WO2022229713A1

WO2022229713A1 - Headrest for motor vehicles

Info

Publication number: WO2022229713A1
Application number: PCT/IB2022/051278
Authority: WO
Inventors: Massimo GILARDI; Stefano Grassini; Marco RAVICINO; Roberto RAVICINO
Original assignee: Gestind S.P.A.
Priority date: 2021-04-28
Filing date: 2022-02-14
Publication date: 2022-11-03
Also published as: IT202100010697A1

Abstract

It is provided a headrest (1) for motor vehicles, comprising a structural support (2) defining a main surface (2a), a cushion body (3) integrally constrained to the structural support (2) in correspondence with the main surface (2a) and defining a contact surface (3a) suitable to support the head of a user, wherein the cushion body (3) comprises a plurality of layers (30) arranged in succession and integrally constrained to each other, the plurality of layers (30) comprising at least a first layer (31) made of polymer foam and a second layer (32) made of polyurethane gel.

Description

DESCRIPTION

HEADREST FOR MOTOR VEHICLES

The present invention relates to a headrest for motor vehicles of the type specified in the preamble to the first claim. The headrest is a device configured to support and hold an individual's head. It can, as is known, be incorporated in a backrest or be separated from it. In the latter configuration, the headrest may be fixed or movable.

In particular, in motor vehicles, the headrest is necessary for the safety of the driver and passengers as it minimises whiplash injury in the event of a road collision. Without the headrest, in the event of a rear-end collision or accident, the driver's and passengers' heads would be subjected to a sudden backward bending that could cause injury to the muscles and/or cervical vertebrae. In addition, under normal driving conditions, the headrest allows the neck muscles to relax, making the journey particularly comfortable. Headrests for motor vehicles can be made of material identical or similar to that of the seat to which they are attached and, in addition, include a padding particularly suitable for absorbing shocks.

Generally, the headrest comprises a structural core, capable of creating the bond between the seat and the headrest, surrounded by a padding made at least in part of elastic material. For example, the patent application PCT WO 2020/201842 A1 , in the name of Gestind S.P.A., teaches to make a headrest including a portion made of viscoelastic material, also called memory foam. This material has the characteristic of slowly returning to its original shape after an initial deformation.

Other headrests are described in patent applications US 2009/0315372 A1 , in the name of Lear Corporation. The main characteristic that a headrest must satisfy is its reactivity in case of sudden impacts.

In addition, the headrest must provide the user with comfortable head support.

The known technique described includes some important drawbacks. In particular, headrests of the known type, in order to have the described qualities, frequently have high thicknesses.

In this situation, the technical task at the basis of the present invention is to devise a headrest for motor vehicles capable of substantially obviating at least part of the aforementioned drawbacks. In the context of said technical task, it is an important scope of the invention to obtain headrests for motor vehicles capable of effectively dissipating shocks.

A further important scope of the invention is to achieve a headrest for motor vehicles with high comfort.

Still another scope of the invention is to realize a headrest with reduced thickness. The technical task and the specified purposes are achieved by headrest for motor vehicles as claimed in the appended claim 1 .

Preferred technical solutions are disclosed in the dependent claims.

The features and advantages of the invention are hereinafter clarified by the detailed description of preferred embodiments of the invention, with reference to the appended drawings, wherein: the Fig. 1 shows a side view of the headrest according to the invention in use; the Fig. 2a illustrates an enlarged cross-section of a portion of a headrest according to the invention in which the cushion body comprises three layers of different material; the Fig. 2b is an enlarged cross-section of a portion of a headrest according to the invention in which the cushion body comprises the three layers of Fig. 2a but in a different succession; and the Fig. 2c shows an enlarged cross-section of a headrest portion according to the invention in which the cushion body comprises two layers made of different material. In the present document, the measurements, values, shapes and geometric references (such as perpendicularity and parallelism), when associated with words like “about” or other similar terms such as “approximately” or “substantially”, are to be considered as except for measurement errors or inaccuracies due to production and/or manufacturing errors, and, above all, except for a slight divergence from the value, measurements, shape, or geometric reference with which it is associated. For instance, these terms, if associated with a value, preferably indicate a divergence of not more than 10% of the value.

Moreover, when used, terms such as “first”, “second”, “higher”, “lower”, “main” and “secondary” do not necessarily identify an order, a priority of relationship or a relative position, but can simply be used to clearly distinguish between their different components.

Unless otherwise specified, as results in the following discussions, terms such as “treatment”, “computing”, “determination”, “calculation”, or similar, refer to the action and/or processes of a computer or similar electronic calculation device that manipulates and/or transforms data represented as physical, such as electronic quantities of registers of a computer system and/or memories in, other data similarly represented as physical quantities within computer systems, registers or other storage, transmission or information displaying devices.

