WO2001028756A1

WO2001028756A1 - Spiral hose making apparatus and method

Info

Publication number: WO2001028756A1
Application number: PCT/AU2000/001291
Authority: WO
Inventors: Michael Macdonald
Original assignee: The Straw Company Pty Ltd.
Priority date: 1999-10-21
Filing date: 2000-10-20
Publication date: 2001-04-26

Abstract

The present invention discloses apparatus for producing twisted tubular plastics material (12) conveniently in a heated softened condition from an extruder or the like, the apparatus including a rotary calibrator (13) to size an external diameter dimension of the tubular plastics material (12), and a rotary drive means (17) arranged to receive the material (12) from the calibrator (13), the rotary drive means (17) including a plurality of rollers (77) arranged in two groups (78, 79) on opposed sides of the tubular plastics material (12), each of said rollers (77) having an edge zone formed to engage at least a zone of the circumference of the tubular plastics material (12), said rollers (77) being driven rotationally to drive said material (12) forwardly in a longitudinal direction (28), said rollers (77) further being mounted on a common support means which is rotated about the longitudinal axis (28) of the material (12) thereby imparting a rotational motion to said material (12) as the material is moved forwardly, the apparatus preferably also including a rotatable device (18) to discharge the tubular plastics material (12) at a distance from the longitudinal axis (28) whereby the material (12) can be deposited in adjacent spirals or loops in a moving mould device (19, 20, 21) to thereby form a spiral hose.

Description

SPIRAL HOSE MAKING APPARATUS AND METHOD

The present invention relates to improved apparatus and methods forming spiral hose typically from polyurethane or polyamides such as nylon. Spiral hose typically comprises tightly adjacent spiral loops of hose with the diameter of each of the spiral loops being substantially the same. The hose may be expanded in length by pulling the adjacent spiral loops apart or contracted in length by allowing the spiral loops to flex back their free position of being closely adjacent each other. Current methods and machinery for producing this type of hose involve lengthy, discontinuous and complicated procedures as a result of which such hoses are relatively expensive. Furthermore, it is often also desired to produce spiral wound hose from previously formed reinforced hose and again current methods of achieving this are complicated and difficult.

The objective of the present invention is to provide both a method and apparatus for producing such spirally wound hose, whether reinforced or not, which simplifies the production of same and reduces its cost of production. In the case of non-reinforced hose, the apparatus and method may involve continuous or semi-continuous production from initial extrusion of the hose through to final formation of the spirally wound hose sections. In the case of reinforced hose, this hose may be first produced as a desired length and subsequently processed in a batch wise process to form the desired length or lengths of spirally wound hose. It will of course be recognised that non- reinforced hose may be similarly processed if desired.

In accordance with a first aspect, the present invention provides apparatus for producing spirally wound hoses including a rotating hose laying means through which the hose passes in a softened condition, said hose laying means having a discharge end which is adapted to rotate about an axis to form spiral loops of said hose adjacent one another while still warm and soft and a former means for holding said spiral loops for a period of time before being released.

Conveniently, the former means is adapted to move away from the discharge end of the hose laying means as the spiral loops are formed therein. In one preferred arrangement, the apparatus may include an extruder for extruding polymer material in the form of a hose and a rotating calibrator for sizing the hose received from the extruder.

In an alternative preferred arrangement, a length of previously formed hose may be placed in or passed through a heating means to heat the hose to a desired soft condition before being passed to the hose laying means.

Preferably in both the aforesaid arrangements, a rotating drive means is provided for drawing the hose from a preceding stage and supplying same to the hose laying means. In accordance with a second aspect, the present invention provides a method of producing spirally wound hose including the steps of :-

• establishing a length of hose in a heated softened condition;

• delivering said hose to a rotating hose laying means whereby a discharge point of said hose laying means follows a circular path; and • forming spiral loops of said hose in holding means as the hose discharges from said hose laying means.

Preferably, the holding means is caused to move away from the discharge point of the hose laying means as the spiral loops are formed therein. Conveniently, the hose is initially formed by extruding polymer material through an extrusion die and thereafter the hose thus formed is passed through a rotating calibrator for sizing the hose received from the extrusion die.

