GB2199913A

GB2199913A - Joint for ducting

Info

Publication number: GB2199913A
Application number: GB08800689A
Authority: GB
Inventors: Franz Werner Hackenberg
Original assignee: Flexadux Plastics Ltd
Current assignee: Flexadux Plastics Ltd
Priority date: 1987-01-15
Filing date: 1988-01-13
Publication date: 1988-07-20
Also published as: GB8800689D0

Abstract

Rigid conduit ends of ventilation ducting 12, (212) and 14 (214) of synthetic plastics or resinous material are jointed in series, male-female fashion. An annular gap 28 (228) between the male and female portions is sealed by providing an expansible seal member 18 (218) in the gap and expanding it. In one embodiment, (Fig 4) the seal member 18 is in the form of a band secured along its edges to the female (outer) conduit end portion 14 and having a flexible elongate element 20 outwardly around it. Tightening of the elongate element around the male conduit end portion 12 expands the band 18 inwards and squeezes it against the outer periphery of the male conduit end portion 12 to effect sealing. In an alternative embodiment (Fig 6) the seal member 218 is in the form of a flexible tube secured within the outer end portion 214 and capable of inflation by means of valve 220. The tube 218 is thus expanded inwards against the outer periphery of the male conduit end portion 212 to effect sealing. <IMAGE>

Description

JOINTING VENTILATION DUCTING THIS INVENTlON relates to ventilation ducting of synthetic plastics or resinous material. It relates more specitucally to a method of sealing jointed conduit ends of ventilation ducting, to a ventilation ducting joint and to a ventilation conduit assembly.

The Inventor believes that the invention will find particular application in ventilation ducting underground in mines, but it is not limited to that application.

In accordance with the invention, there is provided a method of sealing rigid conduit ends of ventilation ducting of synthetic plastics or resinous material jointed male-female fashion, including the steps of providing an annular expansile sealing member in an annular gap between the conduit ends and expanding said sealing member sealingly to fill the annular gap.

The sealing member may be provided sealingly fast with one of the conduit ends, expanding the sealing member being toward the opposed periphery of the other of the conduit ends. In a preferred embodiment, the sealing member may be provided sealingly fast with the outer of the conduit ends, expanding the sealing member being by providing a flexible elongate element outwardly around the sealing member and by squeezing the sealing member around the outer periphery of the inner conduit by tightening the elongate element around the outer periphery of the inner conduit.

In another embodiment, the scaling member may be in the form or a closed, hollow ring which ma) be embedded or pirtially embedded in the conduit end, expanding the sealing nenber being by distendillg it by means of a fluid (such as air or a hydraulic fluid) under pressure, eg pneumatically, hydraulically, or the like.

The invention extends to a ventilation ducting joint including outer and inner rigid conduit ends of synthetic plastics or resinous material jointed male-female fashion; an annular expansile sealing member in an annular gap between the outer and inner conduit ends; and expansion means expanding the expansile sealing member sealingly to fill the annular gap.

The sealing member may sealingly be fast with one of the conduit ends and may be expanded toward an opposed periphery of the other of the conduit ends. The sealing member may be resilient. It may be of synthetic plastics material, natural or synthetic rubber, or the like.

The material may be reinforced, if desired. The sealing member may be in the form of a closed, hollow annulus which may be embedded or partially embedded in a wall of the conduit, the expansion means being in the form of a valve to enable the annulus to be filled with fluid under pressure, eg to be inflated by means of a gas such as air.

In a preferred embodiment, the sealing member may sealingly be fast with the outer of the conduit ends, and the expansion means may include a flexible elongate element outwardly around the sealing member, and tightening means squeezing the sealing member around the outer periphery of the inner conduit end by tightening the elongate element around the outer periphery of the inner conduit end. A portion of the elongate element may extend through passage means in the outer conduit end, and the tightening means may tighten the elongate element through said passage means.The sealing member may be in tiw ion; ot a band, side edges of which are secured to the outer conduit end, ai intermediate portion of the bald being separate from and inward of the inner periphery of the outer conduit end. The band may be a composite band, the intermediate portion of the band being of aru expansile material, and the side edges being of synthetic plastics cloth or tape.

The side edges of the sealing member may be moulded into the outer conduit end. hhen the outer conduit end is of glass tibre-reinforced synthetic plastics or resinous material, the side edges may be sandwiched between rovings of the reinforcing material.

