Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L11/00—Hoses, i.e. flexible pipes
  • F16L11/04—Hoses, i.e. flexible pipes made of rubber or flexible plastics
  • F16L11/08—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall
  • F16L11/081—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall comprising one or more layers of a helically wound cord or wire
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C53/00—Shaping by bending, folding, twisting, straightening or flattening; Apparatus therefor
  • B29C53/36—Bending and joining, e.g. for making hollow articles
  • B29C53/38—Bending and joining, e.g. for making hollow articles by bending sheets or strips at right angles to the longitudinal axis of the article being formed and joining the edges
  • B29C53/48—Bending and joining, e.g. for making hollow articles by bending sheets or strips at right angles to the longitudinal axis of the article being formed and joining the edges for articles of indefinite length, i.e. bending a strip progressively
  • B29C53/50—Bending and joining, e.g. for making hollow articles by bending sheets or strips at right angles to the longitudinal axis of the article being formed and joining the edges for articles of indefinite length, i.e. bending a strip progressively using internal forming surfaces, e.g. mandrels
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C53/00—Shaping by bending, folding, twisting, straightening or flattening; Apparatus therefor
  • B29C53/56—Winding and joining, e.g. winding spirally
  • B29C53/58—Winding and joining, e.g. winding spirally helically
  • B29C53/78—Winding and joining, e.g. winding spirally helically using profiled sheets or strips
  • B29C53/785—Winding and joining, e.g. winding spirally helically using profiled sheets or strips with reinforcements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L59/00—Thermal insulation in general
  • F16L59/14—Arrangements for the insulation of pipes or pipe systems
  • F16L59/143—Pre-insulated pipes
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L59/00—Thermal insulation in general
  • F16L59/14—Arrangements for the insulation of pipes or pipe systems
  • F16L59/147—Arrangements for the insulation of pipes or pipe systems the insulation being located inwardly of the outer surface of the pipe
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L59/00—Thermal insulation in general
  • F16L59/14—Arrangements for the insulation of pipes or pipe systems
  • F16L59/153—Arrangements for the insulation of pipes or pipe systems for flexible pipes
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F13/00—Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
  • F24F13/02—Ducting arrangements
  • F24F13/0245—Manufacturing or assembly of air ducts; Methods therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C2793/00—Shaping techniques involving a cutting or machining operation
  • B29C2793/0045—Perforating
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T156/00—Adhesive bonding and miscellaneous chemical manufacture
  • Y10T156/17—Surface bonding means and/or assemblymeans with work feeding or handling means

