FR2526382A1 - Windscreen-wiper esp. for cars - comprises pressure arm and blade-carrier which are both pivotally attached to reciprocating mounting - Google Patents

Abstract

The vehicle windscreen-wiper comprises an arm (6) which is connected to a blade-carrier (1) by resilient links (10). The arm (6) is spring-biassed to exert a pressure on the blade-carrier (1) towards the windscreen. The blade-carrier (1) is pivotally attached to a reciprocating mounting (3) about an axis (5) which lies perpendicular to the force exerted between the arm (6) and the mounting (3) by the spring (13). The arm (6) itself is pivotally attached to the mounting (3) about the same pivotal axis (5) as the blade-carrier (1) or about an axis (8) parallel to it.

Description

WIPER BLADE
Wiper blades, in particular those for a motor vehicle, include a squeegee blade, an arm capable of exerting pressure on the blade and coupled to a drive hub, and elastic means of connection interposed between the blade and the arm.

 In order to ensure comfort and safety, it is necessary that the sweeping be very effective, a result which is difficult to obtain in modern vehicles, given the large surface area, the inclination and the strong curvature of breeze, especially since. the pressure of the squeegee on the windshield must between high to ensure the permanence and continuity of the contact of the two elements on each other.

 The wiper blades currently produced, in which the pressure arm also ensures the drive of the squeegee blade are not entirely satisfactory. The importance of the stacking overhang, the multiplicity of parts and the accumulation of articulation games make the broom fragile and sensitive to wind, which tends to detach it from the windshield. Often the connection between the blade and the arm is provided by a gantry articulated on the arm and at the ends of which are articulated lifting beams pressing on the blade.

 The ovalization which can occur at the level of the articulation axes favors the appearance of grazing phenomena.

 The present invention relates to an improved wiper blade so as to remedy these drawbacks.

 The brush according to the invention is characterized in that the squeegee blade is articulated about an axis substantially perpendicular to the pressure force exerted by the arm, on the drive hub, so that the hub drives the blade and directly transmits the alternating sweep torque to it, while the pressure arm is articulated on the hub around the pivot axis of the blade or an axis parallel to the latter.

 Under these conditions, the arm simply has the role of exerting pressure on the blade, which facilitates the production of the wiper so that it satisfies the required operating conditions.

 The pressure forces are transmitted in the axis of the connecting stack, therefore under a zero overhang, without the alternating transverse stresses due to the scanning torque acting on it. For its part, the scanning torque is transmitted to a blade very close to the scanning plane, therefore under a very reduced overhang.

 The pressure arm may be integral in rotation with the drive shaft carrying the hub. But it can also simply be immobilized axially on this shaft.

 The elastic connecting means interposed between the blade and the arm can be constituted in the usual manner by a gantry articulated on the arm and at the ends of which are articulated lifting beams pressing on the blade.

 But, in an advantageous embodiment of the invention, made possible by the fact that the scanning torque is transmitted directly to the squeegee blade, these elastic connection means are constituted by a single element, in an elastic manner, comprising a sole in contact with the blade and a series of blocks in contact with the arm. With this arrangement, which gives a very low overhang and has a minimum wind resistance, the aerodynamics are improved, the vertical compactness is increased and the number of articulation parts is reduced.

 The blocks may have longitudinal or transverse recesses. They can Other directed substantially perpendicular to the blade or be oblique with respect to this blade.

 The arm preferably has an enveloping shape so as to laterally hold the elastic connecting element. This enveloping shape further reduces wind resistance; it may include at its end an enlarged part engaged in an enveloping groove formed on the back of the blade. The elastic element is thus perfectly maintained.

 The brush may include at least one auxiliary pressure arm. This can be articulated on the hub around the same axis as the main arm which envelops the auxiliary arm, or else on the main arm.

 The pressure arm can be formed of several elements articulated together and each subjected to the action of specific elastic return means.

Various embodiments of the wiper blade according to the invention have been described below, by way of non-limiting examples, with reference to the accompanying drawings in which
Figure 1 is a perspective view of a first mode of
production;
Figure 2 is a cross section along Il-Il of
Figure 1;
Figure 3 is a perspective view of a second mode from which
production;
Figure 4 is a cross section along IV-IV of
Figure 3;
Figure 5 is a cross section along VV of the
Figure 3;
Figure 6 is a perspective view of a third mode
of achievement;
Figure 7 is an elevational view, partly in section,
a variant of elastic element;
Figure 8 shows in perspective another embodiment
tion of the arm;
Figure 9 is a perspective view of another mode of
making the broom;
Figure 10 is an exploded perspective view of a detail
of a variant.

 As shown in FIGS. 1 and 2, the wiper comprises a blade to which a wiper blade 2 is fixed.

This blade 1 is articulated on a hub 3 fixed on a drive shaft 4, around an axis 5 perpendicular to the direction in which the squeegee 2 must be pressed on the windshield. A pressure arm 6 is fixed to a yoke 7 articulated on the hub 3, around an axis 8 parallel to the axis 5. This arm carries at its end a gantry of connection 9 whose ends in turn carry spreaders 10. The latter are terminated by support heels 11 which are engaged in a groove 12 formed on the upper face of the blade 1. A spring 13 housed inside the yoke 7 tends to pivot the arm 6 towards the blade 1 and thus, via the gantry 9 and the spreaders 10, to press the squeegee 2 on the windshield.

 It can thus be seen that the reciprocating pivoting movement of the shaft 4 is transmitted directly to the blade 1 carrying the squeegee 2, with a very reduced overhang.

