WO2004002791A1

WO2004002791A1 - Elastomeric material profile for wiper blade

Info

Publication number: WO2004002791A1
Application number: PCT/IB2003/002388
Authority: WO
Inventors: Bruno Zeni; Silvano Piva
Original assignee: Bruno Zeni; Silvano Piva
Priority date: 2002-06-24
Filing date: 2003-06-19
Publication date: 2004-01-08
Also published as: AU2003244893A1; ITVI20020135A1

Abstract

A profile elastomer material for a windscreen wiper blade has an elongated shape and comprises a tapered edge (2) for wiping a glass surface and a mounting edge (3) for connection to a blade-holder frame. The base material of the profile (1) is a mixture of elastomer materials containing an additive able to modify uniformly the colouring of the base material. The additive is chosen from among materials able to discolour uniformly and make the base material of the profile (1) transparent or from among pigments able to impart to the said profile (1) a colouring which is uniform and stable over time.

Description

ELASTOMERIC MATERIAL PROFILE FOR WIPER BLADE

Technical field

The present invention can be employed of motor cars and vehicles in general and relates to a profile of elastomer material for wiper blades.

Background art

Profiles for windscreen wiper blades, made by means of moulding or extrusion of elastomer material of various types, for example based on butyl rubber or silicone rubber, are known.

US-A-6311364 and EP-A-1059213 describe a profile of silicone elastomer material for a windscreen wiper blade, having a longitudinal portion able to come into direct contact with a glass surface to be cleaned. This longitudinal portion has a coating of PTFE or particles of silica, graphite or similar materials. The purpose of the coating is to increase the wear resistance of the profile and reduce the friction between blade and glass surface, thus facilitating sliding of the profile over the said surface.

A limitation of this solution consists in the greater complexity of the process for producing the profile, resulting from the need to provide the coating. This limitation assumes particular importance owing to the large number of profiles produced.

US-A-5283927 describes a profile of silicone elastomer material for a windscreen wiper blade, which is obtained by adding a siliceous filler dispersed in the compound. In a similar manner TW-A-412487 describes a profile which is formed by combining additional fluorinated compounds and microscopic particles of glass with the silicone base material. In these solutions the composition of the mixture used for the profile reduces the friction between the blade and the glass surface, without requiring an additional coating.

A drawback common to the above mentioned exemplary embodiments resides in that they provide no particular colouring or pigmentation on the hole profile, which profile generally has an anonymous black colour. The above mentioned patent documents describe solutions for reducing the wear of the blade and increasing its duration, but fail to consider any solutions for providing the same profile with a bright and lasting colour. The user may be induced to replace the elastomer profile of a wiper blade thereby to reach a greater aesthetic satisfaction. Thanks to the negligible cost of the elastomer profile, when compared with the normal running and maintenance costs of a vehicle, it is possible to assume that the user, with a motivation of purely aesthetic nature, is led to replace the profile of the wiper blades with greater frequency.

DE-A-19817419 describes an elastomer profile for a windscreen wiper blade incorporating coloured bands which are visible from the outside. This solution has been adopted in order that the colours furnish immediate information about the product, such as the type or year of production. The coloured bands extend over the whole longitudinal length of the profile, but occupy limited zones of the cross- section and their overall visual impact is limited since they have not been designed for aesthetic purposes.

Disclosure of the invention

A general object of the present invention is that of eliminating the abovementioned drawbacks by providing a profile of elastomer material for a windscreen wiper blade, which is advantageous from a cost-related point of view.

A primary object is that of providing a profile having optimum technical properties, such as flexibility at low temperatures, ageing resistance and flame resistance. A particular object is that of providing a profile which is visually attractive and matches the vehicle on which the wiper is mounted so as to increase the satisfaction and fulfil the aesthetic taste requirements of the user.

A further object of the invention is that of providing a profile, the technical and aesthetic properties of which remain unchanged over time.

Another particular object is that of providing a profile which can be easily assembled on the blade-holder frame and is able to induce the user to replace it more frequently, thereby helping reduce the number of vehicles on the roads having worn and potentially dangerous windscreen wipers.

