Title: Flexible plastic sealing
The invention relates to a flexible plastic sealing for sealingly connecting a housing and an adjustable part extending outwards relative to the housing.
Such flexible sealing is known from practice and is, for instance, used for sealing the connection between a housing for a mirror actuator and an axially adjustable spindle extending outwards relative thereto. The flexible plastic sealing serves to prevent the ingress of moisture and dirt through the opening between the housing and the adjustable part.
A drawback of the known sealing is that it is difficult to mount between the housing and the adjustable part, due to its flexibility. In particular, the engagement of the flexible sealing forms a problem. This problem manifests itself in particular in situations where the housing and the flexible sealing are mass-produced, as is the case with a housing for a mirror actuator for a motor vehicle. In such a. case, the operations of reliably engaging and mounting by means of a robot arm or a like mounting apparatus have proved to be problematic, on account of the flexibility of the sealing, not in the least place because of the additional problem that this requires that the sealings be fed in a predictable orientation.
The object of the invention is to provide a flexible plastic sealing of the type mentioned in the preamble, wherein the above drawbacks are avoided. To that end, the flexible plastic sealing according to the invention is characterized in that it is formed on a substantially form- retaining support by injection molding. The effect thus achieved is that the flexible sealing can reliably be connected, in a manner suitable for mass production, to a substantially form-retaining support and that the flexible sealing can subsequently be reliably engaged and mounted via the form-retaining support. Hence, by forming the flexible sealing on the support, the situation where the
flexible sealing is to be handled as separate unit can be avoided. In addition, a reliable sealing between the support and the flexible sealing can thus be realized in a simple manner. Further, because of its connection to the substantially form-retaining support, the flexible plastic sealing can readily by fed in an automized manner and in a predictable orientation.
The support can be manufactured from any substantially form-retaining material, such as metal, but is advantageously manufactured from synthetic material. Apart from the usual advantages of the use of synthetic material, this has as an additional advantage that the sealing and the support can be connected by means of two- component injection molding and/or two-step injection molding. The effect thus achieved is that the flexible sealing and the support can be manufactured in a simple and efficient manner.
In a further embodiment of the invention, the support forms a cover part for the housing. It is thus provided that the support can also act as cover and that, hence, one part can be saved.
Advantageously, the cover part further comprises a flexible sealing edge for sealingly connecting the cover part to the housing, the flexible sealing and the flexible sealing edge being manufactured simultaneously. It is thus provided that the manufacture and mounting of a separate sealing edge between the cover part and the housing can be omitted. By providing the cover part with first connecting means for forming a snap connection through cooperation with corresponding second connecting means of the housing, it can be effected that the flexible sealing edge can readily be biased to enhance the sealing action. Preferably, the first connecting means and the cover part are manufactured simultaneously. In a further advantageous embodiment, the cover part further comprises at least one flexible retaining member
for retaining a part fitted in the housing, the flexible sealing and the at least one retaining member being manufactured simultaneously. In this manner, the manufacture and mounting of a separate retaining member can be omitted as well .
The invention also relates to a housing for a mirror actuator, a wing mirror unit for a motor vehicle and to a method for sealingly connecting, by means of a flexible plastic sealing, a housing and an adjustable part which extends outwards relative to the housing.
Further advantageous embodiments of the invention are described in the subclaims . The invention will be specified on the basis of an exemplary embodiment shown in the accompanying drawings . In these drawings : Fig. 1 is a perspective view of a mirror actuator in disassembled condition;
Fig. 2 shows a section of a flexible sealing in a flat condition;
Fig. 3 shows a section of a flexible sealing in a hat-shaped condition;
Fig. 4 is a perspective view of a part of a mirror actuator in mounted condition; and
Fig. 5 is a perspective view of the bottom side of a support with flexible sealing. It is observed that the Figures are only schematic representations of a preferred embodiment. In the Figures, identical or similar parts are designated by corresponding reference numerals.
