Patent Application
20150367820
The present invention relates to a wiper assembly of a motor vehicle window comprising a mounting head adapted to be rotatably driven by a motorised drive arm adapted to carry a wiper blade at its end opposite the mounting head.
Such modules are known which more particularly equip the rear windows of motor vehicles. The arrangement of the wiper blade in the axial extension of the drive arm allows a significant surface area of the window to be cleaned with a single wiper assembly. This type of structure, however, has the disadvantage of being fragile, notably when the wiper blade must displace an amount of stagnant snow on the glass. The resulting torque may be excessive for the mechanical structure formed by the arm and by the mounting head, and wiper assembly can break, notably at the junction between the mounting head and the drive arm.
The present invention falls within this context and its purpose is to provide a sufficiently robust wiper assembly, notably for a rear window of a motor vehicle.
Furthermore, such wiper assemblies must be designed to provide a release mechanism, enabling the user to simplify the replacement of a wiper blade when it is worn. The user must be able to rotate the drive arm about an axis of articulation parallel to the window and borne by the mounting head, so as to disengage the blade from the window, and it is convenient for the user that the release position of the blade, inclined at an angle, may be retained mechanically, so that the user can have his hands free to replace the wiper blade.
The release system must be sufficiently secure, i.e. to enable the drive arm to be lifted only under a certain constraint, so as to prevent the drive arm from assuming a release position not deliberately wanted by the user, and notably when the vehicle is passing through a roller cleaning system, which may then result in breakage of the wiper assembly if it rises during the cleaning operation.
The invention, as it was considered in the context of obtaining a sufficiently robust wiper assembly, also aims to provide an alternative to the detachable system that is efficient and secure.
The invention thus proposes a wiper of a motor vehicle window, comprising a mounting head adapted to be rotatably driven by a motorised shaft about a transverse axis of the mounting head, and a drive arm which extends along a longitudinal axis between a proximal end adapted to be pivotally mounted about an axis borne by said mounting head and an opposite distal end adapted to carry a wiper blade, elastic return means being provided to participate in maintaining the arm in position relative to the mounting head.
According to the invention, the drive arm includes a shroud which is disposed at its proximal end and wholly encloses the mounting head, said shroud having projecting means on its inner face, cooperating with complementary projecting means on the outer face of the mounting head to form pivoting means of the arms around the head and means for holding the arm in position relative to the head in different operating positions of the wiper assembly.
According to various features of the invention, taken alone or in combination:
Other features and advantages of the invention will become apparent on reading the detailed description of an embodiment which follows and for better understanding, reference is made to the annexed drawings wherein:
As illustrated in the figures, the wiper assembly comprises a mounting head 2, a drive arm 4 cooperating with said head, and a wiper blade, not shown here and which is mounted on the arm opposite the mounting head.
The mounting head is made integral with a motor shaft, not shown here and which extends substantially perpendicular to the window to be wiped, so as to impart an alternating rotational movement to this mounting head and to the corresponding wiper assembly.
The mounting head 2, illustrated alone in
The base has a substantially cylindrical body 10 pierced in its centre with a through bore 12, and two legs 14 arranged facing one another so as to radially extend said body and to surround the connecting tab.
The axis of the through bore is coincident with the axis of rotation of the motorised shaft. This axis of the mounting head shall be referred to as the transverse axis, and it will be understood that it corresponds to the axis of rotation of the wiper assembly. The through bore has a diameter substantially equivalent to the outer diameter of the motorised shaft, and the fitting means, for example a conical shape, to cooperate with complementary means borne by the motorised shaft, so as to ensure the rotational drive of the mounting head by the shaft.
Each leg 14 has a cylinder portion 16 whose axis is perpendicular to the transverse axis of the mounting head, disengaged from the leg by a material cutout under the cylinder portion which forms a straight-edged abutment portion 18. These two cylinder portions borne by the mounting head have a common axis 20 which forms, as will be described below, a pivot axis of the connecting arm relative to the mounting head.
