EP0320633B1 - Snap-fastener - Google Patents

Abstract

The snap fastener for flat materials 3 which are impermeable to water consists of a top part 1 and a bottom part 2 which can be attached in each case to flat materials 3 to be connected and can be engaged with one another, the top part 1 and the bottom part 2 consisting in each case of a cap 7 with a rivet shank 9 of round cross-section piercing the flat material 3 and of a spring part (ball 13/eye 18) on the other side of the flat material 3, in which spring part the rivet shank 9 is fixed in a receiving borehole 15 which is likewise of round cross-section, and the perforation point 16 in the flat material 3 being sealed off in such a way that no water can penetrate through the perforation point 16 from the outside to the inside. In order to simplify the sealing-off of the snap fastener in the flat material so that automatic assembly of the snap fastener is possible without problems, it is proposed that the receiving borehole 15 has a smaller inside diameter in the spring part 13, 18 than the outside diameter of the rivet shank 9 in the passage region, the inside edge of the perforation point 16 in the flat material 3 being squeezed in the completely assembled state of the snap fastener between the receiving borehole 15 and the rivet shank 9 and forming a sealing region 17 at that point. <IMAGE>

Description

The invention relates to a push button for water-impermeable surface materials, consisting of an upper part and a lower part, each of which can be fastened to surface materials to be connected and locked together, the upper part and the lower part each consisting of a cap with a rivet shaft with a round cross-section penetrating the surface material and consists of a spring part (ball / eyelet) on the other side of the surface material, in which the rivet shaft is fixed in a receiving bore with a round cross-section, and the perforation point in the surface material is sealed such that no water from the outside in through the Perforation point can penetrate.

A push button of this type is known from DE-PS 36 44 690. It is used to connect two surface materials, such as fabric panels, and basically consists of an upper part and a lower part, which can be locked together. The upper part is attached to one surface material and the lower part to the other surface material. The upper part and the lower part of the push button each consist of a cap and are provided on their underside with a rivet shaft which pierces or projects through the surface material. It is a self-piercing version of the push button, in which the rivet shaft is inserted through the surface material without pre-punching. Furthermore, the upper and lower part of the push button consists of a spring part on the other side of the surface material, the spring part being designed as a ball and a corresponding eyelet, the ball and the eyelet being able to be locked together. The spring part is attached to the upper and lower part using a mounting hole in Form of an opening that receives the rivet to form a rivet. For this purpose, the front end of the rivet shaft can either be deformed like a mushroom head by the riveting or, if the rivet shaft is hollow on the inside and open at the front, it can be flanged to the outside. The upper or lower part can be fastened with its spring part centrally in the middle or at several points, for example with multi-point riveting.

Such push buttons are used for example in breathable, rainproof sports or rainwear. The watertightness of such clothing is achieved by incorporating a membrane into the fabric of the clothing, which allows water vapor to pass through from the inside out, but blocks rain from the outside in. Such membranes can be made of Teflon, for example.

If the conventional push buttons are used in these waterproof materials, they perforate the membrane, which is waterproof per se, and allow water to pass through in the area of the perforation point, so that the item of clothing in the area of the push buttons is no longer impermeable to rain. This is particularly noticeable when the user is in the rain for a long time or when the rain is very heavy.

In order to prevent water from penetrating through the perforation point from the outside inwards, the known push button is inserted into the surface material in a self-sealing manner. For this purpose, in the known push button an annular adhesive layer is provided between the underside of the cap resting on the surface material and the surface material around the perforation point in the surface material, the adhesive layer a sealing connection is established between the underside of the cap and the sheet material. However, it has been found that the additional use of an annular adhesive layer can cause problems in the automatic assembly of the push button on the respective surface material.

GB-PS 1 114 649 discloses a push button consisting of a cap having a rivet shaft and a spring part, the cap being arranged on one side of the sheet material and the spring part on the other side of the sheet material. To attach the push button to this surface material, the rivet shaft of the cap pierces this surface material in the manner of a perforation and is received by the spring part, which has a receiving bore for this purpose. Since the outer diameter of the rivet shaft is larger than the inner diameter of the receiving bore in the spring part, the surface material is sheared off in the edge area when the rivet shaft penetrates into the receiving bore. After the rivet shaft is completely penetrated and the edge is flanged in the spring part, the surface material is fixed exclusively between the cap and the bottom of the spring part. The disadvantage here is that water can penetrate through the perforation in the surface material.