The measurements and data reported in this text are to be considered, unless otherwise indicated, as performed in the International Standard Atmosphere ICAO (ISO 2533:1975).

With reference to the Figures, the headrest for motor vehicles according to the invention is globally indicated by the number 1.

The headrest 1 is suitable for supporting the head of a user while driving a motor vehicle and protecting the latter from injury in the event of road collisions.

The headrest 1 is configured to be preferably constrained to a motor vehicle seat. In particular, the headrest 1 may be incorporated in, and thus integrally constrained to, the upper end of the seat back, or may be constrained to it by interlocking. The interlock may in turn be removable or non-removable. In the case of a removable interlock, the headrest 1 preferably comprises translation means configured to allow vertical translation of said headrest 1 relative to the back of said seat. Such vertical translation enables the user to adjust the height of the headrest 1 so that the user's head is optimally supported by the headrest 1 .

The headrest 1 comprises, in brief, a structural support 2 and a cushion body 3. The structural support 2 defines a main surface 2a. The main surface 2a defines substantially the extension of the headrest 1 , preferably the whole of the extension of the headrest 1 , or only a portion thereof, preferably intended to allow the head to be supported. The structural support 2 and the cushion body 3 are integrally constrained at the main surface 2a. This constraint may be achieved by gluing, interlocking or otherwise.

Furthermore, the structural support 2 is preferably connected to the seat of the car. This connection may be made by a portion of the structural support 2 itself or by suitably configured connection means.

In particular, the structural support 2 is preferably made of a rigid material. It is preferably made of plastic. Moreover, it may advantageously comprise metal parts suitable, for example, to realise the constraint with said seat.

The cushion body 3 defines a contact surface 3a. This surface is opposed to the main surface 2a. The contact surface 3a is configured to support and protect the head of a user. It is, therefore, at least partially counter-shaped to the head of a user. In particular, the cushion body 3 comprises a plurality of layers 30. The layers 30, moreover, are arranged in succession starting from the main surface 2a. The layers 30 are integrally constrained to each other. Such constraint may be achieved, for example, by gluing. In particular, the very formation of the materials, for example in a mould, can achieve their mutual gluing in a manner known in itself to the person skilled in the art. The plurality of layers 30 comprises at least a first layer 31 and a second layer 32.

The first layer 31 is made of polymeric foam, preferably polyurethane foam. More preferably, it is made of visco-elastic polyurethane foam or soft elastic foam. Visco elastic polyurethane foam may be, for example, memory foam. The particularity of such material is that it slowly returns to its original shape upon compression. In particular, the said viscoelastic foam material has a percentage damping coefficient of more than 50% with a compression energy of more than 50 N-mm at a crush of 80% or more of the initial thickness.

The first layer 31 preferably has a thickness between 0.5 cm and 5 cm.

It also preferably has a density between 25 g/l and 150 g/l and a bearing capacity between 0.5 kPa and 10 kPa. In detail, the lift is defined as the pressure to be applied, via an established indenter, to a sample in order to compress its initial thickness by 40%.

The second layer 32 is preferably made of polyurethane gel.

The polyurethane gel comprising the second layer is preferably produced by an embodiment process preferably comprising a formulation step followed by a mixing and curing step.

The formulation step comprises the selection and dosage of at least one polyol and isocyanate.

The polyol, preferably has average functionality less than or equal to three. Preferably, the polyol is a poly-propylene glycol and/or polyethylene glycol and/or a polyether polyol or polyester with greater than equal to two functionality (preferably two or three) and/or a polyether monol or a mixture thereof. A particular embodiment involves the combined use of two or more polyols. Such one or more polyols define a polyol compound. The polyol compound is preferably present in a weight percentage of between 85% and 90% of the total obtained from the formulation step.

The isocyanate may be aliphatic or aromatic. For example, it may be based on diphenylmethane-4,4'-diisocyanate. The isocyanate 3 is preferably present in a weight percentage of between 6% and 10% of the total obtained from the formulation step. Furthermore, the formulation step comprises the selection and dosage of a catalyst. The catalyst is suitable to control the polymerisation reaction and therefore allows obtaining a product having desired physical-mechanical characteristics. This catalyst may be amine or metallic. The catalyst is preferably present in a weight percentage of between 0% and 0.5% of the total obtained from the formulation step.

Preferably molecular sieves are chosen and dosed in said formulation step. They are preferably aluminosilicates, more preferably zeolites. The molecular sieves preferably have pores with a diameter of between 3 A and 4 A. The molecular sieves are preferably present in a weight percentage of between 1% and 2% of the total obtained from the formulation step. They are suitable for absorbing traces of water present in the reagent mixture. This absorption is necessary for the finished product to have optimum characteristics. Polymerization, takes place consequently and substantially simultaneously with the mixing of the polyol mixture, to which the catalyst and molecular sieves are preferably added beforehand, and the isocyanate. It preferably takes place at a temperature between 15°C and 80°C. The polymerisation temperature and the amount of catalyst introduced in the first step determine the speed of the polymerisation reaction.

