WO2006048737A2

WO2006048737A2 - Connecting device with snap-on fastening for the passage and protection of electric cables or the like, and method for the production thereof

Info

Publication number: WO2006048737A2
Application number: PCT/IB2005/003277
Authority: WO
Inventors: Jean-Pierre Bloret; Philippe Gourvellec
Original assignee: Cf Gomma S.P.A.
Priority date: 2004-11-03
Filing date: 2005-11-03
Publication date: 2006-05-11
Also published as: WO2006048737A3; FR2883109A1; EP1807917A2

Abstract

The invention relates to a connecting device (1) and to a method for the production thereof, for the passage and protection of electric cables or the like. The inventive device comprises a flexible body (10) with rigid fastening means (20, 30) situated at both ends of said body. According to the invention, the entire connecting device is produced in a single mold on a press having two injection heads, the flexible and rigid parts being joined due to the physical/chemical bonds existing between the two materials.

Description

CONNECTION DEVICE WITH ENCLIPSAGE FOR PASSING AND PROTECTING ELECTRIC CABLES, OR THE LIKE,

AND ITS MANUFACTURING METHOD

The present invention relates to the field of connection devices, bent sleeve type or sheath, and security for the passage of cables or the like. The present invention relates more particularly to this type of connection devices used in motor vehicles, especially at the junction between the passenger compartment and the doors, boot, tailgate.

Such a sleeve, when it extends between two elements that can move relative to each other must be able to deform. Advantageously, it is made of an elastically deformable material. However, for example in a motor vehicle, it is desirable that the securing means of the sleeve respectively on the body and on an opening are rigid in particular to ensure the clipping and optimized retention.

The prior art already knows a method of manufacturing a snap fastening connection device for the protection and passage of electrical cables in cars, at the door openings. This method comprises a first step of molding an elastically deformable rubber part (for example made of EPDM), a second stage of molding end inserts made of thermoplastic (for example polyamide filled with glass fibers), and a third step of assembling the thermoplastic and elastomer parts. Furthermore, a European patent application EP 1193 132 describes the assembly of a thermoplastic insert on an elastomeric thermoplastic body by the so-called "hot blade welding" technique. These types of connection devices are expensive, particularly because their manufacturing process comprises three distinct steps each requiring specific tools and labor and / or significant automation. Moreover, the manufacturing time of a connection device is quite important, particularly because of the vulcanization time for rubber molding.

The present invention intends to overcome the disadvantages of the prior art by providing a connection device with snap-on ends whose manufacturing process is simple, fast, inexpensive and advantageously automated.

To do this, the present invention relates to a connection device for the passage and protection of electrical cables, or the like, comprising a flexible body forming a sleeve and two rigid fixing means at both ends of said flexible body, characterized in that said body flexible and said rigid fixing means form a single block from molding, said flexible body and said rigid fixing means being bonded by physico-chemical bonds existing between the materials of said flexible body and said rigid fixing means.

Advantageously, said flexible body is made of thermoplastic elastomer and said fixing means are made of rigid thermoplastic.

For example, the flexible body will be SEBS (Styrene Ethylene Butadiene Styrene) and the fixing means will be polypropene filled with fiberglass. According to one embodiment of the invention, the fastening means comprise a plurality of snap-fastening elements.

Advantageously, a fastening means comprises at least one latching tongue.

According to one embodiment of the invention, said flexible body comprises a portion having a ring-shaped accordion shape to facilitate the extension and compression of its length as well as its deformation in all planes.

Advantageously, each of said fixing means is placed in the extension of a portion of said flexible body projecting radially flexible sealing lip.

According to a possibility offered by the invention, one of said fixing means is installed around a cylindrical endpiece extending said sleeve beyond said flexible lip.

The present invention also relates to a method for producing a connection device according to any one of the preceding claims, characterized in that it comprises the following steps: injection of the material constituting said rigid fixing means into a mold whose interior volume is partitioned by a removable partitioning means, removal of said removable partitioning means, - injection of the material constituting said flexible body in said mold. The connection device may therefore be entirely manufactured in a single mold on a press comprising two injection heads.

The entire manufacturing operation can be automated, said removable partitioning means, known as "locks" being removed by means of a mechanism associated with the mold.

Advantageously, said mold comprises a core which defines the inner shape of the connecting device and two indentations which define its outer fourme.

According to one embodiment of the present invention, said method comprises, after molding, a step of opening the mold followed by a blowing step for inflating the molded part to allow the withdrawal of the core.

Again, the entire demolding operation can be automated, the opening of the mold and the swelling of the part can be provided by mechanisms associated with the mold.