Fig. 1 shows a housing 1 for a mirror actuator. The housing 1 comprises a spindle 2 which extends outwards relative to the housing and which is adjustable along the axis A. Via a transmission mechanism 3, the spindle 2 is connected to an electromotor 4. The mirror actuator further comprises a cover part 5 and a flexible plastic sealing 6 for sealingly connecting the housing 1 and the spindle 2. The flexible sealing 6 is axially adjustable between the
substantially flat position shown m Fig. 2 and the substantially hat-shaped position shown m Fig. 3. It is thus provided that in assembled condition of the mirror actuator, the flexible plastic sealing 6 can move along with the spindle 2 when it is adjusted inwards and outwards m axial direction by means of the motor 4 and via the transmission mechanism 3. The cover part 5 is manufactured from substantially form-retaining plastic material and constitutes a support for the flexible sealing 6. The flexible sealing 6 is formed on the cover part 5 by two- component injection molding. During the manufacture of the flexible plastic sealing 6, the cover part 5 is preferably in ection-molded first from substantially form-retaining plastic material . After changing the mold cavity m the mold, for instance by slightly adjusting the mold parts relative to each other or by replacing a mold part, substantially flexible plastic material can subsequently be injected for connecting the flexible plastic sealing 6, through injection molding, to the support designed as cover part 5. The connection between the sealing 6 and the cover part 5 can be realized in that the form-retaining material and the flexible material bond together during injection molding, but may also be realized m that the flexible material is conformably injected into recesses of the form- retaining material. The technique of manufacturing parts by means of two-component injection molding is known per se and will hence not be further explained here.
In an advantageous manner, simultaneously with the manufacture of the flexible sealing 6, a flexible sealing edge 7 is injection molded on the cover part 5 for sealingly connecting the cover part 5 to the housing 1. This sealing edge 7 is clearly visible m Fig. 5. By providing the cover part 5 with first connecting means 8 designed as eyes, and providing the housing 1 with second connecting means 9 designed as hooks, forming a snap connection through cooperation, m the assembled condition
of the cover part 5 and the housing 1 shown in Fig. 4, the flexible sealing edge 7 can be biased.
In an advantageous manner, a number of flexible retaining members 11 can be provided on the bottom side 10 of the cover part 5, whereby, in the assembled condition shown in Fig. 4, the motor 4 can be retained between the housing 1 and the cover part 5.
The mirror actuator can be assembled as follows. After the spindle 2, the transmission mechanism 3 and the electromotor 4 have been mounted in the housing 1, the housing 1 should be sealingly connected to the adjustable spindle 2, extending outwards relative to the housing 1. For this purpose, the flexible sealing 6 is connected to the cover part 5 by injection molding in the above- mentioned manner. Because the cover part 5 is form- retaining, it can be fed in a simple manner in a predictable orientation by means of known techniques, for instance by means of a vibrating trough. Optionally, via the cover part, the sealing 6 can be removed from the mold directly after manufacture and by means of a manipulator. Next, the flexible sealing 6 is engaged via the substantially form-retaining cover part 5 by means of a manipulator, such as a robot arm. Then, by means of the manipulator, the cover part 5 is positioned above the housing 1 in which the spindle 2, the transmission mechanism 3 and the electromotor 4 have already been fitted. Finally, the cover part 5 is placed on the housing 1, such that the head 12 of the spindle 2 extends through an opening 13 in the flexible sealing 6. If necessary, an opening 13 in the flexible sealing 6 can be pressed over the head 12 of the spindle 2 to effect a tight connection between the sealing 5 and the head 12 of the spindle 2. The mirror actuator can be accommodated in a wing mirror unit for a motor vehicle, to enable operating a mirror adjustably incorporated therein. Preferably, two spindles are used, each having its own sealing.
It is observed that it is also possible to accommodate the flexible sealing directly, i.e. without housing 1, in a wing mirror unit.
It is further observed that the invention is not limited to the exemplary embodiment shown here, but that a number of other embodiments are possible.
For instance, the flexible sealing may be used for sealing other types of housings than housings for mirror actuators, and the support need not be integrated into a cover. Further, a housing may be provided with several flexible sealings.
Such practical variants will be clear to anyone skilled in the art and are understood to lie within the framework of the following claims.