On the other hand, pressure forces are exerted on this blade by the arm 6; as this arm does not have to transmit sweeping torque at the same time, these forces are perpendicular to the blade so that it deforms while ensuring excellent and continuous contact of the squeegee 2 on the windshield.

 When the windscreen wiper is raised, the blade 1 and the arm 6 pivot around parallel axes, but not merged so that these two elements have a relative longitudinal movement. However, this movement is made possible because the heels 11 of the lifting beams 10 can slide in the groove 12.

 In the embodiment shown in Figures 3 to 5, the gantry 9 and the spreaders 10 are replaced by a single element 15 of elastomeric material. This element comprises an elongated sole 16 which is housed inside the groove -12 of the blade 1. The sole is integral with compression blocks 17 which project relative to the sole 16, and each have a longitudinal recess 18. These blocks could be oblique but extend here in a direction perpendicular to the sole. The arm 6 and the yoke 7 are replaced by an arm 19 which is articulated at 8 on the hub 3 and has a more or less flared U-shaped section so as to cover the element 15 and to maintain it laterally. The volume of each block and its arrangement are determined according to the shape of the windshield so as to distribute the pressure forces to ensure the permanence and continuity of the contact of the squeegee 2 on the windshield. The end of the arm 19 may comprise an enlarged part 19a which is engaged in the end 12a of the groove 12 of the blade 1, of enveloping shape (see FIG. 5).

 The embodiment of Figure 6 is similar in broad outline to that of Figures 3 and 4. But the blocks 17 'are constituted by thick blades which extend obliquely from the sole 16, from the latter towards its end outside.

 Furthermore, an auxiliary pressure arm 20 is provided which is capped by the main arm 19, is shorter than it and is pivotally mounted around the same axis 8 as the arm 19. A spring not shown tends to press the arm 20 on the blocks 17 'located on the side of the hub 3.

 As shown in Figure 7, the blades 17 'may also have longitudinal recesses 18'.

 FIG. 8 shows a variant in which two auxiliary pressure arms 20a and 206 are provided which interpenetrate with the arm 19, that is to say by being cut out from the outside face of this arm 19, and mounted pivotally on axis 8. This improves the possibilities of travel and gives better control of the pressure distribution.

 The support arm 19 can be formed of several elementary arms such as 19a, 19b and 19c which are hinged together at 21 (FIG. 9). Springs not shown and shown schematically by the arrows 22 tend to rotate each element relative to the adjacent element so as to press it on the blocks 17 or 17 'which it surmounts.

 The arm 6 or 19 may not be secured in rotation with the hub 3, but simply locked axially on the motor shaft 4.

 Thus in FIG. 10, the hub is formed of two elements, namely a lower element 3a which is internally grooved and mounted on the grooved end of the motor shaft 4, and an upper element 3b which is mounted mad on this tree 4.

The element 3b has an inner pin 23 which is engaged in a groove 24 of the shaft 4. The reference 25 designates holes provided in the element 3a for the passage of the axis 5; axis 8 is carried by element 3b.

 It goes without saying that the present invention should not be considered as limited to the embodiment described and shown, but on the contrary covers all variants thereof. Thus, in particular, the auxiliary pressure arm (s) could be pivotally mounted on the main arm.

Claims (12)

1.- Wiper blade, in particular for a motor vehicle, comprising a squeegee blade, an arm capable of exerting pressure on the blade and coupled to a drive hub, and elastic means of connection interposed between the blade and the arm, characterized in that the squeegee blade 1 is articulated around an axis 5 substantially perpendicular to the pressure force exerted by the arm, on the drive hub 3 so that the hub drives the blade and directly transmits the alternating sweep torque to it, while the pressure arm is articulated on the hub around the pivot axis of the blade or an axis parallel to the latter. 2. A brush according to claim 1, characterized in that the pressure arm 6 or 19 is integral in rotation with the motor shaft 4 carrying the hub. 3.- A brush according to claim 1, characterized in that the pressure arm is simply immobilized axially on the drive shaft 4 of the hub 3. 4.- Broom according to one of the preceding claims, characterized in that the elastic connecting means interposed between the blade 1 and the arm 6 or 19 are constituted by a single element 15, in an elastic material, comprising a sole 16 to contact of the blade 1 and a series of blocks 17 or 17 'in contact with the arm 19. 5.- A brush according to claim 4, -caractérisé in that the sole 16 is disposed inside a centering groove 12 formed on the back of the blade 1. 6.- A brush according to claim 4 or 5, characterized in that the blocks 17 or 17 'have transverse or longitudinal recesses 18 or 18'. 7.- Broom according to one of claims 4 to 6, characterized in that the blocks are arranged obliquely relative to the blade 1. 8. A brush according to any one of claims 4 to 7, characterized in that the arm 19 has an enveloping shape so as to laterally hold the elastic connecting element 15.  9. A brush according to any one of claims 4 to 8, charac terized in that the arm 19 has at its end an enlarged part 19a engaged in a groove 12a of enveloping shape formed on the back of the blade 1.  10.- A brush according to any one of the preceding claims, characterized in that it comprises at least one auxiliary pressure arm articulated on the hub. 11.- A brush according to claim 10, characterized in that the auxiliary arm 20 is articulated on the hub 3, around the same axis 8 as the main arm 19 and is enveloped by it. 12.- Broom according to one of claims 1 to 9, characterized in that the arm is formed of several elements 19a, 19b and 19c hinged together and each subjected to the action of particular elastic return means.