DE2102420A1 - Plastic sheath - for cables etc - Google Patents

Abstract

Plastic tubular sheath, partic. for a cable with a longitudinal slit which can pref. be closed by a liquid-tight sliding closure, comprising a core tube with a peripherally corrugated wall of relatively hard plastic adhered to which is a smooth tubular sleeve of relatively soft plastic carrying the closure element.

Description

Cladding tube The invention relates to a plastic cladding tube, in particular for cables, with a preferably by means of a liquid-tight slide lock lockable longitudinal slot.

Is known (for example from the German utility model 1 957 365) a cable protection tube, which consists of a thick-walled, cylindrical plastic jacket with longitudinal slot consists. As a closure for this cable duct a rail of a double T-profile is used, which is inserted into the slot, that one flange of the double-T profile on the outside of the protective tube and the other flange the same rests on the inside of the protective tube.

If these known pipes have good rigidity and in particular should also have good crest compressive strength, so is the material consumption extraordinarily high.

The tube is easily so stiff that a cable can be inserted becomes very difficult.

Furthermore, cladding tubes are from German patent specification 1,162,543 Plastic known, which can be shipped flat. These Cladding tubes essentially consist of a plastic tape attached to both of them Longitudinal edges are provided with the two elements of a slide fastener. These Pipes have the advantage over the previously mentioned cable protection pipes a good and tight connection. However, they have the disadvantage of a very great deal low crown compressive strength as well.

In contrast, the invention solves the problem of providing a cladding tube of the initially outlined way to create, which is very much measured by the amount of material high crest compressive strength excels and yet the insertion for example, of cables or other strands through the slot no excessive Opposed resistance. This object is achieved according to the invention in that the cladding tube from a core tube with a wall corrugated in the circumferential direction from relative hard plastic and one adhering to the core tube, at least in the circumferential direction approximately smooth jacket tube made of relatively soft plastic and that the Jacket tube carries the closure elements.

If a slide lock is mentioned here, it is herewith not meant a slide fastener in the strict sense, as it is for example in the German patent specification 1 162 543 is described, but any type of continuous over the entire length of the slot continuous closure elements, for example also those as described in the German utility model 6 905 648 are.

It goes without saying that there is a real slide lock that is also waterproof is preferred. If at all possible, the closure should be resistant to internal pressure forces exerted on the pipe be positive.

The expression "pipe with a circumferentially corrugated wall" denotes here a tube, the wall of which is corrugated as seen in axial section. The curl can of course be angular or rounded. The wave back can run exactly in the circumferential direction or helical lines. The corrugation can be or multiple threads.

If relatively hard plastic is mentioned here, it is meant to be a hardness can be referred to as, for example, plasticizer-free or only polyvinyl chloride containing little plasticizer as it does in large quantities is used to manufacture tubes with walls that are corrugated in the circumferential direction. However, the expression is not to be construed narrowly. May be for the pipe with a corrugated wall also a plastic about the hardness of polyethylene can be used.

The expression “relatively soft” plastic is also to be understood in a broad sense. The plastic for the casing tube must be soft enough to allow it to open and close allow the closure elements without excessive use of force. Here, for example, coincides Polyethylene or polyvinyl chloride with a sufficiently high plasticizer content in question. Of course, the plastics to be used should have a sufficiently high elastic limit have so that they occur when cables and the like. In the duct Deformations as well as the deformations occurring when opening and closing the shutter survive unscathed. The plastics used are preferably thermoplastic Plastics. In the borderline case, the relatively hard plastic and the relatively soft plastic of the same hardness, but usually the plastic of the jacket pipe must be softer than that of the core pipe.

The jacket tube can be a smooth, cylindrical tube.

It can even be corrugated to a small extent in the circumferential direction be, as this can happen under certain circumstances during production. The jacket pipe can also be longitudinally corrugated. However, it is preferably at least approximately cylindrical smooth execution of the jacket tube, its cylindrical shape only through the closure elements is interrupted.

If the core tube of the cladding tube according to the invention is relatively stiff, like this through a particularly hard plastic material or through particularly high Corrugation of the Xandung can be achieved, so the core tube is advantageous over the slot weakened or also slotted. The weakening can for example be caused by the fact that the core tube with respect to the closable slot no Has corrugation. It can also be caused by the fact that the core tube here, for example with a circle saw over its entire thickness or only part of its thickness is sawed open. The core tube is preferably not here over its entire thickness sawed open, so that there is no risk that the jacket pipe is sawn. But one can counteract this danger by the jacket tube is reinforced compared to the closable slot. In this case it is a slight sawing of the jacket tube opposite the closable slot to accept.

The leiverschluß is preferably formed on one side by a groove, which narrows at its open edge, and on the other side of one complementary shaped rib. The slide lock does not necessarily have to be sent to the canton of the one to be locked Connect the slot of the core tube. He can, as will be done later in the form of an exemplary embodiment is also shown, for example, at a distance from this slot from the jacket pipe protruding lobes are worn. Under certain circumstances, this can have manufacturing advantages have, however, necessitates an increased cost of materials.

The invention also includes a method for producing cladding tubes according to the invention. This method is characterized in that it is known per se track the circumferentially corrugated pipe is generated that around this pipe a tube of relatively soft plastic is extruded, which is the two parts of the focal plane shutter preferably carries at a distance from each other, and that then by the distance between the two parts of the buckle through a tube that slits or at least almost slits the circumferentially corrugated tube cut into two half-tubes. This may need to be like this is also the case in a preferred embodiment, the one closure element for the time of the slitting, which is usually done with a circular saw bent out of the area of the circular saw. This prepares no essential Difficulties, as one has appropriate displacement elements in front of and in the area of Circular saw can arrange.