Starting from a push button for water-impermeable surface materials of the type specified at the outset, the object of the invention is to simplify the sealing of the push button in the surface material, so that problem-free automatic assembly of the push button is possible.

As a technical solution , the invention proposes that the receiving bore in the spring part has a smaller inner diameter than the outer diameter of the rivet shaft in the passage area, the inner edge of the perforation point in the surface material being squeezed between the receiving bore and the rivet shaft in the fully assembled state of the push button and forming a sealing area there.

A push button designed according to this technical teaching for water-impermeable surface materials has the advantage that it can be inserted into the surface material in a self-sealing manner without requiring additional parts, for example in the form of a ring-shaped adhesive layer. The seal is achieved solely by squeezing the inner edge of the perforation point in the surface material between the receiving bore in the spring part and the rivet shaft when the spring part is attached to the cap in such a way that a seal is achieved. In order to be able to clamp the inner edge of the surface material between the receiving bore and the rivet shaft, it is only necessary to make the inside diameter of the receiving bore a certain amount smaller than the outside diameter of the rivet shaft. Because of the assembly of additional parts can be dispensed with, an automatic assembly of the push button on the corresponding surface material with the conventional machines is possible without difficulty, so that the automation poses no problems at all.

The undersize of the receiving bore relative to the rivet shank is preferably 5 to 10%. An undersize in this size means on the one hand that the inner edge of the surface material is squeezed in a self-sealing manner and on the other hand that the rivet shaft can still be easily inserted into the receiving bore.

In a first embodiment, the rivet shaft is cylindrical and has a tapered front end. The tapering has the advantage that the rivet shaft can be inserted into the receiving bore in a simple manner, which would otherwise only be possible with difficulty due to the undersize.

In an alternative embodiment it is proposed that the rivet shaft is conical, it only having a larger outer diameter than the inner diameter of the spring part in the area of the passage through the receiving bore. The conical design of the rivet shaft has the advantage that, on the one hand, the rivet shaft can be inserted into the receiving bore in a simple manner and, on the other hand, that a fairly wide inner edge of the surface material is clamped at the perforation point between the receiving bore and the rivet shaft.

In an advantageous development, the spring part is made of plastic and the cap and the rivet shaft are made of plastic and / or Metal. In particular, the spring part made of plastic has the advantage that the spring part can deform in the sealing area in such a way that the receiving bore there, together with the outer casing of the rivet shaft, forms an annular wedge in which the inner edge of the surface material is squeezed at the perforation point. This effect is particularly evident when the rivet shank is made of metal that is harder than the plastic.

The cap of the push button can be formed in one piece with the rivet shaft and made of metal or plastic. The rivet shank and the cap can also be formed separately from one another and connected to one another accordingly. In this embodiment, the rivet shaft is preferably hollow on the inside and open at its front end and molded onto an annular, flat rivet flange. This rivet flange is held in this by flanging the edge of the cap. Since in this embodiment water can penetrate from the outside through the flanging between the bottom of the cap and the back of the rivet flange and then through the hollow rivet shaft, a further seal in this area is proposed according to a further feature of the invention. which is characterized in that a round sealing plate is squeezed between the rivet flange and the cap. This sealing plate, which can be elastically or plastically deformable, achieves a seal between the rivet flange and the cap, which prevents water from penetrating from the outside through the hollow rivet shaft. This seal can be produced in a technically simple manner by inserting a corresponding round sealing plate when mounting the cap with the rivet shaft before flanging the edge.

In a first, preferred embodiment, the sealing plate is squeezed between the rivet flange and the bottom of the cap, so that a large-area seal is created.

In an alternative embodiment, the sealing plate is annular and is squeezed between the rivet flange and the edge of the flanged edge of the cap. In this embodiment, the sealing plate serves as a kind of ring seal between the outside of the rivet flange and the inwardly flanged edge of the cap, so that an effective seal between the cap and the rivet flange is also possible in this way during the manufacturing process.

Finally, the invention proposes that the sealing plate is a plastic film. Such a plastic film can be produced in a simple manner, for example by punching out, and moreover provides an effective seal, the additional material costs being extremely low.