The connecting tab 8 is formed in the continuity of the cylindrical body, and it is centred between the two legs 14, such that the cylindrical body has a larger transverse dimension than the tab. A material cutout 22 is formed on the upper face of the cylindrical body, set back from the cylinder portions 16, to form a bearing face for the screwing means of the mounting head with the motorised shaft.
The connecting tab 8 thus extends the base radially, along a first axis. The tab comprises two lateral uprights 24 which extend facing one another, by connecting at right angles to the outer surface of the cylindrical base, and it further comprises an upper wall 26 that covers both uprights. The side uprights are integral with the cylinder portions which project laterally beyond the outer faces of the lateral uprights. Each lateral upright has a substantially triangular planar shape, a first side of which is integral with the base of the head, a second side is integral with the upper wall and a third side, and the front face 28 of the lateral uprights is inclined by an angle substantially equal to 45° relative to the first axis. A rounded edge 30 is formed at the junction of each of lateral uprights with the upper wall.
As is illustrated and notably visible in
The inner faces 34 of the lateral uprights are defined as those being rotated with respect to one other, and the outer faces 36 of these lateral uprights being the opposite faces, adapted to be opposite the arm when the mounting head cooperates with the drive arms.
The projecting position maintaining and load transfer means borne by the mounting head comprise first knurls 38 formed by an extra thickness on the outer face of each lateral upright of the tab, and they comprise second knurls 40 which are formed on the outer surface of the cylindrical body, and which extend parallel to the transverse axis of the mounting head. Furthermore, third knurls extend parallel to this same axis of rotation under each of the cylinder portions of the base, formed by the straight-edged abutment portion 18.
The drive arm 4, illustrated alone in
The rear end portion 46 comprises a shroud 55 integral with the central portion and cover 56 adapted to overlap the upper edge of the shroud and having at least one hole 57 to allow access to the shroud when the cover is in position.
The shroud comprises two side walls 58 connected to the back of the shroud by a slightly curved, transverse end wall 60. The side walls, near the transverse end wall, are cut diagonally, so that the lower edge of the shroud portion forms a bevel 62.
The shroud defines a rear receiving area 64, of lesser thickness, and a front force transfer area 66, of greater thickness.
In the rear receiving area 64, every side wall presents, from the upper edge to the opposite lower edge, a concave recess 68 machined into the material, and an axial rib 70, that extends under this recess to the inclined wall forming the lower edge of the side wall.
On each side wall, the junction between the rear receiving area and the front force transfer area, for which the side wall has different thicknesses, consists of a shoulder forming edge 72 and the junction has a specific profile in its upper part so that the edge forms a cylindrical seat 74. This cylindrical seat has straight guide walls 76, facing one another and which extend substantially along the longitudinal axis of the arm, and a circular stop wall 78 which connects them forming an open semi-circle toward the proximal end of the arm. As shown in the figures, the lower straight guide wall of the cylindrical seat is extended perpendicularly by the lower part of the shoulder which is a straight portion 80.
In the front force transfer area 66, every side wall features a rib which protrudes inwardly from the arm forming a ramp 82. Advantageously, the ramp has two planes with different inclinations in relation to the longitudinal axis of the arm. A first inclined plane 84, having a first inclination value, is formed from the upper edge of the arm, and a second inclined plane 86, having a second inclination value, extends the first inclined plane. The first inclined plane extends above the second inclined plane, so as to form a ramp from the upper edge of the arm up to mid-height of the latter. The first inclination value is greater than the second inclination value, and, by way of example, a first inclination value substantially equal to 80° and a second inclination value substantially equal to 45° can be foreseen.
Advantageously, the lower end 88 of the ramp 82 is cut so that the end face has an angle, with the face of the second inclined plane turned toward the back of the arm, more than 90°. The advantage of such an orientation will be described in greater detail in the functional description of the wiper assembly.