The invention extends further to a ventilation conduit assembly including a rigid conduit end of synthetic plastics or resinous material adapted to be jointed male-female fashion to an end of a complemental ventilation conduit of synthetic plastics or resinous material; an annular expansile seal member arranged to be positioned in an annular gap between said rigid conduit end and said end of the complemental ventilation conduit when jointed; and expansion means adapted to expand the annular sealing member sealingly to fill said annular gap.

The invention is now described by way of examples with reference to the accompanying diagrammatic drawings.

the drwiigs, FIGURES 1 and @ show, respectively in cross-section and in longitudinal section, a first emboiment of a spigot-and-socket joint prior to sealing in accordance with the invention; FIGURES 3 and 4 correspond respectively to Figures 1 and 2, but after sealing in accordance with the invention has been effected; FIGURES 5 and 6 show, in axial sections, respectively, two further embodiments of spigot-and-socket joints in accordance with the invention; FIGURES 7 and 8 show, in axial sections, a socket end of the spigot-and-socket joint of Figures 1 to 4, respectively, during and after manufacture;; FIGURE 9 shows, to a larger scale, an eye suitable for use in restraining an elongate element of the embodiment of Figures 1 to 4 from loosening; FIGURES 10 and 11 show, respectively in three-dimensional and in side view, two embodiments of tensioners suitable for use with the spigot-and-socket joint of Figures 1 to 4; and FIGURES 12 to 17 show, respectively in part-axial section, progressive steps in the manufacture of a ventilation conduit assembly.

With reference to Figures 1 to 4 of the drawings, a spigot-and-socket joint between a parallel spigot end 12 and a bell-shaped socket end 14 of conduits are generally indicated by reference numeral 10. The conduits are of synthetic plastics or resinous material, and. more specifically are mouldings of glassfibre-reinforced synthetic plastics or resin.

An annular scaling member in accordance with the invention is generally indicated by rferance numeral 16. In this embodiment, it is associated with tie socket enci 14. It has an exposed portion Ib around the inner periphery of the socket end J4. it is fast with a wall 22 of the socket rigid 14 by having peripheral flaps ] 9 thereof moulded into the wall 22.

Although not shown in the drawings, apertures may be provided in the flaps 19 to enhance bonding.

The joint 10 has expansion means in the form of an elongate element which is flexible and resistant to elongation, such as a cable, wire or rope, generally indicated at Lo. The elongate element 2U is sandwiched between the exposed annular portion 18 and the wall 22. It has a looped end 26 extending through an aperture 24 through the wall 22.

An annular gap, which is to be sealed off, is generally indicated by reference numeral 28, between the outer periphery of the spigot end 12 and the inner periphery of the socket end 14.

With reference more specifically to Figures 3 and 4, a handle 30 has been used through the loop 26 to twirl the looped portion 26, thus to tighten the elongate element 20 around the spigot 12 and thus to squeeze the exposed annular portion 18 against the outer periphery of the spigot end 12, to effect sealing.

It is to be appreciated that the method and means illustrated in Figures 1 to 4 are suitable for use where the sealing need not be of high integrity. The area indicated at 31 in Figure 3, ie where the looped portion 26 of the elongate element extends away from the exposed annular portion 18 to extend through the aperture 24, is not fully sealed.

instil relelellce to Figure 9, a convenient way to prevent the hallule 30 iiilnn loosening, is to provide an est (, tixed to the wall 22, and to hock the ilaldle 30 through the eye Jt,.

hitch reference to Figure 5, a further embodiment of a spigot-and-socket joint in accordance with the invention is generally indicated by reference numeral 110. The principle in which sealing is achieved is similar to that described with reference to Figures 1 to 4.

Furthermore, like reference numerals refer to like components or features, and the embodiment 110 is not described in detail.

The embodiment 110 differs from the embodiment of Figures 1 to 4 in that the sealing member 116 is in the form of a closed, hollow annulus embedded or partially embedded in the wall 122 of the socket end 114. A peripheral groove or recess 119 is provided for this purpose. The annulus may adhesively be fixed in the recess 119.

Expansion means in the form of a valve 120, extending through the wall 122, allows the annulus to be filled with fluid under pressure, eg to be pneumatically inflated. Such filling or inflating will expand the exposed portion 118 inwardly, as indicated in dotted outlines, to seal against the outer periphery of the spigot end 112.

With reference to Figure 6, a further embodiment, very similar to the embodiment of Figure 5, is generally indicated by reference numeral 210.

