FR2964170A1 - Sealing skirt for e.g. connecting rod of front windscreen wiper mechanism utilized to wipe panes of motor vehicle, has upper and lower semi-skirts connected together in sealed manner, where ends of skirts comprise winding wound on itself - Google Patents

Abstract

The skirt has an upper semi-skirt that is fixed on an insert of a ball and a socket joint. A lower semi-skirt is fixed on an element carrying the ball and socket joint. The upper and lower semi-skirts are connected together in a sealed manner by circumferential co-operation of respective ends of the skirts, where one of the ends of the skirts comprises a winding (31) wound on itself. Diameter of the upper semi-skirt is greater than that of the lower semi-skirt. The upper semi-skirt comprises a gutter that is made of rigid material.

Description

SEALING SKIRT FOR WINDSCREEN MECHANISM WINDOW MOUNTING POT.

The invention is in the field of vehicle equipment and in particular in the field of wiping windows of vehicles. The invention finds particular application in windscreen wiper mechanisms of motor vehicles.

As can be seen in FIG. 1, a windscreen wiper mechanism (1) typically comprises a motor (3) generating a rotary movement to a crank-motor (5). Said crank-motor (5) drives in a movement back and forth rods (7). The connecting rods (7) are themselves connected to cranks (9) making it possible to transform this reciprocating movement into an alternating rotational movement transmitted to the drive shafts (11) of the windscreen wiper arms. (not shown) Said pins (11) are received in the bearing bores (13). In known manner the rods (7) are connected to the cranks (5, 9) via a ball joint comprising a ball joint (17) received in an insert (15) which links the ball joint (17) in translation but leaves it free in rotation. Generally, the insert (15) of the ball is carried by the rod (7) and the ball is carried the crank (5, 9).

The angle of rotation between the connecting rod (7) and the crank (9) coupled to the drive shaft (11) corresponds to the scanning angle of the brush arms. It is typically of the order of 80 to 90 °.

In order to prevent seizing of the linkage due to water ingress, frost, salt, dust, etc., sealing skirts (not shown) are added at the ball joints. This is usually elastomeric seals, placed between the crank (9) and the insert (15) of the patella so as to be slightly compressed. Unfortunately, with time and therefore because of the aging of the material, the seal is no longer assured. Indeed, the sealing skirt tends to shrink slightly allowing water to pass between the skirt and the insert or between the crank and the skirt or both.

To avoid this problem, it is known to attach the ends of the sealing skirt to both the insert of the patella and the patella. This is the document US3052477 through a waterproof cover for ball joint. This cover is made of a flexible sheet fixedly attached to the ball joint insert by a circlip collar and to the ball itself in a peripheral lip inserted in a groove made in the foot of the patella and in which it can rotate. This system nevertheless has the disadvantage of weakening the patella by the fact of practicing a groove. In addition, the seal is also impaired over time due to wear and aging of the material that forms the lip.

FR2577636 discloses a sealing cap for sealing a seal intended to transmit a torque. For this purpose, the cap is divided into two parts cooperating circumferentially in a sealed manner between them. For example each part is connected to the other by a mechanical interlocking hook (or more precisely throat).

Unfortunately, such a cap offers only two degrees of freedom in the movement, that is to say that the rotational movement must be flat for sealing is ensured. It is therefore not possible to guarantee this seal when the rotational movement comprises three degrees of freedom as in the case of a joint by a ball joint. Finally, the device of the prior art does not adapt to different distances or spacing height between the two elements and therefore lacks flexibility.

The object of the invention is to solve the problems posed by the prior art by proposing a new type of sealing skirt for a ball joint connection offering three degrees of freedom and making it possible to maintain a good seal over time.30 For this purpose, the subject of the invention is a sealing skirt for a ball joint comprising a ball joint received in an insert, which is remarkable in that it comprises: an upper half-skirt intended to be fixed on the insert of the ball joint; lower half-skirt intended to be fixed on the element bearing the ball joint, and in that the two half-skirts are arranged facing one another and are connected together in a sealed manner by the circumferential cooperation of their respective ends, at least one of said ends having a winding on itself.

According to a preferred embodiment of the invention the winding on itself of the end of the half-skirt rotates in a spiral over at least one and a half turns and preferably at least two turns.

