IE80844B1 - An apparatus for making beverages - Google Patents

Description

1 "AULflPFamug., Xox-iMXing Jteygjageg-" This invention relates to an apparatus for making beverages,particularly a coffee brewing apparatus, in particular forcommercial use in a restaurant or the like. £t-atewntg pf Invention According to the invention there is provided an apparatus formaking beverages comprising a liquid reservoir having a liquidinlet and a liquid outlet; an electrically operated liquidreservoir heater for heating liquid in the reservoir; acontroller for the reservoir heater to maintain liquid withinthe reservoir at a preset liquid temperature; a steam boilerhaving a water inlet and a steam outlet; an electricallyoperated steam boiler heater for heating water in the steamboiler to produce steam; a controller for the boiler heaterto maintain the steam at a preset pressure; in which eachheater is connected to a common power supply through aninterlock whereby power is supplied to only one heater at anyone time and preferentially to the heater for the steamboiler, and in which the steam boiler heater is. operated untilswitched off by its controller when the steam within theboiler reaches the preset pressure.

Conveniently the interlock comprises a temperature controllerwhich is provided on the steam boiler and which operates belowa preset sensed steam boiler temperature, being thetemperature achieved when the preset pressure is reached, tosupply power to the steam boiler heater and simultaneously cutoff power supply to the water reservoir heater.

In an alternative arrangement the interlock comprises a pressure switch which is provided on the steam boiler and which operates below a preset sensed boiler pressure to supply power to the boiler heater and simultaneously cut off power supply to the water reservoir heater. 80844 - 2 - In a particularly preferred embodiment the heaters are coil-type electrical heating elements. Preferably the reservoir „heating element is a 2.8 kw element and the steam boilerheating element is in the range 1.0 - 1.5 kw. Advantageouslythe apparatus can thus be operated from a. single 13A powersupply and means is provided for connecting the device to astandard 13A power supply.

In a further embodiment the apparatus has an outer casingwithin which the water reservoir, the steam boiler and theirassociated controllers are housed, and in which the steamboiler incorporates an air vent valve communicating with theexterior of the outer casing for venting of the boiler untila preset pressure is achieved in the boiler on start up. Thusadvantageously, air and steam vented during start up of theapparatus is vented to atmosphere rather than into the casingwhere it might adversely effect operation of the electricalapparatus.

In another embodiment, the apparatus has a water inlet forconnection to a water supply, the water inlet communicatingwith both the liquid reservoir and the steam boiler, and valvemeans operable to control water supply to the liquid reservoirand the steam boiler. Preferably, the valve means is a waterinlet control valve having two water outlets, namely a waterreservoir supply outlet and a steam boiler supply outlet, eachoutlet closed by an associated solenoid-operated valve.Ideally, the solenoid-operated valve is operable in responseto sensed water level in the associated liquid reservoir orsteam boiler to maintain a preset level of water within theliquid reservoir or steam boiler.

In another embodiment the apparatus further includes a coffeeurn having an inlet and an outlet, means for supporting coffeein a filter at the urn inlet, and means for delivering waterfrom the liquid reservoir to the urn inlet for filteringthrough coffee supported at the urn inlet. - 3 - Detailed Description of the Invention .

The invention will be more clearly understood by the followingdescription of an embodiment thereof, given by way of exampleonly, with reference to the accompanying drawings, in which:-* Fig. 1 is a perspective view of a coffee brewingapparatus according to the invention; Fig. 2 is a front elevational view of the apparatus; Fig. 3 is a plan view of the apparatus; Fig. 4 is a side elevational view of the apparatus witha side cover removed; Figs. 5 and 6 show a wiring diagram for the apparatus;and Fig. 7 shows a portion of a wiring diagram of anothercoffee brewing apparatus.

