GB2089455A

GB2089455A - A plug coupling for gas pipes

Info

Publication number: GB2089455A
Application number: GB8131888A
Authority: GB
Original assignee: Medizin und Labortechnik Leipzig VEB
Current assignee: Medizin und Labortechnik Leipzig VEB
Priority date: 1980-12-11
Filing date: 1981-10-22
Publication date: 1982-06-23
Also published as: DD154393A1; CS608481A1; DE3129522A1; GB2089455B

Abstract

A plug coupling for gas pipes comprising a coupling plug (1) and a coupling socket, the socket comprising a casing (2) with a non-return valve (4) therein, a hollow cone (3) attached to the casing (2), conical locking segments (10) arranged in the hollow cone (3) and engageable with the coupling plug (1) and a sleeve (5) arranged on the casing (2) for axial movements to release the locking segments, the coupling plug (1) having an encircling bead (13) which cooperates with an annular groove provided on the locking segments. <IMAGE>

Description

SPECIFICATION A plug coupling for gas pipes The invention relates to a plug connection for gas pipes having a non-return valve which is arranged in the connector socket and is used in particular in compressed air breathing apparatus for the purpose of connecting the low pressure line between pressure reducers and automatic lung machines.

According to West German Offenlegungsschrift No. 1 943 552 a plug connection for gas pipes having a displaceable locking sleeve is known for a ball-type lock. This plug connection makes it possible for the apparatus fixed thereto to be left on the plug connection when no longer under gas pressure. The ball-type lock comprises balls arranged in two planes perpendicular to the plug device, these balls being at a spacing from each other which is greater than the valve stroke of the cut off valve which is actuated by the plug element. As the locking sleeve moves, initially, the balls which lock the plug element in the open position of the cut off valve are released and the other balls are only released when the locking sleeve is moved further.

In accordance with East German Patent Specification No. 18 587 a pull-off coupling for pipes for liquid is known, in which a self-locking valve is housed in each of the halves of the coupling. The two halves of the coupling are retained in their coupled position by a ball or roller catch, said ball or roller catch being released when one of the halves of the coupling undergoes axial tension. The ball or roller catch consists of segments which are provided with conical surfaces on their outer diameter, these concial surfaces being supported in the coupled state against an inner cone of the fixed and assembled casing under the pressure of the balls or rollers forming the catch. Projections are arranged on the side of the segments remote from the conical surfaces and engage encirculing groove of the pipe member. The segments are retained in this groove by a snap ring.In order to assist the coupling process several hooks provided with runup surfaces and into which the hooks arranged on the inner periphery of the casing engage (like a bayonet fixing) are located at the outer periphery of the coupling halves which are preferably firmly assembled. Both couplings are complicated in their construction and are too expensive for the rapid coupling of the type stated at the outset.

The invention seeks to provide a coupling with simple handling when opening and closing the coupling as well as simple construction and economic manufacture thereof.

According to the invention, there is provided a plug coupling for gas pipes comprising a coupling plug and a coupling socket having locking segments displaceably arranged therein and a non-return valve, wherein the socket comprises a casing having the non-return valve and to which a hollow cone is fixed; conical locking segments engageable with a coupling plug are arranged in the hollow cone; the coupling plug is provided with an encircling bead and the locking segments are provided together with an annular groove and a sleeve which releases the locking segments is arranged on the casing.

When inserting the coupling plug into the coupling socket, the individual locking segments are pressed downwards and radially outwards at the same time contrary to the force of a spring by means of the encircling bead until the bead snaps into the annular groove in the locking segments.

Once the bead has snapped into place the locking segments are pressed back against the hollow cone by the force of the spring so that a positive and frictional connection is achieved.

Uncoupling takes place by pressing down the sleeve which moves the locking segments jointly with the coupling plug contrary to the force of the spring. By withdrawing the coupling plug, the selflocking between the bead and the annular groove is removed and the locking segments are pressed radially outwards and the lock is released.

The locking segments are preferably pressed against the hollow cone by a pressure ring, which is spring-loaded in the coupling direction, and the annular groove arranged in the locking segments may have a rear inclined surface.

The coupling plug is preferably so dimensioned that, when coupled, its front end keeps the nonreturn valve in its open position.

In a simple embodiment, pins may be arranged at the outer periphery of the casing and the sleeve, provided with elongate orifices, may be guided by these.

The invention will now be described in greater detail, by way of example, with reference to the related drawings in which:~ Fig. 1 shows a plug coupling in accordance with the invention in the coupled state, and Fig. 2 shows the same plug coupling when uncoupled.

The plug coupling shown in Figs. 1 and 2 comprises a coupling socket and a coupling plug 1. A hollow cone 3 is fixed to the casing 2 of the coupling socket and a ball-type non-return valve 4 is inserted at the opposite end. A sleeve 5 with elongate orifices 6 is placed onto the casing 2 and the hollow cone 3 and is guided on pins 7 arranged on the periphery of the casing 2. A compression spring 8 is arranged in the casing 2 and is supported, on the one hand, against the casing 2 and, on the other hand, against the hollow cone 3 through a pressure ring 9 in the form of a spring guide 3 and through movable conical locking segments 10. The conical locking segments 10 include an annular groove 1 , the rear surface of which, in the coupling direction, has an inclination 12.The coupling plug 1 is provided with an encircling bead 13 which locks into the annular groove 1 1. The coupling plug 1 is so dimensioned in length that, when in the coupled state, it keeps the non-return valve 4 in the open condition.

A substantial advantage of the solution in accordance with the invention lies in the fact that it is impossible to pull the coupling plug violently out of the coupling socket since axial movement of the coupling plug contrary to the coupling direction is prevented by the conical locking elements in the hollow cone. Therefore, radial movement of the locking segments in an outward direction cannot take place in such a manner as to allow the bead of the coupling plug to be released from the annular groove.

A further advantage lies in the fact that the coupling can be actuated regardless of its orientation, i.e. the coupling plug may be locked in any desired radial angular position.

Claims

1. A plug coupling for gas pipes comprising a coupling plug and a coupling socket having locking segments displaceably arranged therein and a non-return valve wherein the socket comprising a casing having the non-return valve and to which a hollow cone is fixed; concial locking segments engageable with a coupling plug are arranged in the hollow cone; the coupling plug is provided with an encircling bead and the locking segments are provided together with an annular groove: and a sleeve which releases the locking segments is arranged on the casing.

2. A plug coupling according to claim 1 wherein the locking segments are pressed against the hollow cone by a pressure ring which is springloaded.

3. A plug coupling according to claim 1 or 2, wherein the surface of the annular groove which is to the rear when considered in the coupling direction in inclined.

4. A plug coupling system according to claim 1, 2 or 3, wherein the coupling plug is so dimensioned that when it is in the coupled state its front end keeps the non-return valve open.

5. A plug coupling according to any one of claims 1 to 4, wherein pins are arranged at the outer periphery of the casing and the sleeve is provided with elongate orifices cooperating with the pins such that the sleeve is guided by these pins.

6. A plug coupling for gas pipes substantially as described herein with reference to the drawings.