Advantageously, one of the two half-skirts, preferably the upper half-skirt, has a diameter greater than the other.

According to a preferred embodiment of the invention, the two half-skirts each have a winding on themselves and the connection between the two half-skirts is by interlacing their respective windings.

According to another embodiment of the invention, only one of the half-skirts has a winding and in that the other half-skirt has at its end of contact with the first half-skirt, a circumferential projection forming a suitable gutter. receiving and retaining the winding of the first half-skirt.

Preferably, the channel extends towards the inside of the half-skirt which presents it.

According to a preferred embodiment of the invention, the half-skirt or skirts having at one of their ends a winding, are of flexible material, for example elastomer. Advantageously, the half-skirt having said gutter is made of rigid material.

Optionally, the end of at least one of the half-skirts intended to cooperate with the end of the other half-skirt has a coating for facilitating sliding of the half-skirts relative to each other.

Optionally, the added height of the unrolled half-skirts is greater than the maximum spacing distance between the insert of the patella and the element carrying the patella, preferably in a ratio of at least 1.5.

The invention also relates to a remarkable ball joint insert in that it has a sealing half-skirt as defined further, preferably the sealing half-skirt is integral with the insert. The invention also relates to a rod for wiper mechanism remarkable in that it has a half-skirt sealing as defined above.

Finally, the object of the invention is a wiper mechanism which is remarkable in that at least one of its ball joints has a sealing skirt as defined above.

It will be understood that the principle underlying the invention is to provide a sealing skirt for protecting a joint between two elements. The skirt is composed of two parts or half-skirts each fixedly connected to one of the two elements, arranged one opposite the other and connected together in a sealed manner. The connection between the two parts of the skirt allows the same degrees of freedom of movement as the joint, that is to say, in the case of a ball joint, that it allows three degrees of freedom. In other words, the skirt according to the invention has both the possibility of varying in height over all or part of its circumference, and at the same time a possibility for its two parts to rotate with respect to one another. 'other. The implementation of the invention consists in allowing the sealing skirt to adapt its height to the spacing between the two elements articulated by unwinding or winding on itself at least one of its parts or half skirts. The implementation of the invention also consists in proposing a two-part sealing skirt, the two parts being hinged together so as to be able to effect angular rotational movement relative to one another. In other words, the two parts of the sealing skirt slide relative to each other while cooperating with each other sealingly. The tightness of the device is enhanced, inter alia, by the succession of several points up and down at the junction between the two parts or half-skirts.

The invention will be well understood and other aspects and advantages will become apparent from the following description given by way of example with reference to the accompanying drawing plates in which: FIG. 1 is a representation of a mechanism of FIG. windscreen wiper; - Figure 2 is a partial sectional representation of a ball joint equipped with a sealing skirt according to the invention; - Figures 3a and 3b are sectional views of a double-winding skirt according to the invention in the average and maximum spacing positions between the crank and the insert of the ball joint; - Figures 4a and 4b show a variant of the invention and are sectional views of a single winding skirt in the average and maximum spacing positions between the crank and the ball joint.

Figure 1 has already been commented on in the introductory part. Referring now to Figure 2 which shows a partial sectional view of a ball joint connection between a crank (9) and a rod (7), the ball (17) being protected by a sealing skirt (19) according to Invention As can be seen, the skirt (19) comprises two substantially cylindrical half-skirts (21, 23) connected together tightly.

Figure 3a shows a sectional view of a first embodiment of a skirt (19) according to the invention. Each of the upper or lower parts (21) and lower half-skirts (23) is respectively fixed to the insert (15) of the ball joint and to the crank (9), for example by bonding one of its ends (25, 29). ). It is also possible to comouler the upper half-skirt (21) with the insert (15) and / or overmold the lower half-skirt (23) with the crank (9). The techniques of comoulage or overmoulding are known to those skilled in the art and therefore will not be detailed further in this memoir. When water flows on the skirt (19) according to the invention, it will flow from the upper half-skirt (21) towards the lower half-skirt (23) under the effect of gravity . The half-skirts (21, 23) of sealing are both made of a flexible material, for example elastomer. The two half-skirts (21, 23) extend in the gap between the insert (15) of the ball joint and the crank (9) in the direction of one another until they meet by their ends free (27, 31). These ends (27, 31) come into contact and seal together while allowing the half-skirts (21, 23) to rotate relative to one another. The rotational movement is made possible by the sliding of the half-skirts (21, 23) between them. According to the invention, it is possible to apply on the end of at least one of the half-skirts (21, 23), and preferably on both, a coating intended to facilitate said sliding of the half-skirts (21 , 23) relative to each other.

