GB2266763A

GB2266763A - An apparatus for making beverages

Info

Publication number: GB2266763A
Application number: GB9309199A
Authority: GB
Inventors: Martin Coughlan
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-05-06
Filing date: 1993-05-05
Publication date: 1993-11-10
Anticipated expiration: 2013-05-05
Also published as: GB9309199D0; BE1005658A6; GB2266763B

Abstract

A coffee making machine comprises a water reservoir 3 enclosing an urn and provided with an electric heater. When required hot water is pumped from the reservoir to a coffee making filter at the top of the urn, from which coffee is drawn by a tap 28 on the front of the enclosing housing. The housing also encloses an electrically heated boiler 7 which supplies steam to nozzle 10. The electric heater of boiler 7 is controlled by a temperature or pressure sensing switch and is linked with the reservoir heater, so that the reservoir heater cannot operate as long as the boiler heater is operating. This enables the machine to be powered from a single 13 amp supply. The reservoir and boiler have level sensors which automatically keep them full of water and control the heaters. A further tap draws hot water from the reservoir. An air vent valve 45 on boiler 7 discharges outside the housing. <IMAGE>

Description

"An apparatus for making beverages" This invention relates to an apparatus for making beverages, particularly a coffee brewing apparatus, in particular for commercial use in a restaurant or the like.

Statements of Invention According to the invention there is provided an apparatus for making beverages comprising a liquid reservoir having a liquid inlet and a liquid outlet, a reservoir heater for heating liquid in the reservoir, a steam boiler having a water inlet and a steam outlet, and a steam boiler heater for heating water in the steam boiler to produce steam at a preset pressure, wherein each heater is an electrical heater and means is provided for connection of each heater to a power supply, said means having an interlock which only permits power supply to one heater at any time.

Preferably the interlock is operable to preferentially supply power to the steam boiler heater.

Conveniently, the interlock may comprise a temperature controller on the boiler operable below a preset sensed boiler temperature to supply power to the steam boiler heater, simultaneously cutting off power supply to the water reservoir heater.

In an alternative arrangement the interlock may comprise a pressure switch on the boiler operable below a preset sensed boiler pressure to supply power to the steam boiler heater, simultaneously cutting off power supply to the water reservoir heater.

In a particularly preferred embodiment the heaters are coiltype heating elements. Preferably the reservoir heating element is a 2.8 kW element and the steam boiler heating element is in the range 1.0 - 1.5 kW. Advantageously the apparatus can thus be operated from a single 13A power supply and means is provided for connecting the device to a standard 13A power supply.

In a further embodiment the apparatus has an outer casing within which the reservoir, steam boiler and electrical control means are housed, the steam boiler having an air vent valve for venting air from the steam boiler at start up, an outlet of the vent valve communicating with an exterior of the casing. Thus advantageously, air and steam vented during start up of the apparatus is vented to atmosphere rather than into the casing where it might adversely effect operation of the electrical apparatus.

In another embodiment, the apparatus has a water inlet for connection to a water supply, the water inlet communicating with both the liquid reservoir and the steam boiler, and valve means operable to control water supply to the liquid reservoir and the steam boiler. Preferably, the valve means is a water inlet control valve having two water outlets, namely a water reservoir supply outlet and a steam boiler supply outlet, each outlet closed by an associated solenoid-operated valve.

Ideally, the solenoid-operated valve is operable in response to sensed water level in the associated liquid reservoir or steam boiler to maintain a preset level of water in the liquid reservoir or steam boiler.

In another embodiment the apparatus further includes a coffee urn having an inlet and an outlet, means for supporting coffee in a filter at the urn inlet, and means for delivering water from the liquid reservoir to the urn inlet for filtering through coffee supported at the urn inlet.

Detailed Description of the Invention The invention will be more clearly understood by the following description of an embodiment thereof, given by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a coffee brewing apparatus 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 with a 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 another coffee brewing apparatus.

Referring to the drawings, and initially to Figs. 1 to 6 thereof, there is illustrated a coffee brewing apparatus according to the invention indicated generally by the reference 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 a cylindrical coffee urn 4. A 2.8 kW electrical heating element 5 (Fig. 5) is provided within the reservoir 3 for heating water in the reservoir 3 for delivery to the urn 4 to brew coffee in the urn 4. A steam boiler 7 is also mounted within the casing 2. A 1.5 kW boiler heating element 8 (Fig. 6) housed within the steam boiler 7 is operable to heat water within the steam boiler 7 to produce steam at 15 psi (1 bar) for discharge through a steam injector 10.

