GB2044419A - An electric tea or coffee making machine - Google Patents

Abstract

The outlet connection 4 of a tea or coffee making machine is formed as a buffer container or reservoir and is fed with hot water by a riser pipe 2 whose mouth is above the level of an overflow-outlet weir 8 through which excess water in the connection can flow back to the fresh water container 1 of the machine. The main outlet 15 leading to a filter holder 6 is positioned downstream of a throttled opening 13 in a transverse member 11. Transverse baffles 16 are provided to damp down surging within the outlet connection and thus keep the flowing hot water calm. <IMAGE>

Description

SPECIFICATION An electric coffee or tea making machine The invention relates to an electric coffee or tea making machine in which water is passed out of a container for fresh water through a flow pass heater, a riser pipe and an outlet connection into a coffee or tea filter.

In use of such machines, hot water leaving the riser pipe runs through the outlet connection directly into the filter. The volume of the water running into the filter per unit of time depends on various factors, and their effect on the manufacture of machines is not known exactly.

Fluctuations in the heat output of the flow pass heater, furring up of the pipes and different temperatures of the fresh water are examples of these factors. In the case of the factor last mentidned, there is the additional point that users frequently fill coffee machines with hot instead of cold water so that the water flows very rapidly through the riser pipe, and this can cause the coffee filter to overflow.

It is also undesirable to have too small a volume flowing through per unit of time, since the level of water in the coffee filter is then too low and this impairs the flavour of the coffee.

It is the object of the invention to so form a coffee or tea making machine that the quantity of water passing out of the outlet connection per unit of time corresponds more close to the actual requirements.

Accordingly, the invention provides an electric tea or coffee making machine in which water is passed out of a fresh water container through a flow pass heater, a riser pipe and an outlet connection into a tea or coffee filter, wherein the outlet connection is constructed as a buffer container and had a throttled outlet opening and an overflow outlet. The overflow outlet preferably opens into the fresh water container.

If hot instead of cold water is now poured into the fresh water container then it is in fact rapidly heated up by the flow pass heater as before and flows correspondingly rapidly through the riser pipe. However, as soon as a certain level of water is reached in the buffer container, the additional water flows back through the overflow outlet into the fresh water container. The quantity of water pouring (per unit of time) into the coffee filter is limited by the throttle opening.

Baffle elements are preferably arranged in the buffer container to calm the water in the container.

A preferred form of coffee or tea making machine in accordance with the invention will now be described by way of example, with reference to the accompanying drawings, in which: Figure 1 shows the coffee machine schematically and Figure 2 shows the outlet connection of the coffee machine in section and enlarged with respect to Figure 1.

A riser pipe 2 is connected to the base of a fresh water container 1 of a coffee machine. The lower part of the riser pipe 2 is heated by a flow pass heater 3.

At its upper end the riser pipe 2 opens into an outlet connection 4 which terminates above a coffee filter 6 placed on a coffee jug 5.

The outlet connection 4 is sufficiently voluminous for its interior to form a buffer container 7. The water level which is possible in the buffer container 7 is limited by an overflow edge 8. The overflow edge 8 is located directly above the fresh water container 1. An angled portion 9 of a cover 10 of the outlet connection 4, is positioned over the over flow edge 8 to form a steam trap limiting the escape of steam.

A throttled opening 13 is provided in a transverse wall 11 of the buffer container 7, adjacent the base 1 2. A tubular outlet portion 14 is arranged downstream of the throttled opening 13, and forms a hot water outlet 1 5 positioned directly above the filter 6.

The outlet connection can also be constructed so that it tapers towards its throttled opening 1 3.

The opening 1 3 may then be positioned directly above the filter 6.

Inside the buffer container 7, baffle elements 1 6 are arranged on the lid 10 and run transverse to the direction of flow of the water. These elements serve to calm water gushing into the buffer container 7 through the riser pipe 2. The elements 1 6 are graduated in height, in order that the water is calmed even at different water levels.

The riser pipe 2 opens into the buffer container 7 above the maximum permitted water level. Thus, water cannot flow back out of the buffer container to the flow pass heater. The base 12 of the outlet connection 4 can be inclined towards the coffee filter 6 in order to ensure that the water from the buffer container 7 flows away completely through the throttle opening 1 3 after the water has been heated to a suitable temperature.

The dimensions of the buffer container 7 can be freely selected within wide limits. The upper limit is determined by the fact that, at most, the water stored in intermediate manner in the buffer container should cool off only slightly. When establishing the lower limit of the dimensions it is important that small increases in the water supply from the riser pipe with respect to normal operation should not cause water to flow back over the overflow edge 8 into the fresh water container.

The cross section of the throttle opening 13 is preferably to be dimensioned so that during normal operation the quantity of water passing out of the throttle opening per unit of time is approximately just as large as in previously known coffee machines. If the throttle opening is made very small then the throughflow time must be extended.

If, in operation of the coffee machine described, normal conditions prevail in which cold water is poured in at a temperature of approximately 1 50C, then the through flow time for ten cups of water is approximately 10 minutes.

If on the other hand fresh water at a temperature of 86 C is poured into the fresh water container, then the duration of the throughflow time is 9.5 minutes for example, also for 10 cups. Therefore there is not any substantial difference in the through flow time. In tests on a coffee machine according to the state of the art on the other hand, the hot water runs through in approximately 4.5 minutes and causes the filter to overflow. In the illustrated machine, the water supplied in excess through the riser pipe 2 flows back over the overflow edge 8 into the fresh water container 1.

Therefore, in the final result, the correct water level in the filter of the coffee machine described is effectively independent of the temperature of the fresh water. The same is true in the case of deviations in the ancillary output of the flow pass heater and fluctuations in the mains voltage from the desired values and in the case of furring up of the riser pipe.

The buffer container 7 causes the water to pass smoothly through the throttled opening 13, when the supply of water through the riser pipe is erratic.

The outlet connection described is simple and cheap to produce and can be ealsily incorporated in conventional designs of coffee machines.

The outlet connection can also be constructed so that the part provided with the throttled opening can be easily exchanged for part with a throttled opening of different cross section.

Claims (6)

1. An electric tea or coffee making machine in which water is passed out of a fresh water container through a flow pass heater, a riser pipe and an outlet connection in to a tea or coffee filter, wherein the outlet connection is constructed as a buffer container and has a throttled outlet opening and an overflow outlet.

2. A machine according to claim 1, wherein the overflow outlet discharges into the fresh water container.

3. A machine according to claim 1 or 2, wherein one or more transverse baffles for calming water surges are provided in the buffer container.

4. A machine according to claim 1, 2 or 3 wherein the riser pipe opens into the buffer container above the bottom level of the container.

5. A machine according to any one of the preceding claims, wherein the outlet connection is shaped to form a steam trap over the overflow outlet.

6. A electric tea or coffee making machine according to the preceding claims, wherein the outlet connection is substantially as herein described with reference to the accompanying drawing.