means of which a force exerted by at least one safety belt (26) for restraining a seat passenger (22) of the seat element upon the seat passenger in the event of an accident is limitable to a predeterminable *..: threshold value, the belt force limitation (32) device comprising: -at least two holding portions (46a, 46b) separated from each other at least partially by at least one wall (48a, 48b) and -at least one guide element (50) for guiding the safety belt (26), wherein the at least one guide element (50) in a first of the holding portions (46a, 46b) is held to the seat element, due to a force exerted by the safety belt (26) upon the guide element (50) in the event of the accident with deformation of the wall (48a, 48b) is movable from the first into the second holding portion (46b), and at least temporarily is to be held in the second holding portion (46b) to the seat element, characterized in that the belt force limitation device (32) comprises: -at least one guide (44) separated from the holding portions (46a-c), -at least one second guide (52) element which is spaced away from the first guide element (50) and movable along the guide (44), and -at least one link element (54) by means of which the guide elements (50, 52) are -connected to each other and by means of which the guide elements (50, 52) are pivotably held on the seat element about a common pivot axis (56). * 4 4 * * *4*s44* * . ** 4 * * * * 4* * ** * 4-4 p ** * * * 4 * -4 -</claim-text>