The invention is described below with reference to the accompanying drawings embodying, preferred # etc. # hrgsforaen of the same are described.

Fig. 1 shows a section through a cladding tube according to the invention the introduction of the slot in the core tube in a normal to the tube axis Cutting plane.

FIG. 2 shows the same section as FIG. 1, but after it has been introduced of the slot with the closure partially bent to insert the slot.

FIG. 3 shows the view from above of FIGS. 1 and 2, the Tube is shown cut in the right half.

Fig. 4 shows a modified embodiment of the pipe according to Fig. 1 to 3, with the core tube also slotted opposite the closable slot Fig. 5 shows a second embodiment of a cladding tube according to the invention.

The cladding tube 1 according to FIGS. 1 to 3 has a core tube 2 made of plasticizer-free Polyvinyl chloride, which is usually produced as a folded tube with a trapezoidal circumferential corrugation is trained. With an outside diameter of 50 mm, for example, the core tube 2 a mean wall thickness of just under 1 mm, it is made of a smooth jacket pipe 3 surrounded, whose wall thickness is also 1 mm, for example.

In this embodiment, the jacket pipe 3 consists of a plasticizer-containing one Polyvinyl chloride, which allows the opening and closing of the to be described below Closure permitted.

The jacket tube 3 adheres sufficiently firmly to the core tube 2. Preferably the liability is cohesive.

It can be brought about, for example, by the fact that the outer ribs of the core tube 2, before they are surrounded by the jacket tube, with a heat-activatable Glue can be provided. Under certain circumstances, however, the liability between Inner tube and jacket tube that arises when the jacket pipe around the soul tube is extruded around.

The core tube 2 is produced in the usual way, then the core tube 2 is passed through a so-called cross spray head in which it is encapsulated with the jacket tube 2. The outlet nozzle of the cross-head has a shape which, apart from the smooth cylindrical part of the jacket tube 2 also the locking elements 4 and 5 of the same can arise.

The cladding tube leaves the cross-head in that shown in FIG Shape. Now the right closure part 5 is bent over in the manner shown in FIG. 2, so that from above with a saw blade 6 indicated by dash-dotted lines between the core tube 2 in the one shown in FIG. 2 through the two closure parts travel can slit.

Now the pipe is ready. After inserting a cable, for example the rib 5a of the right closure part 5, which has a mushroom profile, is inserted into the one approximately complementary T-profile having groove 4a of the left closure part 4 is pressed. In order to ensure a perfect engagement, the space is lar the recording the "mushroom head" of the rib a little deeper than the "mushroom head". To open the shutter it is advantageous to start at one end of the same. Is the plastic for the jacket pipe 3 chosen soft enough, so tan-n he ii can also be opened in the middle, Fig. 4 shows a modification of the construction according to FIGS. 1 to 3, which this is opposite is characterized by easier bendability. The only difference that Construction according to FIG. 4 compared to that according to FIGS. 1 to 3 is that here the core tube 20 is also slotted opposite the closable slot. In order to avoid tearing open or destruction of the entire pipe there, has the jacket tube 30 opposite the second slot 20a of the core tube 20 has a flat one Bead 30a. This acts as a hinge. You can see that it is with this construction nothing harms if the circular saw blade 6, the two slots in the core tube 30 introduces in one operation, also cuts a small piece into the jacket pipe 30.

The cladding tube 7, shown only in section in FIG. 5, also has a corrugated core tube 35 in the circumferential direction, which is also slotted at 36 like the jacket tube 37. In contrast to the construction described above, this has Core tube 35, however, opposite the slot 36, a bead 38 so that along the Slot 36 opposite line of the bending resistance of the core tube 35 strong is decreased. A substantial distance from the slot 36 rise from the cladding tube two flaps 39 and 40, which at their free edges are shaped complementarily to one another, locking elements 39a and 40a which can be snapped into one another.

The tabs 39 and 40 are dimensioned so that when pressed together Slot 36 the closure elements 39a and 40a can just snap into one another and that the tabs 39 and 40 then rest smoothly on the surface of the jacket pipe 37,

Claims (5)

Claims: U duct made of plastic, especially for cables, with a preferably closable by means of a liquid-tight slide fastener Longitudinal slot, characterized in that it consists of a core tube with in the circumferential direction corrugated wall made of relatively hard plastic and an adhering to the core tube, in the circumferential direction at least approximately smooth jacket tube made of relatively soft There is plastic, and that the jacket tube carries the closure elements. 2. cladding tube according to claim 1, characterized in that the core tube is weakened or slit opposite the slot. 3c cladding tube according to claim 2, characterized in that the jacket tube is reinforced compared to the slot. 4. cladding tube according to one of claims 1 to 3, characterized in that that the slide fastener is formed on one side by a groove that is in their narrowed open edge, and on the other side by a complementary shaped Rib. 5. A method for producing a cladding tube according to one of the claims 1 to 4, characterized in that in the known travel in the circumferential direction Corrugated pipe is produced that around this pipe a pipe made of relatively soft Plastic is extruded, which is the two parts of the focal plane shutter preferably at a distance from each other, and that then by the distance between the two Divide the focal plane shutter through a tube that is corrugated in the circumferential direction slitting or at least almost cutting into two half-tubes.