WO2008099056A1

WO2008099056A1 - Windshield wiper

Info

Publication number: WO2008099056A1
Application number: PCT/FI2008/050054
Authority: WO
Inventors: Keijo Vornanen
Original assignee: Keijo Vornanen
Priority date: 2007-02-13
Filing date: 2008-02-12
Publication date: 2008-08-21
Also published as: FI120968B; FI20075099A; FI20075099A0

Abstract

The invention relates to a windshield wiper, comprising a body (1) and a replaceable blade element (2) capable of being attached to the body. The body (1) is substantially rigid. The flexible blade element (2) is attached to a cassette block (7) which, jointly with the blade element (2), constitutes a replaceable blade cassette (2, 7). The blade element (2) includes a flexible member (6), which defines a cavity filled with a fluid type substance (2a) and which is positioned between a block (7) and a blade (2b), enabling distance variations between the cassette block (7) and the blade (2b).

Description

Windshield wiper

The invention relates to a windshield wiper, comprising a body and a replaceable blade element which is capable of being attached to the body.

The windshield wiper according to the invention includes preferably also a heating line in connection with the body and/or the blade element, and a thermostat which connects electric current to the heating line when the outdoor air temperature falls below a predetermined limit and disconnects electric current from the heating line when the temperature rises above a predetermined limit.

Windshield wipers of this type are prior known e.g. from Patent publications US-4,603,451 and US-2004/0006839 Al, as well as US-6,507,973. In addition, the Applicant's earlier patent FI 106370 discloses a heatable windshield wiper, the blade of which releases slight amounts of silicone onto the windshield surface for providing a water-repellent clear coating.

A problem with the prior known windshield wipers is that the wiper arm's elastic force and/or the wiper's specific stiffness is not always sufficient to press the wiper blade over its entire length against the windshield surface, the wiping result being left with blind spots. This problem becomes particularly evident with ice or dirt on the windshield surface.

It is an object of the invention to further develop a windshield wiper of the above type for enabling the pressure applied by the blade to the windshield to be distributed more evenly over the entire blade length. A further object of the invention is to provide an easy replaceability of the blade element, enabling the use of a heated blade in the winter and an unheated one in the summer. This object of the invention is achieved on the basis of the characterizing features set forth in the appended claim 1. Preferred embodiments of the invention are presented in the dependent claims.

One exemplary embodiment of the invention will now be described in more detail with reference to the accompanying drawing, in which

Rg. 1 shows a windshield wiper according to one embodiment of the invention in cross-section;

Rg. 2 shows the windshield wiper of fig. 1 obliquely from above in a perspective view.

Rg. 3 shows a cassette block 7 and a replaceable blade cassette 2, 7 in cross-section, according to a second embodiment.

The windshield wiper comprises a body 1 and a replaceable blade element 2 capable of being attached to the body by means of a cassette block 7. A heating line 3, such as a flat-shaped resistance wire or a wire supplying power to the blade element's heating lines 4, extends between the body 1 and the cassette block 7 and is engaged with and/or embedded in the body 1. The blade element 2 and the cassette block 7 establish jointly a blade cassette 2, 7, which is replaced whenever a blade 2b must be replaced. The blade cassette 2, 7 and the body 1 terminate in a connector 16, which couples the body element's heating line 3 with a heating line 4 present inside the blade element. Alternatively, the connector may be located in the middle of a wiper near the connection point of an arm 9. If desired, the heating line can be arranged to extend either in connection with just the body or the blade element. The body 1 and the cassette block 7 can be made in plastics and manufactured by injection moulding. Coupled with electric power supply wires 3a inside the arm 9 is a thermostat 5, connecting the electric current to the heating line 3,4 as the outdoor air temperature falls below a predetermined limit (e.g. +4°C) and disconnects the electric current from the heating line 3, 4 as the temperature rises above a predetermined limit. The thermostat 5 may also connect directly to the heating line 3, 4, measuring its temperature. In this case, the disconnection of heating current may occur e.g. at a resistance wire temperature of +75⁰C.

The blade element 2 according to the invention comprises a flexible member 6, which defines a cavity filled with a fluid type substance 2a and which is present between the cassette block 7 and the blade 2b, enabling distance variations between the cassette block 7 and the blade 2b. The fluid type substance may comprise a gas such as air, a liquid, a gel, a colloid, soft silicone, etc. This fluid type substance may be in communication with the blade 2b by way of microchannels, leaving tiny amounts of the substance on the glass surface to establish a water-repellent clear coating or skin. Alternatively or additionally, the actual blade 2b itself is manufactured from such components that at least one component releases in a controlled manner a water-repellent clear coating onto the windshield surface. At the same time, such a coating is dirt-repellent, i.e. facilitates working of the blade in its efforts to remove dirt from the windshield surface. The flexible member 6 and the blade 2b can be made of silicone, having its stiffness or elasticity chosen for the purpose.