Definitions

• This invention relates to ducting and, more particularly, to the manufacture of flexible tubular duct such as duct of the kind suitable for use in ducted heating and air conditioning systems.
• the invention provides a method of and apparatus for manufacturing such ducting, as well as a novel flexible tubular duct.
• flexible ducting for heating and air conditioning systems has been manufactured by helically laminating a polymer strip material with a wire reinforcement to form a tube.
• the wire reinforcement ensures roundness integrity, and the tube is substantially non-insulating.
• Thermal insulation is provided by a soft blanket made from fibreglass or polymer based fibre, wrapped about the tube and secured with an outer sheath of polymer film or aluminium tube material. The insulation blanket and the securing outer sheath are generally applied manually as a secondary manufacturing process, with the aid of appropriate jigs and fixtures.
• Australian patent 773565 discloses a flexible tubular duct that comprises a strip of flexible substrate material with a rounded portion that encapsulates a solid core of insulating material and is helically wound to form the tubular duct.
• the core is cylindrical in shape and is a sliver or continuous length of insulation material.
• the tubular duct also includes a helically wound reinforcement element which is encapsulated by the strip of substrate material in the tubular duct.
• the duct construction of patent 773565 exhibits good thermal insulation properties, and is efficiently formed with its insulation in a single automatic manufacturing operation.
• the present invention is directed to providing the encapsulated core of insulating material as a mass of fibrous material fed as a stream of loose fibrous material into the encapsulating portion of the substrate material.
• the present invention provides, in one aspect, a method of manufacturing a flexible tubular duct.
• the method includes feeding an elongate strip of flexible substrate material to a winding station while bending the strip to have a rounded encapsulating portion, feeding a stream of loose fibrous insulating material into the rounded encapsulating portion, and delivering an elongate reinforcing element onto the strip of flexible substrate material.
• the rounded encapsulating portion and the reinforcing element are wound at the winding station in a helical path such that the loose fibrous material is encapsulated as a core in the helically wound rounded encapsulating portion and the reinforcing element is also encapsulated by the strip of substrate material, whereby to form a reinforced flexible tubular duct.
• the step of feeding a stream of loose fibrous material includes entraining the material in a gas stream.
• the gas stream is delivered via a delivery tube.
• the delivery tube may be arranged to define a core cavity in the rounded encapsulation portion into which the loose fibrous material is blown.
• the gas stream maintains the core cavity downstream of the tube, and also assists in internally supporting and maintaining the core cavity during winding.
• heat may be applied to stretch the outer surface of the rounded encapsulating portion as it is wound.
• the flexible substrate material is preferably perforated in the encapsulating portion to facilitate maintenance of the core cavity by allowing gas to pass from the cavity.
• the loose fibrous material is advantageously insulating material.
• the present invention also provides, in another aspect, apparatus for manufacturing a flexible tubular duct.
• the apparatus includes a mandrel, and substrate feeding means for feeding a strip of flexible substrate material to the mandrel.
• Respective means are provided for bending the strip of substrate material to have a rounded encapsulating portion, and for feeding a stream of loose fibrous insulating material into the rounded encapsulating portion.
• Means is further provided for delivering an elongate reinforcing element onto the strip of flexible substrate material.
• the rounded encapsulating portion and the reinforcing element are wound in a helical path around the mandrel so that the loose fibrous material is encapsulated as a core in the helically wound rounded encapsulating portion and the reinforcing element is also encapsulated by the strip of substrate material, whereby to form a reinforced flexible tubular duct.
• the means for feeding a stream of loose fibrous material comprises a delivery tube for a gas stream in which the loose fibrous material is entrained.
• the delivery tube is preferably arranged to define a core cavity in the rounded encapsulating portion, through which cavity the gas stream is blown.
• the gas stream may be provided to the rounded encapsulating portion separate from the delivery of the loose fibrous material.
• the apparatus may further include means for perforating the strip of flexible substrate material to facilitate maintenance of the core cavity by allowing gas to pass from the cavity.
• means is provided to apply heat to stretch the outer surface of the rounded encapsulating portion as it is wound.
• Such means many include an array of heater elements arranged to blow heated air at predetermined temperatures onto the rounded encapsulating portion before and after it enters said helical path.
• the apparatus also includes means for applying adhesive to the strip of substrate material to adhere the portion of the substrate material forming the rounded encapsulating portion to itself.
• the apparatus further includes an air and fibre pump connected to supply the gas stream and loose fibrous material entrained therein, the pump receiving the fibrous material and transferring it into the gas stream.
