AU688857B2

AU688857B2 - Sealed ventilation tubing

Info

Publication number: AU688857B2
Application number: AU16545/95A
Authority: AU
Inventors: Kenneth John Purnell
Original assignee: Acme Group Pty Ltd
Current assignee: Acme Group Pty Ltd
Priority date: 1994-04-28
Filing date: 1995-04-20
Publication date: 1998-03-19
Anticipated expiration: 2015-04-20
Also published as: AU1654595A

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION For A Standard Patent

ORIGINAL

Name of Applicant: Actual Inventor: ACME GROUP PTY LTD KENNETH JOHN PURNELL

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o Address for Service: WRAY ASSOCIATES, Primary Industry House, 239 Adelaide Terrace, Perth, Western Australia, 6000.

Attorney code: WR Invention Title: "SEALED VENTILATION TUBING" Details of Associated Provisional Application: No: PM5393 PM8322 The following statement is a full description of this invention, including the best method of performing it known to me:- -2- THIS INVENTION relates to sealed ventilating tubing and a method of forming sealed ventilating tubing.

It has been a common practice to form ventilation tubing from flexible sheet material which is substantially impervious to airflow. One difficulty that has been encountered in relation to such tubing however, is that it is not totally impervious to airflow since there can be a significant amount of airflow through the sewn interconnections between the various layers of fabric or sheet material.

It is an object of this invention to provide ventilating tubing where the interconnection between layers of sheet material are sealed.

In one form the invention resides in ventilation tubing formed of flexible sheeting material which is substantially impervious and where the M.

edges of the sheet material are sewn together, the sewn junction comprising two or more layers of a sheet material interconnected by at :i least one line of stitching and said sewn junction is sealed.

According to a preferred feature of the invention the sewn junction is sealed by a layer of sealing medium applied at the line of stitching to close the apertures formed in the sheet material along the line of stitching.

According to a preferred feature of the previous feature the layer of sealing medium is interposed between the layers of sheet material.

According to a preferred feature of the previous feature the layer of sealing medium may comprise a strip of material formed of a flexible non rigid material which may be formed of a plastics or elastomeric composition.

Q According to another preferred feature of the invention the layer of sealing medium is fixed to at least one of the exterior faces of the sheet material over the line of stitching.

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1 According to a preferred feature of the previous feature the layer of sealing medium comprises a strip of a plastics material welded to the external face of the sheet material over the line of stitching.

According to a further preferred feature of the invention the sewn junction is sealed by the sheet material in the region of the sewn junction being welded together.

According to a further preferred feature of the invention the sewn junction is sealed by a layer of sealing medium being located at the boundary of the region of overlap of the sheet material at the sewn junction.

According to a preferred feature of the previous feature the layer of sealing medium is overlaid by a layer of a second sheet material.

o°O° The invention will be more fully understood in the light of the following ~description of two several embodiments. The description is made with reference to the accompanying drawing of which:- Figures 1,2,3,4, 5 and 6 are a schematic representation of a sewn junction according to the first, second, third, fourth, fifth and sixth embodiments respectively.

As shown in Figure 1 the first embodiment comprises two layers of sheet material 111 and 112 which are interconnected by the adjacent edges overlapping one another and being sewn together to form a sewn junction 113 The sheet material may comprise a woven fabric which is plastic coated to render the fabric impervious, or alternatively may comprise a reinforced plastics sheeting which is substantially impervious. The sewn junction 113 is formed by a pair of parallel lines of stitching 114 and 115 of conventional form. To seal the sewn junction 113, a strip of flexible plastics material 116 is applied over the lines of stitching 114 and 115 and -4is welded to the sheet material. The strip is formed of a plastics material which is capable of being welded to the sheet material. Subsequent to forming the lines of stitching at the sewn junction 113 the sealing strip is welded in position to the one face of the sheet material 111 over the lines of stitching to form a seal in the region of the lines of stitching.

The second embodiment as shown at figure 2 is a variation of the first embodiment where the sewn junction forms a rib 213 which extends laterally from the body of a structure at the junction of two pieces of fabric 211 and 212. To form the rib the ~et4I,.Pedges are folded outwardly and are sewn together by two lines of stitches 214 and 215. The outer end of the rib supports a continuous strip 217 comprising a folded length of fabric which has a set of eyelets 218 mounted at spaced intervals along its length. The strip is affixed to both sides of the overlapping edges of the two pieces of fabric 211 and 212 and the strip 217 is retained by the two lines of stitches 214 and 215. To seal the sewn junction formed by the composite rib 213, a length of an impervious tape 216 is applied to each ~side of the rib 213 to overlie the lines of stitching 214 and 215. The tape may be sealingly fixed to the rib by a suitable adhesive or by welding.

The third embodiment as shown at Figure 3 relates to a sewn junction of a similar form to the second embodiment of Figure 2. The third embodiment comprises a laterally extending rib 313 formed by tlh junction of two pieces of fabric 311 and 312 which supports a continuous strip 317 of a folded length of fabric which supports a set of eyelets 318 at spaced intervals along its length. The overlapping edges of the two faces of fabric 311 and 312 and the strip 317 are sewn together by two lines of stitching 314 and 315. To seal the rib a layer of adhesive 319 of a form which will harden to form an elastomeric-like composition is applied to the face of the junction of the two pieces of fabric opposite the rib 313 to overlie the junction and thet-a4- edges of the two pieces of fabric 311 and 312.

