FR2899857A1 - Windshield wiper arm disengaging device for motor vehicle, has release plate maintaining wiper arm in active sweeping position, and deformed by buckling, where wiper arm is operated between active sweeping position and disengaged position - Google Patents

Abstract

The device has a drive head (1) fixed on a drive shaft (2), and a windshield wiper arm (12) mounted on the drive head, where the wiper arm is operated between an active sweeping position and a disengaged position. A release plate (14) maintains the wiper arm in the active position, and is deformed by buckling, where the plate is made of elastic material, metal or composite material.

Description

DEVICE FOR DEBRISABILITY OF A WIPER ARM FOR MOTOR VEHICLES

  The present invention relates to the field of wipers, especially for 5 motor vehicles.

  In known manner, the wipers comprise a drive shaft (associated with a motor) and on which is fixed a drive head. On the latter is articulated, along an axis perpendicular to the axis of the drive shaft, a wiper arm, between an active sweeping position where the wiper blade is resting on the window of the vehicle, and a raised or disengaged position (intended in particular to allow the change of the broom).

  In the active sweeping position of the arm, there is provided a biasing means is applying a force on the arm and intended to maintain the blade against the glass.

  A first problem is, in order to achieve an optimal scan, to apply a sufficient force of return on the arm.

  A second problem is to allow the arm to be "disengaged", that is to say placed in the raised position, with the greatest possible displacement, to allow the change of the blade or other operation, the arm being held in position. this position reliably but temporarily.

  A third problem is to limit the thickness of the arms, to make the arms as flat as possible, which would improve the aesthetics and use materials easier to work.

  A fourth problem is to apply a constant restoring force to the arm 30 during its sweeping motion on the window. However, the windows and windshields have curved shapes, which causes an angular movement of the arm around its axis of rotation on the head. During this deflection, called pumping, the application force generated by the spring on the arm is not constant. There are several known devices including a resilient spring element.

  For example, the document FR 2 771 062 describes a device in which the spring 10 is of the helical compression type, arranged around a bore provided in a cylindrical stud of the drive head, and bearing against a bearing surface. arm, and against the bottom of said bore.

  This arrangement has drawbacks: it does not allow disengagement of the wiper arm; - it does not allow the use of "flat arms"; - The spring does not exert on the arm a constant support force, given the pumping phenomenon.

  Furthermore, there is known a device comprising return means consisting of a leaf spring.

  This structure, if it allows the disengagement of the arm, nonetheless has the disadvantage of not allowing the use of a flat arm. Indeed, the compression spring is disposed below the axis of rotation of the arm, in a direction along the arm, away from said axis.

  The present invention aims to remedy these drawbacks and proposes a windscreen wiper equipped with a system for returning the arm which allows both the disengagement of said arm, the use of flat arms, while ensuring a restoring force constant on the arm, when pumping.

  To this end, according to the invention, the device for disengaging a wiper arm comprising: a driving head fixed on a drive shaft; a wiper arm mounted articulated on the wiper arm; the drive, the wiper arm being operable between an operative sweeping position and a disengaged position, and - biasing means consisting of at least one elastically structured element, lo for holding the wiper arm ice in the active position, is characterized in that said elastic element is of elongate shape and able to deform by buckling.

  According to another characteristic, said elastic element is able to maintain said arm stably in the respective two active and disengaged positions of the latter. More specifically, said elastic element is supported by a first end against the proximal end of said arm and by a second end against said head, and in the active position of the arm, the fulcrum of the end of said biasing member. the arm is located in the dial formed by the axis (XX) of the drive shaft and the perpendicular thereto passing through the axis (YY) of rotation of the arm.

  According to a variant, the drive head comprises a generally U-shaped body whose substantially flat base comprises a bore adapted to receive the end of the drive shaft, and said arm being capable of being mounted. articulated on a first branch of said U, while the second branch of said U has a concave shape adapted to form a bearing zone of the or each return element. In order to better control or dose the restoring force on the arm, two elastic return elements are provided on each side of the drive shaft.

  More precisely, this variant has the following characteristics: the arm is mounted on the drive head with a degree of freedom in translation, transversely to the axis of rotation of the arm. the driving head comprises at least one male element materializing the axis of articulation of the arm on the head and adapted to cooperate with, and move in, at least one oblong hole provided at the end of the arm. to the oblong hole has a width barely greater than said male element, and a length between 1.5 and 4 times the diameter of said male element, and preferably between 2 and 3 times. the longitudinal axis of the oblong hole is, in the active position of the arm, substantially parallel to the drive axis of the rotating arm. The fulcrum of said elastic element on the head is arranged, with respect to the drive axis, on the side of the axis of pivoting of the arm. - The arm and the drive head are provided with temporary locking means, for example, the snap type, located beyond the drive axis relative to the axis of rotation of the arm. 20 that there is provided on the drive head, on the side of the drive shaft opposite the axis of articulation of the arm, means for removably holding the arm on the head. said holding means are of the resilient latching type, and more particularly said means are composed of a finger and a hook tab, respectively disposed on the head and the arm.