It can be observed that, in the longitudinal axis of the arm, in the direction from the proximal end to the distal end, a receiving portion of the head, the cylindrical seat, the axial rib, and the ramp have been successively placed in the shroud.
The wiper assembly also includes, besides the arm and the head, a coil spring 90, which is mounted on the latching pin at a first end and the second end of which is mounted on the arm, and a wiper blade, not shown, mounted in a conventional manner at the distal end of the arm.
The central portion of the arm 48 has various stiffening ribs 92 of which one is provided with an opening to accommodate the second end of the spring. The other ribs extend across the arm, although it is understood that their height ensures that they do not interfere with the passage of the spring.
The spring 90 is a coil spring, the end turns of which are extended parallel to the line of action of the spring by a branch 94 at the free end of which fastening means are formed for attachment to the mounting head and to the arm. The attachment means arranged for attachment to the arm have a shape adapted to cooperate with the receiving hole formed in one of the ribs of the central portion of the arm, while the fastening means arranged for attachment to the mounting head are in the form of a C-shaped loop 96, so that this semi-circle shape can engage around the latching pin 32 housed in the tab of the mounting head.
We will now describe the cooperation of the arm and mounting head in different operating positions permitted by the wiper assembly according to the invention. These various positions include a delivery position, visible in
In each of these positions, it can be observed that the base 6 of the head is housed in the rear receiving area 64, of lesser thickness, and that the head is thus protected by the side walls 58 and by the transverse end wall 60 that surrounds it, and that the tab 8 extends into the front force transfer area 66 of the arm, of greater thickness.
Furthermore, in each of these positions, the cylinder portions 16 arranged in a projecting manner on the mounting head cooperate with the cylindrical seats 74 formed on the inner surfaces of the arm, thereby defining a pivot axis of the arm relative to the mounting head by the cylinder/cylinder relationship. Axial stops are formed, in one direction, by the side walls 58 of the arm, in another direction by the straight guide walls 76 of the cylindrical seat, and in a last direction by the circular stop wall 78 of the cylindrical seat and the action of spring 90. As will be described below, according to certain positions of the wiper assembly, the cylinder portions 16 can slide in the corresponding cylindrical seats 74 but both elements are still in contact in order to subsequently return into position.
The delivery position is illustrated in
The operating position is illustrated in
The intermediate release position is illustrated in
The stable release position is illustrated in
The transition from the delivery position to the operating position is achieved by securing the mounting head 2 to the motorised shaft extending perpendicularly to the window. For this purpose, a screw driving head is passed through the hole 57 formed in the cover 56 covering the arm, so that it accesses screwing means suitable for securing the motorised shaft to the mounting head.
The concave recesses 68 formed in the side walls of the shroud of the arm allow for the passage of this screw driving head, as well as the material cutouts 22 formed on the base of the mounting head. The wiper blade is pressed against the window and the drive arm assumes a position substantially perpendicular to the axis of the bore of the mounting head and to the motor axis owing to the force in reaction to the contact of the window. The spring 90 is compressed slightly and provides a force which in turn tends to press the blade against the window.
Transition is made from the operating position to the intermediate release position, described above, by lifting the drive arm so as to rotate it around the axis defined by the cylindrical seat 74 the arm and the cylinder portions 16 of the mounting head. The coil spring 90 is loaded in tension, which requires some effort to raise the drive arm 4 sufficiently. It is understood that this sufficient amount of force to be provided, if calibrated so that it can be easily performed by any user of the vehicle, prevents any inadvertent lifting of the arm and the blade in undesired cases, for example under the effect of wind, or under the action of a vehicle cleaning roller. The presence of the second inclined plane 86 of the ramp, the inclination of which is smaller than that of first inclined plane 84, and requires that a greater effort be provided to move the rounded edge 30 of the tab 8 of the mounting head along this slope, may be sufficient to prevent the arm from rising significantly in undesired circumstances.
