JPS6222770B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to elongated strips for forming tubular objects such as tubes.

The use of plastic tubes for conveying water and other fluids is known, but when buried underground, the requirements for soil loading or pressure testing require a particularly large diameter and wall thickness. must be of considerable size, thus making such tubes expensive.

Another problem with tubing is that it is bulky for transportation, and until now such tubing has been formed from strips, i.e., by winding the strip into a spiral and connecting adjacent edges to form the tubing. was proposed. Such a system is disclosed in U.S. Pat. No. 3,938,558;
This deals with longitudinal corrugated metal strips with edges that can be connected adjacently.

It is also known to form flexible hoses from strips, which when the strip is wound into a spiral, one edge engages into the shape of the other edge to seal the hose and hold it upright. and a longitudinally shaped edge positioned to form a flexible member having a helical shape. However, the strip is relatively narrow.

Methods are also known to use somewhat wider strips made of synthetic material, which also have the ability to engage one edge into the socket of the other edge when the edges are placed adjacently. 3,606,670; This specification also discloses a machine for rotating the strip into a helical configuration and pressure bonding the edges.

The object of the invention is to have several advantages over the prior art, to avoid the need to have heavy parts,
Additionally, it can be used to form tubular objects such as tubes, or can be used in conjunction with preformed tubes to reinforce the tubes. The object of the present invention is to provide a strip with an improved shape.

Another object of the invention is to provide a strip that can be wrapped over a plastic tube to protect the tube and, if necessary, to substantially strengthen the tube.

Another object of the invention is to provide a strip having such a shape that it can be rolled into the shape of a tube and gives sufficient strength to such a tube due to the helical shape of the reinforcement used in the strip. be.

Another object of the invention is that it can be used to form a continuous groove around a tubular object by winding one strip over the other as well as by winding two strips in a helical manner. The purpose is to provide a strip shape that can be used in various ways.

These and other objects will be understood from the following description of the invention.

In accordance with the invention, a continuous strip of plastic material formed by extrusion or similar means comprises an upright barbed rib on one edge, a downwardly formed barbed rib on the other edge; a barbed rib in the intermediate portion, the intermediate rib connecting the first portion of the strip to the second portion of the strip, the first portion and the second portion being displaced in plane by the intermediate rib; a series of spaced upright ribs on a first portion and a series of downwardly formed sockets on a second portion of the strip, said sockets having said sockets positioned above said upright ribs; The elongated strip is positioned to engage the edges of the upright ribs when the strip is wound helically to cause the elongated strip to be wound.

As shown in FIGS. 1 and 2, the strip 71 is shaped such that when it is wound, a sealing groove 76 is provided between the upright ribs 72;
In this case, the strip 71 is connected to the outer connecting rib 72.
a to the intermediate rib 72e. Rib 72a
has a barb 74 on its outer surface, the rib 72e forms an engagement rib with barbs 74 on both sides, and the opposite end of the further extended strip also has a barb 74 on its outer surface but facing downwardly. It has a rib 72f formed in. One portion of the strip has a rib 72 extending in the same direction as rib 72a.
, but the other portions of the strips are spaced apart similarly to the ribs 72, but formed downwardly so that one portion of the strip is not overlying the other portion of the strip. The rib 72 on one portion has a second socket 78.
It can engage the socket 78 of the other part as shown in more detail in the figures. The two ribs 72a and 72f face in opposite directions,
By displacing one strip by half the width of the other during helical winding, the ribs 72a on one part of the strip engage the ribs 72e on the other part of the strip, forming a double wall. structure is provided.

A wound strip such as that schematically described herein may further have a strip above it, preferably wound in opposite directions for reinforcement, so that the portions of the strip are joined together when forming the tube. A binder can be sprayed or otherwise applied to the strip to provide a secure fixation.

FIG. 3 shows the strip 91 being fed between a pair of forming rollers 96 from a reel 94 containing a coil 95 of the strip, which rolls the strip 91 at this point to form a tube 97. When driven from the coil 95 onto the strip itself, it forces the connecting rib into the socket of the engaging rib. The tubing 97 rests on a roller support 98 by which it can be rotated with successive lengths of the strip 91 from the coil 95 continuing onto the strip itself.

Since the present invention is configured as described above, the following effects can be obtained.

By spirally winding the strip, a medium-heavy, double-walled tube with smooth inner and outer surfaces is obtained.

Since a tube with a spiral hollow portion is obtained, the tube has good heat retention and is high in strength.

Since the inner and outer surfaces are smooth, pipes can be joined using simple joints.

Since the materials for the inner and outer surfaces can be made of different materials, the most appropriate characteristics for the inner and outer surfaces can be achieved by using materials that have the required characteristics (e.g., chemical resistance, weather resistance) for the inner and outer surfaces. It is possible to form a tube with

[Brief explanation of the drawing]

FIG. 1 shows strips according to the invention aligned to form continuous sealing grooves longitudinally when the successive strips are connected and formed into a helically oriented tube; FIG. 2 is a somewhat enlarged fragmentary view showing how such strips are joined to form a sealing groove; FIG. 3 is a diagram showing how the strips of the invention are pulled out of the support relay to form a tube. is shown very schematically. 71...Strip, 72...Rib, 72a,
72e, 72f...Rib with jaw, 78...Socket.

Claims (1)

[Claims] 1 A barbed rib in which the strip is formed upright on one edge, a barbed rib formed downward on the other edge,
further comprising a barbed rib on the intermediate portion, the intermediate rib connecting the first portion of the strip to the second portion of the strip, the first portion and the second portion being displaced in plane by the intermediate rib; a series of spaced upright ribs on said first portion and a series of downwardly formed sockets on said second portion of the strip, said sockets having said sockets above said upright ribs; an elongated strip, the elongated strip being positioned to engage an edge of the upright rib when the strip is helically wound to position the elongate strip;