The entire manufacturing pe ^~ ut be fully automated.

The invention will be better understood by means of the description, given below for purely explanatory purposes, of embodiments of the invention, with reference to the appended figures in which: FIG. 1 illustrates a perspective view of the connecting device according to the invention; Figure 2 illustrates an axial sectional view of the device shown in Figure L; Figure 3 illustrates a detail sectional view of a resilient locking means of the connection device of Figure 1 engaged with a sheet; and

- Figure 4 illustrates an axial sectional view of a connection device according to a variant of the invention.

In the examples chosen to illustrate the invention, the connecting device 1 (FIGS. 1, 2 and 3) or 101 (FIG. 4) for electric cable, or the like, also called the beam sheath, is an assembly whose function is provide protection between the body of a motor vehicle and the doors, in particular doors and shutters. In other words, the invention applies in particular to a grommet intended to protect the cables that go into the doors or tailgate of the vehicle and ensure tightness.

With reference to FIGS. 1 to 3, a connection device 1 according to the invention consists of a flexible body 10 and two rigid inserts 20 and 30 acting respectively at the one and the other end of the body 10.

The flexible portion consists of a helical coil bellows 10 of tri-thermoplastic elastomer, such as an ethylene / butylene / styrene SEBS. The bellows is connected to the panels (opening, frame) using the inserts 20 and 30 made of polypropylene reinforced with glass fibers. The flexible portion and the inserts form a single block from molding. Peripheral lips 12 and 16 ensure the sealing of the binding. A manchiette 13 makes it possible to protect the cables which pass through the grommet, inside the panel (opening, frame) or to ensure good radius hold and allows the cables to be tied to the cable gland with adhesive tape, for example.

The body 10 is made of a flexible material, for example a thermoplastic elastomer (TPE) of 60 Shore A hardness, such as SEBS (styrene ethylene butadiene-styrene). This body 10 has generally the shape of a cylindrical sheath wall accordion corrugated. In other words, this wall consists of a juxtaposition of circular rings of the same size. The two ends are each provided with a membrane, respectively 11 and 15, projecting radially outwardly. As can be seen better in FIG. 2, each of these membranes generally has the shape of a disk whose periphery is inclined outwards so as to form a flexible sealing lip, respectively 12 and 16. membrane 11, of larger size, extends a flaring of the wall of the body 10. The membrane 15 extends from the periphery of a narrowing of the wall of the body 10, this narrowing being prolonged by a cylindrical tip or sleeve 13 of smaller diameter at the smallest inside diameter of the main body of the sheath.

The sealing lips 12 and 16 form a sealing means adapted to come into contact with an opening or body sheet in which a hole for the passage of the wires is pierced to prevent the penetration of water and air. , dust, etc. As best seen in FIG. 3, the inclined part of each of the membranes forming the sealing lip starts from a thinned zone of the membrane extending with a slight inclination of the periphery of the radial central portion of the membrane. membrane. The cylindrical tip 13 allows the wrapping of the electrical harness thus ensuring the positioning of the sleeve on the beam if necessary.

The rigid inserts 20 and 30 are made of thermoplastic material, for example polypropylene filled with glass fibers. Each of these inserts has the overall shape of a cylindrical sleeve adapted for fitting into a hole for the passage of electric wires or cables formed in a body or opening plate. The insert 20 is intended to be fitted into a hole of a sheet of an opening and the insert 30, of larger size, is adapted to fit into a hole of a sheet of the body.

Both of these inserts are provided with locking clips 40. In practice, as best seen in FIG. 3, these locking clips 40 consist of extra thicknesses forming planes inclined towards the axis of the device, towards the outside. Inwardly, these clips end with a shoulder defining a housing 42 between an end portion 43 of the insert and the clip. These housings are opposite the inclined portion 47 of the sealing lip recessed relative to the end of this lip. Recesses 44 are formed in the wall of the insert at the housing 42 behind each of the clips, these recesses being extended by longitudinal recesses 41 formed on either side of each of the clips. These locking clips 40 are gradually crushed during the insertion of the insert into the corresponding hole and then relax elastically when the sheet is in the housing 42, ensuring the snap fastening of the insert. When fitting the insert into the corresponding hole, the sealing lip comes to bear against the sheet and deforms elastically. The sheet is in the housing 42 sandwiched between the end portion 43 on the one hand and the clips 40 on the other. This makes it possible in particular to ensure that the sealing lip is held against the sheet 45 as can be seen in FIG.

In the example chosen to illustrate the invention, the inserts 20 and 30 each comprise four locking clips 40, but it is understood that their number may be higher or lower.

