AU2008202438B2

AU2008202438B2 - Espresso machine

Info

Publication number: AU2008202438B2
Application number: AU2008202438A
Authority: AU
Inventors: Ray Corkin
Original assignee: Sunbeam Corp Ltd; Sunbeam Corp
Current assignee: Sunbeam Corp Ltd
Priority date: 2007-06-06
Filing date: 2008-06-02
Publication date: 2014-08-21
Anticipated expiration: 2028-06-02
Also published as: CN101317740A; NZ568731A; AU2008202438A1

Abstract

An espresso machine including a water heater for heating a water supply, a valve arrangement in fluid communication with the water heater, a brew head in fluid communication with the valve arrangement via a brew water conduit, a hot water/steam 5 outlet in fluid communication with the valve arrangement via a hot water/steam conduit, a pump for pumping water from the water supply to at least one of the the brew head and the hot water/steam outlet via the valve arrangement, and a controller for controlling operation of the valve arrangement to selectively direct fluid flow from the water supply to the brew water conduit or the hot water/steam conduit. The espresso machine also 10 includes a pressure release valve for releasing pressure in the hot water/steam conduit independently of the controller via an overflow outlet. < 0 c~rc C)c coc coc

Description

Regulation 3.2 AuSTRALIA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Invention Title: Espresso machine The following statement is a full description of this invention, including the best method of performing it known to us: 2 Espresso Machine Field of the invention The present invention relates to an espresso type coffee maker, and in particular to an espresso machine. 5 Background of the invention Coffee is an extremely popular beverage in today's society. One of the most popular forms of coffee is espresso coffee. Espresso coffee is made by heating water and using pressure to force that heated water through finely ground coffee beans. Modern espresso makers generally provide at least two functions. The first of these is 10 the making of the espresso coffee itself. As noted above, this is done by heating water to create hot water and then creating pressure to force the hot water through ground coffee beans in a brew head. A second function offered by many espresso makers is the creation and outlet of steam to heat and/or froth milk which is to be added to the espresso coffee (to create, for example, a cappuccino or a cafe latte coffee). 15 Often espresso makers are also operable to outlet hot or boiling water to either add to the espresso coffee (to dilute it, for example) or for use in making a pot of tea or other hot beverage. To provide these functions the beverage maker usually includes a water inlet, a pressure pump, a heating block and various outlets through which the espresso coffee, 20 steam and water can pass. Generally a drip outlet is also provided to allow excess water or steam to exit the maker in the case of maintenance of the maker or excess pressure build up. The reliable control and management of the flow of water and/or steam through the beverage maker from the water inlet or tank to the appropriate outlet at the appropriate 25 time under high temperature and pressure conditions is one aspect of espresso makers which makes them quite costly to manufacture.