Power for operation of the apparatus 1 is delivered from a 13A power supply through a standard 13A plug connector (not shown) on the apparatus 1. An interlock is provided such that only one of the heating elements (5, 8) may be operated at any time. The interlock is operable to preferentially supply power 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 boiler temperature, in this case equivalent to 15 psi (1 bar), to supply power to the steam boiler heating element 8. The interlock further comprises an interlock relay 14 (Fig. 5) in the power supply circuit for the water reservoir heating element 5. This relay 14 is fired by the steam boiler heating element line. The contact side of the relay 14 carries the supply line to a contactor 15 (controlling supply to the water reservoir heating element 5) through its normally closed poles. When the steam boiler 7 energises the relay 14 the poles open and disconnect the contactor 15, cutting off power supply to the water reservoir heating element 5.When the pressure within the steam boiler 7 rises to 15 psi + 1 psi (approximately 1 bar) the thermistor 12 cuts off power to the steam boiler heating element 8 thus allowing power supply to the water reservoir heating element 5. Advantageously this allows the apparatus 1 to operate from a single 13A power supply. If both elements 5, 8 were allowed energise simultaneously a 17 A power supply would be required.

The water reservoir 3 has a water inlet line (not shown) for connection to a water supply. A water inlet valve is mounted in 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 on the reservoir 3 and are connected to associated relays 21a and 22a. Hot water can be discharged from the reservoir 3 by a pump 23 through a discharge pipe 24 which opens into a top of the coffee urn 4. A hot water discharge tap 25 is also provided on a front of the casing 2 for discharging hot water from the reservoir 3.

The coffee urn 4 is supplied with water from the water reservoir 3 as previously described. Coffee powder in a filter bag can be supported on a holder (not shown) which can be mounted at an upper end of the coffee urn 4 beneath the outlet of the pipe 24. Thus water delivered from the water reservoir 3 filters down through the coffee powder for collection in the urn 4 as coffee. A sight glass 27 is provided on the urn 4 for viewing the contents of the urn 4.

The sight glass is back lit by an associated sight-glass lamp 17. Coffee can be discharged from the urn 4 through an outlet tap 28 mounted at the front of the casing 2.

In use, with power on, the inlet solenoid 20 is energised to open the water inlet valve allowing water supply to the water reservoir 3. When water level reaches the low level probe 22, power is supplied to the heating line energising the contact 15 supplying power to the heating element 5 to heat the water in the reservoir 3. This is indicated by a "heating" lamp 16.

Water continues to fill the water reservoir until it reaches the high level probe 21 which then cuts off power to the inlet solenoid 20 stopping the water supply.

Water within the reservoir 3 is heated to a temperature of about 92"-96"C, then a thermistor 26 within the reservoir 3 operates an associated heating relay 26a to cut off power supply to the heating element 5. At the same time power is supplied to a "brew ready" light 30 which indicates that water within the reservoir 3 is fully heated.

Either a full brew or a half brew of coffee can be selected, depending of the volume of coffee required by the user.

Coffee in a filter bag is mounted at an upper end of the urn 4 and depending on whether a half brew switch 31 or a full brew switch 32 is operated, the pump 23 operates for a preset time controlled by a timer 33 to deliver the selected quantity of water over the coffee powder which then collects in the urn 4 as coffee. At the end of the timed period the pump 23 cuts out. Coffee collected in the urn 4 can then be discharged through the tap 28 as required.

When water level in the reservoir 3 falls below the high level probe 21 the inlet solenoid 20 is energised to fill the water reservoir 3 again and the thermistor 26 will control power supply to the heating element 5 to maintain the water in the reservoir 3 at a temperature of 92"-960C ready for use.

Operation of the heating element 5 for the reservoir 3 will of course be subject to the condition of the interlock relay 14.

The steam boiler 7 has a water inlet line (not shown) common with the water reservoir 3 for connection to a water supply.

A water inlet valve for the steam boiler 7, mounted in the water inlet line, is also controlled by a solenoid 40 (Fig. 6) which regulates the supply of water to the steam boiler 7. A high level probe 41 and a low level probe 42 are provided on the steam boiler 7 and are connected to associated relays 41a and 42a. Steam boiler pressure is shown by a pressure gauge 43 mounted at a front of the casing 2 and connected to the steam boiler 7. An air vent valve 45 is provided at an upper end of the steam boiler 7. During start up of the steam boiler 7, the air vent valve 45 allows venting of air from the steam boiler 7 until rising pressure causes the vent valve 45 to close. Prior to closing, air and possibly some steam and/or moisture will be discharged through the vent valve 45.

A drainpipe 46 connects between the vent valve 45 and an outlet 47 which vents to atmosphere outside the casing 2.

Thus advantageously, no moisture is discharged within the casing 2 which might adversely effect the electrical equipment.

The drainpipe 46 also connects to an overflow pipe 48 connected to a top of the sight glass 27.

In use, with power on the water inlet solenoid 40 is energised to open the water inlet valve in order to fill the steam boiler 7. When water covers the low level probe 42 power is supplied to a temperature controller relay 49 which puts power out from its normally closed contact to the heating element 8.

