DE2008352A1 - Method and device for the production of screw sutures - Google Patents

Description

PATENT LAWYERS Dr. D. Thomsen H. Tiedtke G. Bühling

Dipl.-Chem. Dipl.-Ing. Dipl.-Chem.

8000 MONKS 2 'VALLEY 33

¹ TELEPHONE 0811/226894

TELEGRAM ADDRESS: THOPATENT

/ MUNICH February 23, 1970 case Q / B. 21739 - T 3510

Imperial Chemical Industries Limited London (Great Britain)

Method and device for the production of screwed wire pipes

The invention relates to a new cantilever mandrel for the manufacture of pipes by a process in which one or more flexible bands are helically wound on a cantilever mandrel (that is, a mandrel supported at one end in a holder and free at the other end) is to obtain a helically wound tubular structure and in which relative axial movement is effected between the mandrel and the helically wound tube obtained for mutual separation .

According to the invention, a cantilever mandrel is proposed which has a head section which, in addition to the holder

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may be and has an impermeable cylindrical viand, further a tail or end portion which is coaxial with the Head portion is and is located at its end facing away from the holder and a smaller diameter than the head portion, wherein at least a length portion of the tail portion has a hollow cross-section and a gas-permeable wall, and a conduit located in the head portion which passes through the hollow portion of the Tail can connect to a source of compressed gas.

According to a further development of the invention, a system for the production of pipes by a method is proposed in which one or more strips are helically wound on a cantilever mandrel, this system having the following features, (a) a holder, (b) one of the Bracket supported cantilever mandrel with a head portion, which can be next to the mandrel holder and has an impermeable cylindrical wall, and with a tail portion which is coaxial with the head portion and is located at its end remote from the holder and has a smaller diameter than the head portion, wherein at least one length of the tail section has a hollow cross-section and has a gas-permeable wall, furthermore a conduit located in the head section which connects the hollow section of the tail to a source for

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can connect compressed gas, (c) a device for supplying at least one flexible sheet or band to the mandrel, (d) means for the Feeding each band from the feeding device to the mandrel at a predetermined angle less than 90 ° to the longitudinal axis of the mandrel, (e) means for rotating or winding the tape or tapes i and about the mandrel axis for the Formation of tape windings on the mandrel, (f) a device synchronized with the rotary device for the axial advance of the tape windings along the mandrel, (g) a support and guide device for the helically wound Tubular product and (h) means for supplying compressed gas to the hollow portion of the mandrel.

In operation, the or the first is wound to and around the mandrel to form the helical Rohrs fed tape is fed to the head section and it then the .Bandwindungen along the mandrel on the Tail section slid on between the wall of the tail section and the bottom of the helical wound body a compressed gas cushion is formed, which is the advance of the body along the mandrel and from this supported down. The head section is impermeable, so that. he is an exact form element for determining the Inner diameter of the helically wound body forms and the use of tapes from a one

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material such as tissue paper or very thin plastic film that cannot cope with heavy loads is allowed, which material is difficult against the

Counterforce of compressed gas can be promoted ". The tail section has a smaller diameter than the head portion so that it provides an annular space for the gas cushion, ■

W Preferably, at least the head portion of the

The mandrel is rotatable about its longitudinal axis to reduce the friction between This section and the tape windings to reduce. If necessary, the head can be driven mechanically.

Furthermore, the head and the tail portion advantageously each have a substantially constant diameter, with a stepped diameter reduction between

the head portion and the tail portion is provided, fc the a regular annular gap of suitable dimensions, forJl provides the cushion of gas between the tail portion and the inner surface of the helically wound body.

According to one embodiment of the invention, which because of their simplicity, ease of assembly and disassembly and flexibility of operation are preferred, the mandrel can be constructed from the following parts: (i) a shaft which at one end (the head) in a

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Bracket can be supported. (Ii) Two sets of hollow
cylindrical units, 'which are coaxial and in end-to-end
Assignment can be placed on the shaft, each set 1 having a substantially uniform diameter and made
consists of at least one unit and both sentences
have different diameters of which the set.
larger diameter mountable on the head of the shaft;

is and has impermeable cylindrical walls, while j

the set of smaller diameter on the tail of the shaft!

■. . ■ ι

is mountable and gas-permeable cylindrical walls be j

sits, (iii) a device for connecting the 'hollow!