3 Summary of the invention In one aspect the present invention provides an espresso machine including: a water heater for heating a water supply; a valve arrangement in fluid communication with the water heater; 5 a brew head in fluid communication with the valve arrangement via a brew water conduit; a hot water/steam outlet in fluid communication with the valve arrangement via a hot water/steam conduit; a pump for pumping water from the water supply to at least one of the the brew 10 head and the hot water/steam outlet via the valve arrangement; a controller for controlling operation of the valve arrangement to selectively direct fluid flow from the water supply to the brew water conduit or the hot water/steam conduit; and a pressure release valve for releasing pressure in the hot water/steam conduit 15 independently of the controller via an overflow outlet. Preferably, the pressure release valve is directly responsive to an increase in pressure in the hot water/steam conduit. The valve arrangement may include a multi-way valve, the multi-way valve preferably being a three-way valve. 20 Conveniently, a first manually controllable valve is located downstream of the pressure release valve, the manually controllable valve being arranged to control flow of hot water/steam through the hot water/steam outlet. the espresso machine may optionally include a hot water outlet in fluid communication with the hot water/steam conduit and a second manually controllable valve arranged to 25 control flow of hot water through the hot water outlet. Preferably, the espresso machine is operable in: 4 a brewing mode in which hot water is supplied under pressure through the brew water conduit to the brew head via the valve arrangement; a hot water/steam delivery mode in which hot water/steam is supplied to the hot water/steam outlet through the hot water/steam conduit via the valve arrangement and 5 manually controllable valve; and a pressure release mode in which the pressure release valve opens in response to an increase in pressure in the hot water/steam conduit, the open pressure release allowing water/steam to flow to the overflow outlet. The pressure release mode may occur after the brewing mode, at which time the valve 10 arrangement redirects the flow of water from the brew water conduit to the hot water/steam conduit. Brief description of the drawings The invention will now be described with reference to the accompanying drawings which show various embodiments of an espresso machine according to the present invention. 15 It is to be understood that the invention is not limited to the features of the embodiments shown in the drawings. Figure 1 shows a schematic representation of the internal components of an espresso machine in accordance with a first embodiment of the invention; and Figure 2 provides a schematic representation of a second embodiment of the espresso 20 machine shown in figure 1. Detailed description of the embodiments As can be seen in figure 1, the heated beverage maker 10 of the preferred embodiment includes a water supply in the form of a water tank 12, a pump 14, a water heater 16, a high pressure water outlet 18, an overflow outlet 20 and a hot water/steam outlet 22. 25 These components are connected by a series of conduits through which the water or 5 steam flows. The settings of the pump 14 and water heater 16 are controlled by a beverage maker microprocessor-based controller 90, via outputs 90A and 90B. The water tank my be provided with a water level sensor(not shown) which provides an input 12A to the controller. At least one temperature sensor(not shown) at the water heater 5 provides one or more temperature inputs16A to the controller. In an alternative embodiment, the positions of the pump 14 and water heater 16 may be reversed. The high pressure water outlet 18 is provided with a bayonet-type receiving mount 18A to which a coffee holder 19 is removably attached. The coffee holder 19 has a brew 10 head with a filter which is packed with finely ground coffee beans and as pressurised water passes out of the high pressure water outlet 18 and through the brew head the espresso coffee is made. The overflow outlet 20 leads to a catchment reservoir, in this case a drip tray 21. The hot water/steam outlet 22 is used to deliver steam and/or water. Conveniently, a wand 15 23 is attached to the hot water/steam outlet 22 and can be placed in a jug or the like for easy delivery of steam and/or hot water. When the espresso maker 10 is in use, water from the water tank 12 is pumped through the water heater 16 by the pump 14. If steam is required the pump 14 pumps water at a relatively slow rate, for example 0.5ml/sec through the water heater 16 and the 20 temperature of the water heater 16 is relatively high, for example 170* Celsius. If instead hot water is required the pump 14 pumps water at a relatively quick rate, for example 2.Oml/sec, through the water heater 16 and the temperature of the water heater 16 is relatively low, for example 11 O 0 Celcius. To direct the flow of water and/or steam which has passed through the water heater 16 25 to one of the outlets 18, 20 or 22, a series of valves is used. These include a multi-way valve 24, a pressure release valve 26 and a needle valve 28. The multi-way valve 24 is controlled by the beverage maker controller 90 via output 90C, and in the preferred embodiment is a solenoid valve. In alternative embodiments flow direction in the 6 espresso maker may be controlled by an alternative valve arrangement which may include one or more valves functioning to direct the flow of water and/or steam through the espresso maker. The multi-way valve 24 has a multi-way valve inlet 30 for water/steam that has passed 5 through the water heater 16, a high pressure valve outlet 32 leading to a brew water conduit 15 and the high pressure water outlet 18, and a low pressure valve outlet 34 leading to a hot water/steam conduit 17 and the hot water/steam outlet 22 (via the pressure release valve 26). The multi-way valve 24 may be operated by the beverage maker controller 90 to direct 10 flow through the brew water conduit 15 to the high pressure water outlet 18 (in which case the high pressure valve outlet 32 is open and the low pressure valve outlet 34 is closed). In this case the multi-way valve 24 is considered to be open. Alternatively, the multi-way valve 24 may be operated by the beverage controller 90 to direct flow through the hot water/steam conduit 17 towards the pressure release valve 15 26 (in which case the low pressure valve outlet 34 is open and the high pressure valve outlet 32 is closed). In this case the multi-way valve 24 is considered to be closed, which is the "natural" state of the multi-way valve 24 (i.e. the state when the beverage maker is switched off or no control option has been selected by a user). The pressure release valve 26 is located on the hot water/steam conduit 17 between 20 the multi-way valve 24 and the needle valve 28. The pressure release valve 26 has a pressure release valve inlet 36 for fluid that has passed through the low pressure valve outlet 34 of the multi-way valve 24, a pressure release outlet 38 leading to the overflow outlet 20, and a through outlet 40 leading to the needle valve 28. The through outlet 40 in the pressure release valve 26 is always open, allowing fluid flow to the needle valve 25 28. Unlike the multi-way valve 24, which requires operation from the beverage maker controller 90, the pressure release valve 26 is directly responsive to pressure within the beverage maker 10 and operates without requiring specific instruction or input from the 7 beverage controller 90, to which it has no connection. In this way the pressure release valve 26 mechanically detects and responds to pressure build up in the beverage maker 10, in particular to pressure build up in the hot water/steam conduit 17, upstream of the needle valve 18 and low pressure outlet 22. 5 The pressure release outlet 38 is biased closed and only opens when there is sufficient pressure build up to overcome that bias. This pressure will be referred to as the threshold pressure of the pressure release valve 38. For example, the pressure release outlet 38 may be constructed of a ball and spring type closure, the resistance of the spring such that the ball blocks the pressure release outlet 38 unless the threshold 10 pressure is reached in the beverage maker 10. If this threshold pressure is reached, the spring deforms and the ball moves away from the pressure release outlet 38 and allows fluid to pass through the pressure release outlet 38 to the overflow outlet 20. Other mechanical arrangements as are known may, of course, be used to create a suitable pressure release valve. 15 The threshold pressure required for the pressure release valve 26 to open may be set, for example, at lower setting of 2 Bar, but more typically at 3.5-4 Bar. Conveniently, the pressure release valve 26 may be provided with an adjustment means in the form of an adjustment screw or the like [not shown] which may be used to make adjustments to the threshold pressure at which the pressure release valve 26 will open. This is typically 20 factory set. That leg 17A of the of the hot water/steam conduit downstream of the pressure release valve 26 may optionally be fitted with a separate hot water line 17B which is fitted with a tap 17C and having a hot water outlet 22A. Clearly the pressure release valve 26 will only operate when the tap is closed. 25 Referring to figure 2, a two-port pressure release valve 26A is fitted to a tee-fitting 27 in conduit 17. This allows for a two-port pressure release valve to be used (rather than the three-port pressure release valve of the previous embodiment). In this embodiment case one branch of the tee-fitting 27 leads to the needle valve inlet 42, and the second branch of the tee-fitting 27 leads to the pressure release valve inlet 36A of the two-port 8 pressure release valve 26A. The pressure release outlet 38A of the two-port pressure release valve 26A is connected to the overflow outlet 20 and operates as previously described. Returning to figure 1, the needle valve 28 has a needle valve inlet 42 for fluid that has 5 passed through the through outlet 40 of the pressure release valve 26, and a needle valve outlet 44 leading to the hot water/steam outlet 22. The needle valve 28 may be opened or closed manually by the user of the beverage maker 10, for example by turning a knob 29. If the needle valve is open, the needle valve outlet 44 is open and fluid can pass through to the hot water/steam outlet 22. If the needle valve is closed, the 10 needle valve outlet 44 is closed and no fluid can pass through to the hot water/steam outlet 22. Operation of the beverage maker 10 is most conveniently discussed with reference to the control options available to a user. These options are selected by activating buttons on a control panel 80, and include an on/off button 82, a steam button 84, a hot water 15 button 86 and a coffee button 88. Each of these buttons sends a command to the beverage maker controller 90 which controls the pump 14, water heater 16 and multi way valve 24 in order to effect the desired operation. Operation of beverage maker when "Steam" option selected If the user selects the steam button 84, the controller 90 activates the components of 20 the beverage maker 10 to outlet steam from the hot water/steam outlet 22. This steam may be used to heat and/or froth milk. To provide steam to the hot water/steam outlet 22 the controller 90 operates the pressure pump 14 at a relatively slow rate, for example 0.4ml/sec, to pump water from the water tank 12 through the water heater 16. The controller 90 also sets the 25 temperature of the water heater 16 to be at a relatively high temperature, for example 1700 Celsius.

