GB1559251A

GB1559251A - Sealing strip

Info

Publication number: GB1559251A
Application number: GB15606/77A
Authority: GB
Original assignee: Industrie Pirelli SpA; Pirelli SpA
Current assignee: Industrie Pirelli SpA; Pirelli and C SpA
Priority date: 1976-04-23
Filing date: 1977-04-14
Publication date: 1980-01-16
Also published as: IT1063560B

Description

(54) SEALING STRIP (71) We, INDUSTRIE PIRELLI SPA., an Italian Company, of Centro Pirelli, Piazza Duca d'Aosta No. 3, 20100 Milan, Italy, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a sealing strip and to a method for its manufacture.

In particular, the present invention relates to a sealing strip of the type having a tubular body which is resiliently deformable in a direcdon normal to its axis, and means for attaching the tubular body to the element which is to support it. The sealing strip is intended for sealing along arcuate lines having a very small radius of curvature and therefore requires supporting from within the tubular body to maintain the correct shape of the seal under such conditions. The present invention relates especially to a sealing strip for doors and luggage compartments of motor vehicles, the sealing strip comprising two parts which are integrally joined. One of dhe parts is of substantially U-shaped transverse cross section and encloses a notched metal plate, and is adapted to be directly attached to the body of the motor vehicle. This part may optionally be covered with a flock or fabric.

The other part is a tubular body which is resiliency deformable and which contains an insert of expanded material.

The present invention also relates to a method for the manufacture of a tubular sealing strip containing, in predetermined areas, one or more inserts of expanded material.

Two types of seal of the kind described hereinabove are known. In one type the insert of expanded material is introduced into the tubular body under pressure and the bond between the insert and the tubular body is maintained solely by dhat pressure.

In dhe other type the insert of expanded material is adhered to the tubular body. For this purpose, an adhesive is introduced inside the tubular body through a hole made in the wall of the latter, and the insert of expanded material is then forced into the tubular body to the location of the adhesive.

Methods of manufacturing these known seals include forcing the insert of expanded material into the tubular body. Where more than one insert is desired, it is necessary to make holes in the tubular body to allow air to escape when the insert is forced into position.

Where dhe insert of expanded material is to be adhered to dhe tubular body, adhesive is expelled from the tubular body as the insert is forced into position, causing unattractive stains on the outside of the seal, especially when the seal has parts which have been flocked or covered with fabric.

We have found that the known seals have other disadvantages, for example: ta) The insert of expanded material fre quently moves from its predetermined position within the tubular body, particu larly in the case where the insert is not glued in position.

(b) Under stress, especially where the insert is glued in position, there is a permanent deformation of the sealing strip in the area where the insert is present, (c) The known seals are very expensive, since they are difficult to manufacture reproducibly, giving rise to a large quan tity of production rejects. One object of the present invention is to provide a sealing strip comprising a tubular body containing one or more inserts of an ex panded material which does not have dhe disadvantages listed in the irnmediately- preceding paragraph, viz., each insert of expanded material is maintainable in a predetermined position, and therefore provides an efflcient seal and under stress the sealing strip is not permanently de formed.

A second object of the present invention is to provide a process for the manufacture of tubular seals containing one or more inserts of an expanded material in predetermined positions.

Accordingly, the present invention provides a sealing strip comprising a tubular body having means for attaching the strip to an article to be sealed, said tubular body containing, in a predetermined position, one or more inserts of an expanded material, each of said inserts being formed in situ and comprising an expanded material covered by a continuous skin.

The present invention also provides a process for the manufacture of a sealing strip comprising a tubular body containing one or more inserts of an expanded material in which the process includes the following stages: (i) injecting through the wall of the tubular body a liquid mixture of self cross-link ing materials to form one or more inserts of an expanded material covered by a continuous skin; (ii) allowing the liquid mixture to expand to produce each insert in situ.

Preferably, each insert is made from a "selfskin" polyurethane foam, e.g. a polyether urethane foam.

Each insert is integrally attached to the tubular body by mechanical bonding between surface irregularities on the inside of the tubular body and corresponding irregularities formed in situ on the insert.

Preferably, the tubular body is made of an elastomeric material and particularly of a resiliently deformable material.

The present invention is described hereinbelow, merely by way of example and with reference to the accompanying drawings in which: Figure 1 is a perspective view (with parts cut away) of a sealing strip in accordance with the present invention; Figure 2 shows schematically one stage in the manufacturing process of a sealing strip in accordance with the present invention.

In Figure 1, a sealing strip 1 comprises two components 2 and 3 which are bonded together.

Component 2 is of substantially U-shaped transverse cross-section and is made of an elastomeric material enclosing a notched plate (not shown). Component 3 is a tubular body which is also made of an elastomeric material.

Inside the tubular body 3 there are inserts 4 which are formed in situ, (only olle IS shown), the inserts being made of an expanded material and covered with a skin 5.

Each insert 4 is attached to the tubular body 3 by mechanical bonding between surface irregularities on the inside of the tubular body 3 and corresponding irregularities formed in situ on the insert 4.