Again, like reference numerals refer to like parts, and this embodiment is not described in detail. The main difference is that the annulus 216 is profiled to enhance location (by way of mechanical interlocking) thereof in the peripheral groove or recess 219. If desired, in iditiuio, it may adhesively be l:xed ill the recess 219. Ii ciesired, only the expose portion 21 18 bleed be expslsile, eg of thin wall thickness.

It is to be appreciated that the embodiments of Figures 5 and 6 allow sealing of higher integrity than the embodiment of Figures 1 to 4, as the exposed portion 118, 218 engages the full outer periphery of the spigot end 112, 212.

With reference to Figures 7 and 8, the socket end 14 of the embodiments of Figures 1 to 4 is formed on a collapsible socket former 40. For purposes of this invention, an aperture 42 is provided through the socket former at the position where the loop 26 is to be formed.

As a first step, an annular strip of expansile material which is to form the closure member 16, is arranged over the socket former 40. A release agent 32 is applied along a central band thereof, to correspond with a desired width of the exposed portion 18. To enhance bonding, apertures may be provided through the edges, outside the central band. The elongate element 20 is then arranged around the strip, and ends which are to form the looped portion 26 are threaded through the aperture 42 into the interior oi the socket former 40. It will be necessary to provide a corresponding aperture through the strip 16.

A few layers of glassfibre-reinforced resinous material, generally indicated at 34, are then wound around the strip 16 over the central portion only which is to form the exposed annular portion 18.

The annular flaps 19 are then folded outwardly and toward each other, as can be seen in Figure 8, and temporarily held in position. The conduit allow socket end 14 is tlieii competed. 'rhe w1 1 22 ii the region of the seling member its h'i li forn a peripheral bulb.

The socket former 40 is removed.

The aperture 24 is formed, eg by drilling, and the ends to form the loop 26 are threaded through the aperture 24.

It is to be appreciated that the release agent 32 ensures that the exposed portion 18 does not adhere to the periphery of the socketlend 14 to allow expansion thereof away from said periphery.

The socket end with the expansile sealing member and elongate element form a ventilation conduit end assembly in accordance with the invention.

With reference to Figure 10, by way of development, a tensioner 40 is used in carrying out the method of the invention in respect of an embodiment similar to the embodiment of Figures 1 to 4.

The tensioner 40 comprises a U-shaped bracket 42 having a base 44 and opposed limbs 46, 48. A shaft 50 is rotatably received through apertures in the limbs 46, 48. A handle 54 is provided on the shaft 50 in a portion projecting beyond the limb 48. An aperture 52 is provided diametrically through the shaft 50, at a position between the limbs.

In use, the tensioner 40 is mounted on a spigot-and-socket joint, such as the joint 10, and such that the shaft 50 extends longitudinally with the conduits 12, 14.

The elongate element @ is crossed within the socketed portion, as indicated at 26.3. prior to threading free ends 26.1, 26.2 thereof respectively through. apertures 24. ] , 24.2. In practice, instead of separate apertures ' 4. , 24.2, an elongate slot may be provided for tilts purpose.

The end '6.' as anchored, as shown at 56. The other end 26.1 is attached, facilitated by the aperture 52, to the shaft 50. Tensioning the elongate element 20 is then effected by winching the end 26.1 onto the shaft 50 of the tensioner 40. The shaft 50, after tightening, can be locked in any convenient fashion.

h'ath reference to Figure 11, another embodiment of a tensioner is generally indicated by reference numeral 60.

The tensioner 60 comprises a first bracket 62 anchored on the socket end 14, as indicated at 64. The first bracket 62 mounts a screw-threaded nut 66 through which a complementary screw-threaded bolt 80 extends.

The tensioner 60 further comprises a second bracket which is a floating bracket 70. The floating bracket 70 is axially located to allow rotation by means of a locating bush 72 at an end of the bolt 80.

The end 26.1 of the elongate element 20 is fastened to the floating bracket 70, as indicated at 74. The end 26.2 of the elongate element 20 is anchored, as indicated at 68, to the first bracket 62.

in usc, selective turning ot tioc bolt Stl threads it through the screw-tiorcaded iout 66 to move the ftoatiig bracket 7() in the direction 76 to tension the elongate eleinellt 20.

It is an advantage of using the tensioners of Figures 10 and 11 that higher sealing integrity can be achieved than with the rudimentary tensioning shown in Figures 3 and 4. if leakage occurs at the position 31, it will be less than in the embodiment of Figures 1 to 4.

With reference to Figures 12 to 17, a further embodiment of a ventilation conduit end assembly, similar to the embodiment of Figures 1 to 4, 7 and 8, is now briefly described.