9 As the steam is to be outlet at the hot water/steam outlet 22, the controller 90 sends a signal to close the multi-way solenoid valve 24 (so that the high pressure valve outlet 32 is closed and the low pressure valve outlet 34 is open). The user can then open the needle valve 28 to allow steam to pass through the needle valve outlet 44 to the hot 5 water/steam outlet 22. If the user selects the steam button 84 and does not open the needle valve 28, a pressure build up will occur in the hot water/steam conduit 17 upstream of the needle valve 18 and hot water/steam outlet 22. If the pressure build up is sufficient to overcome the bias of the pressure release valve 26, for example if the pressure reaches 3.5 to 4 10 Bar, the pressure release valve 26 will automatically open to allow steam to pass to the overflow outlet 20 and relieve the pressure build-up in the conduit 17. Operation of beverage maker when "Hot water" option selected If the user selects the hot water button 86, the controller 90 activates the components of the beverage maker 10 to outlet hot water from the hot water/steam outlet 22 or from 15 the hot water outlet 22A if it is available. This hot water may be used to add to coffee, to make tea or even for general cleaning/sterilising purposes. To provide hot water to the hot water/steam outlet 22 or the hot water outlet 22A the controller 90 operates the pressure pump 14 at a relatively fast rate, for example 2.0ml/sec, to pump water from the water tank 12 through the water heater 16. The 20 controller 90 also sets the temperature of the water heater 16 to be at a relatively low temperature, for example 1100 Celsius. With the exception of the altered operation of the pump and water heater 16, the flow of hot water through the system to the hot water/steam outlet 22/22A is the same as that described above in relation to the flow of steam through the beverage maker 10. 25 Operation of beverage maker when "Coffee" option selected If the user selects the coffee button 88, the controller 90 activates the components of the beverage maker 10 to outlet water from the high pressure water outlet 18 at a 10 relatively high pressure, for example up to around 9 Bar. This water then passes through the coffee holder 19 to make the espresso coffee. To provide the hot water to the high pressure water outlet 18 the controller 90 operates the pressure pump 14 at a relatively fast rate, for example 2.Oml/sec, to pump water 5 from the water tank 12 through the water heater 16. The controller 90 also sets the temperature of the water heater 16 to be at a relatively low temperature, for example 1100 Celsius.

