Classifications

• • 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
  • B29C53/80—Component parts, details or accessories; Auxiliary operations
  • B29C53/82—Cores or mandrels
  • B29C53/821—Mandrels especially adapted for winding and joining
  • B29C53/825—Mandrels especially adapted for winding and joining for continuous winding
  • B29C53/827—Mandrels especially adapted for winding and joining for continuous winding formed by several elements rotating about their own axes
• • 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

Definitions

• the present invention relates to mandrels for manufacturing ducting and other tubular products.
• the present invention relates to mandrels for manufacturing flexible tubular ducts such as ducting of the kind suitable for use in ducted heating and air conditioning systems.
• tubular products have been conventionally produced from a substrate
• a rotating drive system incorporating a mandrel with a series of rollers.
• the rollers are set in bearings located in plates which support one end of the rollers.
• Each of the rollers is set at a predetermined angle to produce a forward helix in the manufactured tube formed by the substrate.
• the mandrel is driven by externally applied means, such as a belt drive or roller drive, which applies pressure to the substrate and one or more of the rollers to effect rotational and helical motion of the substrate.
• the tubular product is formed by adjacent windings of the substrate being wound in contact and fixed together by adhesive.
• rollers of the helix are required to be realigned to produce the correct helix. Re-aligning of the rollers is particularly time consuming as the angle relative to the backing plate must be carefully calculated and each of the rollers finely adjusted.
• Mandrels of the above-described kind periodically require maintenance to replace the bearings in which the rollers are set.
• the bearings require replacement as the forces applied to the bearings from the belt or roller drive are large when compared to the size of the bearings, and cause the bearings to wear excessively.
• the present invention provides a mandrel assembly for manufacturing a tubular product, including:
• At least one cantilever idler roller extending from the first plate
• a strip may be engaged and advanced by the driver roller to the at least one idler roller and thereby wound about the rollers to form a tubular product.
• a motor is provided for driving the drive roller.
• the drive roller is located at the top dead centre of the mandrel.
• the idler roller is preferably of a plurality of spaced such idler rollers arranged in a closed loop that advantageously includes the drive roller.
• the or each idler roller advantageously passes through a respective bearing, preferably self-aligning, in the first plate and is fitted to a second plate displaced behind the first plate.
• the first plate may be rotatably fixed to a spacer separating it from the second plate, and is thereby able to rotate in a vertical plane relative to the second plate.
• the drive roller may include an extended portion for engagement by a connecting sleeve.
• the connecting sleeve is attached to the motor so that the drive roller may be driven.
• the drive roller may also include a surface treatment to assist in the engagement and subsequent advancement of the strip.
• the drive roller is positioned so that it to extends substantially perpendicular to the incoming strip forming the tubular product.
• mandrel may be used to manufacture a wide range of products as the mandrel is driven internally, and not by an external belt drive.
• One such example of this is flexible tubular duct having a p-shaped cross section.
• Figure 1 is a layout diagram of apparatus for producing a tubular product, in particular flexible tubular duct, in accordance with a preferred embodiment of the invention
• Figure 3 is a diagrammatic, partly sectioned plan view of the winding station, as viewed in Figure 2;
• Figure 4 is a view similar to Figure 3 of the winding station after adjustment of the mandrel assembly to produce a helically wound product as shown in Figure 1 ;
• Figure 5 is a side view of the mandrel assembly corresponding to Figure 4.
• Figure 6 is an axial cross-sectional view of the mandrel assembly during production.
• 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 suitable insulating material is continuously fed via delivery tube 116 to form 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.
• 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.
• strip 104, 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 insulating material.
• 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.
• mandrel may be used for producing tubular products for other applications such as non pre-insulated ducting or flexible mining hose.
• the mandrel 134 is connected to a motor drive 218 by a connecting sleeve 220.
• the connecting sleeve 220 allows the motor drive 218 to be connected to the drive roller 202, which drivingly engages the strip 104 to advance the strip over the idler rollers 204 so that it thence winds about rollers 202, 204 and orbits the mandrel 134 to form the tubular product.
