GB2099489A

GB2099489A - Sealing strip

Info

Publication number: GB2099489A
Application number: GB8215753A
Authority: GB
Original assignee: SAIAG SpA
Current assignee: SAIAG SpA
Priority date: 1981-06-01
Filing date: 1982-05-28
Publication date: 1982-12-08
Also published as: AU8429382A; FR2506883A1; DE3220238A1; IT8167741A0; ES265555U; JPS58435A; ES265555Y

Abstract

The anchoring profile (1) of a sealing strip with a reinforcing metal strip (3) constituted by cross bars (4) with broken interconnections (5') has embedded in the dorsal part (1') therein a thread-like or ribbon-like longitudinal reinforcing element (6) of textile material. The textile material avoids elastic elongation of the strip without impairing its flexibility and compressibility. <IMAGE>

Description

SPECIFICATION Extruded sealing strip of rubber, particularly for vehicle bodies The present invention relates to an extruded sealing strip, particularly for vehicle bodies, comprising an anchoring profile of solid rubber of U-shape in cross-section in which a reinforcing strip of sheet metal is embedded.

Typically such sheet metal strip is constituted by a succession of cross bars interconnected by short longitudinal bridges formed integrally with the cross bars and located either centrally or close to the respective ends of the bars, that is in the arms of the U-section of the anchoring profile.

With this type of reinforcement, however, the sealing strip has sufficient flexibility only in the median plane of the U-section and is insufficiently flexible in all other directions so that it is often difficult or quite impossible to mount it on the relative flange of a bodywork element when the said flange has a curved or offset portion.

From U.S. Patent No. 3,222,769 a profiled sealing strip is known in which the said longitudinal connecting bridges of the cross bars are suitably and systematically broken (after extrusion, vulcanisation and folding to the U-shape) so that the cross bars are independent of each other and the sealing strip has adequate flexibility in all directions. With this, however, the sealing strip is easily extensible in longitudinal direction. Consequently, when a segment corresponding to the length of the mounting flange is cut from the sealing strip, extreme care must be taken not to stretch the segment during mounting because otherwise it would be necessary to cut away an excess "tail-end" due to elongation. Clearly this circumstance is a serious inconvenience or complication.

The object of the present invention is to avoid this disadvantage.

The invention therefore provides an extruded sealing strip of rubber comprising an anchoring profile of solid rubber of U-shape in cross-section with a reinforcing strip of sheet metal embedded in the anchoring profile and constituted by a succession of cross bars bent into a U-shape conforming to the said cross-section, with longitudinal, interconnecting bridges systematically broken, whereby the cross bars are independent of each other, the seal sealing strip being characterised in that it further includes a thread-like or ribbon-like continuous string of textile material which is flexible and compressible but substantially inextensible, extending over the whole length of the sealing strip and embedded in the rubber of the anchoring profile, preferably in correspondence with the dorsal part of the said U-shape of the anchoring profile.

Thus, the said string of textile material does not reduce the flexibility of the sealing strip in any direction, but prevents it from stretching under ordinary tension exerted by the assembly worker.

In its most simple form, the said string may be constituted, for example, by a fine cord of cotton or other suitable textile material, or by a tape with a width of, for example, 3 to 5 mm. It is important however that the string is well anchored, over its whole length, in the surrounding rubber, like a longitudinal reinforcing rod in a reinforced concrete beam. Hence the preferred string is constituted by a lace formed from two thread-like stringers spaced transversely from each other and interconnected transversely by thread bridges to form a ladder structure. In each case the said string may be located above or below the dorsal (curved) portion of the metal strip in the extruded sealing strip.

An embodiment of the sealing strip according to the invention is illustrated by way of example in the appended drawings, in which: Figure 1 is a partially broken-away perspective view; Figure 2 shows the sealing strip in partially broken-away perspective view, in the manufacturing stage which precedes the bending to a U-shape and the breaking of the bridges of the metal strip; and Figure 3 is a plan view of the ladder lace used in the extruded strip of Figures 1 and 2.

The extruded sealing strip illustrated is constituted by an anchoring profile 1 of solid rubber, co-extruded with a sealing profile 2 of sponge rubber, which, in the case illustrated, is of tubular form but may be of any other suitable form. The anchoring profile 1 is of a U-section, the dorsal zone of which is indicated by 1'. By "dorsal zone" is meant that part, usually in the form of an arc of a circle, by means of which the two arms of the U are joined together. The anchoring profile 1 is constructed basically according to the teaching of the U.S. Patent cited hereinbefore. Its reinforcing sheet metal strip 3 is originally constituted (Figure 2) by a succession of flat, coplanar cross bars 4 interconnected by short longitudinal bridges 5 punched integrally with the cross bars so that the metal strip 3 may be incorporated into the solid rubber of the profile 1 during extrusion.During this stage the profile 1 is flat, it being curved to the U-shape after the vulcanising stage. During the extrusion, a string 6 is also incorporated into the rubber of the profile 1, the string being in the form of a ladder lace formed from two longitudinal stringers 6' (Figure 3) interconnected at short intervals by transverse thread bridges 6", both the stringers and the bridges being formed, for example, by cotton threads. Compared with the rubber of the profile 1 , the stringers 6' are practically inextensible, although being illimitably flexible. The transverse threads 6" are woven into the structure of the stringers 6'. Laces of this type are usually made in crochet machines.In the manufacture of the sealing strip, the lace is fed to the extrusion head in correspondence with the median longitudinal plane of the metal strip 3 (Figure 2) so that it is located in the dorsal zone of the anchoring profile 1 after folding to the U-shape, as stated above. In the final manufacturing stage the small bridges 5 are systematically broken, as suggested by the cited U.S. Patent, so as to render the cross bars 4 independent of each other. The breaking points are indicated by 7 in Figure 1 and the vestiges 5' of the bridges 5 are seen on the individual cross bars. Recommendably the connecting bridges of the cross bars in the original metal strip (Figure 2) should not be located on the longitudinal median line of the strip, or close to this line, as otherwise the string 6 might be damaged during the stage in which the bridges are broken. For this reason, in the case illustrated, the cross bars 4 are originally interconnected solely and uniquely by bridges 5 located in proximity to the ends of the cross bars and in no other place.

Claims

1. An extruded sealing strip of rubber comprising an anchoring profile of solid rubber of U-shape in cross section, and a reinforcing strip of sheet metal constituted by a succession of cross bars bent into U-form conforming with the U-shape of the anchoring profile and by longitudinal interconnecting bridges systematically broken whereby the cross bars are independent of each other, characterised in that the extruded sealing strip further comprises a thread-like or ribbon-like string of textile material which is flexible and compressible but substantially inextensible, extending over the whole length of the sealing strip and embedded in the rubber of the said anchoring profile.

2. An extruded sealing strip according to claim 1 , characterised in that said string is constituted by a ladder-like lace structure formed by two stringers interconnected transversely by thread bridges.

3. An extruded sealing strip according to claim 1 or 2, characterised in that the said string is embedded in the dorsal zone of the anchoring profile.

4. An extruded sealing strip substantially as hereinbefore described, with reference to and as illustrated in Figures 1 to 3 of the accompanying drawing.