Inside at least one unit of the set of smaller diameters!

knife (preferably the one next to unit j

of the larger diameter set on the shaft \

located) to a source of compressed gas, and (iv) I means for rotating at least one (preferably all) of the units of the larger diameter set

around their axis »,

From the previous description it follows that one with
this embodiment with a number of sets of cylindrical units of different diameters to be applied to the shaft is able to produce any mandrels for the production of helically wound tubes
Diameter can be put together quickly. In the same way
"Arbors of any length can be adapted to the respective

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Purpose to be built.

The hollow interior of each cylindrical unit smaller diameter is preferably connected to a source for "compressed gas characterized in that forming the shaft is hollow and inside stop in this way" of the shaft for a line ensures that a along an.geeigneten points Ψ or more holes which open into the hollow interior of at least one of the smaller diameter units, a device for connecting the conduit to a source of compressed gas being provided at the head end of the shaft whereby the gas pressure at each hole can be varied so that different pressures can be built up along the mandrel.

Furthermore, the shaft is advantageously rotatable in the holder, with at least the larger diameter units are so firmly attached to the shaft that they rotate with this.

. The invention is illustrated below in greater detail Drawings explained in more detail.

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Pig. 1 shows a diagrammatic representation

mandrel according to the invention with partially exposed interior; -

J ¹ Ig. 2 shows on an enlarged scale and in detail. Extended cross-sectional view of a zy

Lindrian unity of the thorn;

Fig. 3 is a perspective view of a Pipe making machine with the mandrel naph Figs. 1 and 2.. ■ '

In Fig. 3, 21 generally designates a mandrel in which at least the head can be rotated. 22a, 22b etc. are spindles., on which rolls of tape sit (two are shown but one or more can be used as needed) of which the tracks are drawn onto the mandrel. 23a ,, 23b etc. are the webs fed in the direction of the arrows, while ' 24, .25, 26 and 2-7 denote rollers through which the belts are weighed, through which the belts are also fed onto the mandrel and by means of which they can be tensioned if necessary, e.g. by using brake cylinders on the rollers or rolling.

28 is a helically wound tube that from the strips by gluing axially adjacent turns

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each band ζ.B. by adhesive strips (as shown) or other suitable means such as the use of pressure sensitive adhesive coatings on the tapes. It is supported by rollers 29 and a traveling peg 30 and out, means for turning and axial advance of the pipe (and thus rotating or winding the tapes around the mandrel and axially Vorschie- ψ of turns ben along the mandrel) is provided , which is formed by a wrapped belt 31 which is driven by a roller 32 and tensioned by a roller 33.

The cantilever mandrel used in the system according to FIG. 3 will now be described with reference to the one shown in FIG and Fig. 2 illustrated preferred embodiment. It has a number of hollow cylindrical units 3 ^, fe sit the coaxial end to end on a rotatable hollow shaft 35, which is free at one end (the tail) and at the ... other end (the head) supported by bearings 36 * 37 and rotated by a motor 38 such as chain and sprockets. The cylindrical units forming the tail of the mandrel have perforated cylindrical walls, while the units forming the head are unperforated and are slightly larger in diameter than the tail units. Each tail unit has a pair of one another

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opposing end plates 39 with recessed flanges facing each other and a cylindrical wall 40 perforated structure, which lies between the end plates and on these, z * B. by welding to form a Hollow cylinder are attached. Additionally or alternatively. the flanged ends can be connected to one another with the help of tie rods. Each flanged end is on one or pierced in several places to form channels through which tie rods & go that attach each unit to the Connect the paddle 42, which is firmly seated on the shaft, causing the units to be rotated by the shaft during use. The head units have a similar structure to those of the Tail, however, larger in diameter and unholed cylindrical walls. The hollow shaft is connected to a line 43, which in turn with a not ^ shown Compressed air source is connected and is equipped with a valve 44 for controlling the supply of compressed air. Along the hollow shaft is provided with a number of holes 45, which connect the hollow interior of each tail unit of the mandrel. Each hole is preferably provided with means for adjusting the opening.

The difference in diameter between the unperforated and the perforated units is preferably not very great. It was found that, for example, diameter

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differences on the order of about 0.025 to 0.13 cm (0.01 to 0.05 inch) are generally useful. The respective value depends of course on the type of Bands and the gas pressure.

In a very expedient embodiment, the units forming the head section of the mandrel can be replaced by ψ units which are essentially identical to the units forming the tail section, in which case a sleeve or sleeves made of impermeable material and of the desired thickness is pushed over these units.

