GB2045065A - Crockery rinsing apparatus - Google Patents

Abstract

Contamination of the mains water supply by backflow of dirty water from the rinsing container of crockery rinsing apparatus in the event of suction in the mains is prevented by a device comprising chamber 2 having fresh water inlet 1 and outlet 9, openings 6, 12, and abutment 8, and a valve member 4 operable in said chamber, the latter being arranged in a vessel 3 in communication with the rinsing container via opening 10 and air vent 11. Normally, when water is supplied to the rinsing container, the valve member is raised and leakage occurs through opening 12. If suction occurs via inlet 1, the valve member drops onto abutment 8, its lowering being assisted by pressure equalisation via opening 12. Outlet 9 is blocked and venting via vent 11 and openings 6, 12 can occur, thereby preventing backflow. <IMAGE>

Description

SPECIFICATION A crockery rinsing apparatus The present invention relates to a crockery rinsing apparatus.

A water feed device of a crockery rinsing apparatus is disclosed in DE-AS 22 888.

Furthermore there is disclosed in DE-AS 1585830 a washing or crockery rinsing machine with a water softener, a water inlet valve, a fresh water duct, and a non-return valve arranged in the fresh water duct between the water inlet valve and the water softener for prevention of return flow. The non-return valve acts as a ventilating valve through which air can be sucked into the fresh water duct when the water mains pressure in the fresh water duct fails. The ventilating valve comprises a ball valve which provides a non-tight valve seat.

The rubber balls used in the known ventilating valves must comprise a rubber material which is resistant to all influences acting on the ball. Its manufacture is therefore relatively expensive. Furthermore, there is the danger that through dirt and chalk deposits, particularly at the stationary valve seat which is non-tight, narrow groove-shaped channels provided in the valve seat clog and the installation between the ball and the valve seat becomes tight, which on wedging or caking of the ball to the valve seat leads to the fresh water duct not being ventilated when the water pressure is absent with resultant undesirable sucking-back of dirty water into the fresh water duct.

According to the present invention there is provided a crockery rinsing apparatus comprising a rinsing container, a leakage vessel, means to communicate the leakage vessel with the rinsing container, and vent means, the vent means comprising wall means defining a chamber provided with liquid inlet and outlet means, a valve passage at an upper region of the chamber, a valve stem displaceable through the valve passage and provided with a closure member which is raisable by liquid pressure within the chamber to close the valve passage, and a pressure relieving opening communicating the chamber with the leakage vessel, the leakage vessel being provided with an air opening which communicates with the valve passage and which has a lower extremity disposed below the upper extremity of the valve passage.

A specific embodiment of the present invention may be arranged such that the danger of the sucking-back of dirty water into fresh water mains, when an underpressure arises in this, is effectively prevented through the valve stem provided with a closure member as well as the pressure-relieving opening. When fresh water flows through the inlet means to the vent means, the closure member is raised, closes the vent passage and the water current passes through the outlet means. Since the closure member leaves the pressure-relieving opening free, a partial water current can flow through this into the leakage water vessel and from there into the rinsing container of the crockery rinsing apparatus.

When the water pressure falls in the vent means, the closure member enhanced by the weight of the valve stem can fall in the vent means to a height above the inlet means which may be determined by an abutment in the vent means. This movement is made possible through the pressure equalisation through the pressure-relieving opening. The closure member in the lower position may largely close the outlet means. When an underpressure occurs in the fresh water duct so that a suction arises at the inlet means, sucking-back of dirty water out of the machine is prevented in that with the closure member at its lower position, air is sucked out of the air opening of the leakage vessel through the vent opening to the inlet means, while the closure member in a given case blocks the outlet means.

Should the closure member in case of a fault not detach from the valve seat, then air can flow out of the leakage vessel through the pressure-relieving opening into the vent means.

The apparatus may comprise a plurality of vent means and inlet and outlet means.

Embodiments of the present invention will now be more particularly described by way of example and -with reference to the accompanying drawing in which: Figure 1 shows in section part of a crockery rinsing apparatus and illustrates a part of a leakage water vessel which is connectible to a rinsing container of the crockery rinsing apparatus and Figure 2 shows a modification of Figure 1.