The ventilation conduit end assembly is of the taper kind and is manufactured on a taper socket former indicated at 340. The taper socket former 340 is shown in Figure 12 in conjunction with an extension 341 of an associated parallel conduit former.

An aperture 342 is provided at a predetermined position in the socket former 340.

Release means, eg in the form of a band of film or foil available under the trade name MYLAR, is placed in a narrow band around the socket former 340 in register with the position of the aperture 342. The band of MYLAR has a width of about 2 inches to 4 inches, ie about 50 mm to 100 mm. In the drawings, for clarity, the band of MYLAR is not shown.

A composite annular sealing member, generally indicated at 316, is then positioned over the band of MYLAR. The sealing member 316 comprises a entral or intermediate band 31S ot an expansile material, eg in the orm of NEOPRENE 30 DURO BAND. Along either edge, edge bands 319.1 and 5i9.? are attacned tu tioe central band 318. The edge bands are conveniently in the form of woven glassfibre-reinforced tape. The edge band 319.1, which is at the free end of the conduit end assembly, has a width of about O inches, ie about 150 mm. The edge band 319.2 has a width of about 4 inches, ie about 100 mm. The edge bands are attached by stapling, sewing, or the like, to the central band 318, as shown respectively at 319.3 and 319.4.The position of the central band 318 corresponds to the position of the band of MYLAR. The edge band 319.1 extends well beyond the free end of the socket former 340. In other embodiments, the edge bands may be of other suitable material which will bond well iioto the material of which the conduit is formed, and which will finish the end of the conduit off (as will become apparent hereinafter) well.

An elongate element, eg in the form of nylon rope, generally indicated at 320, is looped around the intermediate band 318 at a position corresponding to the position of the aperture 342. A corresponding aperture is provided through the intermediate band 318 and the band of bALAR in register with the aperture 342. Free ends 326 of the nylon rope 320 are passed through both apertures to be out of the way.

A further band of MYLAR release film, indicated at 332, is positioned over the rope 320 and overlaps onto the upper surface of the intermediate band 318.

With reference more specifically to Figure 13, one of the edges, eg the inner edge band 319.2, is lifted, as shown at 335.2, and rovings 334@@ of glassfibre-reinforced resin are wound arround the socket formed 340 to a position short of the position of the rope 320. The edge band 339.2 is releases to overlap the rovings 334.2, as indicated in ligure 14. The outer edge band 319.3 is then lifted, as shown at 335.1 in Figure 14, and further rovings 334.1 of glassfibre-reinforced are wound cioto the socket former 340 from its free end to a position short of the position of the rope 320. The edge band 319.1 is then released to overlap the rovings 334.1.

With reference more specifically to Figure 15, further rovings 334.3 are then wound over the socket former 340 and over- the rope 320 which is shielded by the band of MYLAR 332.

It is of significance that the edge band 319.1 is wider than the edge band 319.2, and further that it is positioned such that it extends beyond the free end of the socket former 340, as can best be seen in Figure 12. When the rovings 334.3 have been completed, the edge band 319.1 is folded back over the rovings 334.3, as shown in Figure 16 at 319.5, to provide a smooth and reinforced end ~surface.

When the material of the ducting has cured, it is removed from the socket former 340 and an aperture 324 is drilled in register with the position of the aperture 342. The ends 326 of the rope 320 are pulled through the aperture 324, to be available on the outside of the socket 314.

With reference more specifically to Figure 17, a tightener handle or rod 330 is provided, hooked through the free ends 326 of the rope 320 which are formed in a loop. The tightener handle 330 is used to twirl the free looped portion together to toghten the rope 320, in use An eye 336 is shown to have been moulded into the rovings forming the socket, as shown at at Iii use, the free end of the tightener handle 33u, after twirliiog, Is Iccated in the eye 330 to maintain the rope 320 twirled and thus tight.

The Applicant believes that the invention provides a technically effective method, at low cost, of sealing male/female jointed conduit ends of ventilation ducting of synthetic plastics or resinous material.

This is an important factor in providing an efficient and cost-effective system for both pressure-type and suction-type ventilation ducting systems.

It is a further advantage that large tolerances in the conduits can be accommodated. The conduits can thus be manufactured to such large tolerances, which are conducive to low cost manufacturing.

It is yet a further advantage that the sealing means is of simple construction and is easy to operate. Unskilled labourers can operate the sealing means. These leatures are conducive to low capital costs and low maintenance costs.

