SU487479A3 - A cylindrical mandrel mounted in a rotating support for spiral winding of a flexible tape into a pipe - Google Patents

Description

communicating with the cavity of each cylindrical link of the free part of the channel.

The difference in the diameter of the perforated and non-perforated links is preferably made in the range from 0.01 to 0.05 inches (0.25 to 1.27 mm), depending on the characteristics of the elastic tape and the gas pressure.

It is possible to assemble the entire mandrel from identical cylinders, and in the fixed part of the mandrel, on top of these cylinders, put on a sleeve or several identical bushings from a gas-bearing material of the required thickness.

The mandrel works as follows.

A cylinder model of the same external diameter as the diameter of the pipe to be obtained is put on the tail of the mandrel. The winding rollers are positioned in the required places and in relation to the mandrel to provide the required angle between each belt and mandrel, the belts are sequentially drawn through these rollers, wound around the mandrel and attached to the cylinder model iodine with a corresponding angle. The nerve tape to be coiled is positioned over the corerelated part of the alignment, and the second and subsequent tapes are fed so that at least a portion of their width passes over the free part in order to counteract the tendency of the inner layer created from the first tape to press against the mandrel under the action of the windings, formed by subsequent tape or leiths, due to the gas cushion. The compressed gas is supplied to the mandrel under the desired pressure and the grip belt drive and the mandrel itself are started. The gas pressure of the cushion will depend to some extent on the characteristics of the layer, for example for a paper layer it is preferable to use pressures in the region of about 20-60 pounds per square inch (1.4-4.2 kg / cm) and in particular 40 pounds per square inch ( 2.8 kg / sl1). If the pressure is too low, the desired lubricating effect may not be obtained. However, with too much pressure, there is a tendency for gas pockets or bags to form (i.e. gas accumulation sites) under the aura layer, which ultimately erupt at the seam site.

After the model has passed the grip belt drive, it can be removed, and the process continues, with the grip belt leading through the spiral pipe that is supported by the movable stopper. The mandrel rotates at the same speed as the pipe to reduce or avoid causing friction.

There are other options for making the proposed mandrel. For example, the free part of the mandrel does not need to rotate, but its links can be set so as to rotate freely on the shaft. In addition, the tie rods, by which the links rotate with the hollow shaft, can be replaced by another suitable means. Fianpn.Mcp, na shaft: there can be a grooved keyway, and one or both of the flaps and the end plates of each cylindrical link can be provided with a key (key lug), and equipped with a slide for sliding along the keyway KaiiaBKH. In another embodiment, the cylindrical links forming the mandrel can be rotated with the shaft by means of tapps, for example pressing the links to the flange 10 by means of a second flange applying pressure at the other end of the sump under the action of the screw and nut. In this case, the free part of the mandrel may be fixedly mounted on the shaft, which in turn is also fixedly mounted in the supports 3, 4, while the other part of it is mounted on the shaft so that it can rotate and is moved in any direction.

Perforated walls of cilI: Ndrov can be replaced by permeable walls of sintered metal. It is only necessary that the walls have gas ducts.

The whole complex of mechanisms can be designed to work with a mandrel whose axis is located vertically.

For winding any flexible (elastic) tapes can be used: metal, paper, cartoe, from textiles, synthetic material and plastic. In addition, the thickness of the tape is not limited. An oia may have a simple plating cross section, such as a cross-section or longitudinally extending protrusion, and also have recesses on one or both of its surfaces. It may be composite, for example, it may have a layered structure, and it may be subjected to pretreatment, for example, an adhesive, water-impermeable agent, a sticky one, capable of giving foam, a composition or a protective coating. You can also attach tapes to the expanded material, for example in the form of foam plastic.

The joining of the screw lines of each tape can overlap or overlap in accordance with the requirements, and any suitable means for connecting adjacent spirals can be used — it molds with each other, such as riveting, welding, studs, gluing.

This invention can be particularly well used for the production of thin-walled tubular material of large diameter, as well as for the manufacture of pipes made of oriented plastic material.

The gas supplied to form a gas cushion can be heated or cooled (depending on requirements), due to which it can either supply or remove heat from the pipe as it forms.

Subject invention

Claims (3)

I. A cylindrical mandrel fixed in a rotating support for spiral winding of a flexible tape into a pipe, advanced along the mandrel, characterized in that, in order to facilitate the advancement of the pipe along the mandrel, as well as to wind the flexible tape of unlimited thickness, it is made stepped with a smaller with a diameter in part, adjacent to the unfixed end and having gas pipes in the wall, communicating through the cavity provided in the body of the mandrel with gas supply. 2. The mandrel according to claim 1, characterized in that the difference in diameter between the parts is 0.25-1.27 mm. 3. The voucher for PP. 1 and 2, characterized in that, in order to simplify assembly and disassembly Each part of it consists of a set of identical cylinders rigidly fastened together.