For the manufacture of a sealing strip in accordance with the present invention, the following process may be used: As shown in Figure 2, the tubular body 3 is elastically deformed to an approximate Ushape, the curved portion of the U being at a lower level than the remainder of the tubular body. In one of the vertical arms of the U, at least one hole 6 is made and a liquid self cross-linking mixture 8 is introduced therein by means of a syringe 7.

The tubular body is maintained in its Ushape until the liquid mixture sets to an expanded foam covered with a continuous skin, to forin an insert having the shape of the cavity of the tubular body.

The insert may be formed from any suitable liquid mixture which can produce an expanded polyurethane having a covering of a polyurethane skin.

For example, a liquid mixture having the following composition may be used: Note Ingredient Parts by Weight (a) Polyether polyol 91 (b) Dye 10 (c) Goss-linker 7 Xfd) Catalyst 0.2 to 0.3 Tri-ethylamine 0.5 to 0.8 (e) Blowing Agent 15 (f) Polyisocyanate either in stoichiometric amount or 0.5% excess w.r.t. polyol (a) Notes (a) Available from Bayer AG as Desmophen 3050; (b) Available from Bayer AG as Schwartz paste I; (c) Available from Bayer AG as 3057; (d) Available from Houdry Process Co. as Dabco; and believed to consist essentially of triethylenediamine; (e) A mixture of trichlorofluoromethane and methylene chloride; (f) Available from Bayer AG as Desmodur 44 UT.

"Dabco", ' Desmophen" and "Desmodur" are Registered Trade Marks.

The manufacture of a sealing strip according to the present invention is relatively simple, comprising merely the two stages of introducing a liquid mixture into the tubular body (which has been previously been bent to the required shape) and allowing the liquid mixture to expand to form a foamed insert tn situ.

In addition, once the formation of the foam has occurred, the resulting insert remains firmly fixed in position inside the tubular body, since the insert, being formed in situ, conforms to every irregularity of the inner surface of the tubular body. Moreover, the mechanical bond thus formed allows the tubular body and the insert to be deformed independently of one another. Thus, under conditions of stress, even if the insert has a lower elastic recovery than that of the tubular body, the latter does not remain permanently deformed.

Finally, there is no risk of spoiling the appearance of the sealing strip, since there is no leakage of liquid from the tubular body.

WHAT WE CLAIM IS:- 1. A sealing strip comprising a tubular body having means for attaching the strip to an article to be sealed, said tubular body containing, in a predetermined position, one or more inserts of an expanded material, each of said inserts being formed in situ and comprising an expanded material covered by a continuous slain.

2. A sealing strip according to claim 1, in which each insert is integrally attached to the tubular body by mechanical bonding action between surface irregularities on the inside of the tubular body and corresponding irregularities formed in situ on the insert.

3. A sealing strip according to claim 1 or 2, in which the tubular body is made of an elastomeric material.

4. A sealing strip according to claim 1, 2 or 3, in which the tubular bodv is made of a resiliently-deformable material.

5. A sealing strip according to any one of claims 1 to 4, in which each insert is made of a self-skinned polyurethane foam.

6. A sealing strip according to claim 5, in which each insert is made of a self-skinned polyether urethane foam.

7. A sealing strip, substantially as hereinbefore described, with reference to and as illustrated in Figure 1 of the accompanying drawings.

8. A process for the manufacture of a seal ing strip comprising a tubular body contain ing one or more inserts of an expanded material, in which the process includes the following stages: (i) injecting through the wall of the tubular body a liquid mixture of self-cross-link ing materials to form said one or more inserts of expanded material covered by a continuous skin; (ii) allowing the liquid mixture to expand to produce each insert in sitz 9. A process according to claim 8, substantially as hercinbefore described, with reference to and as illustrated in Figure 2 of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. The manufacture of a sealing strip according to the present invention is relatively simple, comprising merely the two stages of introducing a liquid mixture into the tubular body (which has been previously been bent to the required shape) and allowing the liquid mixture to expand to form a foamed insert tn situ. In addition, once the formation of the foam has occurred, the resulting insert remains firmly fixed in position inside the tubular body, since the insert, being formed in situ, conforms to every irregularity of the inner surface of the tubular body. Moreover, the mechanical bond thus formed allows the tubular body and the insert to be deformed independently of one another. Thus, under conditions of stress, even if the insert has a lower elastic recovery than that of the tubular body, the latter does not remain permanently deformed. Finally, there is no risk of spoiling the appearance of the sealing strip, since there is no leakage of liquid from the tubular body. WHAT WE CLAIM IS:-

1. A sealing strip comprising a tubular body having means for attaching the strip to an article to be sealed, said tubular body containing, in a predetermined position, one or more inserts of an expanded material, each of said inserts being formed in situ and comprising an expanded material covered by a continuous slain.

8. A process for the manufacture of a seal ing strip comprising a tubular body contain ing one or more inserts of an expanded material, in which the process includes the following stages: (i) injecting through the wall of the tubular body a liquid mixture of self-cross-link ing materials to form said one or more inserts of expanded material covered by a continuous skin; (ii) allowing the liquid mixture to expand to produce each insert in sitz

9. A process according to claim 8, substantially as hercinbefore described, with reference to and as illustrated in Figure 2 of the accompanying drawings.