EP0681555B1 - Dispensing nozzle for keg fittings - Google Patents

Abstract

A dispensing nozzle for keg fittings comprises a sliding guideway (3) containing an O-ring (24) and a guide track, for sliding the dispensing nozzle over the projecting edge of a collar (30) of the keg fitting. At least the sliding guideway (3) of the dispensing nozzle consists of resilient material and a projection guide rib of the guideway engages under the collar. The modulus of elasticity of the material forming the guideway (3), as well as the geometry and dimensions of the guide rib are selected so that the guide rib (33) is deformed at a specified gas pressure in the dispensing nozzle housing, and a gap is formed between the collar and the O-ring which relieves any gas overpressure.

Description

The invention relates to a tap head for keg fittings according to the preamble of claim 1.

Such a tap head is known from DE-PS 39 02 527.

With such dispensing heads, it is often desirable and sometimes also prescribed by the authorities to provide a pressure relief valve that opens at a predetermined gas overpressure in the keg and dispensing head in order to prevent the barrel-like keg and the dispensing head from bursting explosively in the event of excessive gas pressure. Known pressure relief valves (DE-OS 29 39 536) for this purpose are designed as special components, they have to be manufactured separately and subsequently used in a sealed manner in a wall of the dispensing head housing.

It is an object of the invention to design a generic dispensing head so that the relaxation of an impermissibly high gas pressure in the keg and dispensing head is possible without the use of a separate pressure relief valve.

The object is achieved in a generic dispensing head by the features in the characterizing part of claim 1.

From DE-OS 37 01 432 it is known to let pressurized gas escape through a gap between a drum-side plate and a ring-head ring seal when the shut-off valves of a tap head are closed. However, the known arrangement cannot be used as a pressure relief valve. DE-GM 91 10 371 shows in a tap head of a different type a slide guide attached to the tap head housing as a separate component for a barrel fitting.

Preferred embodiments of the invention are the subject of dependent claims 2 and 3.

Fig. 1

eine teilweise geschnittene Seitenansicht eines Zapfkopfes für Keg-Armaturen mit Gleitführung im normalen Betriebszustand;

Fig. 2

den Zapfkopf aus Figur 1 in einer infolge Gasüberdrucks von der Keg-Armatur abgehobenen Stellung;

Fig. 3

eine Draufsicht des Zapfkopfes aus Figur 2;

Fig. 4

eine teilweise geschnittene Vorderansicht des Zapfkopfes mit abgeschraubtem Anschlußstutzen in Richtung des Pfeiles A in Figur 1 und

Fig. 5

eine Vorderansicht des Zapfkopfes ähnlich wie in Figur 4 in Richtung des Pfeiles B in Figur 2.

The following description serves in conjunction with the accompanying drawing for further explanation. Show it:

Fig. 1

a partially sectioned side view of a tap head for keg fittings with sliding guide in normal operating condition;

Fig. 2

the dispensing head of Figure 1 in a position raised due to gas pressure from the keg fitting;

Fig. 3

a plan view of the tap head of Figure 2;

Fig. 4

a partially sectioned front view of the tap head with unscrewed connecting piece in the direction of arrow A in Figure 1 and

Fig. 5

a front view of the tap head similar to that in Figure 4 in the direction of arrow B in Figure 2.

The dispensing head shown on the drawing for a keg fitting comprises a housing 1 with a connecting piece 2 for the introduction of compressed gas, for example compressed air or CO ₂ , and a sliding guide 3 arranged on the underside of the housing 1, with the aid of which the housing 1 the keg fitting of the barrel-like container, for example a beer or lemonade container, can be pushed on and fastened in a known manner, so that the tap head and the keg fitting are firmly and tightly connected to one another.

An essentially hollow cylindrical slide 4 is displaceable in the housing 1 parallel to the longitudinal axis of the housing 1. On the slide 4, a connection piece 5 for the liquid to be drawn, for example beer or lemonade, is arranged at the top. The slide 4 contains in its interior a loose, spherical valve body 6, which cooperates with a valve seat (not shown) on the slide 4 and forms a check valve for the tapped liquid.

