GB2123148A

GB2123148A - Liquid level regulation

Info

Publication number: GB2123148A
Application number: GB08314580A
Authority: GB
Inventors: Helmut Jerg
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-07-01
Filing date: 1983-05-26
Publication date: 1984-01-25
Also published as: IT8321839A0; DE8218877U1; GB8314580D0; GB2123148B; FR2529696A1; IT8321839A1; FR2529696B1; IT1163617B

Abstract

Liquid level (16) in a container (15) is controlled by regulating means comprising a first small chamber (4) connected by way of a siphon (5) with a second chamber (14). Water is supplied to the container via inlet (2) and an outlet (3) of the second chamber. When liquid rises above level (16) liquid flows through the syphon (5) into the chamber (4) causing a float to use and operate a switch 8 to cut off the supply. When the level falls chamber (4) empties via the syphon. The level in chamber (4) may be sensed by optical means. <IMAGE>

Description

SPECIFICATION Liquid level regulation in apparatus operable with liquid The present invention relates to apparatus operable with liquid, for example a dishwashing machine, and has particular reference to liquid level regulation in such apparatus.

In a level regulating equipment disclosed in GB 10 81 082, a first chamber ofthe equipment is connected through a hossductwith an emptying pump,whilea second chamber, which is arranged upstream of the firstchamberthroughaseparatingwallwhich has an overflow edge, communicates through hose ducts with a waterfeed and the induction side ofthe pump.

A pressure monitor, connected to an airtrap of the first chamber, effects the closing of an inletvalve in a freshwaterfeed duct when the water level of the chamber exceedsthetarget level of an air trap.

Although this equipment enablesthe quantity of water to be filled into the vat of a laundry or dishwashing machineto be determined relatively accurately, the provided multi-chamber arrangement with numerous separating walls and emptying hoses is, however, expensive.

There is accordingly a need for simplification of such equipment and improvement of its monitoring function, while avoiding the arrangement of air trap chambers which tend to become clogged.

According to the present invention there is provided apparatus operable with liquid and comprising a containerfillable with liquid by way of controllable filling means and level regulating meansforcontrolling the filling means to regulate filling of the container in accordance with a predetermined level, the level regulating means comprising housing means defining a first chamber and a second chamber each provided with vent means at the top thereof, thefirst chamber having a volume substantially smaller than that of the container and being in flow communication with the second chamber by way of a siphon having its bend disposed atthe predetermined level and the second chamber communicating with liquid feed means and liquid outlet means, and a level sensor disposed in the first chamber and so responsive to the level of filling thereof as to cause filling ofthe container bythefilling means to be regulated in accordance with said predetermined level.

In a predetermined embodiment, the level regulating means comprises a first chamberwhich is of low volume and which is connected with a vat of the apparatus,forexamplea dishwashing machine, in terms offlow by way of an overflow edge at the height ofa certain filling level of the vat, whilst a second chamber, arranged by way ofthe overflow edge upstream ofthe chamber, stands in communication with a water feed and the induction space of an emptying pump.The housing means forming the chambers has a ventilation opening and a switching device for blocking the water feed into the vat is connected to the first chamber. Both chambers have ventilation openings at the top, and the first chamber is connected in terms offlow with the second chamber through a siphon conducted overthe overflow edge. A sensor actuating the switching device is arranged in the first chamber and responds to its filling level, and the housing means is fastened to the vat at such a heightthatthe overflow edge ofthe siphon bend is disposed atthe height of the filling level,to be determined, of the vat.Such level regulating means may serve to accurately determine the quantity of water needed in a dishwashing machine or washing machine through filling independently of time and pressure in orderto be able to operate the machine in water-saving manner. lnthatcase, both chambers are combined in housing means which includes the sensor and the switching device and is fastened, with reduction in hose connections, directly to the vat wall ofthe machine.

Embodiments of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which: Fig. lisa schematic sectional view of level regulating equipment in a first dishwashing or washing machine embodying the invention; Fig. 2 is a furtherview of the level regulating equipment shown in Fig. 1, showing its position in the machine; Fig. 3 is a schematic sectional view of level regulating equipment in a second machine embodying the invention; and Fig. 4 is a schematic sectional view of level regulating equipment in a third machine embodying the invention.

Referring nowto the drawing, there is shown in Figs. 1 and 2 level regulating equipment comprising a housing 1, which is formed buy a plastics material part and which has a waterfeed stub pipe 2 and a connecting stub pipe 3 leading to the induction space of a pump orto the outlettrough 9 of a vat 15 of a dishwashing machine or a laundry washing machine.

