Fluid-tight slide fastener

Description

[0001] The present invention relates to the sector of fasteners, also called "zip fasteners", and more particularly to those which must provide a fluid-tight closure, namely form a barrier which prevents the passage of fluids (liquids or gases) exerting a given pressure.

[0002] As is known, these fasteners join together two hems of fabric or other impermeable material by connecting two facing rows of teeth arranged in between one another and mechanically connected by means of the action of a slide, and the fluid-tight seal is obtained by arranging the said two hems next to one another by means of closing of the fastener and by exerting a predetermined compressive force on them; since the hems are made of elastic material, they thus create a linear fluid-tight seal along the entire length of the fastener.

[0003] According to the present state of the art, in fact, the said two hems which possess a certain degree of elasticity are arranged on top of one another and a pressure is exerted on them perpendicular thereto owing to closing of the fastener.

[0004] This system has some significant limitations and major functional drawbacks, including the fact that closing of the fastener must exert a considerable compressive preloading force on the said hems, with accentuated elastic yielding thereof capable of ensuring the fluid-tight seal even when a predetermined pulling force, tending to separate them from one another, is exerted on the two hems; in view of the geometrical configuration of the fastener and the necessary - albeit small - amount of play between the various teeth, a pulling force in the direction described always causes a given relative rotation of them which tends to separate the compressed hems, reducing the compressive (and hence sealing) force acting on them.

[0005] This is why it necessary that the said elastic yielding effect should be of a magnitude such as to ensure the desired fluid-tight seal even in the presence of the said relative rotation of the teeth and a certain elastic return movement of the two superimposed hems.

[0006] This fact has the consequence that the slide must exert a considerable force on the teeth in order to connect them together and this results in a great deal of effort needed to operate the fastener, so much so that it is difficult for a person wearing, for example, a wet suit which is closed by means of such fasteners, to perform alone the operations of opening or closing the said fastener.

[0007] Another drawback consists in the fact that the fasteners in question, because of their configuration, when closed create an aesthetically unattractive bulge in the form of a bead.

[0008] In order to avoid the drawbacks described hitherto, the inventor of the present invention has devised a fastener with specially shaped teeth divided into two parts which rest on opposite sides of the hem onto which they are applied and which contain inside them an elastic cord which extends at least over the whole length of the fastener.

[0009] The two cords of the two rows of opposite teeth are arranged next to one another frontally and compressed to a given degree as a result of closing of the fastener performed by the slide.

[0010] A similar solution is disclosed by Patent US-A-2 910 754 but, owing to a particular, innovative shape of the said two cords, the force required for operation of a fastener according to the invention is very light, the fastener itself, when closed, having however the dimensions and the aesthetic appearance of a normal fastener.

[0011] More particularly, the subject of the present invention consists of a fastener according to the preamble of the accompanying Claim 1 characterized by the technical characteristics described in the characterizing part of the same claim.

[0012] A more detailed description of a preferred exemplary embodiment of the fastener according to the invention will now be given, during which reference will also be made to the accompanying drawings, in which:

Figure 1 shows schematically a cross-sectional view of a fluid-tight fastener according to the state of the art;

Figure 2 shows a cross-sectional view of a preferred embodiment of the fluid-tight fastener according to the invention;

Figure 3 shows a side view of a tooth of the fastener according to Figure 2;

Figure 4 shows the plan view of a portion of the fastener according to Figures 2 and 3.

[0013] As can be seen in Figure 1, the fasteners according to the state of the art, as already explained, superimpose the two hems 103, 104 of impermeable fabric to be joined together by arranging them against one another and exerting a compressive force on the superimposed portion as a result of the closing action performed by the slide (not shown).

[0014] The fastener 101 is sensitive to the action of forces F which tend to move the two hems apart since the teeth 102 engaged together tend to rotate with respect to one another, diminishing the magnitude of the elastic compressive force acting on the hems to be joined together.

[0015] The fastener, moreover, when it is closed, forms an aesthetically unattractive bead which is raised with respect to the flat walls of the hems of impermeable fabric.

[0016] The fastener 1 according to the invention, on the other hand, is composed of two facing rows of teeth 2 which are formed as can be seen in Figure 2; each of them consists of two parts 2a, 2b which are connected together and arranged on opposite sides of one of the two hems 3, 4 made of fabric or other impermeable material and accommodates internally a cord 5 (see Figure 3) of elastic material (for example neoprene) arranged in an intermediate position between the said two parts 2a, 2b.