Referring to the drawing, the rinsing apparatus comprises a rinsing container and a fresh water feed duct, from which branch ducts downstream of program-controlled inlet valves branch off for example to a direct fresh water inlet into the rinsing container, to a water softener and to a salt vessel.

An inlet valve (not shown) opens for the introduction of soft water into the rinsing container so that fresh water can flow to an inlet stub 1 of a first vent valve 2 of a leakage water vessel 3. When water flows a closure member 4 is acted on by water pressure and is raised to the position shown and pressed against a valve seat Sofa vent opening 6.

The closure member 4 comprises plate or piston disposed at the lower end of a stem 7. To accelerate the lowering of the closure member 4, when the water pressure drops in the vent valve 2, a pressureequalising opening 12 is provided in the vent valve.

An abutment 8 in the vent valve 2 determines the lowermost position of the closure member 4.

In the illustrated position of the closure members 4, the main water current of the fresh water entering through the inlet stub 1 and deflected in the vent valve 2, by for example a guide surface 13 of the closure member 4 shown in Figure 2, is conducted through an outlet stub 9 to a water softener or salt vessel, - while a partial current flows through the pressure-equalising opening 12 into the leakage water vessel 3 and through the outlet opening 10 thereof into the rinsing container. The tolerance of the piston-shaped closure member4shown in Figure 2 is such that relative to the cylindrical inside wall of the vent valve a gap 14 is provided for the pressure-equalising opening 12.The closure member 4 can be axially guided in the vent valve, for example by a groove and a web or the like and be secured against rotation. Ventilation through the vent opening 6 and the pressure-equalising opening 12 is particularly effective, almost no suction occurring in the connecting duct of the outlet stub by the closure member still blocking the outlet stub 9 on top of this. By the provision of the pressureequalising opening 12, the closure member 4 can moreover drop more rapidly from the valve seat 5 and prevents sucking-back of dirty water if in the event of a fault the closure member would not detach from the valve seat. In order that in the event of a backwash of dirty water from the rinsing container of the machine into the leakage water vessel 3, the vent opening 6 of the vent valve 2 remains free, it is disposed at a higher level than the air opening 11, arranged above the water level of the rinsing container, of the leakage water vessel.

An advantage of the above described embodiment is that free ventilating paths are secured while avoiding the disadvantages of ball ventilating valves.

Claims (8)

1. A crockery rinsing apparatus comprising a rinsing container, a leakage vessel, means to communicate the leakage vessel with the rinsing container, and vent means, the vent means comprising wall means defining a chamber provided with liquid inlet and outlet means, a valve passage at an upper region of the chamber, a valve stem displaceable through the valve passage and provided with a closure member which is raisable by liquid pressure within the chamber to close the valve passage, and a pressure relieving opening communicating the chamber with the leakage vessel, the leakage vessel being provided with an air opening which communicates with the valve passage and which as a lower extremity disposed below the upper extremity of the valve passage.

2. An apparatus as claimed in claim 1, compris ing program-controlled inlet valves disposed downstream of the inlet means.

3. An apparatus as claimed in either claim 1 or claim 2, comprising at least one of a water softener and a salt vessel connected to the outlet means.

4. An apparatus as claimed in any one of the preceding claims, wherein the closure member comprises a piston which is provided with a configuration to promote deflection of the liquid from the inlet to the outlet means, defines a gap with the wall means for leakage of the liquid through the pressure-relieving opening, and which at its lower most position largely closes the outlet means.

5. An apparatus as claimed in any one of the preceding claims, comprising abutment means with in the chamber to define the lowermost position of the closure member.

6. An apparatus as claimed in any one of the preceding claims, wherein the chamber is elongate and has a longitudinal axis which is co-axial with the axis of displacement of the closure member.

7. A crockery rinsing apparatus substantially as hereinbefore described with reference to Figure 1 of the accompanying drawing.

8. A crockery rinsing apparatus substantially as hereinbefore described with reference to Figure 2 of the accompanying drawing.