As the fluid type substance 2a has its pressure distributed evenly over the entire length of the flexible member 6, the pressure applied to the glass by the blade 2b is respectively distributed evenly over the entire length of the blade.

The body 1 is a trough-like section of moderate rigidity, which is shaped as a U- or C-section receiving the blade element. In a preferred embodiment of the invention, the cassette block 7 consists of block members which are linked to each other by means of a membrane hinge 11, which extends longitudinally of the wiper and around which the cassette block's 7 members are pivotable to a limited extent. The membrane hinge 11 has a sufficient stiffness for holding the cassette block in a rest position as shown in fig. 1 or 3, in which it is insertable inside the body 1. The hinge 11 nevertheless allows for opening the cassette block 7 for installation of the blade element 2. The cassette block 7 is provided with clamping claws 12, between or behind which the blade element's 2 clamping bracket 13 is squeezed or engaged, when the cassette block 2 is in a rest condition in which it is insertable inside the body 1. The embodiment of fig. 3 differs from fig. 1 in the sense that the cassette block 7 of fig. 3 is provided with two membrane hinges 11 and the blade element 2 has its flexible member 6 provided at its top corners respectively with two clamping brackets 13, which are locked behind the claws 12 of the cassette block 7. This provides the flexible member 6 with a better bracing than the attachment of fig. 1. With the cassette block 7 inserted in a receptacle defined by the body 1, the cassette block is fixed by the body to its configuration so as to disallow opening of the membrane hinge or membrane hinges 11 and to hold the blade element 2 firmly in the cassette block.

The cassette block 7 is locked to the body 1 by clamping elements 15 whose engagement claws snap into recesses in the body 1, when the cassette block 7 is in its position inside the body 1. The locking can be released by turning the clamping elements' engagement claws outward. The clamping elements are implemented e.g. by providing the body 1 with spring-loaded rocking arms whose ends snap into recesses in the cassette block 7 as the cassette block 7 pushed into its position inside the body 1. In this case, the release is effected by pressing the levers to turn the same against a spring load, whereby the locking is released and the blade cassette 2, 7 can be disengaged and replaced with a new one. This simple replaceability is also important for the reason that the blade cassette intended for summertime use needs no heating. If the replacement of a blade cassette was an inconvenient procedure, the user would not always replace the blade but would use the more expensive heated blade also in the summer.

The heating line 3, or a line 3a supplying power thereto, is provided with a signal light 10, indicating that heating is on. In the illustrated case, the signal light 10 is included in a wiper arm 9.

Inside the blade element 2 is provided preferably one or more longitudinal braces 8. Heating resistances 4 are insertable side by side into a channel 2c in the blade element 2, immediately above the blade 2b.

The wiper arm 9 is fixed to the body 1 by any appropriate mechanism, which allows for an angular deflection within a narrow range between the longitudinal directions thereof. In its rest condition, the body 1 can be slightly more arcuate or straighter than the curvature of a windshield, the elasticity of the blade 2b and the flexible member 6 allowing the blade curvature to settle in conformity with the windshield curvature in response to a bias pressure applied by the arm element 9 to the body l. By virtue of a rather stiff nature of the body element 1 and an elastic nature of the blade element 2, the pressing of the blade 2b can be managed against windshield surfaces of various curvatures with a constant force over the entire length thereof. The wiping result does not develop blind spots, even with irregularities of ice or dirt on the surface to be wiped.

In a preferred embodiment of the invention, the blade element 2 has its flexible member 6 provided with bellows-like folds 14 for increasing a flexible travel distance of the blade 2b with a relatively narrow fluctuation range of pressure force applied to the blade.

The pressure of fluid existing in the cavity of the flexible member 6 must be chosen to fit the purpose, the same applying also to the elasticity and wall - o

thickness of the flexible member material. Consequently, the blade 2b declines to an appropriate wiping angle as the wiper travels back and forth.

