Espresso coffeemaker with removable water reservoir

Translation of description of equivalent WO 2004000083 A1

ESPRESSO-TYPE COFFEE MACHINE WITH AMOVILE WATER RESERVOIR

The present invention relates to espresso-type electric coffee makers comprising a cold water tank, an electric pump, a boiler assembly and a filter container for receiving the ground coffee which will be infused with hot pressurized water from Boiler.

The boiler assembly, hereinafter called thermoblock, generally consists of an electric heating element in thermal relation with a water circuit, the water being circulated during operation of the pump. At the end of the coffee beverage production cycle, it is necessary to realize a pressure relief in the hydraulic circuit of the machine, this relaxation is done for the vast majority of coffee machines by redirecting the flow of water under pressure to the cold water tank which thus receives the return flow.

Such a coffee machine is known from FR 2 316 901 where a pump is mounted in the base of the machine and a cold water tank in the vertical column connecting the base to the upper part of the machine. The tank is removably mounted by being positioned in a frame belonging to the base of the machine. The mount receiving the removable reservoir has a cylindrical bore in the upper portion for communicating with the outlet of the tank and a bottom communicating with two downwardly connected pipes connected to the suction pipe of the pump and the another to a return duct in the tank. Operating to satisfaction, we realized that in the situation where the user withdraws from inadvertently the tank of its seat when a flow of hot pressurized water arrives to the tank, the return is in the form of a jet hot and hot and projected splashing may then burn the user. In addition, there is rejection on the worktop of a large amount of hot water.

In order to overcome this problem, some solutions have been envisaged consisting, for example, in using an electronic circuit using a sensor for detecting the presence of the reservoir, the sensor information then being used by this circuit to control the cycle of the sensor. operation of the machine. These solutions complicate the production of a coffee machine and increase the cost of manufacture.

A simplified solution is described in document FR 2544 604 in which the weight of the tank pushes a control lever which actuates a switch of the electric circuit of the machine, making it possible to operate the latter only from a pre-established weight. However, the simple detection of the weight of the tank is not sufficient to ensure a correct return of the flow of pressurized water to the tank, it is still necessary that it is properly put in place. In the absence of proper communication of a removable tank with its sealing seat, the overflow of the return flow accumulates around the tank seat causing dirty leaks and cleaning problems thereafter.

The object of the present invention is to overcome the aforementioned drawbacks and to provide an espresso coffee machine with removable tank operating efficiently while providing increased protection for the user when using the machine.

Another object of the invention is an espresso machine of easy maintenance type, avoiding any problem of overflow or uncontrolled water flow when the removable tank is handled by the user.

A further object of the invention is an espresso type coffee machine of simple and inexpensive construction, while being reliable in operation.

These goals are achieved with an espresso type coffee machine with a removable tank connected to a main hydraulic circuit with a pump that draws water from the tank and sends it into a thermoblock and from here through the coffee grind contained in a filter holder, said reservoir also being connected to a hydraulic circuit allowing the return of the water leaving the thermoblock, because the connection device of said reservoir with said hydraulic circuits comprises means for relaxing the incoming jet of water by the hydraulic circuit back to the tank and means for orienting said jet to a storage area.

Thus, this connection device first ensures a tight communication between the cold water tank of the machine and the rest of the hydraulic circuit. This tight connection can be achieved by an O-ring belonging to said connection device or to the reservoir, a seal located between two re-entrant pipes of the two parts in communication. The tubing of the reservoir generally includes a valve that automatically closes the access to the tank when it is removed from its seat and opens the passage to the hydraulic circuit of the machine when the tank is put back in place.

The connection device also has the role of communicating the cold water tank with the main hydraulic circuit, which connects it to the suction pipe of the pump, as well as to the return circuit to the tank by a pipe of relaxation.

According to the invention, the connection device comprises first means of expansion of the water jet returning to the reservoir. During the operation of the machine, more particularly at the end of the coffee-making cycle, the pressure must be lowered in the hydraulic circuit leaving the thermoblock and for this reason, the flow of hot water is returned by the expansion pipe. to the tank. If the tank is in communication with the expansion pipe, this flow returns to the tank. On the other hand, if the reservoir is not in place, the strong return flow is in any case broken by the said first means, which has the effect of obtaining a quiet jet and thus protecting the user against splashing. hot water under pressure.