These objects, together with others which will appear more clearly below, are achieved in accordance with Claim 1 by a profile of elastomer material for a wiper blade, having an elongated shape and comprising a tapered edge for wiping a glass surface and a mounting edge for connection to a blade-holder frame, characterized in that the base material of the profile is a mixture of elastomer materials containing an additive able to modify uniformly the colouring of the base material. The additive is chosen from among materials able to discolour uniformly and make the base material of the strip transparent or from among pigments able to impart to the profile a colouring which is uniform and stable over time.

Owing to this particular configuration it will be possible to obtain a profile which is visually pleasing and matches aesthetically the vehicle on which the windscreen wiper will be mounted.

Preferably, the pigments are of the fluorescent or phosphorescent type.

Owing to this particular characteristic feature it will be possible to obtain a profile which is clearly visible also in poor lighting conditions, such as for example at night-time or inside tunnels. Suitably the mixture of elastomer materials is chosen from among silicone materials in order to increase the brightness and shininess of the colouring.

Owing to this particular feature it will be possible to obtain a profile having optimum technical properties such as flexibility at low temperatures, ageing resistance and flame resistance.

Brief description of the drawings

Further features and advantages of the invention will be more clearly understood from the detailed description of some preferred, but not exclusive embodiments of a profile according to the invention, illustrated by way of a non-limiting example with the aid of the attached illustrative plate in which:

FIG. 1 shows a partial perspective view of a profile according to the invention.

Detailed description of the preferred embodiment(s)

With particular reference to the said figures, a profile according to the invention, which is made from elastomer material, is described and denoted overall by the reference number 1.

The profile 1 has an elongated shape and comprises a tapered edge 2 for wiping a glass surface and a mounting edge 3 for connection to a blade-holder frame.

The cross-section of the profile 1 is formed so as to allow mounting thereof inside a series of substantially hook-shaped securing elements integral with the blade- holder frame. After the profile 1 has been inserted in the blade-holder frame along the whole length of the latter, the profile 1 is cut to size and forms the wiper blade. Moreover, the profile 1 is provided with longitudinal recesses 4 for seating lateral reinforcements and for facilitating fixing in the blade-holder frame. The base material of the profile 1 is a mixture of elastomer materials containing an additive able to modify uniformly the colouring of the base material. This additive is chosen from among pigments which are able to impart to the said profile 1 a uniform and stable colouring over time, it being possible to choose from among a wide range of colours, making it feasible, for example, to combine the colour of the wiper blade with that of the bodywork on which the wiper will be installed.

Suitably the additive is chosen from among the materials able to discolour uniformly, so as to make the base material of the profile 1 transparent.

An additional possibility is that the pigments, which are able to impart to the profile 1 a uniform and stable colouring, are of the fluorescent type. Owing to this characteristic, the profile 1 , when it is acted on by an exciting agent, is able to emit light radiation with a very short delay and is easily visible in poor lighting conditions. The fluorescence effect ceases as soon as the exciting agent stops acting.

The pigments, able to impart a uniform and stable colouring to the profile 1 , may be of the phosphorescent type. In this way the profile 1 continues to emit light radiation for a long period of time, when acted on by an exciting agent, and is easily visible in poor lighting or night-time conditions. Phosphorescence differs from fluorescence in terms of the duration of the light rays emitted after the exciting agent ceases to act. This duration varies from fractions of a second to several days in the case of phosphorescence and is substantially zero in the case of fluorescence.

In order to obtain a very bright and shiny colour, the mixture of elastomer materials is of the silicone type. This enables the quality of the colouring to be enhanced and to be kept unchanged over time. The optimum duration of the colouring in silicone rubbers contrasts with that of some organic plastics or rubbers where the colours fade in a short time and irreversibly, becoming unaesthetic. In addition to the undoubted advantages in terms of the colouring, provided by the mixture of elastomer materials of the silicone type, said mixture also has other notable technical properties such as, for example, the capacity to keep unchanged its flexibility at low temperatures, the low sensitivity to light and atmospheric agents, the optimum ageing resistance, the high flame resistance and the properties of not developing toxic gases in the event of a fire.