Power is also supplied to the interlock relay 14 to prevent power supply to the water reservoir heating element 5. When water within the steam boiler 7 reaches the high level probe 41 power to the inlet solenoid 40 is cut off stopping the water supply to the steam boiler 7. The water within the steam boiler 7 is heated and steam is produced raising the pressure within the steam boiler 7. When the pressure rises to 15 psi +1 psi (approximately 1 bar), the thermistor 12 operates to cut off power supply to the heating element 8, simultaneously releasing the interlock relay 14 to allow power supply to the water reservoir heating element 5 if required.

The heating element 8 in the boiler 7 cuts in and out as required to maintain boiler pressure within the desired limits.

It will be appreciated that the apparatus according to the invention advantageously allows the brewing of coffee and the production of steam by the one apparatus which can conveniently be connected to a single standard 13 amp power supply. Thus conventional coffee and cappuccino-type coffee can be prepared using the apparatus.

A further advantage of the apparatus is that there is only one water inlet for connection to a water supply, the water inlet 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 steam boiler 7. When the water level in the reservoir 3 falls below the high level probe 21 a signal is sent via relay 21a on the brewer PCB (Fig. 5) to the appropriate solenoid 20 on the double solenoid valve causing it to operate and deliver water to the reservoir 3 via one of its two outlets.

Similarly, when the water level in the steam boiler 7 falls below the high level probe 41 the associated solenoid 40 on the double solenoid inlet valve is operated to supply water to the steam boiler 7. To prevent water from the steam boiler 7 forcing its way (under pressure) into the reservoir 3 a spring loaded non-return valve is fitted between the solenoid valve and the steam boiler 7.

Referring now to Fig. 7 there is illustrated a portion of a wiring diagram of another coffee brewing apparatus showing a circuit for operation of the steam boiler. Parts similar to those described with reference to the apparatus of Figs. 1 to 6 are assigned the same reference numerals. In this case the interlock comprises a pressure switch 50 on the steam boiler 7 operable below a preset sensed boiler pressure, typically 15 psi (1 bar), to supply power to the steam boiler heating element 8. The apparatus operates in similar fashion to the apparatus of Figs. 1 to 6. In this case, when pressure within the steam boiler 7 rises to 15 psi + 1 psi (approximately 1 bar) the pressure switch 50 cuts off power to the steam boiler heating element 8 thus allowing power supply to the water reservoir heating element 5.

The apparatus for making beverages may be of any suitable materials of construction.

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

Claims

1. An apparatus for making beverages comprising a liquid reservoir having a liquid inlet and a liquid outlet, a reservoir heater for heating liquid in the reservoir, a steam boiler having a water inlet and a steam outlet, and a steam boiler heater for heating water in the steam boiler to produce steam at a preset pressure, wherein each heater is an electrical heater and means is provided for connection of each heater to a power supply, said means having an interlock which only permits power supply to one heater at any time.

2. An apparatus as claimed in claim 1 wherein the interlock is operable to preferentially supply power to the steam boiler heater.

3. Apparatus as claimed in claim 2 wherein the interlock comprises a temperature controller on the boiler operable below a preset sensed boiler temperature to supply power to the steam boiler heater, simultaneously cutting off power supply to the water reservoir heater.

4. An apparatus as claimed in claim 2 wherein the interlock comprises a pressure switch on the steam boiler operable below a preset sensed boiler pressure to supply power to the boiler heater simultaneously cutting off power supply to the water reservoir heater.

5. An apparatus as claimed in any preceding claim wherein the heaters are coil-type heating elements.

6. An apparatus as claimed in claim 5 wherein the reservoir heating element is a 2.8 kW element and the steam boiler heating element is in the range 1.0 - 1.5 kW.

7. An apparatus as claimed in any preceding claim wherein the apparatus has an outer casing within which the reservoir, steam boiler and electrical control means are housed, the steam boiler having an air vent valve for venting air from the boiler at start up, an outlet of the vent valve communicating with an exterior of the casing.

8. An apparatus as claimed in any preceding claim wherein the apparatus has a water inlet for connection to a water supply, the water inlet communicating with both the liquid reservoir and the steam boiler, and valve means operable to control water supply to the liquid reservoir and the steam boiler.

9. An apparatus as claimed in claim 8 wherein the valve means 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.

10. An apparatus as claimed in claim 9 wherein each solenoid operated valve is operable in response to sensed water level in the associated liquid reservoir or steam boiler to maintain a preset level of water within the liquid reservoir or steam boiler.

11. An apparatus as claimed in any preceding claim wherein the apparatus further includes a coffee urn having an inlet and an outlet, means for supporting coffee in a filter at the urn inlet, and means for delivering water from the reservoir to the urn inlet for filtering through coffee supported at the urn inlet.

12. A coffee brewing apparatus substantially as hereinbefore described with reference to the accompanying drawings.