Referring to the drawings, and initially to Figs. 1 to 6thereof, there is illustrated a coffee brewing apparatusaccording to the invention indicated generally by thereference numeral 1. The apparatus 1 has an outer casing 2.A box-shaped water reservoir 3 is mounted within the casing 2.Centrally located within the water reservoir 3 is acylindrical coffee urn 4. A 2.8 kW electrical heating element5 (Fig. 5) is provided within the reservoir 3 for heatingwater in the reservoir 3 for delivery to the urn 4 to brewcoffee in the urn 4. A steam boiler 7 is also mounted withinthe easing 2. A 1.5 kW boiler heating element 8 (Fig. 6)housed within the steam boiler 7 is operable to heat waterwithin the steam boiler 7 to produce steam at 15 psi (1 bar)for discharge through a steam injector 10. - 4 - Power for operation of the apparatus 1 is delivered from a 13Apower supply through a standard 13A plug connector (not shown)on the apparatus 1. An interlock is provided such that onlyone of the heating elements (5, 8) may be operated at anytime. The interlock is operable to preferentially supplypower to the steam boiler heating element 8.

In this case the interlock comprises a thermistor 12 (Fig* 6)on the steam boiler 7 operable below a preset sensed boilertemperature, in this case equivalent to 15 psi (1 bar), tosupply power to the steam boiler heating element 8. Theinterlock further comprises an interlock relay 14 (Fig. 5) inthe power supply circuit for the water reservoir heatingelement 5. This relay 14 is fired by the steam boiler heatingelement line. The contact side of the relay 14 carries thesupply line to a contactor 15 (controlling supply to the waterreservoir heating element 5) through its normally closedpoles. When the steam boiler 7 energises the relay 14 thepoles open and disconnect the contactor 15, cutting off powersupply to the water reservoir heating element 5. When thepressure within the steam boiler 7 rises to 15 psi ± 1 psi(approximately 1 bar) the thermistor 12 cuts off power to thesteam boiler heating element 8 thus allowing power supply tothe water reservoir heating element 5. Advantageously thisallows the apparatus 1 to operate from a single 13A powersupply. If both elements 5, 8 were allowed energisesimultaneously a 17 A power supply would be required.

The water reservoir 3 has a water inlet line (not shown) forconnection to a water supply. A water inlet valve is mountedin the inlet line and is controlled by a solenoid 20 (Fig. 5).A high level probe 21 and a low level probe 22 are mounted onthe reservoir 3 and are connected to associated relays 21a and22a. Hot water can be discharged from the reservoir 3 by apump 23 through a discharge pipe 24 which opens into a top ofthe coffee urn 4. A hot water discharge tap 25 is also - 5 - provided on a front of the casing 2 for discharging hot waterfrom the reservoir 3.

The coffee um 4 is supplied with water from the waterreservoir 3 as previously described. Coffee powder in a 5 filter bag can be supported on a holder (not shown) which canbe mounted at an upper end of the coffee um 4 beneath theoutlet of the pipe 24. Thus water delivered from the waterreservoir 3 filters down through the coffee powder forcollection in the um 4 as coffee. A sight glass 27 is 10 provided on the um 4 for viewing the contents of the um 4.The sight glass is back lit by an associated sight-glass lamp 17. Coffee can be discharged from the um 4 through an outlettap 28 mounted at the front of the casing 2.

In use, with power on, the inlet solenoid 20 is energised to IS open the water inlet valve allowing water supply to the waterreservoir 3. When water level reaches the low level probe 22,power is supplied to the heating line energising the contact15 supplying power to the heating element 5 to heat the waterin the reservoir 3. This is indicated by a "heating" lamp 16. 20 Water continues to fill the water reservoir until it reachesthe high level probe 21 which then cuts off power to the inletsolenoid 20 stopping the water supply.

Water within the reservoir 3 is heated to a temperature ofabout 9296°C, then a thermistor 26 within the reservoir 3 25 operates an associated heating relay 26a to cut off powersupply to the heating element 5. At the same time power issupplied to a "brew ready" light 30 which indicates that waterwithin the reservoir 3 is fully heated.