In an alternative embodiment, a length of previously formed hose may be placed in or passed through a heating means to heat the hose to a temperature sufficient to soften the hose to a desired condition. Preferably the temperature is in the range of 140 to 180°C. After the hose has been softened to the desired condition, it is passed to the hose laying means.

Preferably in both the aforesaid arrangements, the hose is drawn by a rotating drive means before being delivered to the rotating hose laying means. Further preferred aspects and features of this invention will be apparent from claims 2 to 18 and 20 annexed hereto which are made part of this disclosure by this reference thereto. In accordance with a further aspect, it is desired to be able to conveniently and easily produce a length of tubular plastics material including hose or the like which is twisted along its longitudinal length. In accordance with this aspect there is provided apparatus for producing longitudinally twisted tubular plastic material including a rotary drive means having first forward drive means to move said tubular plastics material forwardly in a longitudinal direction of the tubular plastics material, and second rotational drive means to impart a twisting motion to said tubular plastics material as said tubular plastics material moves in a forward direction, said second rotational drive means being adjustable to vary pitch of the twist imparted to said tubular plastics material independently of operation of the first forward drive means. Conveniently, the first forward drive means includes a plurality of roller means, each having a circumferential edge engaging said tubular plastics material and configured to at least partially surround an outer surface of said tubular plastics material, said roller means being arranged in at least two groups with the roller means of each said group being located on opposite sides of said tubular plastics material, said roller means being rotationally driven to move said tubular plastics material forwardly in the longitudinal direction of the tubular plastics material, said roller means further being mounted from a common support means rotatable about a longitudinal axis of said tubular plastics material, said second rotational drive means being provided to drive said common support means to impart rotational movement thereto as the tubular plastics material is moved in said longitudinal direction.

Further preferred aspects and features relevant to the foregoing apparatus may be as defined in claims 23 to 30 as annexed hereto, which are hereby made part of this disclosure.

The invention will now be described with reference to preferred embodiments illustrated in annexed drawings, in which :-

FIG. 1 is a schematic view of apparatus capable of performing the present invention;

FIG. 2 is a more detailed view of the rotating haul off mechanism for the extruded hose shown in FIG. 1 ; FIG. 3 is a more detailed view of the rotating calibrator forming part of the apparatus of FIG. 1

FIG. 4 is a schematic view similar to FIG. 1 showing an alternative preferred form of apparatus for carrying out this invention; FIG. 5 is a section view taken along line N-N of FIG. 1 ;

FIG. 6 illustrates features of a potential variation to the embodiment illustrated in FIGS. 1 or 4;

FIG. 7 is a section view taken along line N-N of FIG. 6 and

FIG. 8 is a section view taken along line NI-NI of FIG. 6. The apparatus generally disclosed in FIG. 1 includes an extruder 10 having an extruder die 11 for extruding polymer materials such as polyurethane or polyamide into a hose form 12. The hose form 12 passes into a rotating calibrator 13 located within a cooling fluid (typically water) 14 held within a stationary vacuum tank 15. The hose form 12 passes through the vacuum tank 15 to be drawn by a haul off arrangement 17 including a series of rollers 16 mounted in a rotating support structure 16 and thereafter delivered to a rotating flyer 18 to be laid in a spiral pattern in the longitudinally extending cavity 19 of circular cross-section formed between two adjacent legs of upper and lower caterpillar endless tracks 20, 21. The thus spirally wound hose 12 is maintained within the cavity 19 for a time sufficient for the hose to set in this formation and be discharged as a complete spirally wound hose section at a discharge end of the caterpillar tracks 20, 21. The flyer 18, the rotatable structure 17 of the haul off rollers 77 and the rotating calibrator all are conveniently driven rotationally from a common drive D. The haul off rollers 77 are themselves driven by a separate variable speed motor.