[0017] The cords 5 located between the teeth 2 of the two facing rows which are connected in a known manner by a slide of the conventional type (not shown) are coplanar and are dimensioned and arranged so as to be compressed and rest frontally against one another when the abovementioned teeth 2 are connected together by the said slide, as shown in Figure 3.

[0018] As already mentioned, the force required to compress the two cords 5 arranged opposite one another frontally is very low and consequently the force to be exerted on the slide in order to perform closing (and opening) of a fastener 1 according to the invention is also very small.

[0019] In order to reduce this force to a minimum, the inventor of the present invention has envisaged shaping the cords 5 with a section which is tapered with a predetermined convergence closed by a rounded portion in the zones where they frontally come into contact when the fastener 1 is closed.

[0020] The said rounded section has the effect of increasing the pressure which is exchanged between the cords for the same compressive force acting on them, therefore reducing the latter and ensuring elastic deformation of the contact zones sufficient to create a reliable fluid-tight seal capable of preventing the infiltration of fluids exerting a pressure even greater than 2 bar.

[0021] As can be seen in Figure 3, the said two parts 2a, 2b forming a tooth 2 are connected together by a connecting element 6 which is fixed integrally to them and which passes through the elastic cord 5 and the hem of fabric or other impermeable material 3 arranged on top of one another (it obviously being necessary to form suitable holes in them for this purpose).

[0022] Each tooth 2 exerts its action on a shoulder 5s of the cord 5 by means of an abutting element 2t.

[0023] The inventor, in order to distribute radially in a uniform manner over the whole length of the cord 5 itself the pressure exerted by the said abutting elements 2t, has envisaged shaping, in a substantially cylindrical manner with a suitable curvature, the portion of each of the abutting elements 2t which is in contact with the cord 5.

[0024] The teeth 2, according to a preferred embodiment, are made of synthetic resin and may be formed as one piece, already connected to the cord 5 and to the hem 3, 4 of fabric, by means of injection moulding.

[0025] The construction of the fluid-tight fastener using synthetic resin offers, moreover, the advantages of a reduced weight and a high resistance to the corrosive action of aggressive physical or chemical elements.

[0026] A plan view of a portion of the fastener according to the invention is shown in Figure 4.

[0027] The two elastic cords 5 contained in a fastener 1 according to the invention advantageously extend beyond the end of the two rows of teeth 2 over a predetermined length so as to form a fluid-tight closing stop which can be realized by the compression exerted onthemby the said slide when it brings them together, travelling an additional distance with respect to that which it must cover in order to perform closing of the fastener.

[0028] It is preferable, moreover, for the fastener to be provided with means which are connected to it, or to the hems of impermeable fabric, and which are designed to be reversibly inserted so as to keep the slide fixed in the position in which it is located when it has realized the closing stop in question.

[0029] Normally these means, which are already essentially known, may consist of fixed parts which can be connected to the pull-piece of the slide. The said closing stop and the means for fixing the slide are not shown in the drawings.

[0030] A further advantage provided by the fluid-tight fastener according to the invention consists in the fact that, for its operation, the hems of impermeable fabric which are to be joined together need not consist of a material which is elastic upon compression, since the seal is not produced by compressing the hems themselves, but the said elastic cords which are connected to the said hems. The preferred exemplary embodiment described hitherto and shown in the drawings is neither binding nor limiting in respect of other embodiments which may be obtained by referring to that which is stated in the accompanying claims: these embodiments also fall within the scope of protection defined by the present patent application.

Claims

1. Fastener (1) for joining together in a fluid-tight manner two hems (3, 4) of fabric or other impermeable material, comprising two rows of teeth (2) engaging with one another as a result of the action of a slide and applied respectively onto each of the said two hems, the said fluid-tight seal being obtained by compressing two elastic members each integral with one of the aforementioned hems, each of the said teeth (2) consisting of several parts (2a, 2b) which are connected together and arranged on opposite sides of the said fabric or impermeable material, and the said elastic members consisting of cords (5) of elastic material which are arranged in an intermediate position between the said two parts (2a, 2b) of the said teeth (2) of each row, the abovementioned cords (5) being dimensioned and arranged so as to be coplanar and so as to be compressed and rest frontally against one another with a predetermined force when the abovementioned teeth (2) are connected together by the said slide, characterized in that
the said two elastic cords (5) have a tapered section closed by a rounded portion (e) in the zone where they come frontally into contact when the respective rows of teeth (2) are connected together by the said slide.

2. Fastener according to Claim 1, in which the said tapered part of the elastic cord has, in the direction of the associated tooth, a shoulder (5s) against which an abutting element (2t) present on one of the said two parts of each tooth (2) engages.