Disposed in the housing lisa first chamber 4, which is fillablethrough a siphon 5from a second chamber 14 and emptiable back into the chamber 14. The housing 1 is so fastened to the vat 1 5through fastening and adjusting elements 6 that the overflow edge of the siphon bend is disposed at the height of a filling level 16, to be monitored, ofthe vat. Ifthewater level in the vat 15 and in the housing 1 connected therewith in terms offlow rises,forwhich the housing isfillable by way ofthe pipe 2 by hard orsoftwater andas communicating pipesbythe pipe 3, to the filling level 16, then waterflowsfrom the second chamber 14 throughthesiphon Sintothefirstchamber4.

In the embodiment according to Fig. 1, a float7 is raised through the water flowing intothefirstcham- ber and actuates a switch 8 fastened to the housing 1 and controlling the closing of a water inlet valve (not shown). When the rinsing liquid is pumped away, the water level falls in t evat 15 and in the housing 1, in which case the chamber 14 initially empties through the pipe 3 into the outlettrough 9. The siphon 5 is then effective to also empty the chamber 4. When the float 7 is lowered, the switch 8 is switched back automatically. The housing 1 is provided with openings 17 and 18 atthetopforthe ventilation ofthe chambers 4 and 14.The water feed to the housing 1, the water outlet from the housing 1 into the outlet trough 9 and the feed of hard or soft water into the trough are indicated by arrows in Fig. 2.

In the embodiment of Fig. 3, the float 7 carries a permanent magnet 12 and a read switch 13 is provided atthe housing 1. the permanent magnet co-operates with the read switch, the electrical contacts of which consist of thin, magnetically sensitive tongues. When thefloatwith the permanent magnet is raised on filling ofthe chamber4, which has a guide 19, then the reed switch assumes the switch position for closing ofthe water inletvalve. When the float has fallen down,the reed switch is set back into its initial position.

Illustrated in Fig. 4 is an embodiment in which a light-conducting rod 11 projects into the chamber 4. At its upper end portion the rod has a light entry surface facing a light source 20 and at its lower end portion it has two surfaces extending approximately at 45" and reflecting lightwhen not immersed in the liquid. When the liquid in the chamber4 rises to the extent that the rod 11 dips into the liquid, then the ray path is altered and a light barrier 10 registering this alteration switches the water inlet valve off.

Claims

1. Apparatus operable with liquid and comprising a containerfillablewith liquid by way of controllable filling means and level regulating meansforcontrolling the filling means to regulate filling of the container in accordance with a predetermined level, the level regulating means comprising housing meansdefining first chamber and a second chamber each provided with vent means at the top thereof, the first chamber having a volume substantially smallerthan that ofthe container and being in flow communication with the second chamber byway of a siphon having its bend disposed atthe predetermined level and the second chamber communicating with liquid feed means and liquid outlet means, and a level sensor disposed in the first chamber and so responsive to the level offilling thereof as to cause filling ofthe container by the filling means to be regulated in accordance with said predetermined level.

2. Apparatus as claimed in claim 1, wherein the second chamber communicates with the outlet means byway of an outlet port in the base ofthe chamber, and the lower end ofthegravity portion ofthesiphon is disposed at a spacing above the base.

3. Apparatus as claimed in either claim 1 or claim 2, wherein the sensor comprises a float arranged to actuate a switch mounted on the housing means, the filling means being controllablethrough the switch.

4. Apparatus as claimed in claim 3, wherein the float is provided with a permanent magnet and the switch comprises a reed switch responsive to the magneticfield ofthe magnet in dependence on movement of the float.

5. Apparatus as claimed in either claim 1 or claim 2, wherein the sensor comprises a light-conductive rod element arranged to conduct lightfrom a light source and provided at its lower end portion with reflective surface means arranged to reflectthe conducted lightto light-responsive means when and only when said surface means is not immersed in liquid in the first chamber, the filling means being controllable through the light-responsive means.

6. Apparatus substantially as hereinbefore de scribedwith reference to Figs. 1 and 2 of the accompanying drawings.

7. Apparatus substantially as hereinbefore de scribed with reference to Fig. 3 of the accompanying drawings.

8. Apparatus substantially as hereinbefore described with reference to Fig. 4 of the accompanying drawings.