The cost of the elastomer strip 1 and its replacement is negligible when compared with the normal running and maintenance costs of a vehicle, particularly if only the wiper blade made of elastomer material and not the whole blade-holder frame is replaced. This means that the cost does not constitute a serious obstacle to replacement of the wiper blade and the quality colouring of the profile 1 according to the invention may be an incentive to perform replacement thereof.

Suitably the mixture of elastomer materials comprises fluorinated additives in order to diminish the friction between the blade and the glass surface. In particular, the percentage by weight of the fluorinated additives in the mixture of elastomer materials is less than 10% and suitably between 0.01% and 8% by weight. The fluorinated additives reduce the tendency of the mixture of elastomer materials of the silicone type to adhere to the glass surface and facilitate sliding of the wiper blade during operation, without losing the other positive characteristics of elastomer materials of the silicone type described above.

In order to increase the rigidity and strength of the blade, it is possible to add also to the mixture of elastomer materials microscopic glass globules which may be internally hollow so as not to weight down the profile.

Advantageously the profile 1 of elastomer material is an extruded product of indefinite length. In this way, when it is required to replace a blade, it is possible to remove the new profile 1 to be mounted from a roll and cut the blade to the desired length. From that described above it seems obvious that the profile according to the invention achieves the predefined objects and in particular increases the satisfaction and fulfils more closely the aesthetic taste requirements of the user owing to the possibility of choosing between different colours. Moreover, the aesthetically pleasing colour of the profile provides an incentive for replacement thereof and results in a reduction in the number of potentially dangerous vehicles on the roads with worn windscreen wiper blades.

The profile according to the invention may be subject to numerous modifications and variations all falling within the inventive idea expressed in the accompanying claims. All the details may be replaced by other technically equivalent elements and the materials may be different according to requirements, without departing from the scope of the invention.

Although the profile has been described with particular reference to the accompanying figure, the reference numbers used in the description and in the claims are used in order to facilitate understanding of the invention and do not impose any limitation on the scope of protection claimed.

The instant application is based upon and claims priority of patent application no. VI2002A000135, filed on 24.06.2002 in Italy, the disclosure of which is hereby expressly incorporated here in reference thereto.

Claims

1. Elastomer material profile for a wiper blade, with an elongated shape, comprising a tapered edge (2) for wiping a glass surface and a mounting edge (3) for connecting to a blade-holder frame, characterized in that the base material of the profile (1) is a mixture of elastomer materials containing an additive able to modify uniformly the colouring of said base material.

2. Profile according to Claim 1 , characterized in that said additive is chosen from among materials able to discolour uniformly and make said base material of the profile (1) transparent.

3. Profile according to Claim 1 , characterized in that said additive is chosen from among pigments able to impart to the said profile (1) a colouring which is uniform and stable over time and can be combined with the colour of the bodywork of the vehicle on which the windscreen wiper will be installed.

4. Profile according to Claim 3, characterized in that said pigments are of the fluorescent type.

5. Profile according to Claim 3, characterized in that said pigments are of the phosphorescent type.

6. Profile according to one or more of the preceding claims, characterized in that said mixture of elastomer materials is chosen from among silicone materials in order to increase the brilliance and shininess of said colouring.

7. Profile according to Claim 6, characterized in that said mixture of elastomer materials comprises fluorinated additives in order to reduce the friction between the wiper and the glass surface.

8. Profile according to Claim 7, characterized in that the percentage by weight of said fluorinated additives in said mixture of elastomer materials is less than 10%.

9. Profile according to Claim 8, characterized in that the percentage by weight of said fluorinated additives in said mixture of elastomer materials is between 0.01 and 8%.

10. Profile according to Claim 6, characterized in that said mixture of elastomer materials comprises microscopic glass globules in order to increase the rigidity and the strength of the blade.

11. Profile according to Claim 1 , characterized in that it consists of an extruded product.

12. Profile according to Claim 11 , characterized in that said extruded product is of indefinite length.