Either a full brew or a half brew of coffee can be selected, 30 depending of the volume of coffee required by the user.Coffee in a filter bag is mounted at an upper end of the um4 and depending on whether a half brew switch 31 or a full - 6 - brew switch 32 is operated, the pump 23 operates for a presettine controlled by a timer 33 to deliver the selected quantityof water over the coffee powder which then collects in the urn.4 as coffee. At the end of the timed period the pump 23 cutsout. Coffee collected in the urn 4 can then be dischargedthrough the tap 28 as required.

When water level in the reservoir 3 falls below the high levelprobe 21 the inlet solenoid 20 is energised to fill the waterreservoir 3 again and the thermistor 26 will control powersupply to the heating element 5 to maintain the water in thereservoir 3 at a temperature of 92°-96°C ready for use.Operation of the heating element 5 for the reservoir 3 will ofcourse be subject to the condition of the interlock relay 14.

The steam boiler 7 has a water inlet line (not shown) commonwith the water reservoir 3 for connection to a wafer supply.A water inlet valve for the steam boiler 7, mounted in thewater inlet line, is also controlled by a solenoid 40 (Fig. 6)which regulates the supply of water to the steam boiler 7. Ahigh level probe 41 and a low level probe 42 are provided onthe steam boiler 7 and are connected to associated relays 41aand 42a. Steam boiler pressure is shown by a pressure gauge43 mounted at a front of the casing 2 and connected to thesteam boiler 7. An air vent valve 45 is provided at an upperend of the steam boiler 7. During start up of the steamboiler 7, the air vent valve 45 allows venting of air from thesteam boiler 7 until rising pressure causes the vent valve 45to close. Prior to closing, air and possibly some steamand/or moisture will be discharged through the vent valve 45.A drainpipe 46 connects between the vent valve 45 and anoutlet 47 which vents to atmosphere outside the casing 2.Thus advantageously, no moisture is discharged within thecasing 2 which might adversely effect the electricalequipment. 7 The drainpipe 46 also connects to an overflow pipe 48connected to a top of the sight glass 27.

In use, with power on the water inlet solenoid 40 is energisedto open the water inlet valve in order to fill the steaa 5 boiler 7. When water covers the low level probe 42 power issupplied to a temperature controller relay 49 which puts powerout from its normally closed contact to the heating element 8.Power is also supplied to the interlock relay 14 to preventpower supply to the water reservoir heating element 5. When 10 water within the steam boiler 7 reaches the high level probe41 power to the inlet solenoid 40 is cut off stopping thewater supply to the steam boiler 7. The water within thesteam boiler 7 is heated and steam is produced raising thepressure within the steam boiler 7. When the pressure rises 15 to 15 psi ±1 psi (approximately 1 bar), the thermistor 12operates to cut off power supply to the heating element 8,simultaneously releasing the interlock relay 14 to allow powersupply to the water reservoir heating element 5 if required.The heating element 8 in the boiler 7 cuts in and out as 20 required to maintain boiler pressure within the desiredlimits.

It will be appreciated that the apparatus according to theinvention advantageously allows the brewing of coffee and theproduction of steam by the one apparatus which can 25 conveniently be connected to a single standard 13 amp powersupply. Thus conventional coffee and cappuccino-type coffeecan be prepared using the apparatus. Λ further advantage of the apparatus is that there is only onewater inlet for connection to a water supply, the water inlet 30 supplying both the water reservoir 3. and the steam boiler 7. A double coil, double outlet solenoid valve is mounted at the water inlet, one coil controlling water supply to the water reservoir 3 and the other coil controlling water supply to the - 8 - steam boiler 7. When the water level in the reservoir 3 fallsbelow the high level probe 21 a signal is sent via relay 21aon the brewer PCB (Fig. 5) to the appropriate solenoid 20 onthe double solenoid valve causing it to operate and deliver 5 water to the reservoir 3 via one of its two outlets.Similarly, when the water level in the steam boiler 7 fallsbelow the high level probe 41 the associated solenoid 40 onthe double solenoid inlet valve is operated to supply water tothe steam boiler 7. TO prevent water from the steam boiler 7 10 forcing its way (under pressure.) into the reservoir 3 a springloaded non-return valve is fitted between the solenoid valveand the steam boiler 7* Referring now to Fig. 7 there is illustrated a portion of awiring diagram of another coffee brewing apparatus showing a IS circuit for operation of the steam boiler. Parts similar tothose described with reference to the apparatus of Figs. 1 to 6 are assigned the same reference numerals. In this case theinterlock comprises a pressure switch 50 on the steam boiler 7 operable below a preset sensed boiler pressure, typically 15 20 psi (1 bar), to supply power to the steam boiler heating element 8. The apparatus operates in similar fashion to theapparatus of Figs. 1 to 6. In this case, when pressure withinthe steam boiler 7 rises to 15 psi t 1 psi (approximately lbar) the pressure switch 50 cuts off power to the steam boiler 25 heating element 8 thus allowing power supply to the waterreservoir heating element 5.

