LU87255A1 - METHOD FOR MANUFACTURING A PNEUMATIC SHUTTER AND SHUTTER CARRIED OUT BY THE IMPLEMENTATION OF THIS PROCESS - Google Patents

Description

J_ p] h 1 2 1 8—1 Λ g- jT GRAND-DUCHÉ-DE LUXEMBOURG - _ - _ 21 auin Ï9M ^ MjH Minister Λ "du --------------- ------------------ the Economy and the Middle Classes Λ, Λ., Intellectual Property Service

Book title_____________________________________ gç # _; _ iggg LUXEMBOURG. ......

Invention Patent Application ----------------------- (1) I. Request ...... La ... sQei'.été di ..te-ME.BEAL.ON .. Li mit ed ______________________________________ (2) .......................... I ...... ....................................... 223 Regent Street LONDON WIR 7DB___________________________________

Represented by: E.T. FREYL1NGER & E. MEYERS. Ing. Cons. in PI _ (3) • ............: ________________________________________________________________________ 46, rue du Cimetière LUXEMBOURG MANDATAIRES "__________ deposit) this twenty-one June one thousand nine hundred eighty eight _______ ^ - at - hours, at the Ministry of Economy and the Middle Classes, in Luxembourg: 1. this request for obtaining a patent of invention concerning: ...... '. l-Rr.océdé ... de f abr icati , we ... d.!. un ... obturat.eup .pneuma.t.ï.que ... et - .. obtureur ------------------ -------- (5) .............. réaü.s.é ... pa.r .....!. A .... bet .... en .... d'ov.re.de .... ce ... pr: .océ.déî! _________________________________________________________________ 2. description in language ............. ............... French .................................. .....— of the invention in triplicate; 3 ................................... ............ 1 ....................... drawing boards, in triplicate; · 4. the receipt of taxes paid at the Registration Office in Luxemb ourg, _________ June 21, 1988____________.

5. the delegation of power, dated ......................................... ............................... the_________________________; 6. the successor document (authorization); declaring) by assuming responsibility for this declaration, that the inventor (s) is (are): (6) claims (s) for the above patent application the priority of one (s) application (s) of (7) ____________________________________________________________________________ "filed in (8) _________________ on (9) ------------------------------- ---------------------------------------—--- under No. (10) ___________________________________________________ on behalf of (11) _________________________________________________________________________________________________________________________ elects (elect) domicile for him / her and, if designated, for his / her representative, in Luxembourg________________________ --------------------- -4 &, _ me_.dyXlmatiene .____________________________ (12) requests) the grant of a patent for the invention for the subject described and represented in the abovementioned appendices, with postponement of this grant to .......... ...............................month. (13)

The depositor / agent: ^ ____ ~ _________________________________________________________ 1_ (14) ^ Π. Filing Minutes • The above invention patent has been deposited with the Ministry of the Economy and the Middle Classes, Intellectual Property Service in Luxembourg, on: June 21, 1988 15 00 f · 'Pr. The Minister of Economy and the Middle Classes, _ at _______________ hours / il p. d.

I? \ ÿ The head of the intellectual property department, A68007 _ - ~~, _ ~ - EXPLANATIONS RELATING TO FOHMK ^ party "" (1) if applicable "Request for certificate of additionWwiewmpal, at patent request principal No .. * ......... from .....'...... "- (2) enter the surname, first name, profession, - _ address of the applicant, when the latter is an individual or corporate name, legal form, address of head office, when the applicant is a legal person - (3) enter • f ** - /. ~ the name, first name, address of the professional representative, industrial property attorney, with special powers, if applicable; "represents by ............ acting as agent” Js f / * _ - ^ 4) date of filing in full - (5) title of invention - (6) register the names and surnames, addresses of the inventors or the indication "(see) separate designation (will follow)", when the des- - f / A - gnatian sc does or will be done in a separate document, or the indication "do not mention ”, When the inventor signs 0U4igncra a document of no mention to be added to a designation ~~" "** '* present or future - Π) patent, certificate of addition, utility model, European patent (EPC), international protection ( PCT) - (8) State in which the first filing was made BL 4121 Descriptive memory filed in support of a patent application for: "Process for manufacturing a pneumatic shutter and shutter produced by placing using this process "

MERFALON Limited 223 Regent Street LONDON W1R 7DB

• *

PROCESS ..... OF ...... MANUFACTURE ...... OF ON ...... SHUTTER ...... TIRE

AND ...... SHUTTER ..... REALIZED ...... BY IMPLEMENTING .....

PROCESS

The present invention relates to a method of manufacturing a pneumatic shutter or inflatable plug as well as a shutter produced by this method.

5 This type of plug is commonly used to temporarily plug gas or liquid lines, for example, for maintenance or repair. These shutters, which generally consist of a flexible envelope based on natural or synthetic rubber with a woven or other textile support, are simply pushed into the pipe and the plugging is carried out by swelling of the shutter.