The layer then has a protective layer of fabric 320 applied over it to cover the layer of adhesive. On application of the adhesive it will permeate into the junction between the two pieces of fabric 311 and 312. The application of the protective layer then serves to ensure that the adhesive extends to each side of the junction and protects the layer of adhesive from mechanical damage and contamination.

The fourth embodiment as shown at Figure 4 relates to a sewn junction of a similar form to the third embodiment of Figure 3. The embodiment comprises a laterally extending rib 413 formed by the junction of two pieces of fabric 411 and 412 which supports a continuous strip 417 of a folded length of fabric which supports a set of eyelets 418 at spaced inte-3v!ls along its length. The overlapping edges of the two faces of fabric •ego 411 aid 412 and the strip 417 are sewn together by two lines of stitching 414 :and 415 to seal the rib layer. To seaJ the rib, an adhesive 419, is "iapplied to the opposing surfaces of the abwti@-edge portions of the two pieces of fabric 411 and 412 on the side of the lines of stitching 414 and o 415 closest to the body of the structure. The adhesive is of a form which will harden to form an elastomeric like composition.

0*o* The fifth embodiment as shown at Figure 5 relates to a sewn junction of a similar form to the fourth embodiment of Figure 4. The embodiment comprises a laterally extending rib 413 formed by the junction of two pieces of fabric 511 and 512 which supports a continuous strip 517 of a folded length of fabric. The overlapping edges oi the two faces of fabric 511, 512 and the strip 517 are sewn together by two lines of stitching 514 and 515 to seal the rib layer. To seal the rib, an adhesive 519, is applied to the opposing surfaces of the two pieces of fabric 511 and 512 on the side of the lines of stitching 514, and 515 which is closest to the body of the structure. The adhesive is of the form which will harden to form an elastomeric like composition.

Ml-1 The sixth embodiment is directed to ventilation tubing which is formed of C reinforced plastic sheet material. In forming the sheet material, a length of Ssheeting 611 is cut and the opposed sides of the sheeting are

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-6interconnected at a sewn junction to form a rib 613. In forming the sewn junction, a hanging fin 617 is also applied to the ebeA edges of the sheet material and the 1izig edges and the hanging fin a re interconnected by lines a stitching 614 and 615. The hanging fin is provided with a series of longitudinally spaced eyelets 618 to facilitate fixing of the ventilation tubing to a suitable support. In order to seal the sewn junction such that there is no air flow from within the ventilation tubing to atmosphere through the sewn junction, a strip of impervious plastic sheet material 620 is applied over the inner face of the ventilation tubing to both sides of the internal face of the rib 613. The impervious sheet material is bonded at both edges to the internal face of the 0•o• ventilation tube to either side of the sewn junction 619, The bonding may be effected by means of a suitable adhesive or alternatively by welding.

o:'I The presence of the strip of impervious plastic sheet material being applied to the inner face of the ventilation tubing to both sides of the sewn junction serves to prevent any loss of air through the sewn junction.

The plastics or elastomeric composition which is referred to above as for providing the sealing and/or adhesive medium may comprise a 20 composition such as a "Mastic" sealant compound or a "Silicone" sealant composition.

It should be appreciated that the scope of the present invention need not be limited to the particular scope of the embodiment described above.

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Claims

1. Ventilation tubing formed of flexible sheeting material which is substantially impervious where ai"Tbhg edges of the sheet material are sewn together, the sewn junction comprising an overlap of adjacent edges of two or more layers of sheet material interconnected by at least one line of stitching, said sewn junction being sealed wherein the over lapping edges of the layers of sheet material define a laterally extending rib.

2. Ventilation tubing as claimed at claim 1 wherein the sewn junction is sealed by a layer of sealing medium being located at the inner face of the region of the junction by the sealing medium overlaid over the junction.

Ventilation tubing as claimed at claim 1 or 2 wherein the sealing medium is overlaid by a layer of a second sheet material.

4. Ventilation tubing as claimed at claim 1, 2 or 3 wherein the sealing medium comprises a medium formed of a flexible non rigid material which may be formed of a plastic or elastomeric composition.

5. Ventilation tubing as claimed at any one of claims 2 to 4 wherein the sealing medium comprises a strip of impervious sheet material :bonded to the layers of sheet material at each side of the junction.

6. Ventilation tubing as claimed at claim 1 wherein the overlapping adjacent edges are sewn together and the oposing faces are bonded together. -8-

7. Ventilation tubing as claimed at claim 6 wherein the opposing faces are welded together.

8. Ventilation tubing as claimed at claim 7 wherein the opposing faces are bonded together by a layer of a plastics or elastomeric composition therebetween.

9. Ventilation tubing substantially as herein described. DATED this NINETH day of SEPTEMBER 1997. ACME GROUP PTY LTD Applicant WRAY ASSOCIATES Perth, Western Australia Patent Attorneys for the Applicant e 9 *9* *e *9* e Abstract Ventilation tubing formbed of flexible sheeting material which is substantially impervious where the abutting adges of the sheet material are sewn together, the sewn junction comprising an overlap of adjacent edges of two or more layers of sheet material interconnected by at least one line of stitching, said sewn junction being sealed. 0 0* 0 0 0* 0 f* oooo 0 0 0o 00* 0 0* 0 0 0000 0 o*00 0 0* a