The apparatus for making beverages may be of any suitablematerials of construction.

The invention is not limited to the embodiment hereinbefore 30 described which may be varied in both construction and detail.

Claims (11)

1. Apparatus £ojc making beverages comprising a liquidreservoir having a liquid inlet and a liquid outlet;an electrically operated liquid reservoir heater forheating liquid in the reservoir; a controller for 5 the reservoir heater to maintain liquid within the reservoir at a preset liquid temperature; a steamboiler having a water inlet and a steam outlet; anelectrically operated steam boiler heater for heatingwater in the steam boiler to produce steam; a 10 controller for the boiler heater to maintain the steam at a preset pressure; in which each heater isconnected to a common power supply through aninterlock whereby power is supplied to only oneheater at any one time and preferentially to the IS heater for the steam boiler, and in which the steam boiler heater is operated until switched off by itscontroller when the steam within the boiler reachesthe preset pressure.

2. Apparatus as claimed in claim 1 wherein the interlock 20 comprises a temperature controller which is provided on the steam boiler and which operates below a presetsensed steam boiler temperature, being thetemperature achieved when the preset pressure isreached, to supply power to the steam boiler heater 25 and simultaneously cut off power supply to the water reservoir heater.

3. An apparatus as claimed in claim 1 wherein theinterlock comprises a pressure switch which isprovided on the steam boiler and which operates below 30 a preset sensed boiler pressure to supply power to the boiler heater and simultaneously cut off powersupply to the water reservoir heater. 10 -

4. An apparatus as claimed in any preceding claimwherein the heaters are coil-type electrical heating -elements. *4f

5. An apparatus as claimed in claim 4 wherein thereservoir heating element is a 2.6 kN element and thesteam boiler heating element is in the range 1.0 - 1.5 kN.

6. An apparatus as claimed in any preceding claimwherein the apparatus has an outer casing withinwhich the water reservoir, the steam boiler and theirassociated controllers are housed, and in which thesteam boiler incorporates an air vent valvecornsninicating with the exterior of the outer casingfor venting of the boiler until a preset pressure isachieved in the boiler on start up.

7. An apparatus as claimed in any preceding claimwherein the apparatus has a water inlet forconnection to a water supply, the water inletcosmunicating with both the liquid reservoir and thesteam boiler, and valve means operable to controlwater supply to the liquid reservoir and the steamboiler.

8. An apparatus as claimed in claim 7 wherein the valve^gleans is a water inlet control valve having two water outlets, namely a liquid reservoir supply outlet and a steam boiler supply outlet, each outlet closed by an associated solenoid-operated valve.

9. An apparatus as claimed in claim 8 wherein eachsolenoid-operated valve is operable in response tosensed water level in the associated liquid reservoir 11 or steam boiler to maintain a preset level of waterwithin the liquid reservoir or steam boiler. 9 CTAIMS

10. An apparatus as claimed in any preceding claimwherein the apparatus further includes a coffee urn 5 having an inlet and an outlet, means for supporting coffee in a filter at the urn inlet, and means fordelivering water from the reservoir to the urn inletfor filtering through coffee supported at the urninlet. 10

11. A coffee brewing apparatus substantially as hereinbefore described with reference to theaccompanying drawings. CBDICKSHAHK & CO. ->z