The rotating calibrator 13, as shown in FIG. 1 and FIG. 3, preferably comprises a hollow perforated metal pipe 70 having a first narrow section 22 and a downstream wider section 23. The first section 22 has an internal diameter equal to that of the hose 12 intended to be produced and acts to size the outer diameter of the hose 12. Appropriate seals are provided between end walls 24, 25 of the tank 15 and the calibrator 13 to ensure water does not leak therefrom. The perforations in the calibrator allow the water to contact and cool the hose and the vacuum conditions above the water ensures that the outer diameter of the hose is maintained both circular as well as at the desired dimension. Appropriate bearings 26, 27 within the tank and/or end bearings 71, 72 may be provided for the calibrator 13 to support same during rotation within the tank 15. The calibrator tube 70 may be rotated by gear or pulley means 63 connected to the tube 70 being rotated via drive line means 74 from a drive motor 75 (FIG. 2). It will of course be appreciated that other form of rotary calibrator might be used including those utilising a cooling fluid spray rather than a bath as described above.

Referring to FIG. 2, a novel arrangement 17 is shown for enabling the hose 12 to be drawn through the rotary calibrator 13 from the extruder 10 and simultaneously twisted at any desired pitch. The arrangement 17 includes a number of rollers 77 in a first aligned group 78 and a second group 79 of rollers 77 with each group being located on opposed sides of the hose 12. The peripheral edge surfaces of the rollers 77 are concavely grooved to conform with at least a part of the external surface of the hose 12 whereby they contact same and, upon rotation, drive the hose in a forward direction longitudinally of the hose itself. The support structure 76 for the rollers 77 is supported via suitable bearings for rotation about the longitudinal axis 28 of the hose. In addition the rotary flyer 18 is similar supported in bearings and appropriate drive line means 80 and 74 are provided from a drive motor 82 so that both are rotated synchronously with one another. Each of the rollers 77 are driven via shafts 83 or 84 carrying suitable worm gears or the like. In an alternative, timing belt drive arrangement may be utilized. The drive shafts 83, 84 may in turn be driven by gearing, pulley drives or the like 85 rotatably mounted in the support structure 76 via the drive line 86 from a separate motor 87, conveniently independent from the drive motor 82. The speed of the two motors 82, 87 may be controlled by a microprocessor 88 or the like to ensure that the rotational motion imparted by the motor 82 corresponds correctly to the forward movement of the hose 12 to ensure the spiral loops of hose are correctly formed as described hereinafter.

The rotary flyer 18 conveniently rotates about the central longitudinal axis 28 coincident with the axes of the extruder die 11 , the rotary calibrator 13, the rotary haul off structure 17 and the cavity 19 of the caterpillar tracks 20, 21. The flyer 18 further includes a discharge end 29 radially spaced from the axis 28 such that hose leaving this end travels a circular path with its outer most surface approximating the distance the surface of the cavity 19 is spaced from the axis 28. In this manner the hose may be laid in closely adjacent spiral loops within the cavity 19.

The arrangement discussed above essentially produces a spiral hose of any desired length in a semi-continuous fashion. If desired, the length of spiral hose produced may be divided into shorter lengths.

Figure 4 illustrates a possible alternative to the apparatus shown in Figure 1 , particularly adapted to form previously manufactured hose into spirally wound hose as may be desired. The hose may be either reinforced or not reinforced. In this arrangement the extruder and the rotating calibrator are replaced with a hose heating means 60. The heating means may be an oven or any other suitable means for heating the preformed hose to a desired softening temperature. One possible embodiment may be to hold the preformed hose on a spool 61 which itself can rotate about its own horizontally arranged axis 62 and further is mounted on a turntable 63 for rotation about a vertical axis 64. The turntable 63 is driven at an appropriate speed from the common drive D that also rotates the rotatable haul off structure 17 and the rotary flyer 18 similar to the arrangement of Figure 1. In this manner twisted softened hose 12 is delivered to the rotary flyer 18 in a similar condition to the hose 12 of Figure 1 and the formation of the spiral loops occurs in exactly the same manner as with Figure 1 and as further described hereinafter.

