The present invention relates to the sector of hermetically sealed zip fasteners, namely those type of zip fasteners which must form an impenetrable barrier preventing the passage of fluids.
Recently numerous solutions have been devised with the aim of preventing the passage of water, air and gases under pressure between the two rows of teeth which face each other and are mounted on strips of material with a relative compressive elasticity. As is known, the said teeth are joined together by a member, called a slider, which is movable and is displaced by gripping a gripping member such as a pull tag or the like.
When the zip fastener is closed, on its end part where the abovementioned slider is mounted, there is the risk of infiltration between the zone of the teeth and the slider part which is necessarily situated between them, and the abovementioned preventive measures are of no use and effective only in the zones where the teeth are joined together and their strips pressed against each other.
In order to overcome this drawback, the inventor of the subject of the present invention has devised a zip fastener of the type described hitherto in which, however, a first and a second concave capsule having a form which is substantially a mirror-image of each other and arranged with the perimetral edges of their concavities opposite and facing each other are provided on the slider and on opposite sides thereof.
One of the said capsules has a pin which is perpendicular thereto and able to slide through the slider body and through a hole formed in the other capsule, and the abovementioned gripping member is connected to means which, when they are actuated, cause a simultaneous displacement of both the capsules towards each other in a direction perpendicular to the plane of the zip fastener, with the result that the two strips of elastic material supporting the teeth are gripped between the said capsules with a desired pressure. In this way the already described zone where the teeth and slider are joined together, where there is a potential risk of infiltration, remains enclosed within the perimetral edges of the abovementioned capsules, which act as a barrier against the passage of a liquid.
The object of the present invention is therefore to provide a hermetically sealed zip fastener in accordance with that described in the accompanying claim 1.
Two preferred examples of embodiment of a zip fastener according to the invention will now be described and, during the course of the description, reference will also be made to the accompanying drawings in which:
If we consider first of all
In the zip fastener 1 according to the invention, however, the said slider 7 is provided, on opposite sides of the said strips 5, 6, with a first concave capsule 10 and a second concave capsule 11 having a form which is substantially a mirror-image of each other and arranged with the perimetral edges 12, 13 of their concavities opposite and facing each other.
The said first capsule 10, which is shown in the lower position, has a perpendicular pin 14 which is directed upwards and passes through a cavity 15 inside the slider 7 as well as a hole 16 formed in the second capsule, so that the two capsules 10, 11 may slide perpendicularly relative to each other along the abovementioned pin 14.
The pull tag 8 is keyed integrally onto a spindle 19 which is pivotably mounted at the ends onto a cap 24 forming part of the slider 7 and the pull tag 8 itself has externally a cam surface 17 which makes contact with the upper wall 11s of the said second capsule 11. The abovementioned spindle 19 passes through a transverse hole 20 (see also in this connection the enlarged detail in
The arrangement described above produces the effect that the perimetral sides 12, 13 of the two aforementioned capsules 10, 11 exert, when the pull tag 8 performs a rotation through 180°, two substantially equal and opposing thrusts on the opposite sides of the already described strips 5, 6 which are gripped between them.
The abovementioned cylindrical portion 9c also has externally a second thread 21 which has a direction opposite to that of the first thread 22 and which engages inside a threaded hole 23 formed in the second capsule 11, the pitch and direction of the various threads being such that a rotation R of the said knob 9 causes two displacements B, D of the two capsules 10, 11 in an opposite direction, parallel to the axis of the said pin 14, so that they are able to grip between them the strips 5, 6 with a desired pressure, as shown in
In both the cases described hitherto, the advantage—important for a hermetically sealed zip fastener—of being able to achieve the above described gripping of the elastic strips (namely hermetic closure of the zone exposed to the risk of infiltration) with movements and/or rotations of a limited degree has been obtained. In both cases, in fact, the rotational movement Y of the pull tag 8 and the rotational movement R of the knob 9 both cause, simultaneously, two closing movements (Δx, −Δx, B, D), the sum of which produce a double gripping action on the strips 5, 6 between the capsules 10, 11, between the end parts 12t, 13t of the perimetral edges 12, 13.
In order to ensure an effective action of the capsules 10, 11 on the strips 5, 6, the inventor envisages forming, on the set or sets of teeth 3, 4 which are situated between the perimetral edges 12, 13 of the capsules 10, 11, grooves 26 able to contain in a complementary manner the end parts 12t, 13t of the said perimetral edges when they have been moved towards each other as fully as possible, namely when the zip fastener 1, 2 has been closed and sealed hermetically by means of gripping of its strips 5, 6 between the capsules 10, 11.
A further measure envisaged by the inventor for ensuring the hermetic closure of a zip fastener provided in accordance with the invention consists in designing the strips 5, 6 on which the teeth 3, 4 are mounted so that they form a whole, as shown in
In order to illustrate this measure more clearly in the drawings the strip part of the said zone Z shown on the right-hand side of the slider in all the figures has been indicated by the reference numbers 5, 6 relating to the two parts of the strips situated on the left of the slider.
Number | Date | Country | Kind |
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02107/04 | Dec 2004 | CH | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/IB05/03696 | 11/30/2005 | WO | 00 | 5/31/2007 |