II As the water is to be outlet at the high pressure water outlet 18, the controller 90 sends a signal to the multi-way valve 24 such that the low pressure valve outlet 34 is closed and the high pressure valve outlet 32 is open. The multi-way valve 24 therefore directs the water to the high pressure water outlet 18 whilst at the same time prevents any 5 water from passing through the low pressure valve outlet 34 towards the pressure release valve 26. Operation of beverage maker when "Onloff" option or no option is selected If the beverage maker 10 is off and the user selects presses the on/off button 82 the beverage maker 10 will switch on. 10 If the beverage maker 10 is on and a user selects to switch the beverage maker 10 off by using the on/off button 82, or if no option from the control panel 80 is selected, power to the pump 14, the water heater 16 and the multi-way valve 18 are cut. Without power the multi-way valve 24 is closed, i.e. configured such that the high pressure valve outlet 32 is closed. Any residual water/steam in the beverage maker 10 15 (recalling that the pump is no longer operational and not actively pumping water/steam) therefore passes through the low pressure valve outlet 34 of the multi-way valve 24 and into the hot water/steam conduit 17. If the needle valve 22 and the tap 17C where applicable has been left closed by the user and sufficient residual steam/water is left flowing through the beverage maker 10 20 after power has been switched off, pressure may build up in the pressure release valve 26. If this pressure reaches the threshold level at which the pressure release valve 26 opens, for example 3.5 Bar, the pressure release valve 26 will open allowing the steam/water to flow through the pressure release valve outlet 38 to the overflow outlet 20.

12 The table below provides a summary of the various beverage maker functions: Function Pump Heating Multi- Needle Pressure release valve flow block way valve/Tap rate valve Steam Slow 1700 C Closed Open Open or closed depending on pressure build up Hot water Fast 1100 C Closed Open Open or closed depending on I pressure build up Coffee Fast 1100 C Open Closed Closed Off/no Off Off Closed Closed Open or closed depending on option pressure build up selected It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features 5 mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.

Claims

1. An espresso machine including: a water heater for heating a water supply; a valve arrangement in fluid communication with the water heater; 5 a brew head in fluid communication with the valve arrangement via a brew water conduit; a hot water/steam outlet in fluid communication with the valve arrangement via a hot water/steam conduit; a pump for pumping water from the water supply to at least one of the the brew 10 head and the hot water/steam outlet via the valve arrangement; a controller for controlling operation of the valve arrangement to selectively direct fluid flow from the water supply to the brew water conduit or the hot water/steam conduit; and a pressure release valve for releasing pressure in the hot water/steam conduit 15 independently of the controller via an overflow outlet.

2. An espresso machine according to claim 1, wherein the pressure release valve is directly responsive to an increase in pressure in the hot water/steam conduit.

3. An espresso machine according to either claim 1 or claim 2, wherein the valve arrangement includes a multi-way valve. 20

4. An espresso machine according to claim 3, wherein the multi-way valve is a three-way valve.

5. An espresso machine according to any one of the preceding claims further including a first manually controllable valve located downstream of the pressure release valve. 14

6. An espresso machine according to claim 5, wherein the first manually controllable valve is arranged to control flow of hot water/steam through the first hot water/steam outlet.

7. An espresso machine according to either one of claims 5 or 6 which includes a 5 hot water outlet in fluid communication with the hot water/steam conduit and a second manually controllable valve arranged to control flow of hot water through the hot water outlet.

8. An espresso machine according to any one of the preceding claims, wherein the espresso machine is operable in a brewing mode in which hot water is supplied under 10 pressure through the brew water conduit to the brew head via the valve arrangement.

9. An espresso machine according to any one of the preceding claims, wherein the espresso machine is operable in a hot water/steam delivery mode in which hot water/steam is supplied to the hot water/steam outlet through the hot water/steam conduit via the valve arrangement and manually controllable valve. 15

10. An espresso machine according to any one of the preceding claims, wherein the espresso machine is operable in a pressure release mode in which the pressure release valve opens in response to an increase in pressure in the hot water/steam conduit, the open pressure release valve allowing water/steam to flow to the overflow outlet.

11. An espresso machine substantially as hereinbefore described with reference to 20 the accompanying drawings. Dated : 2 June 2008 Freehills Patent & Trade Mark Attorneys Patent Attorneys for the Applicant: Sunbeam Corporation Limited 25