If it is desired to produce a spiral hose having short start and tail sections extending in the longitudinal direction with the spiral wound loops in between, then modifications to the apparatus as shown in Figures 6 to 8 might be used. Figure 6 represents a portion of the caterpillar endless tracks 20 and 21 each formed by adjacent block members 30, 31. Each of these block members has a semi-circular surface forming an inner recess 32 which together form an elongate cavity 33 similar to the cavity 19 of Figure 1 or 4. The number of block members 30, 31 or alternatively the length of the cavity 33 formed by co-operating block members 30, 31 defines the length of the hose portion formed by adjacent spiral loops. Each section of block members 30, 31 are interspaced by specially formed block members 40, 41 and 50, 51 as shown in Figure 6. The block member 41 includes a downwardly directed recess or slot 42 having a width equivalent to the diameter of the rotary flyer 18. The block members 50, 51 each include semi-circular recesses 52, 53 with the member 51 further including a downwardly extending slot 54 also having a width equivalent to the diameter of the rotary flyer 18. The depth of the slots 42 and 54 are the same and are the same distance from the axis 28 as is the surface of the recesses 32.

The above described arrangement may operate as follows. With the flyer 18 rotating about axis 28, spiral loops are formed in the cavity 33 formed by a section of block members 30, 31 , members 30, 31 , for example, the right hand block members 30, 31 shown in Figure 6. At the same time, the calibrator and the hose haul off structure 17 are rotated as described above. Then, as block members 40, 41 approach the flyer 18, the flyer stops rotating at bottom dead centre so that the hose 12 engages within the slot 42. The speed of movement of the caterpillar tracks 20, 21 is then increased while the flyer 18 is stationary to compensate for the fact that no spiral hose loops are being laid. A desired length of straight hose 12 is then produced until block members 50, 51 come into position with the slot 54 engaging the straight length of hose. Thereafter, the flyer 18 may again commence rotating such that a further spiral loop section is produced and the speed of the caterpillar tracks slow down to allow spiral loops to form. Once these hose sections are discharged from the downstream end of the caterpillar tracks 20, 21 , the straight hose sections 12' can be cut or otherwise separated at an intermediate position to form respectively a straight tail and start portion. As will be apparent from the foregoing, the short straight sections extend longitudinally but adjacent the circumferential edge of the spiral loops. If it is desired for these straight sections to extend longitudinally but at or adjacent the central axis of the spiral loops, then the central circular apertures 52, 53 may be used to form the straight portion 12'.

Other modifications or variations will be apparent to those skilled in the art and are included within the scope of this invention.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. Apparatus for producing spirally wound hoses including a rotating hose laying means through which the hose passes in a softened condition, said hose laying means having a discharge end which is adapted to rotate about an axis to form spiral loops of said hose adjacent one another while still warm and soft and a former means for holding said spiral loops for a period of time before being released.

2. Apparatus according to claim 1 , wherein the former means is adapted to move away from the discharge end of the hose laying means as the spiral loops are formed therein.

3. Apparatus according to claim 1 or claim 2, further including an extruder for extruding polymer material in the form of a hose in a heated softened condition.

4. Apparatus according to claim 3, further including a rotating calibrator for sizing the hose received from said extruder.

5. Apparatus according to claim 1 or claim 2, further including heating means arranged to heat a length of said hose to a desired softened condition as the hose is retained therein or passed therethrough, the hose thereafter being delivered to the hose laying means.

6. Apparatus according to claim 5, further including a rotating drive means for drawing the hose from a preceding stage and supplying same to the hose laying means.

7. Apparatus according to claim 6 wherein said rotating drive means includes a plurality of rollers, each having a circumferential edge engaging said hose and configured to at least partially surround an outer surface of said hose, said rollers being arranged in at least two groups with the rollers of each said group being located on opposite sides of said hose, said rollers being driven rotationally to drive said hose forwardly in a longitudinal direction of the hose, said rollers further being mounted from a common support means which is rotated about the longitudinal axis of said hose to impart a rotational motion to said hose as the hose is moved forwardly.

8. Apparatus according to claim 7 wherein the rollers of each said group of rollers are longitudinally aligned and spaced apart in the longitudinal direction of said hose.

9. Apparatus according to any one of claims 6 to 8, wherein each of said rotating drive means and said hose laying means are rotated in the same direction about the longitudinal axis of the hose.