The transition from the intermediate release position illustrated to the stable release position is made by continuing to rotate the drive arm in relation to the mounting head that remains fixed, integral with the motorised shaft. In order to release the arm, the presence of second inclined plane 86 of the ramp, the inclination of which is smaller than that of first inclined plane 84, requires that additional force be provided in order to load the coil spring in tension. The hardness of the spring 90 generates a relative translational movement between the mounting head and the arm. While the head remains fixed, the arm moves forward under the wedge effect in the direction away from the head, substantially in the direction defined by the shape of the arm in the intermediate release position. The cylinder portions 16 borne by the head move back into the cylindrical seats 74 of the arm, i.e. they are no longer in contact with the circular stop wall 78, but remain engaged in the straight walls 76 of the cylindrical seats.
This translational movement between the arm and head in opposite direction continues if the user continues to exert sufficient force, and until the rounded edge 30 of the tab goes beyond the lower end of the ramp.
Once the rounded edge has gone past this lower end and it is no longer in contact with the ramp, the arm is pulled back by the effect of relaxation of the spring so that it produces a reverse translational movement between the arm and the head, in the direction toward one other, the cylinder portions 16 moving back against the stop walls 78 of the cylindrical seats 74. The firm stop formed by the contact of the bevel of the arm on the motor unit stops the user in his arm lifting action and the arm can be released. The upper wall 26 of the tab, which has passed below the lower end 88 of the ramp when the arm and head were brought together, forms a vertical stop when the arm returns to its operating position, the lower end of the ramp formed on the arm coming into contact with the upper wall of the tab of the mounting head.
Finally, when the blade is replaced, we return to the operating position by pressing on the arm so as to force it to rotate in relation to the head in the opposite direction to that performed in the preceding steps. The inclination of the lower end 88 of the ramp can be calculated so that, in the stable release position, the contact surface between the ramp 82 and the tab 8 is limited as much as possible so that the ramp can slide easily along the upper wall of the tab.
Furthermore, it is interesting that the contact area between the upper wall and ramp is arranged as close as possible to the rounded edge 30 of the tab. Under the effect of the vertical pressure on the arm, the arm moves translationally relative to the head, the ramp sliding along the upper wall until it no longer provides a stop and allows the arm to gradually return to the operating position, the rounded edge of the tab remaining in contact with the ramp during this return to position. Again, in order to allow the translational movement of the head relative to the arm, the cylinder portions 16 are moved in the cylindrical seats 74.
The user can push the arms until the wiper blade meets the window, in the operating position of the wiper assembly.
The above description clearly explains how the invention achieves the objectives it has set, and notably how it proposes a wiper assembly that is particularly rigid, ensuring efficient transmission of forces between the mounting head and the drive arm.
A drive arm is proposed that allows the mounting head to be covered, this enclosure also integrating means cooperating with this mounting head to form a rugged wiper assembly. These cooperating means also provide a stable release function enabling easy replacement of the wiper blade, and at a relatively shallow angle compared to the assemblies of the prior art. Advantageously, blockage occurs at approximately 30°. The wiper assembly thus extends less high in this stable release position, and therefore it is more resistant if a force is exerted on the blade and the drive arm.
Stable release is dependent on the shape and length of the ramp 82, and is obtained through contact between the upper wall 26 of the tab 8 and the lower end 88 of the ramp 82. By contrast with the solutions of the prior art, there is no longer any need for the line of action for rotation of the spring to extend beyond the axis of pivoting 20 of the connecting arm 4 with respect to the mounting head 2 in order to obtain this stable release position.
Of course, those skilled in the art may make various modifications to the structures of the wiper assembly, which have been described by way of non-limiting examples, notably in the form cooperating means of the arm and head, as long as they provide a rugged wiping assembly, within the context of a fully shrouded arm covering the mounting head and having, on its inner face, means to facilitate the transfer of force with the head and means facilitating a stable release position.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1455678 | Jun 2014 | FR | national |