For this purpose, the ends (27, 31) of the half-skirts (21, 23) are bent and curl on themselves, rotating in a spiral. Preferably, they each have a convolution or winding (27, 31) of at least one and a half turn and preferably at least two turns. The connection between the two half-skirts (21, 23) is by interleaving their respective windings (27, 31). This interlacing is made possible by the flexible nature of the half-skirts (21, 23).

As will be readily understood with reference to FIG. 3b, the invention is particularly advantageous in that it allows, while maintaining a good seal of the skirt (19), to absorb variations in height of the gap. between the ball insert (15) (17) and the crank (9). Indeed, the windings (27, 31) of the half-skirts (21, 23) can take place slightly or almost completely so as to adapt to the height of the gap. The unwinding can be done either steadily or periodically when for example the relative rotational movement between the connecting rod (7) and thus the insert (15) which it carries and the crank (9) is not plan. It is of course understood that the half-skirts (21, 23) are of sufficient size that the distance between the insert (15) and the crank (9), and therefore the unwinding of the windings (27, 31), do not lead to the separation of the two half-skirts (21, 23). That is to say that at the maximum height of separation between the insert (15) and the crank (9), the two half-skirts (21, 23) are always in contact. To do this, each half-skirt (21, 23) will for example have an unwound length at least equal to about 75% of the mean interval between the insert (15) and the crank (9), preferably this unrolled length is equal to the height the average interval between the insert (15) and the crank (9). In order to avoid any risk of separation of the two half-skirts (21, 23) and any break in tightness, the skilled person will have the advantage that the added height of the half-skirts (21,23) unwound is greater at the maximum spacing distance between the insert (15) of the ball and the element carrying the ball joint, namely the crank (9), preferably in a ratio of at least 1.5.

The assembly of the two half-skirts (21, 23) is done by unwinding their ends so that each half-skirt (21,23) has substantially the shape of a cylinder. One of the half-skirts (23) is then inserted into the other (21). Releasing the force exerted on the ends of the half-skirts (21, 23) to maintain them unwound allows their interlacing by winding one on the other. It will therefore be advantageous for one of the half-skirts (21) to have a greater diameter than the other (23).

According to a preferred embodiment of the invention, the winding (27) of the end of the half-skirt (21) having the largest diameter is towards the inside of the skirt (21) so as to that the winding (27) is inscribed in said half-skirt (21). The winding (31) of the end of the half-skirt (23) having the smaller diameter is to the outside of said half-skirt (23). Preferably, the half-skirt having the largest diameter is the upper half-skirt (21) so as to further improve the seal by an umbrella effect. Furthermore, it will be understood that the sealing of the device is also enhanced by the succession of several high and low points at the junction between the two parts or half-skirts (21, 23). Indeed, if water still managed to penetrate the interlacing windings (27, 31), it would not be possible for him to cross this interlacing and thus to enter the skirt. In addition, even in case of shrinkage of the material due to aging, the seal remains assured since this seal is provided by an additional length, or even in excess, of the wall of the skirt forming a winding and not because of adjusting the length of the skirt wall so as to form a sealing lip as was the case in the prior art. The tightness of the skirt (19) according to the invention is not the fact of a sealing lip subject to retraction, but is the fact of a contact between two surfaces, which minimizes the effects of shrinkage of the material as it ages.

According to a variant of the invention shown in Figures 4a and 4b, only one of the two half-skirts (23) is flexible and has a winding (31) at one of its ends. The other half-skirt (39) is rigid and has at its end (33) of connection with the other half-skirt, a circumferential projection forming a gutter (35) adapted to receive and retain the winding (31). ) of the other half-skirt (23).

The assembly of the sealing skirt (19) according to the invention is then done in the following manner: each half-skirt (23, 39) is fixed rigidly on the element (15, 9) which is intended to receive it. When placing the ball (17) in its insert (15), the winding (31) is inserted into the gutter (35) by acting on the deformability of the material. The fact that the rigid half-skirt (39) is carried by the insert (15) can not be limiting to the definition of the invention, any more than the fact that the gutter is turned towards the inside of the half-skirt (39). skirt (39).

