DE9007463U1 - Coupling device for creating a non-detachable pipe connection - Google Patents

Description

PATENT ATTORNEY

DlPL-ING.

MARTIN SCHROETER

5860 ISERLOHN

IM TÜCKWINKEL 22 TELEPHONE 02371/20785

03.07. 1991

F &igr; rma

Gebr. Beul GmbH & Co.KG

Cologne Street 92

5952 Attendorn

"Coupling device for producing a loose pipe connection"

The invention relates to a coupling device for producing a non-detachable pipe connection, in particular for plastic pipes to be connected, according to the preamble of claim 1, as well as a method for producing a pipe connection with the claimed coupling device.

In such a coupling device known from EP-PS O 159 997, the pipe end section is pressed into a positive connection with a nozzle of a pipe fitting inserted into the pipe end section by means of zone-by-zone cold forming using an axially displaceable press ring. The closed sleeve to be pushed onto the pipe end section has an annular outer bead which is deformed when the press ring is pressed on so that the sleeve displaces the pipe end section in the bead zone radially inwards into annular grooves provided on the outside of the nozzle. The press ring is displaced on site using special tools,

via which high pressures can be applied mechanically or hydraulically. In order to be able to apply these high pressures, appropriately dimensioned tools are required. The operation of the mechanically acting tools requires a relatively large working space, which in practice is often not available on site. The known tools of this type use clamping tools that use thread ratios to apply the necessary high pressing forces. The operation of these ratios requires access options for the operator. Due to the high contact forces required as a result of the necessary material deformation, the use of the known coupling devices is limited to pipes with a small external diameter.

The object of the invention is to propose a coupling device of the type mentioned at the beginning, which requires lower pressing forces for the press ring to be axially displaced or, if necessary, also for the sleeve to be displaced accordingly, with a sufficient positive connection of the pipe end section with the nozzle of the pipe fitting inserted therein.

The inventive task is solved with a coupling device with all the features of claim 1. By using the slotted sleeve proposed according to the invention and applying the radial pressure to the contact pressure required to displace the material of the pipe end section inwards via the wedge effect with self-locking between the corresponding external design of the sleeve and the internal design of the press ring, the forces required to move the press ring are greatly reduced. The slotted sleeve is no longer deformed when the press ring is pushed on, but is only compressed radially due to the free space in the slot area.

According to a preferred embodiment of the invention, the slot runs at an acute angle to the sleeve axis. This ensures that the contact pressure acting on the pipe end section also acts sufficiently on the pipe end section in the corresponding areas of the slot.

In addition to the displacement of the press ring, the invention also proposes a method in which the sleeve is pressed into the annular space between the fixed outer press ring and the pipe end section pushed onto the nozzle of the pipe fitting.

The invention is explained in more detail below using an illustrated embodiment. They show:

Fig. 1 a section through the connection of a pipe end section with a pipe fitting both before the pressing ring is moved and after the pressing ring is moved into the final, non-detachable assembly position,

Fig. 2 the partially sectioned view of the corresponding pipe fitting,

Fig. 3 the partially sectioned view of a sleeve

and

Fig. 4 is a partially sectioned view of an associated press ring according to Fig. 1.

Fig. 1 shows the connection of the pipe end section of a plastic pipe 1 with a pipe fitting 2 for a connecting screw connection. A nozzle 21 on this pipe fitting

2 is inserted into the inside and outside smooth pipe end section 1 of the plastic pipe as an internal support. On the outside of the nozzle 21, ring-groove-like recesses 22 are provided, into which material from the pipe end section is displaced via the coupling device described below to form a positive connection.

The pipe end section 1 is pushed onto the nozzle 21 over the ramp 25 until it stops in a groove 24 of the flange 23 on the pipe fitting 2. The slotted sleeve is also pushed onto this pipe end section until it stops in the groove 24.

3, the details of which can be seen in Fig. 3. This sleeve 3 has a narrow slot 33, which runs at an acute angle to the sleeve axis. A front section 32 of the sleeve 3 is cylindrical, which is adjoined by a conical section 31. The angle of inclination of this conical section 31 is between 1 3°, preferably 1° 30'.

As can be seen from Fig. 1, the press ring designated with the number 4 is pushed onto this sleeve 3. In accordance with the angle and length ratios of the sleeve 3, a conical section 41 and an adjoining cylindrical section 42 are provided inside this press ring 4. When this press ring 4 is pushed on, the sleeve 3 is compressed radially, the slot 33 provides the necessary clearance. At the same time, radial pressure is exerted on the pipe end section 1, whereby material from this pipe end section is displaced into the recesses 22 of the nozzle 21 under cold deformation, thereby achieving a positive connection. In the final assembly position, the press ring 4 strikes the flange 23 of the pipe fitting 2. In this position, there is a gap between the

Wedge surfaces of the conical section 31 of the sleeve 3 and the conical section 41 of the press ring 4 in the contact area Self-locking, so that the press ring cannot come loose.

Instead of pressing on the press ring 4, an assembly method is also possible in which the slotted sleeve is pressed into the annular space between the fixed outer press ring and the pipe end section pushed onto the nozzle of the pipe fitting.

Due to the possibility of compressing the sleeve radially over a relatively wide range, the coupling device according to the invention can also overcome high tolerances in the dimensions of the parts that act in a force-locking manner. Since the contact forces when assembling such a coupling device are relatively low, the use of the proposed coupling device is also possible for large pipe diameters.

Summary of reference symbols pipe end section

2 Pipe fitting 21 Support 22 Deepening 23 flange 24 Groove 25 On 1 on slanted 3 Sleeve 31 conical section 32 cylindrical section 33 Schiitz 4 Press ring 41 conical section 42 cylindrical section

Claims (4)

Protection claims 1. Coupling device for producing a non-detachable pipe connection, in which the externally smooth pipe end section is pressed by cold forming using an axially displaceable press ring to form a positive connection with a socket inserted into the pipe end section with one or more external radial recesses of a pipe fitting, wherein a sleeve is provided to be pushed onto the pipe end section, which displaces pipe end section material radially inwards into the recesses of the socket when the press ring is pressed on, and wherein the pipe fitting has a flange against which the pipe end section, the sleeve and the press ring come to a stop, characterized in that the sleeve (3) which is slotted approximately in the axial direction has a front conical section (31) on the outside and an adjoining cylindrical section (32) directed towards the stop side and on the inside on the press ring (4) to be pushed on in the sliding direction seen, a corresponding conical section (41) and an adjoining cylindrical section (42) are provided, the dimensions of these sections (31, 32 or 41, 42) being coordinated with one another in such a way that self-locking occurs between the conical sections (32 or 42) at least in the mounted stop position. 2. Coupling device according to claim 1, characterized in that the slot (of the sleeve) runs at an acute angle to the sleeve axis. 3. Coupling device according to claim 1, characterized in that the angle of inclination of the conical section (31) of the sleeve (3) is 1 - 3°, preferably 1° 30'. 4. Coupling device according to claim 1, characterized in that a groove (24) is provided on the flange (23) of the pipe fitting (2) on the front side, in which In the final assembly position, the pipe end section (1) and the sleeve (3) or its cylindrical section (32) come to a stop, whereby the pushed-on press ring (4) stops outside this groove (24).