10. Apparatus according to claim 3 or claim 4 further including rotating drive means for drawing the hose from a preceding stage and supplying same to the hose laying means.

11. Apparatus according to claim 10 wherein said rotating drive means includes a plurality of rollers, each having a circumferential edge engaging said hose and configured to at least partially surround an outer surface of said hose, said rollers being arranged in at least two groups with the rollers of each said group being located on opposite sides of said hose, said rollers being driven rotationally to drive said hose forwardly in a longitudinal direction of the hose, said rollers further being mounted from a common support means which is rotated about the longitudinal axis of said hose to impart a rotational motion to said hose as the hose is moved forwardly.

12. Apparatus according to claim 11 wherein the rollers of each said group of rollers are longitudinally aligned and spaced apart in the longitudinal direction of said hose.

13. Apparatus according to any one of claims 10 to 12 wherein each of the calibrator, the drive means and said hose laying means are rotated in the same direction.

14. Apparatus according to claim 13 wherein axes of rotation for the calibrator and the drive means are coaxial with each other and with the axis of rotation of the hose laying means.

15. Apparatus according to anyone of claims 1 to 14, wherein the former means includes a pair of endless track members having adjacent track legs arranged to move away from the discharge end of the hose laying means that co-operate to form at least one moving mould cavity into which the spiral loops of said hose are laid.

16. Apparatus according to claim 15. wherein each said track member is formed by a plurality of adjacent mould members each of which have a mould surface which forms part of the moving mould cavity when the mould member is positioned in a respective one of the adjacent track legs.

17. Apparatus according to claim 16, wherein the mould surfaces are semi- cylindrical.

18. Apparatus according to claim 10 or claim 11 , wherein a plurality of said adjacent mould members are provided in at least one section separated by cooperating means to enable formation of a straight length of the hose between spiral loop portions of said hose.

19. A method of producing spirally wound hose including the steps of :-

• establishing a length of hose in a heated softened condition;

20. A method according to claim 19, wherein the holding means is caused to move away from the discharge point of the hose laying means as the spiral loops are formed therein.

21. Apparatus for producing longitudinally twisted tubular plastics material including rotating drive means having first forward drive means to move said tubular plastics material forwardly in a longitudinal direction of the tubular plastics material, and second rotational drive means to impart a twisting motion to said tubular plastics material as said tubular plastics material moves in a forward direction, said second rotational drive means being adjustable to vary pitch of the twist imparted to said tubular plastics material independently of operation of the first forward drive means.

22. Apparatus according to claim 21 wherein the first forward drive means includes a plurality of roller means, each having a circumferential edge engaging said tubular plastics material and configured to at least partially surround an outer surface of said tubular plastics material, said roller means being arranged in at least two groups with the roller means of each said group being located on opposite sides of said tubular plastics material, said roller means being rotationally driven to move said tubular plastics material forwardly in the longitudinal direction of the tubular plastics material, said roller means further being mounted from a common support means rotatable about a longitudinal axis of said tubular plastics material, said second rotational drive means being provided to drive said common support means to impart rotational movement thereto as the tubular plastics material is moved in said longitudinal direction.

23. Apparatus according to claim 21 or claim 22 further including an extruder for extruding polymer material in the form of said tubular plastics material in a heated softened condition.

24. Apparatus according to any one of claims 21 to 23, further including a rotating calibrator for sizing the tubular plastics material prior to delivering same to said rotating drive means.

25. Apparatus according to claim 24 wherein said calibrator and said rotating drive means are rotated in the same direction.

26. Apparatus according to claim 24 wherein the rotary calibrator includes a rotatable tube through which the hose passes having a first part with an inner diameter equal to a desired outer diameter of the hose and a second part downstream of said first part having an inner diameter larger than the inner diameter of said first part.

27. Apparatus according to claim 26 wherein at least said second part of the rotatable tube is perforated.

28. Apparatus according to claim 27 wherein said rotatable tube is rotated within a cooling liquid bath.

29. Apparatus according to claim 28 wherein pressure conditions less that atmospheric pressure is established above said cooling liquid bath.

30. Apparatus according to claim 29 wherein vacuum conditions are established above said cooling liquid bath.