The rigid half-skirt (39) can be directly molded with the element that carries it, for example the insert (15), or be comoulée or overmolded. When one of the half-skirts (21, 23, 39) is intended to be fixed by gluing on the element (15, 9) which receives it, the skilled person will advantageously add a foot (37) or collar circular to assist in fixing and sealing the skirt (19).

The invention is remarkable in that the connection between the two half-skirts (21, 23 or 23, 39) makes it possible, during the kinematics of the linkage assembly, to rotate with respect to one another in a substantially plane. parallel to the crank (9), but also retains its sealing characteristics during a non-plane movement between the rod (7) (and the insert) and the crank (9). In addition, the flexible nature of at least one of the half-skirts (21, 23) of sealing makes it possible to absorb the positioning tolerances between them, in particular concerning the spacing. Finally, the flexible nature of at least one of the half-skirts (21, 23) will allow it if necessary to twist slightly at the time of rotation.

The invention is not limited to the embodiments described above, given only by way of example, but encompasses all the variants that may be envisaged by those skilled in the art within the framework of the definition that has been given. In particular, the invention also applies to the ball joints of the motor cranks.

Claims (14)

CLAIMS1 - Sealing skirt (19) of a ball joint comprising a ball (17) received in an insert (15), characterized in that it comprises: - an upper half-skirt (21, 39) intended to be fixed on the insert (15) of the ball joint (17), - a lower half-skirt (23) intended to be fixed on the element (9) bearing the ball joint (17), and in that the two halves skirts (21, 23, 39) are arranged facing each other and are sealed to each other by the circumferential cooperation of their respective ends, at least one of said ends having a winding (27, 31) on herself. 2 - skirt (19) according to claim 1 characterized in that the winding (27, 31) on itself of the end of the half-skirt (21, 23) rotates in a spiral over at least a lap and a half and preferably at least two turns. 3 - skirt (19) according to one of claims 1 or 2 characterized in that one of the two half-skirts (21, 23, 39), preferably the upper half-skirt (21, 39), has a diameter greater than the other (23). 4 - skirt (19) according to one of claims 1 to 3 characterized in that the two half-skirts (21, 23) each have a winding (27, 31) on themselves and in that the connection between the two half-skirts (21, 23) is made by interleaving their respective windings (27, 31). 5 - Skirt (19) according to one of claims 1 to 3 characterized in that only one of the half-skirts (23) has a winding (31) and in that the other half-skirt (39) presents to its end (33) of contact with the first half-skirt (23), a circumferential circumference forming a gutter (35) adapted to receive and retain the winding (31) of the first half-skirt (23). 6 - Skirt (19) according to claim 5 characterized in that the channel extends 5 towards the inside of the half-skirt (39) which has it. 7 - Skirt (19) according to one of claims 1 to 6 characterized in that the or half-skirts (21, 23) having at one of their ends a winding (27, 31) on themselves are material flexible, for example elastomer. 8 - Skirt (19) according to one of claims 5 to 7 characterized in that the half-skirt (39) having said channel (35) is of rigid material. 9 - skirt (19) according to one of claims 1 to 8 characterized in that the end 15 of at least one of the half-skirts (21, 23, 39) for cooperating with the end of the other half-skirt (21, 23, 39) has a coating for facilitating the sliding of the half-skirts (21, 23, 39) relative to each other. 10 - Skirt (19) according to one of claims 1 to 9 characterized in that the added height of the half-skirts (21, 23, 39) unwound is greater than the maximum spacing distance between the insert (15 ) of the ball (17) and the element (9) bearing the ball joint, preferably in a ratio of at least 1.5. 11 - Insert (15) ball (17) characterized in that it has a half-skirt (21, 25 39) sealing according to one of claims 1 to 10. 12 - insert (15) ball (17) according to claim 11 characterized in that the half-skirt (39) sealing is integral with the insert (15). 30 13 - Connecting rod (7) of mechanism (1) wiper front characterized in that it has a half-skirt (23, 39) sealing according to one of claims 1 to 10. 10 14 - Wiper mechanism (1) characterized in that at least one of its ball joints has a sealing skirt (19) according to one of claims 1 to 10.