DE1030124B - Plastic conduit pipe and process for its manufacture - Google Patents

Description

GERMAN

In recent times, pipes made of plastic, in particular drinking water pipes, are often used for pipes z. B. made of polyethylene. These line pipes bring about the previously usual metallic Rohiren with a whole series of advantages. So can such pipes, if they are out of proportion elastic material are rolled up on cable drums, transported and in proportion long lengths. Furthermore, such pipes are against influences either by the the media flowing through them or could have a destructive effect on them from outside are significantly more resistant than metal pipes.

In addition to these pipes, more and more pipes made of a harder material are used, since these can be exposed to a significantly higher mechanical load and therefore also with larger Duirchmesser, z. B. as sewer pipes, can be relocated. Due to their hardness and diameter, such pipes are in However, longer lengths on drums are no longer possible. Similar to metal pipes, they must be used in certain, specified lengths are manufactured and laid.

With these pipes, the problem of connecting the individual pipe lengths to one another, which plays a minor role in the case of pipes made of more elastic material, comes to the fore again. Up to now, the pipe ends have usually been heated and compressed conically at the installation location at the joints, and then connected with metallic clamp connections. This solution is not completely satisfactory insofar as metallic parts are again used in the line, so that the advantages of the non-metallic line are partially or completely canceled out. Another proposal that has become known is to use connecting pieces made of plastic which are designed in a manner similar to the metallic clamping cone connections. Instead of upsetting the pipe ends, threads were cut into them, onto which the corresponding connecting pieces were screwed. However, this requires a certain minimum wall thickness of the pipes in order not to weaken them too much at the points with the cut threads. Finally, it has already been proposed to connect the pipe ends to one another by sliding sleeves into which metallic wires are embedded. These heat up when an electric current is introduced, soften the plastic surrounding them and thus bring about a connection between the two pipe ends and the sleeve pushed over them. Here, too, it is only a question of the permanent connection of two pipe ends, where pipe made of plastic
and its method of manufacture

Applicant:

Theysohn & Heumach,
Pirmasens (Palatinate), Glockenstr. 16-20

Albert Theysohn, Pirmasens (Palatinate),
has been named as the inventor

due to the not precisely controllable heat

ao admission can still be sources of error can.

The most satisfactory solution so far, however, is the plastic flanges prefabricated onto the tube weld on. The welding on of these flanges is, however, relatively cumbersome, in addition Here, too, the control whether a faultless connection is made between the pipe end and the welded flange was very difficult.

The invention has set itself the task of creating an improvement here that is flawless Ensures connection between pipe and flange or other parts and also saves working time brings with it in the manufacturing process. The invention solves this problem by means of conduits made of plastic, each of which has a certain minimum wall thickness to accommodate the forces acting on it mechanical loads without permanent deformation consequences must have on their ends Connection fittings, such as flanges, threads or even entire fittings, sprayed on or pressed on are. Then the connection fittings have to do with it about the same thickness as the wall thickness of the pipe. You may be weaker, however, should not be much stronger. The spraying or pressing takes place in a normal Injection molding machine by means of a dome in a divided one Shape onto which the pipe ends are pushed. The material forming the connection fittings becomes hot, injected into the remaining space between the mold and the end of the pipe, so that an intimate and permanent, uniform fusion with the pipe end over the entire contact area takes place. The pipe end and fitting then form a homogeneous body.

809 510/259

A similar method has already been proposed for attaching tube heads to tubes, however, in this procedure it was necessary to use one with a zinc sleeve or one for the tube jacket other metal insert provided plastic jacket 5 to use, otherwise the tube sleeve on the later joint with the tube head, since it is only consists of relatively thin-walled material, would have been destroyed. In the present case can on the other hand, since the pipe end and the fitting to be applied are roughly in terms of their material thickness the same parts act, a substantial softening take place, the prerequisite for the proper Amalgamation is.

Further features of the invention and details of the advantages achieved by the same emerge from the description of the embodiment of the subject matter of the invention shown in the drawing and the manufacturing process.

In the drawing is schematically a partial section of an injection molding machine with a mold for formation of a pipe flange with the pipe on the end of which the flange is to be applied. With Iund2 are the two jaws of the injection molding machine referred to, which move on the bars 3 and 4 against each other. The form is divided and exists from parts 5 and 6, which move with the jaws 1 and 2 against each other and close, after the pipe end 7 has been pushed onto the mandrel 7 ', which is also designed as part of the mold is. The material forming the flange is fed to the mold by the machine through the nozzle 8. the The illustration already shows the flange 9, which was sprayed or pressed onto the pipe end 7. the Figure thus shows the device after completion of the injection or pressing process.

Due to the heat of the material to be sprayed on, there is an intimate and permanent fusion of the formed flange or thread, including entire fittings such as T-pieces or the like, with the pipe end. The operations for making the | Flange or other parts and the application? on the pipe end are combined, so that an ER f heblidhe saving in working hours and labor; j | machines results. Furthermore, the applicable proportionate \ moderately difficult deformation of the pipe ends at ^ installation site, and it accounts for all of the disadvantages in? Compound would occur with the use of metallic arm & r i doors. I is also particularly advantageous; the application of threads according to the process described, since the remaining pipe thickness is no longer marked with '}'; ¹ Consideration of the thread that would otherwise have to be cut ξ; must be kept excessively thick. -:; Ϊ

Claims (2)

Patent claims? 1. Line pipe made of plastic, thus gdseim-> .: draws that its ends with connections; [; fittings roughly the same thickness as the Wands Si strength of the pipe, possibly weaker, jfe | but not much stronger, from sprayed ^ or made of pressed-on plastic, such as flanges, · ί Threads or even whole fittings, provided! are in such a way that the pipe end and fitting have one; ·. ';! represent homogeneous bodies. | j 2. Process for the production of Leituags «;; Pipes according to claim 1, characterized in that "the pipe ends on a mandrel in a ge« :! shared shape of a normal injection molding mask are postponed, then the connection4 | Material forming fittings is hot in the veisl remained space between form and M! .injected, so that an intimate and bare, across the entire touch panel cfo, gki <Jia | moderate, a homogeneous body resulting> |> Melting is achieved with the pipe end. : | Documents considered: German Patent No. 858 772; British Patent Nos. 574 656, 574 657. 1 sheet of drawings © 809 510/259 5.58