  The or each return element consists of a blade of elastic material, such as metal or a composite material. The invention will be well understood in light of the following description relating to examples shown by way of illustration, but in no way limiting of the invention, with reference to the accompanying drawings in which:

  Figure 1 shows an exploded perspective view of the drive head, motor shaft and associated nut, without the wiper arm;

  FIG. 2 is a perspective view of the head of FIG. 1 on which the wiper arm and the return element are positioned in the active scanning position according to a first embodiment; FIG. 3 is a diagram showing the wiper device side with the head, the arm in the disengaged position and the return element;

  Figures 4 and 5 show views of an alternative embodiment, longitudinal sectional view of the head, on which are mounted the arm and the spring, respectively active and disengaged position of the arm.

  For the sake of convenience, in all the figures, the arm is only partially represented, namely its proximal portion associated with the drive head. The constituent elements of the wiper arm and the associated brush, known in themselves, are not shown.

  Reference is made to FIGS. 1 to 3, describing a first embodiment of the invention. FIG. 1 shows a drive head 1, a windscreen wiper blade (not shown) for motor vehicles that can be rotated by a drive shaft 2; the head 1 is associated with a motor (not shown). The shaft 2 is of the type known per se, of cylindrical shape and has a threaded end 3, preceded by a conical portion 4.

  The drive head 1 has a general U-shape whose base 5, which is substantially flat, is provided with a hole 6 of corresponding shape and able to receive the end 3 and the conical part 4 of the shaft 2. On Figure 1, the head 1 and the shaft 2 are shown dissociated from one another. It is understood that when the head 1 is fixed on the shaft 2, the rotation along an axis XiX thereof, causes the rotation of the head.

  The U formed by the driving head 1 comprises a first lateral branch 7 lo having a curved shape, the concavity of which is turned towards the base 5 of the head 1, and a second lateral branch 8 provided on its sides with two pivots 9 and protruding from either side of said leg 8. On the two aligned pivots 9 and 10 is rotatably mounted a wiper arm (not shown) along an axis YyY transverse to the axis XûX of rotation of the head 1. To ensure the fixing of the head 1 on the shaft 2, there is provided a nut 11 adapted to cooperate with the threaded end 3 of the shaft 2.

  Referring to Figure 2, there is shown the head 1 fixed on the shaft 2, and an arm 12, carrying a wiper blade (not shown). The proximal end 13 of the arm 12 forms a return relative to the longitudinal axis of the arm and is rotatably mounted on the head 1 around the two pivots 9 and 10, by engagement of the latter in corresponding bores provided on the end 13 of the arm 12.

  The head 1 and the arm 12 are rotated along the axis XX, in a known manner, in a reciprocating rotational movement.

  The arm 12 can be moved in rotation, along the Y Y axis between two extreme positions, namely a first active scanning position where the wiper blade 30 bears against the window of the vehicle, to wiping, and a second raised position, also called disengaged, where the arm 12 is no longer resting on the glass, but forms an angle of the order of 90 degrees or more with the glass. The disengaged position of the arm allows for example to change the broom, or perform any other operation on the wiper or glass, for example for cleaning the glass.

  Figure 3 shows the drive head 1 (the shaft 2 is not shown for simplification), on which is mounted the arm 12, shown in the disengaged position, where the arm 12 forms an angle of about 110 to 150 with the glass. For understandable reasons, it is necessary that the arm 12 can be maintained, temporarily (to move from one extreme position to another), in each of said extreme positions. To do this, there are provided return means exerting a force on the arm. The return means consist (FIGS. 2 and 3) of at least one return element, having elastic properties, and more specifically constituted by a blade 14 made of metal or composite materials, such as for example a blade The resilient blade 14 has the following dimensions, for example: length: 40 mm, width: 7 mm, thickness: 1 mm. at the head 1 and the arm 12, in the following manner: a first end 15 bears against, and is housed in, the concave or concavity housing of the branch 7 of the head 1, while the second end 16 is in resting on, and is housed in, a housing 17 provided on the end portion of the proximal end of the arm 12.10 The return blade 14 is able to undergo buckling under the effect of forces applied to the blade at both ends 15 and 16 of it, following a direction corresponding substantially to its longitudinal axis. The term buckling (also called buckling) must be understood according to its usual definition, namely a deformation or curvature experienced by an elongate member, under the effect of a compressive force applied to one or both end (s).