• Drive roller 202 includes an extended portion 222 to engage with connecting sleeve 220 for driving the drive roller 202, and a cantilevered portion 224 to engage with the substrate 104.
• the drive roller also includes a surface treatment (not shown) applied to the cantilevered portion 224 to enhance the driving engagement with substrate 104.
• back plate 212 which also serves as a support plate for the assembly.
• This support plate 212 is upstanding in a vertical plane from a base plate 250 that is rotatably mounted at 251 on a table 290 for rotation by a motor 257 with threaded drive 258, through fine angular displacements about a vertical axis 252.
• Axis 252 lies in the plane of front plate 206 and intersects the axis of drive roller portion 222.
• the rotation of base plate 250, and therefore of support plate 212 defines a selected helix angle in the manufacture of the tubular product. It will be seen that axis 252 is also generally parallel to the planes of front plate 206 and back plate 212.
• the top dead centre of drive roller 202 is held at a fixed position 292 relative to table 290 by a restraining bar 294 fixed to plate 206 at a three-dimensional flexible bearing 295.
• Figures 3 and 4 are plan views showing the effect of a rotation of base plate 250 on the position of the mandrel relative to the incoming strip 104.
• the angle is exaggerated: in reality, base plate 250 needs to be rotated approximately 1 to 4° to induce a commercially acceptable helix in the tubular product.
• the front plate 206 will rotate on its horizontal axis as base plate 250 rotates about axis 252, to realign the drive roller 202, accommodated by the self-aligning bearings 205 and 205a, to be perpendicular to the incoming substrate 104.
• the drive roller 202 maintains an orientation at 90° to the incoming material.
• Idler rollers 204 while remaining parallel to roller 202 when viewed in plan, are inclined upwardly on one side and downwardly on the other, as best appreciated from the side view of Figure 5. These inclinations are accommodated by self-aligning bearings 205, 205a.
• motor drive 218 In view of the adjustment of the alignment of drive roller 202 relative to back plate 212, motor drive 218 must correspondingly be able to adjust. To this end, motor drive 218 is fitted to mounts, e.g. on a cradle 219 ( Figure 6) carried by plate 212, that allow the motor drive to swivel slightly as the relative alignment of drive roller 202 alters.
• the output shaft of motor drive 218 is also flexibly supported by connecting sleeve 220, which is in turn connected to support plate 212.
• the motor drive 218 is flexibly connected so as to remain unstressed when the support plate 212 is rotated to accommodate the helix.
• the substrate 104 itself forms a belt-like action on the mandrel at the completion of the first helixing orbit.
• a degree of tension or braking effect must be provided to the supply of the substrate means 104.
• the wire re- enforcement dispensing means may also maintain a degree of tension (or breaking effect) as between the drive roll 202 and the parallel incoming substrate 104 and wire 118. The circumstances thus created cause a tightening of the substrate (and the wire re-enforcement) against the rotating surfaces of the rollers 202, 204, thus negating the normal requirement for an external driving force such as a separate drive belt or drive roller means.
• the manufacture of the tubular product may be further enhanced by the use of substrates for strip 104 having additives that aid the surface grip characteristics in rotating the idler rollers.
• additives may include adhesives which maintain grip on the idler rollers, but do not affect the finished tubular product.
• a significant advantage of the described mandrel is that minimal time is required to adjust the back plate 212 and rollers 202, 204 for manufacturing tubular products of various size helixes.
• Motor 257 may have multiple digital settings preset to correspond to a variety of helix outcomes: adjustment then involves simply selecting and activating one of these settings.
• a further advantage is that, by virtue of the aforementioned tension or braking effect and of the surface finish on the cantilevered portion of the drive roller, the mandrel is able to engage and advance the strip 104 of substrate material to form a helical tubular product without the need for an exterior drive belt, thereby extending the life of the bearings supporting the rollers.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Shaping Of Tube Ends By Bending Or Straightening (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (6)

Cited By (1)

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Citations (7)

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• 2005
  • 2005-06-27 US US11/630,429 patent/US7549310B2/en not_active Expired - Fee Related
  • 2005-06-27 JP JP2007516898A patent/JP5057970B2/ja not_active Expired - Fee Related
  • 2005-06-27 CA CA2582288A patent/CA2582288C/en not_active Expired - Fee Related
  • 2005-06-27 NZ NZ552368A patent/NZ552368A/en not_active IP Right Cessation
  • 2005-06-27 WO PCT/AU2005/000937 patent/WO2006000051A1/en not_active Ceased
• 2007
  • 2007-01-25 ZA ZA200700699A patent/ZA200700699B/en unknown

Patent Citations (7)

Non-Patent Citations (5)

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