The connection device of the invention further comprises second means for directing the flow of water back to a storage area. Thus, the quiet jet obtained with the first means is then directed to an area to collect the return flow, especially in the case where the tank is absent or if it is incorrectly positioned or, if for any reason, the sealing between the latter and the connection device is broken. This prevents overflows on the outside of the machine or prevents the accumulation of stagnant water inside the machine in areas inaccessible for cleaning.

Advantageously, the expansion means direct the water jet in a direction other than that of the main axis of the connection device of said tank with the hydraulic circuits of the machine.

By main axis of the tank connection device includes in particular the axis of the tubing of the tank where is arranged the valve, or the axis of the valve. This axis is, for most applications, vertical or normal to the work plane, but it can also be arranged in another direction. Directing the return water jet in a direction different from that of the main axis of the tank connection device, causes the powerful jet to undergo a pressure drop and at the same time it is deflected from the direction normal to the work plane or the seating plane of the connection device, so that it protects the user when the return jet is in the absence of the tank.

Preferably, said connection device comprises a central bore placing it in communication on one side with said reservoir, on the other side the bore opening into two orifices communicating one with the main hydraulic circuit and the other with the hydraulic return circuit, wherein said means of expansion of the water jet are arranged in the extension of the axis of the orifice which communicates with the hydraulic return circuit.

Thus, the turbulent jet that arrives through the return circuit in the orifice provided for this purpose in the connection device is calmed by expansion means which are arranged in the axis of this orifice thus having a direct effect on the jet powerful under pressure. This return jet undergoes a loss of pressure coming into contact with the relaxation means, which makes it less dangerous for the user.

Usefully, said detent means comprise a plurality of parallel fins arranged alternately on a common axis.

These fins constitute a buffer device for the powerful jet back and, by their arrangement on an axis opening into the inlet port of the jet of return water, force this jet of water to follow a sinuous course having effect a significant pressure drop and obtaining a jet of water sufficiently calm to be oriented or recovered later.

Advantageously, said common axis comprises a deflector located in the axis of the closure valve of the reservoir when the latter is connected to the connection device.

Thus, with a deflector located on the axis supporting the fins ensuring the relaxation of the water flow, especially in the upper part of this axis facing the water tank, it ensures the opening of the closure valve of the tank during its implementation in the connection device in a simple manner, without using an additional piece to put the tank in communication with the rest of the hydraulic circuit of the machine.

Preferably, said water jet orientation means are arranged downstream of said water jet expansion means in the direction of flow of the water jet.

One could have imagined first orienting the turbulent water jet towards a recovery zone and then relaxing it, but it was observed that it is more advantageous to relax it first, because a jet of water Quiet is easier to channel eventually to a recovery or storage area.

Advantageously, said means for orienting the water jet comprise at least one passage putting in communication the inside of the bore of the connection device with a funnel surrounding said bore.

Thus, the jet of water expanded inside the central bore of the connection device, is oriented towards a space close to this bore and concentric with the latter, a passage being provided for establishing a communication between said spaces containing the fluid that is back to the tank.

Preferably, said means for directing the water jet of the coffee machine of the invention comprise a first passage situated downstream of an O-ring sealing the reservoir and the bore of the connecting device such as as seen in the direction of flow of the water jet back to the tank.

Thus, when the reservoir is put in place and the O-ring seals between the reservoir and the central bore of the connection device, the return jet is returned to the inside of the reservoir. On the other hand, if the tank is absent or incorrectly positioned, the seal no longer fulfills its role, so that the return water jet is directed by a passage located next to and downstream of the gasket. sealing in a storage area constituted by the funnel surrounding said bore. This first passage can be arranged at the upper edge of said bore or by making an opening located closer to the location of the seal in order to prevent the return jet from making long journeys before reaching the zone of storage.

Preferably, said first passage is made between the upper portion of the bore and the inner face of a plate affixed to the funnel.

In this configuration, a plate is provided in the upper part of the funnel, at least one opening being provided between the two so that the return water jet follows this opening to reach the interior of the funnel. The water jet is thus easily channeled to the funnel closed by said plate, which prevents overflow or splashing inside the latter, for example following projections on the internal walls of the funnel, etc.. Usefully, said water jet orientation means comprise a second passage in the form of an opening made in the plate, opening located downstream of the first passage as seen in the direction of flow of the return water jet. to the tank.

