DE2126698A1 - Manufacture of helically wound hoses - Google Patents

Description

Dr. F, Zumstein sen. - Dr. E. Assmann Dr. R. Koenfgsbergrer - DlpF.-Phys. R. Holzbauer - Dr. F. Zumstefn Jun.

PATENT LAWYERS

TELEPHONE: COLLECTIVE NO. 225341

TELEX 529979

TELEGRAMS: ZUMPAT CHECK ACCOUNT: MUNICH 91139

BANK ACCOUNT: -BANKHAUS H. AUFHÄUSER

8 MUNICH 2.

BRÄUHAÜSSTRASSE 4 / III

4 / Ma
GH.4828

DUNLOP HOLDINGS LIMITED, London / Great Britain,

Manufacture of helically wound hoses

The invention relates to the manufacture of hoses and more particularly of flexible hoses with a reinforcement layer made of helically wound reinforcement wires.

In the manufacture of hoses, the circumferential forces as a result can withstand pressures of, for example, a fluid in the hose, will generally be one or more Layers of reinforcement material applied to the tubular carcass.

The reinforcement can be in the form of braided wire, helically wound wire, or a combination have out of both, but in case the hose is a frequent one

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Is subject to bending, reinforcement is made of braided material Wire not entirely satisfactory. With a reinforcement made of braided wire, the wires lie one on top of the other and will possibly break as the hose bends causes the wires to move over and against each other scrub.

In the case of a hose with a reinforcement of helically wound wires, the wires lie in each individual layer parallel to one another and successive layers are separated from one another by | f a layer of polymeric material. Therefore Hoses with reinforcement made of helically wound wire have a longer service life than hoses with braided reinforcement and can also be used in tougher conditions.

However, difficulties have been encountered in finding an inexpensive, quick and economical process for making to create helically wound hoses. Conventionally, such hoses are manufactured in lengths of up to 18 m, by applying the layers of hose to a steel mandrel, and this method is general k laborious and slow, although it is in the case of tubing with large diameter which, if built up in greater lengths, would be too heavy and troublesome to handle would be.

It is an object of the invention to provide an improved method for the production of helically wound hoses.

In accordance with the present invention, a method for making helical Coiled hoses involve the extrusion of a hose carcass in the form of a layer of polymeric material a flexible mandrel and the helical winding of one or more layers of reinforcement wires on top of it Schi auchkark as s e «

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When using a flexible dome of suitable length, a large length of flexible hose with reinforcement can be used from continuous helically wound Reinforcement wires are made. Conveniently, the flexible mandrel can be 300 m long if the wire winding machine which can carry reinforcement wires of suitable length.

The hose is preferably made with two reinforcement layers, wherein a layer is formed from wires which are wrapped around the tubular carcass in a sense, and the another layer is formed by wires wound in opposite directions around a tube of symmetrical Form construction. A layer of polymeric material is provided between the adjacent reinforcement layers, to prevent contact between the reinforcement wires of the adjacent layers.

According to another embodiment of the invention comprises a method of making a helically wound Tubing involves extruding a tubular carcass in the form of a layer of polymeric material onto a flexible one Mandrel, the application of a layer of elastic material to the tubular carcass, and the helical winding of one or more layers of fine reinforcing wires on the tubular carcass.

When helically winding a reinforcement layer made of fine Wires have found it difficult to maintain uniform and equal tension across all wires and it may happen that one or more wires have a higher tension than the rest. If the Tube is subsequently cured, initial softening of the tube carcass material occurs and the wires with the higher tension cut into the carcass, where-

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causing the hose to soften and possibly a leak of the finished hose. Attaching a layer of elastic material, such as from fabric material or from a layer of flakes, which are applied to the tubular carcass, forms one - Padding or buffer layer and prevents the tendency for one or several of the fine wires to cut into the carcass, or make them very small.

In the following, an embodiment of the invention will now be explained in more detail as an example, with reference to the attached Reference is made to the drawing, which is a side view in section of a winding machine for applying a wire reinforcement on a tubular carcass formed on a flexible mandrel.

A flexible hose of circular cross-section two helically wound thread-like reinforcement layers embedded, which extend in the radial direction in at a distance from one another, with a buffer layer of elastic flake material adjacent to the radially inner reinforcement layer is provided.

A polymer material is used to manufacture the hose such as a natural or synthetic rubber on a flexible mandrel in the form of a solid nylon rod of circular cross-section extruded to form a tubular carcassis. Then the tubular carcass coated with adhesive and passed through a flocking machine to make a layer of buffer material, such as Nylon flakes, to be applied to the radially outer surface of the carcass.

The flocking device can use an electrostatic technique, in which the flakes are applied to the tubular carcass by an electric field. As other possibilities

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the flocking device can be a mechanical device, e.g. use a paddle mixer to stir the flakes to be applied to the adhesive, which is the radially outer surface the carcass coated, in which case it is advantageous to move the carcass so that the seizing the flakes are supported on the adhesive layer.

When passing through a flocking machine of the mechanical or electrostatic type, the carcass can be wrapped around its Axis can be rotated to ensure complete and even coverage.

A winding machine as shown in the attached drawing is used to screw numerous fine reinforcement wires 1 of great length around the to wind carcass 2 coated with flakes. The reinforcing wires can consist of one or more strands and have a diameter in the range of, for example, 0.25 mm to 0.75 mm (0.01 to 0.03 inches). Preferably are the reinforcement wires are steel wires with high tensile strength,

4 which have a tensile load on the order of 2.5 χ 10 kg / cm (150 tons / squ.inch) and also have a high elastic modulus to have.

