DE19716924C2 - Upholstery element with areas of different elasticity - Google Patents

Description

The invention relates to a cushion element with a Core made of elastic material, the two areas has its surface, its elastic properties differ.

Upholstery elements, such as for the Seats used in motor vehicles include a core of elastic material, such as one Foam or rubber hair, the surface of the core usually from a reference and counter if necessary, the intermediate layers below is covered. Occasionally, the core consists of several elements, for example, one above the other sensitive, voluminous layers of material or elements for lateral support of a user on Edge of its seat.

It is often desirable that the elastic Properties of the cushion element, in particular the indentation hardness number as well as the compression hardness, in different areas of its surface under divorce. So it is with a vehicle seat from before partly if the seat is in its central area, the so-called mirror surface, which the user supports ordinary use of the seat, comparatively  is soft for comfortable sitting too enable. In the adjacent marginal areas of the In contrast, the seat is a greater hardness wants a side support for the user zers, for example when cornering. A further differentiated coordination to the requirements Stakes allow cores with a surface of three and more areas with different elastic egg properties.

In the prior art, the core is in its individual areas from different materia lien that in the case of a foam core a multi-zone foam are formed. Most of them are Different foams in the individual zones which mixtures of the same starting materials are produced, that is different proportions of the plastic components and the blowing agent. In the mold, through foaming the core or a core element is produced is a mixture of Foams of different compositions to avoid by a complex subdivision. It is common to use separating swords, that engage in the mold. A disadvantage is that for each area of the multi-zone a separate foam mixing head is required is in which the respective mixture of foam educts of substances and propellants when injected into the molding tool is created. The result is form tools for producing a foam molding from a multi-zone foam and therefore complex expensive.  

From German utility model 92 15 452 is a mattress made from a foamed Material known. This mattress has their entire area evenly distributed Pin holes, whereby to adapt to the ge wanted elastic properties of the mattress Pin holes of different diameters Zones justify different elasticity.

From German utility model 296 02 363 a cushioning element is known to reduce the surface tension in the area of its entire Surface is slotted like a grid. In the area are the intersection points of the slot grid through recesses provided for Serve ventilation.

From US Pat. No. 3,028,610 is known as an upholstery element that covers its entire Surface evenly distributed recesses in the form of a sack has holes. Through this even distribution is a division of the cushion element in several individual elements are made possible.

Against this background, it is the invention task, a cushion element with area Chen different elastic properties develop that inexpensively and easily can be produced.

This object is achieved by a cushion element according to the teaching of claim 1.

The basic idea of the invention is the core from a uniform material places and areas of different elasticity due to the local geometric shape of the core cause. For this purpose one of the areas points a variety of depressions in its surface on while the adjacent area of depressions remains free. In this way it is achieved that the Core deformed more easily under pressure, so is softer, since ver Dodge the pressed material into the wells can.

Distance and diameter of the round or angular Wells are small against the diameter of the objects and bodies to be supported by the upholstery, in the case of a seat, for example, the through knife of a human back or arm. As Diameters of the depressions have been found to be expedient  proven in the range between about 1 mm and 10 mm. The distance between the wells is one another preferably in the range of a few mm to cm. by virtue of the large number of wells below the supported body arises on average evenly ß elasticity of the surface in the respective Be rich. Small-scale variations in the immediate environment of a single well are everyone if detectable by pointed objects that without can destroy the upholstery. In addition, there is usually a distribution of Loads and thus a compensation on a small scale different elastic properties a cover located above the core and counter if necessary, intermediate layers.

So despite the small diameter of the recess changes the elastic core cores shafts in a sufficiently thick, for the loading user-noticeable layer of the core, it is required that the depth of the recesses be their Diameter exceeds. It is preferably around one many times larger than the diameter. suitable Depths are therefore dependent on the diameter of the Wells between about 0.3 cm and 10 cm.

By varying the areal density, the depth and the diameter of the recesses can be Properties of the upholstery element on its upper surface vary within wide limits. The deepening can be both regular and statistical be arranged.  

in the With regard to the diameter and spacing of the wells instead of uniform values over one whole range possible that the values change continuously and thus also the mate rial properties vary accordingly. To this Ways are clear lines between the one individual areas avoidable. Finally there is also the possibility that the depth of each Wells in one area with each other different. By using recesses different depths that are regular or sta are arranged statistically, for example possible that the surface of the core due to egg ner high density is very soft. On the other hand the areal density increases with increasing depth Inside of the cushion, so that its hardness after rises quickly inside.

The advantage of the cushion element according to the invention is that areas of different ela stical properties of the surface Core made of uniform material are possible. On this way he can manufacture the core lighter and in particular the necessary Make mold much easier, because we of devices for dividing different Foams still several mixing heads to their on injections are necessary. In addition, at the produk tion error due to unwanted diameter the foams are excluded. Grundsätz Lich, however, it is also conceivable the core of the invention  Upholstery element as a multi-zone to produce foam from different materials len to the possible variations for the Mate rial properties to expand.