Thus, in the case where the return water jet is not sufficiently braked by the expansion means, overflows can rise and exceed this first passage. These overflows are then collected by said opening located at a higher level with respect to said first passage in the direction of flow of the water jet, which ensures even more control of the return water jet, allowing it to be channeled towards the funnel even in case of unexpected increase of the pressure of the latter.

Advantageously, said means for orienting the water jet comprise channeling ribs located on either side of an orifice of the plate communicating with the bore of the connecting device, ribs arriving close to said opening.

Thus, said possible overflows passing through the bore of the connection device, arrive on the upper face of the plate provided with channeling ribs which collect these overflows and channel them to said opening opening into the funnel which captures these overflows.

Usefully, said means of orientation of the water jet communicate through a funnel outlet with a recovery tray removably mounted in the machine.

Thus, the overflows stored temporarily in the funnel are returned to a recovery tank of larger dimensions than the funnel and which, in addition, is mounted removably relative to the body of the machine allowing the user to the empty easily. Said recovery tank comprises a gutter extension forming a recuperator coming under a recovery nozzle which is connected to a discharge pipe of the funnel.

Advantageously, said recovery tank holds the brewing container holder.

The infusion collection container holder is in the form of a grid held on its periphery by the rim of the recovery tank. This allows to collect in the same tray any drops resulting from the infusion of coffee. This keeps the machine environment clean and easy to clean.

The invention will be better understood from the study of the embodiments taken in no way limiting and illustrated in the appended figures in which:

- Figure 1 shows a longitudinal sectional view of a coffee machine according to the invention;

- Figure 2 is a perspective view of the rear part of the machine with the water tank removed from its seat and shown beside;

- Figure 3 shows a perspective view of the lower part of the base of the machine, a part of the parts constituting the outer casing of the machine being removed for easy viewing;

- Figure 4 is an axial sectional view of the connection portion of the tank with the corresponding portion of the base of the machine.

FIG. 1 illustrates a coffee machine according to the invention comprising a body 1 whose lower part comprises a base 2 which is connected to the upper part of the body 1 by a vertical upright 3 serving to support a water tank 4 cold. The body 1 encloses the hydraulic circuit of the machine comprising the reservoir 4, a pump 5, a thermoblock 6, a distributor 7 and a cylinder 8 for compressing the coffee grounds.

The ground coffee is placed in a cup provided with a filtering wall called filter holder 9 which is, in the example described, slidably mounted in a horizontal direction in the grooves of a fixed support of the infusion head 10 The jack 8 comprises a nose mounted vertically sliding relative to the body 1 of the machine adapted to penetrate, during each operating cycle, inside the filter holder 9 to compress the grind. The water supplied by the pump 5 actuates the hydraulic cylinder 8 which pushes the nose against grinding. From a predefined value of the pressure, a valve located inside said nose allows the passage of water from the thermoblock 6 to the filter holder 9 from which the infusion flows into a collection container located on a support 11 of the base 2.

The coffee machine comprises a boiler or thermoblock 6 for heating the pressurized water supplied by the pump 5 before injecting it into the coffee grounds of the filter holder 9. The thermoblock 6 comprises heat exchanger channels 17 enabling the flow of water inside the thermoblock 6 which furthermore comprises an electric heating element 12 and a temperature sensor 13. The water coming from the pump 5 arrives via an inlet channel 14 of the thermoblock 6 and can emerge along two paths of the latter, depending on the position of the distributor 7. Either the water comes out cold through an outlet channel 15, which forms with the inlet channel 14 a very short circuit that does not allow the water to warm up in the thermoblock, which is thewater comes out hot through an outlet channel 16 after having circulated through the heat exchanger channels 17 of the thermoblock 6.

At the end of extraction of the coffee drink, the distributor 7 is returned to the rest position by the user, so that the pressurized hot water of the hydraulic circuit is sent through an expansion pipe to the tank 4.

The tank 4 is removably mounted on the machine of the invention and comprises, as can be seen in FIG. 2, hooks 20 which can engage in eyelets 21 provided for this purpose in the front wall screwed to vertical tank 3. The tank 4 has a generally parallelepipedal shape open at its upper part to facilitate its filling and closed at its bottom by a valve 23 (Figure 4) located inside a column 22. The flap 23 is normally closed under the action of a return spring 24 which maintains its upper part 23 pressed against the bottom of the tank 4 by interposition of a sealing washer 26. When the reservoir 4 is put in place, the column 22 rests in a bore 29 of the base 2,means being provided in the base to open the valve 23 and put in communication the liquid of the tank 4 with the lines of the hydraulic circuit of the machine.