Fig. 1a

ein Oberteil des Druckknopfes (teilweise im Schnitt) vor der Montage an einem Flächenmaterial;

Fig. 1b

das zu Fig. 1a korrespondierende Unterteil des Druckknopfes, ebenfalls vor der Montage an einem zweiten Flächenmaterial;

Fig. 2a

das Oberteil aus Fig. 1a nach dem Zusammenfügen und Vernieten der Kappe mit dem Federteil;

Fig. 2b

das zu Fig. 2a korrespondierende Unterteil des Druckknopfes, ebenfalls nach dem Zusammenfügen und Vernieten der Kappe mit dem Federteil.

Further details and advantages emerge from the following description of the associated drawings, in which an exemplary embodiment of a push button according to the invention for water-impermeable surface materials is shown schematically. The drawings show:

Fig. 1a

an upper part of the push button (partly in section) before mounting on a surface material;

Fig. 1b

the lower part of the push button corresponding to FIG. 1a, also before assembly on a second surface material;

Fig. 2a

the upper part of Figure 1a after assembling and riveting the cap with the spring part.

Fig. 2b

the lower part of the push button corresponding to FIG. 2a, also after the cap has been assembled and riveted to the spring part.

1a and 1b, a push button according to the invention is shown before assembly. It consists of an upper part 1, which is shown in Fig. 1a, and a lower part 2, which is shown in Fig. 1b. Both the upper part 1 and the lower part 2 of the push button are to be attached to a water-impermeable surface material 3. In the exemplary embodiment shown, this surface material 3 is a fabric web that has a central membrane 4, which can be made of Teflon, for example. This membrane 4 is breathable and at the same time impervious to rain, i.e. it only lets water vapor through from the inside out, but from the outside in it blocks rain, so that the fabric can be used for sports or rainwear. An outer layer 5 and an inner layer 6, which can be made of polyester or polyamide, are applied to both sides of the membrane 4.

The top part 1 of the push button shown in FIG. 1 a initially consists of a cap 7 (for example made of metal) in which an annular, flat rivet flange 8 of a rivet shaft 9 is fixed by flanging the edge 10 of the cap 7. The rivet flange 8 and the rivet shaft 9 are formed in one piece and are preferably made of metal. As can be seen in Fig. 1a, the rivet shaft 9 is hollow-cylindrical and tapers towards the front end. This front end of the rivet shaft 9 pierces or perforates the surface material 3.

A sealing plate 12 is inserted between the surface of the rivet flange 8 facing away from the rivet shaft 9 and the bottom 11 of the cap 7 and is squeezed between these two parts. This sealing plate 12 is in particular a round, punched-out plastic film which effects a seal between the cap 7 and the rivet flange 8.

On the other side of the surface material 3, the upper part 1 has a spring part in the form of a ball 13 with a protruding snap region 14 and a central receiving bore 15, through which the rivet shaft 9 of the cap 7, after the surface material 3 has been pierced or perforated, and flanged to the outside becomes, as can be seen in Fig. 2a.

As indicated in Fig. 1a, the receiving bore 15 in the ball 13 has a slightly smaller inner diameter than the outer diameter of the rivet shaft 9 in its cylindrical root region. The difference in diameter is preferably between 5 and 10%.

While the state before the assembly of the upper part 1 is shown in FIG. 1 a, the state after the assembly of the cap 7 including the rivet with the ball 13 is shown in FIG. 2 a to form the complete upper part 1 on the surface material 3. After the rivet shaft 9 has been pierced by the sheet material 3, a puncture point in the form of a perforation point 16 is formed therein, as can be seen in FIG. 2a. After piercing, the front end of the rivet shaft 9 is riveted in the usual manner, as can also be seen in FIG. 2a.

The difference in diameter between the receiving bore 15 in the ball 13 and the rivet shaft 9 creates an interference fit between the outer wall of the rivet shaft 9 and the inner wall of the receiving bore 15, which is impermeable to water. In addition, the inner edge of the sheet material 3 surrounding the perforation point 16, and in particular its water-impermeable membrane 4, is clamped and squeezed between the rivet shaft 9 and the receiving bore 15, so that a sealing area 17 is formed which prevents water from penetrating from the outside inwards . As can be seen in FIG. 2a, when the rivet shaft 9 is pushed through the receiving bore 15, the ball 13 in the sealing region 17 is deformed in such a way that an annular wedge is formed.