3. Fastener according to Claim 2, in which the said abutting element (2t) rests against the said shoulder (5s) of the elastic cord (5) with a substantially cylindrical portion rounded with a predetermined profile so as to distribute radially in a uniform manner the compressive forces acting on the cord (5) itself when the two rows of teeth are connected together.

4. Fastener according to one of the preceding claims, in which the said two parts (2a, 2b) of each tooth (2) are connected by a connecting element (6) which is integral with them and passes through one of the said elastic cords (5) and one of hems (3, 4) of fabric or impermeable material which are arranged on top of one another.

5. Fastener according to one of the preceding claims, in which each tooth (2) formed by two parts (2a, 2b) connected together is a single piece obtained by means of injection moulding.

6. Fastener according to Claim 5, in which the said teeth (2) are made of synthetic resin.

7. Fastener according to one of the preceding claims, in which the said two cords (5) of elastic material extend beyond the end of the said rows of teeth (2) over a predetermined length so as to form a fluid-tight closing stop which can be realized by the compression exerted on them by the said slide when it brings them together, travelling an additional distance with respect to that which it must cover in order to perform the said connection between the two rows of teeth (2) themselves.

8. Fastener according to Claim 7, characterized in that it is provided with means which can be inserted reversibly and which are designed to keep the said slide fixed in the position in which it realizes the said closing stop.

Ansprüche

1. Verbinder (1) zum fluiddichten Verbinden zweier Ränder (3, 4) eines Stoffs oder eines weiteren undurchlässigen Werkstoffs miteinander, mit zwei Reihen aus Zähnen (2), die infolge der Wirkung eines Schiebers ineinander in Eingriff sind und jeweils an einem der beiden Ränder angebracht sind, wobei die fluiddichte Abdichtung erreicht wird, indem zwei elastische Elemente, die jeweils mit einem der zuvor erwähnten Ränder einteilig ausgebildet sind, zusammengedrückt werden, wobei jeder der Zähne (2) mehrere Teile (2a, 2b) enthält, die miteinander verbunden sind und an gegenüberliegenden Seiten des Stoffs oder des undurchlässigen Werkstoffs angeordnet sind, und wobei die elastischen Elemente Schnüre (5) aus einem elastischen Werkstoff enthalten, die in einer Zwischenposition zwischen den beiden Teilen (2a, 2b) der Zähne (2) jeder Reihe angeordnet sind, wobei die obenerwähnten Schnüre (5) so dimensioniert und angeordnet sind, daß sie koplanar sind und zusammengedrückt werden und mit einer vorgegebenen Kraft frontal aneinander ruhen, wenn die zuvor erwähnten Zähne (2) durch den Schieber miteinander verbunden sind, dadurch gekennzeichnet, daß
   die beiden elastischen Schnüre (5) einen verjüngten Abschnitt aufweisen, die in einem gerundeten Abschnitt (e) in der Zone abschließt, in der sie frontal in Kontakt gelangen, wenn die entsprechenden Reihen der Zähne (2) durch den Schieber miteinander verbunden werden.

2. Verbinder nach Anspruch 1, bei dem der verjüngte Teil der elastischen Schnur in Richtung des zugehörigen Zahns eine Schulter (5s) aufweist, mit der ein vorstehendes Element (2t), das an einem der beiden Teile jedes Zahns (2) vorhanden ist, in Eingriff gelangt.

3. Verbinder nach Anspruch 2, bei dem das vorstehende Element (2t) an der Schulter (5s) der elastischen Schnur (5) mit einem im wesentlichen zylindrischen Abschnitt, der mit einem vorgegebenen Profil gerundet ist, anliegt, um die Druckkraft, die auf die Schnur (5) selbst wirkt, wenn die beiden Reihen von Zähnen miteinander verbunden sind, radial gleichmäßig zu verteilen.

4. Verbinder nach einem der vorhergehenden Ansprüche, bei dem die beiden Teile (2a, 2b) jedes Zahns (2) durch ein Verbindungselement (6) verbunden sind, das mit ihnen einteilig ausgebildet ist und entweder durch eine der elastischen Schnüre (5) oder einen der Ränder (3, 4) des Stoffs oder des undurchlässigen Werkstoffs verläuft, die übereinander angeordnet sind.

5. Verbinder nach einem der vorhergehenden Ansprüche, bei dem jeder Zahn (2), der aus zwei miteinander verbundenen Teilen (2a, 2b) gebildet ist, ein einzelnes Teil ist, das durch Druckguß hergestellt ist.