  FIG. 3 shows the blade 14 in the buckling position, taking into account the respective positions of its ends 15 and 16. It thus exerts a force tending to keep the arm 12 in the disengaged position.

  To move from the disengaged position of FIG. 3 to the active scanning position of FIG. 2, the user grasps the arm by exerting a moderate force on the arm perpendicular to the axis of rotation Y.sub.Y. The very first part of the rotation movement of the arm, printed by the user, goes against the restoring force due to the buckling of the blade 14. Once the rotational position of the housing 17 of the arm 12 exceeds a certain angular position, relative to the axis YûY, the restoring force due to the buckling of the blade 14, 20 accompanies and pushes the end 13 in rotation so as to drive the arm to the active scanning position. This leads to the position of Figure 2.

  It should be noted that, in the active sweeping position of the arm 12, the end 16 of the return element 14 bears on the arm in a zone (housing 17) situated in the dial 25 formed by the axis XX of the shaft 2 and the perpendicular thereto passing through the Y-Y axis of rotation of the arm.

  It is also noted that the housing 17 receiving the end 16 of the blade 14 is disposed beyond the hinge axis YY of the arm on the head, starting from the distal end of the arm 12 towards the head 1 drive.

  Furthermore, in this embodiment, the abutment points of the ends 15 and 16 of the blade 14 are arranged on either side of the XUX rotation drive axis of the head (Figure 3). Currently, there are two return blades on either side of the head 1. A single blade could be shown in Figures 2 and 3, given the perspective and the side view.

  The fact of providing two blades makes it possible to better control the return force generated by them. Indeed, we know that the force is a function of the cube of the thickness of the blade. However, the manufacturing constraints lead to an uncertainty on the thickness. A variation of 1 / 10th of a thickness results in a 30% variation of the force. Thus, according to the invention, it is possible, after precise measurement of the thickness of the return blades, to theoretically determine the return forces generated, and thus to pair (symmetrically) two blades. whose respective characteristics are compensated. In this way, a value return force 20 is obtained, corresponding almost exactly to the needs. In this case, as indicated above, this restoring force must be constant during the movement of the blade on the window, despite the evoked phenomenon of pumping.

  A further embodiment of the invention will be described hereinafter with reference to FIGS. 4 and 5, wherein elements identical or similar to those shown in FIGS. 1 to 3 bear the same numerical references.

  The arm 12 is shown in the active position in FIG. 4, and in the disengaged position 30 in FIG. 5. The driving head 1 comprises a cylindrical central body 18, provided with a central bore 19 adapted to receive the part 4 and the threaded end 3 of the shaft 2, the nut 11 being housed and fixed on the threaded portion 3. The upper part of the central body 18 comprises, diametrically opposite, on the one hand a branch 20 having two lateral hinge pivots 9 and 10, and on the other hand a finger 21.

  The arm 12 is rotatably mounted along the Y-axis on the branch 20, by engagement of the two pivots 9 and 10 in the housings provided at the end 13 of the arm 12.

  According to this embodiment, the holes or housings cooperating with the pivots 9 and 10 (a single housing 22 being shown), have a particular shape. In this case, the holes are oblong or elongated, having a dimension in the longitudinal direction greater than the diameter of the pivots 9 and 10 associated, and a width dimension substantially equal (slightly greater) to said diameter. There are provided return means in the form of a blade, and preferably two blades, similar to that of the embodiment of Figures 1 to 3. Said blade has buckling capabilities. Thus, the blade 14 has a first end 23 adapted to bear against and be housed in a complementary housing 24 provided on the end 13 of the arm 12, and a second end 25 adapted to bear and be housed in a housing 26 on the drive head 2.

  Note that in this embodiment, the receiver housing 26 of the end 25 of the blade 14 is located below a plane perpendicular to both the XiX axis and the YiY axis. In the embodiment of Figures 1 to 3, the same receiving housing (provided in the concave branch 7 of the head) is disposed above said plane.

  Referring to Figures 4 and 5, it is also noted that the receiving housing 26 of the end 25 of the blade 14 is located in the dial formed by the axis XùX and an axis perpendicular to the latter and passing through the axis YùY . According to a variant not shown, this same receiver housing 26 can be placed beyond the axis XX, with respect to the axis YYY.

  In the active position of the arm 12, see Figure 4, the arm is also maintained on the head 1 by means of a tongue 27 forming a hook and provided on the arm 12, in the lower position (that is to say turned towards the head), and able to cooperate with the finger 21 provided on the head.