It is another advantage that the construction of the sealing means, eg its low profile and relatively rugged construction, facilitates transport and assembly of conduits, without damage to the sealing means.

Claims

1. A method of sealing rigid conduit ends of ventilation ducting

of s)llthetic plastics or resinous material jointed male-female fashion, including the steps of providing an annular expansile sealing member in ail annular gap between the conduit ends and expanding said sealing member sealingly to fill the annular gap.

2. A method of sealing as claimed in Claim 1, in which the sealing member is provided sealingly fast with one of the conduit ends, expanding the sealing member being toward the opposed periphery of the other of the conduit ends.

3. A method of sealing as claimed in Claim 1, in which the sealing member is provided sealingly fast with the outer of the conduit ends, expanding the sealing member being by providing a flexible elongate element outwardly around the sealing member and by squeezing the sealing member around the outer periphery of the inner conduit by tightening the elongate element around the outer periphery of the inner conduit.

4. A method of sealing as claimed in Claim 1, in which the sealing member is in the form of a closed, hollow ring, and in which expanding the sealing member is by distending it by means of a fluid under pressure.

5. A ventilation ducting joint including outer and inner rigid conduit ends of synthetic plastics or resinous material jointed male-female fashion; an annular expansile sealing member in an annular gap between the outer and inner conduitends; and expansion ideals cxpandiiig tile expansile sealing member sealingly to jill tlie annular gap.

t. A joint as claimed in Claim 5, in which the sealing member is sealingly fast with one of the conduit ends and is expanded toward an opposed periphery of the other of the conduit ends.

7. A Joint as claimed in Claim 5, in which the sealing member is sealingly fast with the outer of the conduit ends, and in which the expansion means includes a flexible elongate element outwardly around the sealing member, and tightening means squeezing the sealing member around the outer periphery of the inner conduit end by tightening the elongate element around the outer periphery of the inner conduit end.

8. A joint as claimed in Claim 7, in which a portion of the elongate element extends through passage means in the outer conduit end, and in which the tightening means tightens the elongate element through said passage means.

9. A joint as claimed in Claim 7, in which the sealing member is in the form of a band, side edges of which are secured to the outer conduit end, an intermediate portion of the band being separate from and inward of the inner periphery of the outer conduit end.

10. A joint as claimed in Claim 9, in which the band is a composite band, the intermediate portion of the band being of an expansile material, and the side edges being of synthetic plastics cloth or tape.

1. .\ t joint as claimed in Claim 9, in which the side edges of the seililig' member are moulded into the outer conduit end 12. A joint as claimed in Claim 11, in which;,:the outer conduit end is of glassfibre-reinforced synthetic plastics or resinous material and the side edges are sandwiched between rovings of the reinforcing material.

13. A ventilation conduit end assembly including a rigid conduit end of synthetic plastics);r resinous material adapted to be jointed male-female fashion to an end of a complemental ventilation conduit of synthetic plastics or resinous material; an annular expansile seal member arranged to be positioned in an annular gap between said rigid conduit end and said end of the complemental ventilation conduit when jointed; and expansion means adapted to expand the annular sealing member sealingly to fill said annular gap.

14. A ventilation conduit end assembly as claimed in Claim 13, in which the conduit end is an outer conduit end, in which the sealing member is sealingly fast with the conduit end,9 and in which the expansion means includes a flexible elongate:element outwardly around the sealing member, and tightening means adapted to thighten the elongate element around the outer periphery of the inner conduit end to squeeze the sealing member around the outer periphery of the -inner conduit end in use.

15. A ventilation conduit end assembly as claimed-in Claim 14, in which a portion of the elongate element extends through massage means in the outer conduit end, and in which the tigtening means is adapted to tighten the eleongate element through said pasage means.

16. A ventilation conduit end assembly as claimed in Claim 14, in which the sealing member is in thc form of a band, side edges of which are secured to the outer conduit end, an intermediate portion of the band being separate from and inward of the inner periphery of the outer conduit end.

17. A ventilation conduit end assembly as claimed in Claim 16, in which the band is a composite band, the intermediate portion of the band being of an expansile material, and the side edges being of synthetic plastics cloth or tape.

18. A ventilation conduit end assembly as claimed in Claim 17, in which the side edges of the sealing member are moulded into the outer conduit end.

19. A ventilation conduit end assembly as claimed in Claim 18, in which the outer conduit end is of glassfibre-reinforced synthetic plastics or resinous material and the side edges are sandwiched between rovings of the reinforcing material.