Two hooking tabs 35 are provided on the insert 30. These tongues are used to assemble the electrical connector which allows the continuity of the electrical circuit as a socket. In the same way as above, it is quite possible to have one or more tabs 35.

The connections at the interfaces between the elastic body 10 and the rigid inserts 20 and 30 are provided by a physico-chemical reaction between the two materials during overmoulding of the elastic portion 10. The physico-chemical bond between the elastic body and each inserts is provided, as can be seen in Figure 3, at the elbow of the inclined portion of the membrane forming a sealing lip. On the side of the membrane, it is the peripheral end of the radial central portion of the membrane, the thinned portion of this membrane and the beginning of the bent portion forming a sealing lip that support this physico-chemical bond. On the side of the insert, it is the end portion 43 which supports this connection. The device which has just been described is manufactured by single mold molding on a press with two injection heads.

The mold includes a core that defines the inner shape of the connecting device and two indentations that define its outer shape. It is associated with a removable partitioning mechanism comprising removable elements, known as locks, adapted to axially partition the volume of the mold so as to delimit volumes corresponding to the inserts 20 and 30.

The manufacturing cycle of the device comprises the following steps:

the pressing of the mold, the locks being in the partitioning position,

the injection of polypropylene,

The operation of the partitioning mechanism in order to remove the locks,

the injection of the SEBS, the demolding.

This manufacturing process is fully automated and therefore requires no human manipulation.

The demolding can be ensured by swelling of the piece. For this, after molding, a mobile part of the core is removed under the action of a jack and the space thus released is used to bring a nozzle carried by the hand of a demolding robot. This nozzle will inject air so as to take off the part of the core. The nozzle comprises an inflatable membrane providing sealing between the nozzle and the part during blowing. The robot's hand may include a peripheral envelope to limit swelling to what is needed for demolding. Stripper plates or actuator-actuated ejector assemblies can make it possible to take off the rigid inserts from the core and to accompany these inserts during demolding in order to avoid retention on the core during the demolding movement.

After separation from the core, the piece is fed by the robot to a carpet or receiving container.

A connection device 101 according to another embodiment of the present invention is shown in FIG. 4. This connection device 1 is similar to the connection device 1 except that its corrugated wall body 110 generally has the shape of a connector. a conical sheath. In other words, this wall consists of a juxtaposition of helical rings whose size decreases between a connection insert to the body 130 and an insert connection to the opening 120.

The invention is described in the foregoing by way of example. It is understood that the skilled person is able to realize different variants of the invention without departing from the scope of the patent.

Claims

1. Connecting device (1, 101) for the passage and protection of electrical cables, or the like, comprising a flexible body (10, 110) forming a sleeve and two rigid fixing means (20, 30, 120, 130) for two ends of said flexible body, characterized in that said flexible body and said rigid fixing means form a single block coming from molding, said flexible body and said rigid fixing means being able to be connected by physico¬chemical links existing between the materials of said flexible body and said rigid fixing means.

2. Connecting device according to claim 1, characterized in that said flexible body (1, 101) is elastomeric thermoplastic and said fixing means (20, 30, 120, 130) are rigid thermoplastic.

3. Connection device according to any one of the preceding claims, characterized in that the fastening means (20, 30, 120, 130) comprise a plurality of snap fasteners (40).

4. Connection device according to any one of the preceding claims, characterized in that a fastening means (30, 130) comprises at least one latching tongue (35).

5. Connection device according to any one of the preceding claims, characterized in that said flexible body (10, 110) comprises a portion having a wave-shaped accordion.

6. Connection device according to any one of the preceding claims, characterized in that each of said fixing means (20, 30, 120, 130) is placed in the extension of a portion of said flexible body radially projecting flexible lip sealing (15, 11, 115, 111).

7. Connection device according to any one of the preceding claims, characterized in that a plate (45) in a hole of which said connecting device (1, 101) is inserted is sandwiched between an end portion (43) a fastening means (20, 120) on the one hand and fastening clips (40) of said fastening means on the other hand.

8. Connection device according to any one of the preceding claims, characterized in that one of said fixing means (20) is installed around a cylindrical end piece (13) extending said sleeve beyond said flexible lip ( 15).

9. A method of manufacturing a connection device according to any one of the preceding claims, characterized in that it comprises the following steps: - injection of the material constituting said rigid fixing means in a mold whose interior volume is partitioned by a removable partitioning means, removal of said removable partitioning means, injection of the material constituting said flexible body into said mold, in that said mold comprises a core which defines the inner shape of the connection device and two indentations which define its outer shape, and in that it comprises, after molding, a step of opening the mold followed by a blowing step for inflating the molded part to allow removal of the core.