• This pump may comprise an element such as e.g., a rotatable drum, having a plurality of chambers, which element is moveable between a first station at which the chambers receive respective tufts of the fibrous material travelling in a first path, and a second station at which the tufts are ejected into the gas stream travelling in a second path.
• the present invention further provides, in a still further aspect, a flexible tubular duct comprising a strip of flexible substrate material formed to have a rounded encapsulating portion which encapsulates a core of fibrous material.
• the rounded encapsulating portion is helically wound to form the tubular duct.
• the tubular duct also include a helically wound reinforcing element which is encapsulated by the strip of substrate material in the tubular duct.
• the invention still further provides an apparatus for delivering a gas stream, with loose fibrous material entrained therein, comprising an element having a plurality of chambers, which element is moveable between a first station at which the chambers receive respective tufts of the fibrous material travelling in a first path, and a second station at which the tufts are ejected into the gas stream travelling in a second path.
• Figure 1 is a layout diagram of apparatus for forming a flexible tubular duct in accordance with a preferred embodiment of the invention
• Figure 2 is a fragmentary cross-sectioned diagram showing three successive windings in a duct formed with the apparatus of Figure 1 ;
• Figure 3 is a diagram depicting the delivery of the fibrous insulation core in the apparatus of Figure 1 ;
• Figure 4 is a partially exploded and partly sectioned view of an air and fibre pump suitable for use in the apparatus of Figures 1 and 3;
• Figure 5 is an axial cross-section view of the pump of Figure 4.
• Figure 6 is a diagram showing an exemplary device for perforating the strip of flexible substrate material.
• FIG. 1 shows an apparatus 100 for manufacturing flexible tubular duct 102 in accordance with an embodiment of the invention.
• Apparatus 100 includes a winding station 130 having a mandrel 134 to which a strip 104 of flexible substrate material is fed, from a reel or other supply of the material, and helically wound, in a manner to be described, to form flexible tubular duct 102.
• Substrate feeding means 132 for feeding strip 104 to mandrel 134 comprises suitable guide structure depicted in Figure 1 purely by representative diagram elements 136.
• Structure 136 also carries means 133 for bending the strip 104 to form a rounded encapsulating portion 106 of initial cross-section determined by a delivery tube 116 about which the strip is wrapped.
• a core cavity is defined by delivery tube 116, downstream of the mouth 117 of the tube.
• a stream 108 ( Figure 3) of loose fibrous insulating material is continuously fed via delivery tube 116 from blower or pump 111 ( Figure 3).
• This stream 108 forms an insulating core 109 encapsulated by rounded portion 106 of strip 104.
• Rounded portion 106 is formed by only part of the width of strip 104: the balance remains substantially flat and defines a tail portion 128, so that the strip assumes the appearance of a P-shape in cross-section ( Figure 2).
• the folded-over rounded portion 106 terminates in an edge lip 105 that folds out flat onto tail portion 128.
• the third principal component of the duct is an elongate reinforcement element in the guise of a wire 118 that is delivered, by means 110 including suitable wire guides, against and under portion 128 so as to lie parallel to strip 104 and rounded portion 106.
• the assembly of strip 105, wire 118 and rounded portion 106 encapsulating insulating core 109, is wound up helically on mandrel 134 so that successive windings abut and combine to form flexible duct 102.
• Duct 102 is formed such that the helix spacing is less than the external diameter of the core 109 of encapsulated loose fibrous material 108.
• the duct has somewhat of the appearance of a lobster tail.
• the rounded encapsulating portion 106 of each successive winding overlies and abuts the tail portion 128 of the previous winding, and wire 118 is encapsulated between these two successive tail portions.
• An adhesive film 119 applied to the strip 104 by a suitable applicator ensures that the edge lip 105 of the rounded encapsulating portion is adhered to its own tail portion at adhesive film 119, and that the rounded portion of the next winding is adhered to that tail portion.
• the successive windings might alternatively be adhered together by employing microwave welding or other heat sealing techniques.
• blower or pump 111 ( Figure 3) is an air/fibre feed pump to which gas, typically air, is drawn in via gas inlet duct 186, while fibre is received at fibre intake duct 180 and entrained in the air stream within the pump. The air stream and its entrained mass of fibre is then delivered by the pump along delivery tube 116.
• Air/fibre feed pump 111 is designed both to maintain an air stream of sufficient flow and pressure to expand rounded encapsulating portion 106 and to provide an adequate density of fibres entrained in the air stream. To this end, pump 111 defines separate fibre and air circuits, and transfers fibres to the air stream via multiple transfer chambers 165 in a rotating cylindrical drum 160.
• pump 111 has a pair of end plates 162, 163 coupled by tie bars 164 or similar.
• Drum 160 is supported for rotation between end plates 162, 163, by an axle 167 journalled in suitable roller or sleeve bearings in the end plates.
• Axle 167, and therefore drum 160, is rotatable by motor 168.
• Drum 160 has a number of similarly dimensioned, open-ended, cylindrical chambers 165.
• Chambers 165 are parallel to the axis 161 of drum 160 and are equi-angularly spaced about the axis.
• ports 170, 172 and 174, 176 are connected to the axis 162, 163, so as to be momentarily in register with chambers 165 as they pass.