In operation .wird against the tail end of the mandrel a dummy cylinder with the same diameter as the one set forming tube and it becomes the

h Belt drive wound around and adjusted to the correct angle to the longitudinal axis in order to obtain the desired ratio of rotary movement to axial movement. The rollers 24, 25 and 26, 27 are brought into the correct position with respect to the mandrel in order to produce the required angle between each belt and the mandrel, the belts being drawn successively through the rollers, wound around the mandrel and up to the dummy cylinder in the connected at the correct angle. The first tape to be wound sits over the head portion of the mandrel while the second and later tapes

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preferably so fed; be that at least a part their width extends über.den tail section, whereby by, the air cushion is prevented that the inner layer formed by the first band by the turns of the later band or bands is pressed onto the mandrel. Then air becomes air with the thorn The correct pressure is applied, and the winding belt drive is activated and the mandrel drive switched on. The air pressure for that. upholstery depends to some extent on the type of Stopped, but good results were obtained with paper

"'·" ■ "at pressures ranged from about 1.4 to 4.2 kg / cm

(20 to 60 pounds / square inch) especially about 2.8 kg / cm (40 pounds square inches) achieved. Is the pressure too low, the desired lubricating effect cannot be obtained will. If the pressure is too high, gas pockets can form under the layers, which eventually burst the hem or seam.

Has the 'blind end over the winding belt drive moved out, it can be removed, the process being continued with the winding belt, which coiled pipe propels which is supported by the traveling stake 30. The mandrel is preferably at least rotated as fast as the pipe to avoid frictional strain.

The advancing helically wound

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Pipe can be cut to the desired lengths, e.g. with the help of a flying saw, not shown, which comes with wanders along the pipe, cutting it in the process and then quickly returning to its starting position.

Alternatives to the devices explained are obvious to a person skilled in the art Thorn does not have to turn, they can form the tail-

^ the units sit freely rotatable on the shaft. aside from that

the tie rods by which the units are rotated with the hollow shaft can be replaced by other suitable means will. For example, the shaft can extend axially with a. the keyway and can have one or both of flanged end pieces each cylindrical unit can be provided with an engaging key in the keyway. According to a As a further alternative, the arrangement can be made so that the cylindrical ones forming the head and the tail Units rotate by friction with the mandrel shaft, i.e.

P by pressing the units against the surface 42, with the help of a second flange, which with the help of screw and nut from the other end of the shaft one Exerting pressure. In a further alternative, the tail unit or. Tail units firmly attached to the shaft be attached, which is firmly seated in bearings 36 »37 while the head portion is rotatably mounted on the shaft and

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if necessary rotated by any suitable means. ;

The perforated walls of the cylinder can through permeable sintered metal walls are replaced.

The system can also be arranged to operate with the mandrel axis vertical.

The rollers 29 for supporting and moving the rotating pipe can be pulled through guide and it can he. Hiking pegs can be replaced by support rails. The guidance and support functions can be performed by the same Rails can be taken over if necessary.

The winding belt can be driven by another drive device be replaced.

According to a further alternative (not shown) of this embodiment, the 'tape rolls can be placed on spindles which can rotate around the mandrel axis'. For example, the spindles can be arranged radially on a revolving housing, the axis of which is parallel to the longitudinal axis of the mandrel and is preferably arranged coaxially to the mandrel, in which case the tube is not around the

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The mandrel needs to be rotated but only has to be removed when molding. In this case it is advisable the means for axially advancing the helically wound ribbon or ribbons along the mandrel a pipe extraction device. The frame is expediently arranged either around the mandrel and on the side of the mandrel, which is remote from the one on which the formed tube is withdrawn.

Any flexible tapes such as metal, paper, cardboard, textile, and plastic can be used in the operation of the present invention. In addition, the tape can have any width. It can also have a simple or complex cross-section, for example ribs or indentations on one or both surfaces. It can also consist of composite material, for example have a layer structure and can be pretreated, for example with a glue, a waterproof agent, an adhesive, a foamable compound or a protective coating. Even bands can of expanded material used, such as plastic foam. - -

The contiguous turns of each band can overlap or butt together

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and any means for gluing or connecting adjacent turns to one another can be used, for example riveting, welding, pinning or gluing. ■,

The invention is particularly suitable for the production of thin-walled pipes of large diameter and for the production of pipes from oriented plastic material. ■ ■

Another advantage of the invention is that \ - that the gas supplied to form the gas cushion or gas cushion can be heated or cooled as required, thereby adding or withdrawing heat as the tube is formed. For example, a tape or can several tapes with a heat sensitive adhesive be coated, the gluing through the use

■ ■ '- ■ ■■ ■ ι

can be caused by heated gas as a gas cushion. -

In another example, one or more ribbons can comprise a fibrous material, e.g. is impregnated with a thermosetting resin, the hardening of which can be assisted by heating the gas. Other facilities for using this form of heat control will be apparent to those skilled in the art.