In an advantageous embodiment of the invention, the depressions have a cylindrical or ko African shape, with the cylinder or Ko Nut axis preferably perpendicular to the core surface is aligned. As a result, there is a possibility the ease of making the recess by a pin-shaped displacement body the inner surface of the mold. The zy Lindrical or conical shape avoids problems during demolding, especially a rear hook of the sinker with the core. So did he also facilitates the vertical alignment of the ver Depression axis to the surface of the demolding.

According to the invention, the core consists of a foam, with polyurethane in particular as a material has proven.

Is also according to the invention the distance between the wells is large the average pore diameter of the foam. This avoids that between the Deepening only a small number of art fabric bridges and the cohesion of the Foam is thus impaired. One there The corresponding recess distance consequently improves the Stability of the core material and facilitates its De-molding from a mold with displacement bodies  essential for the production of the wells Lich.

An advantageous mold for producing the As is known in the art, Kerns includes a lockable, foamable volume into which the educts of the foam and, if appropriate Propellant can be introduced. It is also conceivable a reinforcement or a frame in front of the expansion men into the mold which the finished molded part reinforced. On at least one inner surface of its volume shows the form tool on a large number of displacement bodies, which is cylindrical or growing with increasing ab stood tapering from the surface, e.g. B. tapered or have a pyramidal shape. Suitable is in particular the shape of a pen or Na gel, i.e. a cylindrical or slightly ko body with a tip that goes inside of the volume to be foamed. The Longitudinal axes of the displacement body are preferred wise parallel to each other and perpendicular to the upper area of volume aligned. Diameter and Length of the displacement body corresponds to that of to produce recesses in the surface of the Core. The areal densities or dimensions of the ver pushing bodies differ in at least two areas on the inner surface of the work tool. In the majority of cases it is useful ßig that displacement body only in one loading rich in surface area while a other area is free of displacement bodies. As a result, an upholstery element is created  depressions in an area of its surface having. Limitations of the possible geometric The parameters of the wells result because the Demolding of the hardened core with increasing Area density and length of the displacement body becomes more difficult and there is a risk that the Core tears during demolding and in parts between the sinker gets stuck.

Further details, features and advantages of the Er can be found in the following description remove exercise part in the exemplary embodiments are explained in more detail with reference to the drawing. she shows in principle representation

FIG. 1 view of the core a cushion member according to the invention,

Fig. 2 view of an area of the inner upper surface of a mold to its position.

The reproduced in Fig. 1 core 1 of a pole sterelementes has on its surface two un terschiedliche regions 2, 3, of which the portion 3 is provided with a plurality of recesses 4 in small distance from each other. The depressions 4 facilitate the deformation of the core 1 and thus cause the area 3 , which for example forms the central area of the seat surface of a vehicle seat, to be substantially softer than the adjacent area 2 . In this way, different elastic properties arise on the surface of the core 1 , which is preferably provided with a cover fabric before.

Fig. 2 shows an element 5 of a mold, which is used to manufacture the core 1 . Its surface 6 , which forms a section of the inner surface 6 of the foamable volume of the molding tool, is provided with a multiplicity of pin-shaped displacement bodies 7 , which displace the foam introduced into the molding tool and thus produce the depressions 4 in the core 1 during its curing. According to the arrangement of the recesses 4 to be produced , the surface 6 of the element 5 also has an area 8 in which the displacement bodies are arranged by 7 , while the adjacent area 9 is free of displacement bodies 7 . In order to facilitate the demolding of the core 1 after curing, the longitudinal axes of all the displacement bodies 7 are expediently aligned parallel to one another.

The result is the core of one Upholstery element with different areas Chen elastic properties as well as a tool to its manufacture, the manufacture being essential is simplified.

Claims (3)

1. Motor vehicle seat cushion element with a core made of elastic material, in particular a foam that has two areas of its surface, the elastic properties of which differ, wherein
one of the areas ( 3 ) has a plurality of depressions ( 4 ) in its surface,
the depth of the depressions ( 4 ) is greater than their diameter,
the distance and the diameter of the depressions ( 4 ) are small compared to the diameter of the body to be supported by the cushion element,
the distance between the depressions is large compared to the average pore diameter of the foam, and
the adjacent area ( 2 ) being free of depressions. 2. Motor vehicle seat cushion element according to claim 1, characterized in that the areas ( 2 , 3 ) of the core ( 1 ) consist of the same material. 3. Motor vehicle seat cushion element according to claim 1 or 2, characterized in that the recesses ( 4 ) have a cylindrical or conical shape with axis perpendicular to the surface of the core ( 1 ).