• Ports 170, 172 in end-plate 162 comprise one or more fibre inlet ports 170 and a single pressurised or outlet port 172.
• Ports 174, 176 in end-plate 162 comprise one or more vacuum ports 174 aligned with fibre inlet ports 170, and a pressurised air intake port 176 aligned with port 172.
• Port 170 is coupled by duct 180 to a conventional textile fibre opener represented at 190.
• Port 174 is connected via duct 184 to a vacuum pump 185.
• Port 176 connects via duct 186 to a suitable air blower, eg. compressor 196, and port 172 is coupled to fibre and air delivery tube 116.
• Each chamber 165 has a filter 166 sufficient to retain fibre in the chamber but not to significantly block airflow, and the chambers are spaced circumferentially by a distance less than their diameter so that before each chamber 165 has fully crossed an aligned pair of ports 170, 174, the next chamber will also be connecting the ports.
• vacuum pump 185 is connected via duct 184, one or more chambers 165, and duct 180 to the fibre opener, thereby defining a first path along which fibres are continually drawn into chambers 165, where they accumulate as tufts 169 against filters 166. These tufts 169 are then expelled into delivery tube 116 as the respective chambers momentarily couple ports 176, 172, defining a second path in which the gas stream travels. Because the air/fibre delivery speed is much greater than the speed of delivery of strip 104, the tufts 169 re-contact and from a continuous entrained fibre stream in tube 116.
• Some degree of air sealing between rotating drum 160 and end plates 162, 163 may be provided by teflon bushes (not shown) that project from both ends of chambers 165 to brush the end-plates, but complete hermetic sealing is not important, or indeed desirable, in the vacuum circuit.
• the portion 106 is, however, kept satisfactorily expanded by a balanced combination of air pressure within, delivered by pump 111 , and stretching of the radially outer side of rounded encapsulating portion 106.
• the air pressure is balanced within by multiple perforations 200 in the strip material, of a size and spacing to determine the rate of outflow, while the stretching is achieved by an overhead heater array 150 that softens the material of the encapsulating portion sufficiently for it to stretch as the assembly is wound.
• Heater array 150 comprises a sequence of at least three heater elements
• each downdraft of heated air is predetermined to achieve a controlled pre-heating or softening.
• the apparatus may also include infrared probes (not shown) for monitoring the temperature of the rounded encapsulating portion.
• the blown-in air may also be pre-heated if desired or necessary.
• the substrate material may take any suitable form, for example a polymeric plastics material such as polyester, polypropylene, polyvinyl chloride (PVC) or polyethylene.
• the strip may comprise a laminated or partially laminated material such as a metal/plastics laminate.
• the reinforcement element is typically wire, eg. metal wire, preferably of spring-grade hardness.
• the core 109 may be formed of insulating material, for example fibreglass, fibrous polyester or any other suitable fibrous material.
• insulating material for example fibreglass, fibrous polyester or any other suitable fibrous material.
• Each fibre is itself a fine tube: a medium of such fibres exhibits high thermal insulating properties.
• Figure 6 illustrates one suitable means 201 for forming perforations 200 in the strip of flexible substrate material 104.
• This means includes a pin-wheel 202 having pins or spikes 204, rotatably mounted on shaft 206. As the strip of flexible substrate material 104 is fed towards the winding station 130, the wheel 202 rotates on shaft 206 to pierce the substrate 104 to create perforations 200.
• the number and dimension of the perforations 200 may be calculated, in conjunction with the air volume to be evacuated via the perforations, to maximize the accuracy and density of the selected volume of fibres contained within the rounded portion 106 of strip 104.
• a significant advantage of the described arrangement is that the cross- sectional size of the rounded encapsulating portion and its insulating core can be selectively varied by modifying parameters such as the blown-in air pressure, the delivery rate of the fibrous material, the heater temperature and the cross-section or diameter of the delivery tube: in this manner the apparatus 100 is adaptable to produce duct of different specifications.
• the fibrous material delivered along delivery tube 116 may include a small proportion of melt fibres that liquefy and disperse so as to glue some or most of the other fibres together.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Rigid Pipes And Flexible Pipes (AREA)
• Thermal Insulation (AREA)
• Duct Arrangements (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=35241753

Family Applications (1)

Country Status (7)

Cited By (2)

Families Citing this family (7)

Citations (8)

Family Cites Families (10)

• 2005
  • 2005-04-29 JP JP2007509834A patent/JP4359936B2/ja not_active Expired - Fee Related
  • 2005-04-29 NZ NZ551704A patent/NZ551704A/en not_active IP Right Cessation
  • 2005-04-29 NZ NZ585676A patent/NZ585676A/en not_active IP Right Cessation
  • 2005-04-29 WO PCT/AU2005/000622 patent/WO2005106315A1/en not_active Ceased
  • 2005-04-29 US US11/579,006 patent/US7918955B2/en not_active Expired - Fee Related
  • 2005-04-29 CA CA2583044A patent/CA2583044C/en not_active Expired - Fee Related
  • 2005-04-29 AU AU2005238551A patent/AU2005238551B2/en not_active Ceased
• 2006
  • 2006-11-30 ZA ZA200610017A patent/ZA200610017B/en unknown
• 2010
  • 2010-09-30 AU AU2010226895A patent/AU2010226895A1/en not_active Abandoned

Patent Citations (8)

Non-Patent Citations (4)

Also Published As

Similar Documents

Legal Events