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Claims (13)

Claims 1.J Cantilever mandrel for use as a temporary support for pipes wound by helical winding one or more flexible bands are produced on the mandrel and can be moved axially with respect to the mandrel, characterized by a head portion which, in addition to the ^ The mandrel holder (36,37) can be arranged and a impermeable cylindrical wall, through a tail portion which is coaxial with the head portion and is at the end applied to the bracket and is smaller in diameter than the head portion, wherein at least part of the length of the tail portion has a hollow cross-section and has a gas-permeable wall (40), and by a conduit provided in the head portion for connecting the hollow part of the tail to one P source of pressurized gas. 2. Mandrel according to claim 1, characterized in that at least the head portion is rotatable about its longitudinal axis is. 3. Mandrel according to claim 1 or 2, characterized in that net that the head portion and the tail portion each have substantially constant diameters, with between the head section and the tail section, one step in front of 009836/1526 is seen. . ' 4. mandrel according to claim 3> characterized in that the diameter difference between the head portion and the tail portion is about 0.025 to 0.13 cm. 5. Mandrel arrangementV characterized by ' i (i) a shaft (35) supported at one end (the head) in a holder (36, 37), ■■ '■■'. . ι (ii) two sets of hollow cylindrical units (3.4) which; Can be coaxially arranged face to face on the shaft, j ■ · 'i each set being of substantially uniform diameter. ! and consists of at least one unit and wherein the two sets have different diameters of which the larger diameter set at the head portion of the "shaft ^ and has impermeable cylindrical walls and of which the set of smaller diameter at the tail end can be arranged on the shaft and has gas-permeable cylindrical walls (40), -. . (iii) means for connecting the hollow interior of at least one smaller diameter unit to one another Pressurized gas source and ■ (iv) a facility for rotating at least one of the Units of the larger diameter set around their axis. 009836/1526 6. Arrangement according to claim 5, characterized in that that the shaft (35) is rotatable in the holder (36, 37) and at least one set of units of larger diameter can be firmly mounted on the shaft in order to rotate with it. 7. Arrangement according to claim 5 or 6, characterized in that the device for connecting the hollow interior of the unit of smaller diameter to a source of pressurized gas a line located in the shaft (35) having, with one or more holes (45) along its length is provided, which is smaller during use in the hollow interior of at least one of the units Can open diameter, at the head end of a device (43,44) for connecting the line a compressed air source is provided. 8. Arrangement according to "Claim 7> characterized in that that each hole (45) in the line has an adjustable opening owns. . ' 9. Arrangement according to one of the preceding claims 5 to 8, characterized in that the set of units of larger diameter is replaced by at least one unit which is substantially identical to the units forming the set of smaller diameter, on this 009836/1526 ^; Unit at least one sleeve made of impermeable material and the required thickness can be attached. 10. mandrel or mandrel arrangement according to one of the preceding Claims ι to 9, ^ characterized by a Operating position in which the axis lies essentially in a vertical plane. 11. Hollow cylindrical unit for a mandrel arrangement. according to one of the preceding claims 5 to 10, characterized in that the hollow cylindrical unit can be placed on a mandrel shaft (35) and has a perforated cylindrical wall (40). 12. Hollow cylindrical unit according to claim 11, characterized by a pair of opposing end plates (39) with recessed annular flaps, | facing each other and by a cylindrical wall (hO) perforated structure that sits between and is attached to the end plates. ' 13. Plant for the production of pipes by helically winding one or more flexible strips, characterized by (a) a holder (36, 37) which (b) a cantilever ^{mandrel according to one of claims 1 to 1} J and 10 or according to the mandrel arrangement one of the previous 009836/1526 according to claims 5 to 10, supported by (c) means (22a, 22b) for feeding at least one flexible band (23a, 23b) to the mandrel, by (d) means by which each band from the feeding means is underneath a predetermined angle of less than 90 to the longitudinal axis of the mandrel tangential to the mandrel, by (e) means for rotating or winding the tape or tapes around the mandrel axis to form tape windings on the mandrel, by (f) a Device synchronized with the rotating device for the. axial advancement of the tape windings along the mandrel, by (g) a support and guide device (* 30) for the helically wound tubular product "and by (h) a device (43, ^ ² O for supplying pressurized gas to the hollow part of the mandrel. 0 09836/1526