On the housing 1, an actuating lever 11 is pivotally mounted by means of a horizontally continuous bolt 9, which in the region of the housing 1 (see FIG. 3) has a relatively large recess 12 with which it encompasses the upper part of the housing 1, so that it is between an upper and lower position is pivotable back and forth. Of the 12 fork-shaped in the region of the recess Operating levers 11 project in the area of this recess 12 from two pins 13, 14 which engage in recesses 15 of the slide 4 on both sides. As can be seen from FIGS. 1 and 2, the cutouts 15 have widening openings for inserting the pins 13, 14.

When the actuating lever 11 is pivoted between its two extreme positions, the slide 4 is carried along via the pins 13, 14. The upper position is the closed position, the lower position the open position of the dispensing head. In the closed position, the tap head can be removed from the side of the keg fitting or connected to it by means of the slide guide 3. In the open position, the connecting pieces 2, 5 are connected in a manner known per se to corresponding (not shown) passages of the keg fitting for gas or liquid.

On the housing 1, which in the illustrated embodiment, like the other parts of the tap head, is made of plastic, a spring tongue 18 (also made of plastic) is formed in one piece, which protrudes freely upwards and has a catch 19 in the upper region. As shown, the upper end of the spring tongue 18 constantly engages in the recess 12 of the actuating lever 11. When the actuating lever 11 is pivoted from its upper position into its lower position (shown in FIGS. 1 and 2), the spring tongue 18 comes under elastic prestress until it is finally located with its latching lug 19 above the upper side of the actuating lever 11, this latching lug 19 via an associated locking edge 31 of Recess 12 protrudes (Figures 1, 2 and 3) and the actuating lever 11 is thereby locked in this lower position.

An annular collar 21 provided at the bottom of the slide 4 with openings (not shown) for the gas passage can rest against an annular stop edge 22 of the housing part 1 when the dispensing head is in its closed position. A seal (not shown) provided on the slide 4 below serves in the open position of the dispensing head (FIGS. 1 and 2) to seal the slide 4 on the keg fitting, which is known per se.

The sliding guide 3 contains an annular seal 24, the cross-sectional shape of which can be seen in FIGS. 1 and 2 and which also seals towards the keg fitting. As shown, an inwardly directed annular collar 20 is formed on the sliding guide 3, which engages in an outwardly opening annular groove of the ring seal 24 and thus serves as a holder for this ring seal 24. If, in the open position of the dispensing head (FIGS. 1 and 2), the slide 4 is pressed down by the actuating lever 11, the outer edge of the annular collar 21 provided on the slide 4 engages a conical inclined surface formed on the seal 24 and thereby presses this seal sealing against a plate 30 of the barrel-side keg fitting (FIG. 4).

The sliding guide 3 can be formed as a separate part from the housing 1 from resilient plastic. The sliding guide 3 is subsequently firmly connected to the housing 1, which is generally also made of plastic, for example by screwing, welding or gluing. In the embodiment shown, the sliding guide 3, the outline of which can be seen essentially from FIG. 3, is inserted into a recess of the housing 1 corresponding to this outline.

As can be seen from the drawing, the sliding guide 3 has a U-shaped guide track 32 for the plate 30 of the keg fitting. The guideway is formed by an upper wall of the sliding guide and an inwardly projecting guide web 33 which is arranged at a distance below this wall. This groove-shaped guideway 32 is open to the left in Figure 1 and closed to the right by the U-bend, so that the dispensing head can be pushed onto the plate 30 of the keg fitting from the right, the guide web 33 being the edge of the plate 30 engages. When the dispensing head is pushed onto the plate 30, the actuating lever 11 is in its upper position (not shown) and thus the dispensing head is in the closed position.

In Figures 1 and 4, the dispensing head is clamped in its normal operating position on the plate 30 of the keg fitting, the ring seal 24 being pressed firmly and sealingly onto the surface of the plate 30 by the slider 4 brought into its lower position, so that in the usual way liquid can be drawn from the container provided with the keg fitting.

If an inadmissibly high gas pressure builds up in the housing 1 of the dispensing head and thus also in the container (keg) carrying the keg fitting via the connecting piece 2, For example, if the connector 2 is connected to a CO ₂ bottle via a hose with the interposition of a pressure reducing valve and this pressure reducing valve is defective, the housing 1 with the ring seal 24 rises, as shown in FIGS. 2 and 5 from the surface of the plate 30, so that a gap 34 is formed between the ring seal 24 and plate 30, through which compressed gas can escape to the outside and a gas overpressure can be released. In Figures 2 and 3, the gas flowing out into the open is indicated by arrows.