For such a shutter to be effective, there must be good adhesion between the outer wall of the shutter and the inner wall of the pipe so that the shutter remains in place and resists backing -pressure of gas or liquid in the pipe. At the same time the shutter must ensure sufficient sealing to prevent gas or liquid leaks, especially if these products are dangerous, for example toxic or flammable. However, these two criteria are not always mutually compatible and the known shutters generally do not have sufficient adhesion when they are sufficiently tight and, vice versa, are not sufficiently tight when they have good adhesion.

The object of the present invention is to fill this gap and to provide a shutter having both good adhesion and good sealing, as well as a method of manufacturing such a shutter.

2

To achieve this objective, the manufacturing process proposed by the present invention is essentially characterized by the following stages: 5 - A cylindrical bladder made of raw elastomer with an inflation opening is made in a manner known per se;

Two rectangular layers are made of raw coated cloth coated with elastomer of a length slightly greater than the axial length of the bladder and of a width corresponding substantially to the circumference of the bladder; - The two layers are placed one on top of the other so that their threads cross at an angle between 15 ° and 45 °; - Petals are cut in the two sides forming the width of the two layers; - We form by winding the two layers 20 a cylindrical shell which we thread on the bladder; - The two bases of the bladder are closed by folding the petals of the ferrule and by gluing, on each of the bases, at least one sheet of non-elastic woven fabric and - The whole is vulcanized in a cylindrical mold having numerous air leak holes and an inner circular groove. Each of the plies used for closing the bases of the shell preferably consists of a woven polyamide support coated on each of these faces with raw elastomer.

The inner bladder is preferably slightly inflated before the two bases are closed.

The mold used for vulcanization preferably consists of at least two cylindrical elements 3 with a smooth inner wall and clamped to one another, the junction between two juxtaposed elements defining said circular groove.

Vulcanization can be carried out by injecting dry hot vapor into the bladder.

The shutter proposed by the invention is essentially characterized in that it comprises a vulcanized laminated wall, substantially cylindrical, consisting of an inner elastomer bladder, surrounded by at least two cylindrical ferrules in coated fabric coated with elastomer raw and closed on the bases by woven supports coated with elastomer and in that the external cylindrical surface is smooth with the exception of at least one protruding elastomeric circular joint.

Other particularities and characteristics will emerge from the detailed description of an advantageous embodiment described in detail below, by way of illustration, with reference to the appended drawings in which:

Figure 1 schematically illustrates the arrangement of the layers used to form the side wall of the shutter; FIG. 2 schematically illustrates the production of the shutter and

Figure 3 shows schematically the vulcanization of the shutter.

The first step consists in producing, in a manner known per se, a sealed internal bladder 4 shown in FIG. 2. This bladder 4 is made of raw rubber or elastomer, that is to say without textile support. It has a substantially cylindrical shape with a size about 5 cm smaller than the vulcanization mold and is provided with an inflation opening 16. The seal of this bladder 4 will preferably be checked under low pressure.

Two layers 1 and 2 are then made up, shown in part in FIG. 1. Each of these 5 layers is made of a raw cloth covered with parallel threads embedded in an elastomer. Each of the layers should have a substantially rectangular shape of a length slightly greater than the axial length of the bladder 4 and of a width corresponding substantially to the circumference of the bladder 4. On the two sides forming the width of each of the layers cutouts are defined defining petals 3 over the entire width of the two sides. These two layers 15 are then placed one on the other as shown in FIG. 1 so that the tip of the petals 3 of one of the layers is placed in the middle of two petals 3 of the other layer and so that their son 6 are crossed at an angle 20 from 15 ° to 45 °. This crossing of the wires allows, during a pull on the two layers 1 and 2, an elongation in the direction of the pull and a retraction in the other direction. The two layers 1 and 2 are then wound on themselves and welded together along the sides defining the length to form a cylindrical shell 17.

This ferrule 17 is then threaded onto the bladder 4 until the petals 7 exceed the upper and lower edges of this bladder.

The next step consists in closing the two opposite bases of the bladder 4. To this end, a non-elastic circular sheet 5 is woven on each of the bases in woven polyamide support (warp and weft) coated on each of the elastomer faces. 35 The bladder 4 is then slightly inflated to put the ferrule 17 under tension and the petals 3 of the internal layer 1 of the ferrule 17 are then folded down onto the ply 5. The cutting of the petals 7 allows this folding down without folds and without overlaps of the tissues of the shell 17. The number of petals 3 will therefore depend on the diameter of the bladder 4 and their length will depend on the mechanical strength of the support used for the layers 5.