In Fig. 1b, the lower part 2 of the push button is shown, which is designed corresponding to the upper part 1 in Fig. 1a. The only difference is that the spring part is not designed as a ball 13 but as an eyelet 18 with a front snap area 19, the front snap area 14 of the ball 13 being in the snap area 19 of the eyelet 18 for connecting the upper part 1 to the lower part 2 snaps into place. Corresponding to the upper part 1, the cap 7 of the lower part 2 also has a sealing plate 12 between the bottom 11 of the cap and the rivet flange 8 of the rivet shaft 9. Likewise, the receiving bore 15 in the eyelet 18 has a smaller inner diameter than the outer diameter of the cylindrical rivet shaft 9, so that in this respect identical relationships to the upper part 1 from FIG. 1a result. For this reason, in the lower part 2, the inner edge in the sheet material 3 is squeezed around the perforation point 16 in the fully assembled state of the lower part 2 between the receiving bore 15 of the eyelet 18 and the rivet shaft 9, so that there is also a sealing area Forms 17, which prevents water from penetrating from the outside through the perforation point 16.

Finally, also in the lower part 2, the sealing plate 12 creates a seal between the cap 7 and the rivet flange 8, so that here, too, no water can penetrate from the outside in through the hollow rivet shaft 9.

Overall, a water-impermeable connection of the upper part 1 and the lower part 2 of the push button with the water-impermeable surface material 3 is thus created.

Reference symbol list

1

Top

2nd

Lower part

3rd

Surface material

4th

membrane

5

Outside location

6

Inner layer

7

cap

8th

Rivet flange

9

Riveting

10th

edge

11

ground

12

Sealing plate

13

Bullet

14

Snap area

15

Location hole

16

Perforation point

17th

Sealing area

18th

eyelet

19th

Snap area

Claims (9)

1. A press stud for waterproof sheet materials (3), comprising a top part (1) and a bottom part (2) each securable to sheet materials (3) for fastening, the bottom part and top part being inter-engageable, the top part (1) and the bottom part (2) each consisting of a cap (7) having a rivet shank (9) of round cross-section piercing the sheet material (3), and of a resilient part (ball 13/eyelet 18) on the other side of the sheet material (3), in which the rivet shank (9) is fixed in a receiving bore (15) also of round cross-section, the perforation (16) in the sheet material (3) being so sealed off that no water can penetrate inwards from outside through the perforation (16), characterised in that the receiving bore (15) in the resilient part (13, 18) has a smaller inside diameter than the outside diameter of the rivet shank (9) in the passage zone, the inner edge of the perforation (16) in the sheet material (3), in the finally assembled state of the press stud, being pinched between the receiving bore (15) and the rivet shank (9), where it forms a sealing zone (17).
2. A press stud according to claim 1, characterised in that the receiving bore (15) is 5 to 10% smaller than the rivet shank (9).
3. A press stud according to claim 1 or 2, characterised in that the rivet shank (9) is cylindrical and tapers at its front end.
4. A press stud according to claim 1 or 2, characterised in that the rivet shank (9) is conical.
5. A press stud according to any one of claims 1 to 4, characterised in that the resilient part (13, 18) consists of plastic and the cap (7) and the rivet shank (9) of plastic and/or metal.
6. A press stud according to any one of claims 1 to 5, in which the rivet shank (9) is internally hollow and open at its front end and is moulded on an annular flat rivet flange (8) and in which the rivet flange (8) is held in the cap (7) by the edge (10) thereof being flanged thereover, characterised in that a round sealing washer (12) is pinched between the rivet flange (8) and the cap (7).
7. A press stud according to claim 6, characterised in that the sealing washer (12) is pinched between the rivet flange (8) and the base (11) of the cap (7).
8. A press stud according to claim 6, characterised in that the sealing washer (12) is of an annular construction and is pinched between the rivet flange (8) and the edge of the flanged-over edge (10) of the cap (7).
9. A press stud according to any one of claims 6 to 8, characterised in that the sealing washer (12) is a plastic film.

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