In addition, a rigid body 1 attached directly to the arm provides an assembly more beneficial than those of the prior art in terms of power supply and the disposition of resistance wires. The wires shall not remain exposed and, thus, shall not be susceptible to damage (attrition, twisting, etc.). Distribution of electric power can proceed from a fuse box. Position of the thermostat 5 is also selectable in view of providing a high operating reliability in freezing winter conditions. Heating is automatically on, whenever needed. The replacement of a worn-out blade element 2 can be performed easily and quickly without having to replace the wiper body 1, which can be permanently attached to the arm 12, yet in such a way that it can be replaced by means of tools in case the body element 1 becomes damaged. Because the body element 1 has a long service life, it is preferred solution to construct a wash liquid spraying mechanism in connection therewith. In the illustrated case, spray channels 17, along with nozzles 18 therefor, are placed on either side of the body 1 at outer and lower edges of the body. Both channels 17 are supplied with wash liquid by means of specific supply conduits 17a, placed within the arm 9 or possibly mounted also on top of the arm 9. The supply conduits 17a may connect to a dispensing valve, which dispenses wash liquid alternately into various supply conduits 17a and into various spray channels, such that the spraying is only or mainly effected from the wiper edge leading the way in the wiper traveling direction. This type of mechanism has been described in the Applicant's patent FI-85356.

A windshield wiper according to the invention reduces the number of road accidents by improving visibility even in difficult driving conditions.

Claims

1. A windshield wiper, comprising a body (1) and a replaceable blade element (2) capable of being attached to the body, the blade element (2) including a flexible member (6) present between the body (1) and a blade (2b) enabling distance variations between a cassette block (7) and the blade (2b), the body (1) being substantially rigid, characterized in that the flexible blade element (2) is attached to the cassette block (7) which, jointly with the blade element (2), constitutes a replaceable blade cassette (2, 7), the cassette block (7) of which is capable of being locked in a receptacle of the body (1) in a replaceable fashion.

2. A windshield wiper as set forth in claim 1, characterized in that the body (1) is a trough-like section of moderate rigidity, which is designed as a U- or C-section capable of receiving the blade cassette (2, 7).

3. A windshield wiper as set forth in claim 1 or 2, characterized in that the cassette block (7) consists of block members, linked to each other with a hinge (11) around which said members of the cassette block are pivotable to a limited extent, and that the cassette block (7) includes clamping claws (12), between or behind which the blade element (2) has its clamping bracket (13) squeezed or engaged when the cassette block (7) is in a rest condition in which it is capable of being inserted inside the element (2).

4. A windshield wiper as set forth in any of claims 1-3, characterized in that it further includes a heating line (3, 4) in connection with the body and/or the blade element, and a thermostat (5) which connects electric current to the heating line (3, 4) when the outdoor air temperature falls below a predetermined limit and disconnects electric current from the heating line (3, 4) when the temperature rises above a predetermined limit. O

5. A windshield wiper as set forth in any of claims 1-4, characterized in that the heating line (3) extends along the body element (1), which is provided at the end or in the middle with a connector (16) coupling the body element's heating line (3) with a heating line (4) present inside the blade element (2).

6. A windshield wiper as set forth in any of claims 1-5, characterized in that inside the blade element (2) is a brace (8) extending in its longitudinal direction.

7. A windshield wiper as set forth in any of claims 1-6, characterized in that the blade (2b) is manufactured from such components that at least one component provides the windshield surface with a clear coating of controlled water repel lency.

8. A windshield wiper as set forth in any of claims 1-7, characterized in that the blade element (2) contains a substance, which is in communication with the blade (2) by way of microchannels and which forms a water repellent clear coating on the windshield surface.

9. A windshield wiper as set forth in any of claims 1-8, characterized in that the blade element (2) has its flexible member (6) provided with bellows- like folds (14) for increasing a flexible travel distance of the blade (2b) with a relatively narrow fluctuation range of pressure force applied to the blade.

10. A windshield wiper as set forth in any of claims 4-9, characterized in that the heating line (3), or a line supplying power thereto, is provided with a signal light (10), indicating that heating is on.

11. A windshield wiper as set forth in any of claims 1-10, characterized in that on either side of the body are wash liquid spray channels (17), along with nozzles (18) therefor.

12. A windshield wiper as set forth in any of claims 11, characterized in that the supply of wash liquid is adapted to proceed alternately into various spray channels (17), such that the spraying occurs each time only or predominantly from the wiper edge which leads the way in the wiper traveling direction.

13. A windshield wiper as set forth in any of claims 3, characterized in that the cassette block is provided with two membrane hinges (11) spaced from each other, and the blade element (2) respectively with two clamping brackets (13) located at the blade element's top corners.

14. A windshield wiper as set forth in any of claims 1-13, characterized in that the flexible member (6) defines a cavity which is filled with a fluid type substance (2a) or very soft silicone.