After the petals 3 of the inner layer 1 have been folded down, a second ply 10 of the same type as the first ply 5 is glued onto these folded petals. 7 on each of the bases of the ferrule 4. The closure is then completed by gluing on 15 the folded petals of the outer layer and on the second ply 7 a third ply 8 similar to plies 5 and 7. A connection was therefore made by sandwich between the fabric petals coated with the shell 17 and the woven fabric of the bottoms 5, 1, 8 of the two bases, which assures a perfect homogeneity of the assemblies at the mechanical level.

It should be noted that if the mechanical strength requirements require it, a shell 17 can be formed with four coated layers, either by repeating the operations of FIGS. 1 and 2, or by using wider layers 1 and 2 and by wrapping them twice around themselves.

The vulcanization is then carried out by placing the embodiment according to FIG. 2 in a vulcanization mold shown in vertical section in FIG. 3. This mold is machined from metallic material resistant to the vulcanization temperature and consists of several cylindrical ferrules 10 , 11 with smooth inner walls flanged and fixed to one another by bolts 15 at the level of the flanges and closed on both sides also by means of bolts 15 by upper and lower covers 13. The upper and lower rounded edge corners 14 are machined in the covers 13.

In an important aspect, a peripheral groove with a triangular section 18 is defined inside the mold at the juxtaposition of the flanges of the adjacent ferrules 10 and 11. Furthermore, both the covers 13 and the ferrules 10 and 11 are provided numerous openings 9 to allow air to leak.

After having introduced the shutter of FIG. 2 into the mold and after having bolted the covers 13 on the ferrules 10 and 11, the vulcanization itself can be carried out. Ce11e-15 ci can be performed in an autoclave or an oven after having previously inflated the bladder 4 through the opening 16. The simplest and most economical means however is to inject into the bladder 4 through the opening 16 dry steam at the vulcanization temperature.

The obturator being previously sealed by the bladder 4, it perfectly fits the interior wall of the mold thanks to the pressure created in the bladder and thanks to the evacuation of air through the 25 leakage orifices 9.

At the softening temperature of the elastomer, the different layers of the shutter are melted together to form a tight laminated envelope. The circular groove 18 between the two ferrules 10 and 11 allows, during the softening of the elastomer, the formation of a projecting peripheral seal 12 around the shutter. It is this soft and flexible elastomer seal which makes it possible, when the obturator is used, to ensure a perfect seal by optimally matching the shape of the pipe to be sealed. The rest of I · 7, the surface of the obturator being perfectly smooth, moreover, ensures perfect adhesion to the wall of the pipe to be closed and thus makes it possible to contain high pressures.

5 It should be noted that it is possible to provide several seals 12 at the periphery of the shutter by simply increasing the number of ferrules constituting the vulcanization mold.

Claims (7)

1. A method of manufacturing a pneumatic shutter, characterized by the following steps: - In a manner known per se, a cylindrical bladder (4) is made of raw elastomer 5 with an inflation opening (16); Two rectangular layers (1,2) are made of raw cloth coated with elastomer, of a length slightly greater than the axial length of the bladder (4) and of a width corresponding substantially to the circumference of the bladder ( 4); - The two layers are placed one on the other, so that their wires are crossed at an angle between 15 ° and 15 45 °; - Petals (3) are cut in the two sides forming the width of the two layers (1) and (2), a cylindrical shell (17) is formed by winding the two layers (1) that are 20 threads on the bladder (4); - The two bases of the bladder (4) are closed by folding the petals (3) of the ferrule (17) and by gluing, on each bottom of at least one sheet of non-elastic woven fabric and 25. The whole is vulcanized in a cylindrical mold having numerous orifices (9) for air leaks and an inner circular groove (18). 2. Method according to claim (1), characterized in that the two bases of the shell 30 (17) are closed by gluing a first circular sheet (5), by folding down the petals (3) of the inner layer ( 1) of the ferrule (17), by gluing a second circular sheet (7), by folding down the petals (3) of the outer layer 9 "> r (2) of the ferrule (17) and by gluing a third circular sheet (8). 3. Method according to claim (2), characterized in that each of the circular plies 5 (5, 7, 8) is in woven polyamide support coated on each of its faces with raw elastomer. 4. Method according to claim (1) / characterized in that the inner bladder (4) is slightly inflated before the closure of the two bases. 5. Method according to claim (1), characterized in that the mold consists of at least two cylindrical elements (10, 11) with smooth internal walls and clamped to each other, the junction between two elements juxtaposed (10,11) defining said circular groove (18). 6. Method according to claim (1), characterized in that the vulcanization is carried out by injection of dry and hot steam into the bladder (4). 7. Pneumatic shutter produced by the implementation of the method according to any one of claims (1) to (6), characterized in that it comprises a vulcanized laminated wall, substantially cylindrical, consisting of an inner bladder (4) in raw elastomer surrounded by at least one double cylindrical shell (17) in coated fabric coated with raw elastomer and closed on the bases by woven supports coated with elastomer and in that the outer cylindrical surface is smooth exception of at least one protruding elastomeric circular joint (12).