The resulting gap 34 can have a height of approximately 1 to 2 millimeters, for example. The width of the gap (see FIG. 3) can be, for example, approximately 60 millimeters. The gap 34 thus forms a sufficiently large opening to allow excess gas to escape quickly in large quantities and to reduce an inadmissible gas overpressure.

It has been found that foreign bodies, for example ice, sugar residues or the like, are blown away from the escaping gas through the large gap opening. So there is no blockage. In contrast to separate pressure relief valves, the arrangement according to the invention, in which the entire dispensing head lifts off the keg fitting in an emergency, functions in a self-cleaning and maintenance-free manner.

The opening pressure at which the dispensing head is to lift off the keg fitting can be adjusted by appropriately designing the resilient guide web 33 on which the edge of the plate 30 rests. It is possible to adjust the modulus of elasticity of the material forming the sliding guide, in particular plastic, as well as the geometry and the dimensioning of this guide web 33 so that the dispensing head lifts off at a desired gas pressure with the formation of the gap 34 and thus acts as a pressure relief valve. Liquids are normally drawn from containers with keg fittings at an operating pressure of approx. 3 bar. The maximum permissible pressure in the dispensing head and in the container is approximately 7 bar. The guide web 33 responsible for lifting off the tap head is thus designed such that the tap head lifts off at a pressure which is greater than approximately 7 bar.

The opening cross section of the gap 34 depends on the prevailing pressure, i. H. the gap opening becomes larger at higher pressure and vice versa, which in turn is based on the elastic flexibility of the guide web 33, which engages under the edge of the plate 30 and, when the gas pressure is released, guides the sliding guide 3 with the seal 24 back to the surface of the plate 30.

As shown in FIGS. 1 and 4, it is expedient to design the guide web 33 to run obliquely upward because it then deforms slightly downward into the position shown in FIGS. 2 and 5 when the gas pressure occurs. In principle, the guide web 33 can, in the normal case, that is to say without a gas overpressure, run horizontally or even downward. This does not change the basic mode of operation of the dispensing head as a "pressure relief valve".

In the embodiment shown there is the tap head essentially entirely of plastic. That means, in addition to the sliding guide 3, which is made of resilient plastic, the housing 1, the slide 4, the actuating lever 11 and the spring tongue 18 (integrally formed on the housing) are made of plastic. In other embodiments of the invention, however, these parts can also be made of other materials, for example metal, as long as the slide guide 3 with its guide web 33 is made of resilient material or at least this guide web 33 consists of resilient material, so that the dispensing head is lifted off to enable the plate 30 of the keg fitting.

Claims (3)

1. Dispensing head for keg fittings, having a housing (1), having a ring seal (24) which is disposed in the housing and forms a seal with respect to the keg fitting, having a slide (4) which can be moved in the housing, having an operating lever (11) which is pivotably mounted on the housing and linked to the slide, having detachable fixing means for the operating lever, having connections (2, 5) for gas and liquid which can be linked by the slide to corresponding passages in the keg fitting, and having a slide guideway (3) disposed at the underside of the housing and forming a guide track (32) for pushing the dispensing head onto the projecting edge of a collar (30) adjoining the ring seal, at least the slide guideway (3) of the dispensing head being composed of resilient material and a projecting guide ridge (33) of the guide track engaging under the edge of the collar, characterized in that the modulus of elasticity of the material forming the slide guideway (3) and also the geometry and the dimensioning of the guide ridge (33) are selected so that the housing (1) of the dispensing head lifts from the collar (30) of the keg fitting at a certain gas pressure with deformation of the guide ridge (33) and, in this process, a gap (34) via which a gas overpressure can be relieved is formed between the collar (30) and the ring seal (24).
2. Dispensing head according to Claim 1, characterized in that the gap (34) increases with rising gas overpressure and closes again with falling gas overpressure.
3. Dispensing head according to Claim 1, characterized in that the guide ridge (33) which engages under the edge of the collar (30) is directed upwards at an angle.

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