The carcass 2 coated with flakes is supported by the flexible mandrel 3 which extends through the winding machine 4 extends coaxially with the axis of rotation of the winding machine and coaxially through a drawing die 5 which has an inner bore of a size effective to compress the reinforcement wires 1 into a single tightly wound layer. / or to solidify.

Each reinforcement wire 1 is fed from a spool 6 which has sufficient wire to continuously wind the length of the hose. Each coil is on its own

Carrier 7 attached and is so under spring tension that it rotates on the carrier against a spring tension brake, the carrier being fixed to a rotatable holder or a Disk 8 is attached, but slightly from this disk is removable, which has a central opening coaxial with the axis of rotation of the rotatable disc, so that with Flake-coated carcass 2 can pass through it «Depending on the total number of wires to be wound, can be more than one wire on each spool.

Each wire from each spool 6 runs back and forth over pulleys 9, 10 on the associated carrier 7 in order to tension the wire, .over a first spacer ring 11, and radially inward to an annular guide plate 12 coaxial with the rotatable disc 8 is attached. Each wire runs individually through a hole 13 which is nearby in the guide plate of the outer circumference of the guide plate is formed, via a second spacer ring 14, and in the drawing mold 5, which tightly surrounds the tube so as to force the wires into a single tightly packed layer.

The discs 9, 10, the spacer rings 11, 14, the guide plate 12 and the drawing die 5 all act to cause the "breaking" of the wires, i.e. they act to prearrange the wires and to bend back to reduce the resilience of the wires and to give the wires a bias so that they have a residual resilience in one direction that tends to wrap them around the tubular carcass to hold the coiled position.

A pulling device, not shown, is provided to the to pull the reinforced hose through the die, where the The withdrawal speed and the rotational speed of the rotatable disk 8 are related in such a way that the desired pitch angle of the helically wound

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Wires is generated.

Subsequent to the coating of the reinforced hose with another layer of polymeric material, which is a Intermediate layer is, and if desired, after the application of another buffer layer, a second additional layer of helically coiled wires onto the hose in the opposite direction Sense applied to the first layer so as to balance the forces acting in the hose, and one final covering layer made of polymeric or other material is applied to the outside of the hose.

In a favorable manner, a hose of the type described, of the two reinforcement layers and an intermediate layer made of polymer Material has to be produced in an apparatus comprising two rocking machines which are arranged so that they wrap the reinforcements in opposite directions in superimposed layers, and the one device for Applying a layer of polymeric material between the two layers of wires.

The constructed tube is then covered with a flexible lead sleeve that allows the tube to be cured for vulcanization is wound on a drum. After vulcanizing, the hose is unrolled from the drum and the lead sheath is slit lengthwise and peeled from the tube. A compressed air supply can connected to one end of the hose to assist in pulling it off the mandrel.

Although the invention has been described with reference to a hose having two layers of reinforcing wires, it is applicable to the manufacture of long length tubing of other construction where it is desired to have a reinforcement layer from continuously helically wound wires.

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The invention therefore provides a method which enables long lengths of hose to be formed with a reinforcement layer from continuously helically wound wires and at low cost. Next is the required Equipment cheap and the process allows high speed production of helically wound Long tubing.

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Claims (10)

Claims \ l.i Process for the production of a helically wound V ^ th hose, characterized in that a hose carcass in the form of a layer of polymer ^ material. a flexible mandrel is extruded and one or more layers of reinforcement wire helically onto the
Hose carcass to be wound. 2. The method according to claim 1, characterized in that reinforcement The wires are helically wound around a tubular carcass around a first reinforcement layer to form that an intermediate layer of polymeric * material is applied to the first reinforcement layer, and that
Reinforcement wires helically around the liner
wrapped around a second reinforcement layer
form. 3. The method according to claim 1, characterized in that the Reinforcement wire is a high tensile strength wire. 4. The method according to any one of the preceding claims, characterized in that the tubular carcass with elastic
Material is covered to form a buffer layer for the reinforcement wires wrapped around the tubular carcass. 5. The method according to claim 4, characterized in that
a textile material is applied to the tubular carcass in order to form a buffer layer. 6. The method · according to claim 4, characterized in that a layer of flakes is applied to the tubular carcass to form a buffer layer. 7. The method according to any one of the preceding claims, characterized characterized in that a flexible lead sleeve is applied to the hose prior to vulcanization to provide a removable one Form cover layer. 8. The method according to any one of the preceding claims, characterized characterized in that a winding machine and a compressing machine Draw form used to apply the reinforcement wires in a helical manner around the tubular carcass, wherein the drawing die is arranged close to the winding machine in order to transfer the wires from the machine to the Pressing the carcass and forming a single tightly wrapped ply. 9. Apparatus for performing the method according to claim 1, with a winding machine with 'several bobbins, the . are fixedly attached to a rotatable holder, characterized in that each spool carrier (7) is arranged to carry a spool (6) so that the spool rotates against a spring tension brake about an axis parallel to the axis of rotation of the rotatable holder (8) may that at least one washer (9, 10), a guide plate (12), and a spacer ring (11, 14), which are fixedly attached with respect to the rotatable bracket, are attached so that they provide a tortuous path for the reinforcement wire (1 ) withdrawn from the spool so as ^{to provide a "break 1} " of the wire so that a compressive drawing die (5) is provided to pull the reinforcement wires into a single tightly wound layer around a tubular carcass (2) to press. 10. Apparatus according to claim 9, characterized in that at least two of these winding machines (4) in one axially spaced to provide reinforcement wire in opposite directions in one above the other to wind lying layers, and that a device is provided to a layer of polymeric Apply material between the two layers of wire. 10 9849/1798 Blank page