6. Verbinder nach Anspruch 5, bei dem die Zähne (2) aus Kunstharz hergestellt sind.

7. Verbinder nach einem der vorhergehenden Ansprüche, bei dem sich die beiden Schnüre (5) aus elastischem Werkstoff über das Ende der beiden Reihen von Zähnen (2) hinaus um eine vorgegebene Länge erstrecken, um eine fluiddichte Trennwand zu bilden, die durch die Kompression realisiert werden kann, die durch den Schieber auf sie ausgeübt wird, wenn er sie zusammenbringt, wobei sich der Schieber in bezug auf die Strecke, die er zurücklegen muß, um die eigentliche Verbindung zwischen den beiden Reihen von Zähnen (2) auszuführen, um eine zusätzliche Strecke bewegt.

8. Verbinder nach Anspruch 7, dadurch gekennzeichnet, daß er mit Mitteln versehen ist, die reversibel eingesetzt werden können und vorgesehen sind, um den Schieber in der Position festzuhalten, in der er die Trennwand realisiert.

Revendications

1. Fermeture à glissière (1) pour la jonction étanche de deux bords (3, 4) de tissu ou autre matériau imperméable, comprenant deux rangées de dents (2) s'engageant mutuellement sous l'action d'un curseur et appliquées respectivement sur chacun des dits deux bords, ladite fermeture étanche étant obtenue en comprimant deux éléments élastiques qui sont chacun d'un seul tenant avec l'un des bords mentionnés ci-dessus, chacune des dites dents (2) étant constituée en plusieurs parties (2a, 2b) qui sont reliées ensemble et disposées sur des côtés opposés du dit tissu ou matériau imperméable, et lesdits éléments élastiques étant constitués de cordes (5) en matériau élastique qui sont disposées dans une position intermédiaire entre lesdites deux parties (2a, 2b) des dites dents (2) de chaque rangée, les cordes mentionnées ci-dessus (5) ayant des dimensions et une disposition telles qu'elles sont dans un même plan et qu'elles sont comprimées et reposent frontalement l'une contre l'autre avec une force prédéterminée quand les dents (2) mentionnées ci-dessus sont jointes ensemble par ledit curseur, caractérisée en ce que lesdites deux cordes élastiques (5) ont une section conique fermée par une partie arrondie (e) dans la zone où elles viennent en contact frontalement quand les rangées respectives de dents (2) sont jointes ensemble par ledit curseur.

2. Fermeture à glissière selon la revendication 1, dans laquelle ladite partie conique de la corde élastique a, dans la direction de la dent associée, un épaulement (5s) contre lequel s'engage un élément d'aboutement (2t) présent sur l'une des dites deux parties de chaque dent (2).

3. Fermeture à glissière selon la .revendication 2, dans laquelle ledit élément d'aboutement (2t) repose contre ledit épaulement (5s) de la corde élastique (5) par une partie sensiblement cylindrique arrondie à profil prédéterminé de façon à distribuer radialement de façon uniforme les forces de compression qui agissent sur la corde (5) elle-même quand les deux rangées de dents sont jointes.

4. Fermeture à glissière selon l'une des revendications précédentes, dans laquelle lesdites deux parties (2a, 2b) de chaque dent (2) sont reliées par un élément de liaison (6) qui est d'un seul tenant avec elles et traverse une des dites cordes élastiques (5) et un des bords (3, 4) de tissu ou de matériau imperméable qui sont superposés .

5. Fermeture à glissière selon l'une des revendications précédentes, dans laquelle chaque dent (2) formée de deux parties (2a, 2b) reliées ensemble est en une seule pièce obtenue par moulage par injection.

6. Fermeture à glissière selon la revendication 5, dans laquelle lesdites dents (2) sont en résine synthétique.

7. Fermeture à glissière selon l'une des revendications précédentes, dans laquelle lesdites deux cordes (5) en matériau élastique se prolongent au delà de l'extrémité des dites rangées de dents (2) sur une longueur prédéterminée de façon à former une butée de fermeture étanche qui peut être réalisée par la compression exercée sur elles par ledit curseur quand il les rapproche, en se déplaçant sur une distance additionnelle par rapport à celle qui doit être couverte pour réaliser ladite jonction entre les deux rangées de dents (2) elles-mêmes.

8. Fermeture à glissière selon la revendication 7, caractérisée en ce qu'elle comporte des moyens pouvant être introduits de façon réversible et conçus pour maintenir pour maintenir ledit curseur immobilisé dans la position dans laquelle il réalise ladite butée de fermeture.

Drawing