DE2758432A1 - SECURITY LATCH, IN PARTICULAR FOR FUEL TANK - Google Patents

Description

Dlpl.-Phy ». ü. M. Hell β MCnchen 22. den

Maximiliansir IS Tel. 29 48 IS

Compagnie des Produits Industrieis de L'Ouest, B.P. 1226, 44023 Nantes Cedex, France

Safety lock, in particular for fuel tanks

The present invention relates to a safety lock, in particular for fuel tanks in motor vehicles.

The problem of venting fuel tanks is well known. It must be ensured that a gas exchange between the container and the atmosphere can take place in both directions, so that both the decrease in the fuel level in the tank due to consumption and a certain expansion of the fuel can be taken into account due to a temperature increase without being inside the fuel tank a harmful underpressure or overpressure occurs.

These demands must now with the new safety regulations be brought into agreement, according to which when changing

tilt the motor vehicle only a very limited fuel leakage is permitted, for which a special safety lock is necessary.

Such closures are already known which limit the escape of fuel when the vehicle tips over and at the same time allow a gas exchange between the interior of the container and its surroundings. These closures have, among other things an outflow brake on or a porous sintered material. A disadvantage of this is that, under the circumstances outlined above, none absolute tightness can be achieved.

If, however, the tank filler neck is closed absolutely tightly, the disadvantage again arises that no gas or air exchange occurs between the tank and its surroundings is possible.

The object of the present invention is to provide a safety lock specify that meets all the requirements placed on him and avoids the above disadvantages.

This problem is solved by the features specified in Claimi.

Advantageous configurations of the safety lock according to the invention are described in the subclaims.

In the following the invention is explained in more detail with reference to an embodiment shown in the drawing. Show it:

Figure 1 is a section through a main part of the invention Safety lock;

Figure 2 shows a section through the entire closure and

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FIG. 3 shows a section along the horizontal plane according to A-A of FIG.

The safety lock according to the invention consists essentially from an upper part 1, which also serves as a decorative cap and a lower part 2 with a centrally arranged cavity 12, in which a plug made of elastomer 3 is arranged and which is in communication with the environment via an opening 26, which is shown in FIG its upper half is attached. Parts 1 and 2 are preferably made by molding a thermoplastic material made of the polyacetal type and bonded together by pressure using the relative flexibility of the materials, of which they are made.

In Figure 2 it is shown that the decorative cap 1, the surface of which can be circular and the outer edge of which is bent is to form a clamping edge, has on its inside a wall-shaped to the outer edge concentric edge 5, the outside of which is provided with a bead 6 which is used to connect the decorative cap and the lower part 2. The latter has a recess on its inside and on its upper part, which is thereby in contact with the edge 5 states that it has a complementary shape to the bead so that it is used for connection between the lower part and the decorative cap serves.

Between the outside of a molded piece 7 of the lower part 2 and the inside of the clamping edge 4 of the decorative cap is located an annular channel 8, into which a tight seal for the tank feed nozzle 9 of the fuel tank can be used can. This closure consists of a ring seal 10 made of plastic, which is attached to the outside of the molded part 7 is, the latter having a U-shaped transverse

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in

has section, which is in the direction of the inside of the clamping edge 4 is open and its interior is partially filled with a sponge-like material 11 such as an elastomer. Furthermore, a channel 24 is provided between the parts 1 and 2, which connects the interior of the closure with the outside environment connects.

The elastomer stopper 3 used in connection with the present invention is shown in detail in FIG. It is preferably obtained by molding a synthetic rubber which is resistant to hydrocarbons and which, after being removed from the mold, is exposed to a hydrocarbon vapor for some time to make it stable To give spatial form.

The stopper 3 consists of a cylindrical body 13, the top of which merges into a cover 15 which extends into a circumferential lip 16 continues, both of which are penetrated by a channel 14; the channel 14 widens at its lower end a concave recess 25 arranged symmetrically to it.

Walls 17 are arranged on the underside of the cylindrical body (Figure 3), which are centrally connected via a tubular element 21 in which a ball 18 made of stainless steel is located by openings 19, which are arranged in the walls 17 due to the elasticity of which is introduced.

The stopper 3 is inserted into the central opening 12 of the lower part 2 pressed in until the lip 16 rests on the shoulder 20 of the part 2, with the part 2 being an extension of the central Opening of the tube 21 has an opening 22. Otherwise will the stopper 3 is held in place by means of a projection 23 which is provided on its inside when the decorative cap 1 is poured.

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The operation of the device described above is as follows: In normal use, the ball 18 rests in its seat 21 due to gravity. The space 19 between the walls 17 enables air to be exchanged between the fuel tank and the surrounding atmosphere via the filler neck 9, the opening 22 in the lower part 2, the channel 14 in the Lid 15 and the channel 24 between the fixed closure parts 1 and 2.

In the event of the vehicle overturning or a very strong inclination leaves the ball its seat 21 and is pressed into the concave recess 25 of the plug, whereby the channel 14 is tightly closed. The pressure of the fuel pushing upwards from the container through the filler neck 9 is increased nor the pressure of the ball on the channel, so that no fuel can flow out.

If, however, excessive pressure occurs in the fuel tank in this situation, a certain pressure can occur Exchange with the environment via the opening 26 in part 2 and the channel 24 take place in that the lip 16 of the plug is raised, causing a sudden drop in pressure in the fuel tank is made possible.

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L e r s e

Claims (4)

Dlpl.-Phys. UM detention β Munich 22nd Patent attorney MaximHianstr. 15th Ti) 1.294818 Claims VJy safety lock, especially for fuel tanks from Motor vehicles, consisting of an upper part provided with a clamping edge, which is connected to a lower part, which has a central recess in which at least one plug is arranged, which can be provided with a ball can, characterized in that the plug is made of a molded synthetic elastomer which is resistant against hydrocarbons is that it has a cylindrical hollow body, the top of which by a is closed lip-shaped to the outside widening lid, which rests on an edge in the recess of the lower part, that both the lower and the upper part are made of a molded thermoplastic synthetic material, e.g. Polyacetal, and that the cylindrical body is provided at its other end with a tubular element which is connected to the cylindrical body by vertical walls in such a way that it provides a seat for a stainless steel ball Form steel so that the ball rests on the opening of the tubular element. 2. Safety closure according to claim 1, characterized in that the upper part of the plug at its 809 8 * 6/06 81 ORIGIiYAL INSPECTED Underside has a concave recess symmetrical to the tubular element, and that a channel opens into it, which the
Connects the inside of the plug to the outside environment. 3. Safety device according to claims 1 and 2, characterized in that the lower part is penetrated by two openings, one being arranged on the underside of the central recess and symmetrically to the tubular element opposite it and the other being arranged on the upper side of this recess is up and close to the
Underside of the lip of the plug extends. 4. Safety device according to claim 3, characterized in that g e k e η η - ζ ei c h η e t that a channel is provided between the rigid connecting surfaces of the upper and lower part in such a way that it connects the interior of the closure with the external environment.