It can also be made from expanded polyurethane gel. Such expansion may be, for example, realised during the polymerisation reaction. In particular, the expansion may be realized by introduction and saturation of gas in the reactant mixture or by introduction of inert expandable microspheres in the mixture which are suitable to expand during the polymerization.

The second layer 32, in case it is made of non-expanded polyurethane gel, preferably has a thickness between 1 mm and 15 mm. Furthermore, it preferably has a density between 1000 g/l and 1200 g/l. The expansion allows the thickness of the second layer 32 to be increased by at least 10% compared to the same second layer made of non-expanded polyurethane gel. Furthermore, it preferably has a density between 250 g/l and 1100 g/l.

The second layer 32 is interposed between the first layer 31 and the main surface 2a. In particular, the plurality of layers 30 may comprise only the first layer 31 and the second layer 32.

Alternatively, the plurality of layers 30 may additionally comprise a third layer 33. The third layer 33 is preferably made of polymeric foam, preferably polyurethane foam. The material of the third layer 33 is particularly suitable for shock absorption. Specifically, said material preferably has a thickness between 0.5 cm and 5 cm, a density preferably between 25 g/l and 150 g/le a bearing capacity preferably between 2 kPa and 25 kPa. Furthermore, the third layer 33 may be interposed between the second layer 32 and the structural support 2. An alternative embodiment comprises the third layer 33 interposed between the first layer 31 and the second layer 32.

The cushion body 3, formed by joining two or three layers as described above, has a total thickness preferably between 1 cm and 15 cm, more preferably between 2 cm and 7 cm.

Furthermore, the headrest 1 advantageously comprises an outer covering 5. The outer covering 5 is suitable for covering at least the cushion body 3. Preferably, it may cover both the cushion body 3 and the structural support 2. In particular, the portion of the outer covering 5 in contact with the outer surface of the first layer 31 defines the contact surface 3a. The outer covering 5 may preferably be made of leather or fabric.

The function of the headrest 1 described above in structural terms is to support the head of a user while driving or travelling in a motor vehicle. In particular, in the event of a road impact due to an accident or a rear-end collision, the headrest 1 protects the user's head by preventing it from abruptly folding backwards and causing injury. If the headrest 1 is movable, the user should adjust the height of the headrest 1 before travelling.

The headrest 1 according to the invention achieves important advantages.

Indeed, the presence of the polyurethane gel layer, in addition to known polymeric materials, ensures high shock absorption.

Furthermore, the plurality of layers of the headrest 1 provides a highly comfortable support element.

The headrest 1 is particularly suitable in situations where high shock absorption and low thicknesses are desired at the same time. The invention is susceptible to variations within the inventive concept defined by the claims. Within this scope, all details are substitutable by equivalent elements and the materials, shapes and dimensions can be any.

Claims

1. Headrest (1 ) for motor vehicles comprising:

- a structural support (2) defining a main surface (2a),

- a cushion body (3) integrally constrained to said structural support (2) in correspondence with said main surface (2a) and defining a contact surface (3a) capable of supporting the head of a user, and characterized by that:

- said cushion body (3) consists of a plurality of layers (30) arranged in succession and integrally constrained between them,

- said plurality of layers (30) comprises at least:

- a first layer (31) made of polymeric foam,

- a second layer (32) made of polyurethane gel.

2. Headrest (1) according to claim 1 , wherein said second layer (32) is interposed between said first layer (31) and said main surface (2a).

3. Headrest (1) according to any one of the preceding claims, wherein said first layer (31) is made of polyurethane foam

4. Headrest (1) according to claim 3, wherein said first layer (31) is made of viscoelastic polyurethane foam.

5. Headrest (1) according to any one of the preceding claims, wherein said second layer (32) is made of expanded polyurethane gel.

6. Headrest (1) according to claim 5, wherein said second layer (32) in expanded polyurethane gel has a density between 250 g/l and 1100 g/l.

7. Headrest (1) according to any one of the preceding claims, wherein said plurality of layers (30) comprises a third layer (33) made of polyurethane foam having a density between 25 g/l and 150 g/l.

8. Headrest (1) according to claim 7, in said third layer (33) it is interposed between said second layer (32) and said main surface (2a).

9. Headrest (1) according to claim 7, wherein said third layer (33) is interposed between said first layer (31) and said second layer (32).

10. Headrest (1) according to any one of the preceding claims, wherein said plurality of layers (30) comprises only said first layer (31 ) and said second layer (32).

11. Headrest (1) according to any one of the preceding claims, wherein said cushion body (3) has a thickness comprised between 1 cm and 15 cm.

12. Headrest (1 ) according to any one of the preceding claims, comprising an outer coating (5) capable of covering at least said cushion body (3).