  The finger 21 and the tongue 27 are shaped and made of materials such that they cooperate to achieve a detachable engagement snap. In other words, starting from the position of the active arm of FIG. 4, the user exerting a slight force on the arm, directed substantially along the axis XX, causes elastic deformation of the one and / or the other of the finger 21 and the tongue 27, the release of the arm, and therefore the rotation thereof around its axis YùY.

  At the beginning of this movement, the end 13 of the arm 12 acts on the return blade 14, compressing a little more it. However, the arm has a degree of freedom in translation relative to the branch 20 on which it is mounted. Indeed, the arm can move relative to the pivots 9 and 10, by the oblong hole 22.

  After a rotation of a few degrees of the arm, about the axis YùY, the end 13 30 of the arm is relative to the pivots 9 and 10, in the position shown in Figure 5, where the pivot 9 abuts against the lower end (facing the head) of the oblong hole 22. Of course, it is the same for the other pivot 10 associated with the other oblong hole (not shown in Figures 4 and 5).

  At the end of the rotational movement of the arm about the axis YiiY, it leads to the disengaged position of the arm, shown in Figure 5. In this position, the return blade 14, although having a reduced buckling relative to the occupied position when the arm is in the active position, still remains in buckling so as to exert a force on the arm 12, and therefore a torque to maintain the arm in this disengaged position.

  The longitudinal direction of the oblong hole 22 is, in the active position of the arm, preferably substantially parallel to the axis XuX (Figure 4).

Claims (15)

  1. Device for disengaging a wiper arm comprising: - a driving head (1) fixed on a drive shaft (2), - a wiper arm (12) mounted articulated on the driving head (1), the wiper arm (12) being operable between a sweeping active position and a disengaged position, and - returning means (14) consisting of at least one element ( 14) with structure. elastic, to maintain the wiper arm (12) in the active position, lo characterized in that said elastic member (14) is elongate in shape and able to deform by buckling.   2. Device according to claim 1, characterized in that said elastic element (14) is adapted to maintain said arm (12) stably in the respective two active and disengaged positions of the latter.   3. Device according to one of claims 1 or 2, characterized in that said elastic member (14) is supported by a first end (16) against the proximal end (13) of said arm (12) and by a second end (15) against said head (1).   4. Device according to one of claims 2 or 3, characterized in that, in the active position of the arm, the fulcrum of the end (16) of said biasing element (14) on the arm (12), is located in the dial formed by the axis (XX) of the drive shaft (2) and the perpendicular thereto passing through the axis (YY) of rotation of the arm.   5. Device according to one of claims 1 to 4, characterized in that there are provided two elastic return elements (14) arranged on each side of the drive shaft (2).   6. Device according to one of claims 1 to 5, characterized in that the drive head (1) comprises a generally U-shaped body whose base (5) substantially planar comprises a bore (6) adapted to receiving the end (3) of the drive shaft (2), and said arm (12) being articulately mountable on a first leg (8) of said U, while the second leg (7) of said U has a concave shape capable of constituting a bearing zone of the or each return element (14).   7. Device according to one of the preceding claims, characterized in that the arm (12) is mounted on the drive head (1) with a degree of freedom in translation, transversely to the axis of rotation (YY) of the arm (12).   8. Device according to claim 7, characterized in that the drive head (1) comprises at least one male element (9) embodying the axis of articulation (YY) of the arm (12) on the head (1). and adapted to cooperate with, and move in, at least one oblong hole (22) provided at the end of the arm.   9. Device according to claim 8, characterized in that the oblong hole (22) has a width slightly greater than said male element (9), and a length between 1.5 and 4 times the diameter of said male element, and preferably between 2 and 3 times.   10. Device according to one of claims 8 or 9, characterized in that the longitudinal axis of the oblong hole (22) is, in the active position of the arm (12), substantially parallel to the drive axis (XX) arm (12) rotating.   11. Device according to one of claims 7 to 10, characterized in that the fulcrum (24) of said elastic element on the head (1) is arranged with respect to the drive shaft (XX). on the side of the pivot axis (YY) of the arm (12).   12. Device according to one of claims 7 to 11, characterized in that the arm (12) and the drive head (1) are provided with temporary locking means (21,27), preferably of the snap type , located beyond the drive axis (XX) relative to the axis of rotation (YY) of the arm.   13. Device according to one of claims 7 to 12, characterized in that it is provided on the drive head (1), on the side of the drive shaft (XX) opposite the axis of articulation (YY) of the arm, removable holding means (21, 27) of the arm (12) on the head (1).   14. Device according to claim 13, characterized in that said holding means (21, 27) are of the elastic snap type, and more particularly said means are composed of a finger (21) and a tongue (27). forming a hook, respectively disposed on the head (1) and the arm (12).   15. Device according to one of the preceding claims, characterized in that the or each return element (14) consists of a blade of elastic material, such as metal or a composite material.