As best seen in Figures 3 and 4, the bore 29 is formed in a concave shaped part called funnel 30 supported by fixing studs 31 to the base 2 of the machine. The base of the funnel 30 has a plurality of communication ports with the lines of the hydraulic circuit of the machine. Thus, two orifices 33 and 34, are formed at the bottom of the bore 29, on either side of the axis of the latter, and communicate one with an expansion pipe 37 and the other with a pipe of the main circuit 38. A peripheral orifice 35 is provided for communicating the funnel 30 with a discharge pipe 39.

By conduit of the main circuit 38 is included a pipe which connects the funnel 30, respectively the tank 4, to the pump 5, while the expansion line 37 comprises a pipe which connects the outlet pipe of the thermoblock 6 to the funnel 30. The exhaust pipe 39 connects the funnel 30 to a recovery tank, as will be explained later.

The pipes 37, 38 and 39 are flexible pipes, made for example of rubber, which are connected to vertical hollow end pieces materializing said orifices 33, 34 and 35, as can be seen in FIG. 4. In the same way, the the opposite end of each pipe is brought into communication by connecting elements of the same type with its respective hydraulic circuit element.

The bore 29 is defined by the inside diameter of a cylindrical wall 40 formed approximately at the center of the funnel 30. As best seen in FIG. 3, the funnel 30 has an oblong shape presenting, along its axis main, a curved front wall 42 and an opposite wall 42 'planar. The funnel 30 being a piece of fairly complex shape, it can advantageously be made of a plastic material by an injection technique.

The upper surface of the cylindrical wall 40 (Figure 4) has a groove 41 in which is placed an O-ring 43. The O-ring 43 bears on the outer surface of the column 22 of the tank 4 when it is placed on the coffee machine, this seal having the role of sealing between the tank 4 and the bore 29 of the cylindrical wall 40 of the funnel 30, respectively between the tank 4 and the rest of the hydraulic circuit of the machine. The O-ring 43 is held in place by the crenellations 46 of a plate 45.

The plate 45 is positioned above the funnel 30 so as to close at least partially, this plate 45 being fixed in turn by fixing studs provided for this purpose in the base 2. The plate 45 has in its central portion a through hole 29 'located in the extension of the bore 29 of the cylindrical wall 40 of the funnel 30 and having a diameter slightly greater than the diameter of the latter.

The inner surface of the plate 45, which faces the funnel 30, has a ring provided with crenellations 46 bordering the orifice 29 '. The solid portion of these crenellations 46 has the role of keeping in place the O-ring 43, while the cuts between two crenellations 46 form passages 32 having the role of communicating the interior of the bore 29 with its periphery. , therefore with the peripheral part of the funnel 30.

On the outer part of the plate 45, facing the reservoir 4, are formed two guide ribs 47 parallel to each other, disposed on either side of the orifice 29 'being perpendicular to the end walls 42, 42'. The plate 45 has, at the edges of the ribs 47, an opening 48 which again allows, but at a higher level, communication with the peripheral portion of the funnel 30. By higher level includes a level located downstream from the crenellations 46 in the flow direction of the return flow of hot water to the tank at the end of the cycle.

Moreover, and as shown in FIG. 4, at the bottom of the bore 29 is fixed a vertical jet breaker assembly 50 of longitudinal axis coaxial with that of the bore 29 and, respectively, that of the column 22 of the tank 4. The jet breaker assembly has in its upper part a prominent baffle 51 which bears on the lower part 25 of the valve 23 to cause it to open when the reservoir 4 is put in place. The lower part of the jet breaker assembly 50 comprises a plurality of vanes 52 arranged alternately eccentrically, one above the other, along the longitudinal axis of the jet breaker assembly 50.

As seen in Figure 4, two adjacent fins touch with part of their periphery the two opposite ends of the inner surface of the bore 29, a zigzag path being thus formed between their free ends, this path opening into the orifice 33 communicating with the expansion line 37. The fins 52 may have a disk shape or any other flat or left shape adapted to the desired purpose. Such an arrangement forces the jet of water arriving through the bottom of the bore 29 to have a sinuous path, by furrowing the baffles formed by the offset ends of the fins 52, which has the effect of the loss of load or the reduction of the pressure of the water jet back to the tank.

Referring to Figure 3, it is noted that the exhaust pipe 39 from the bottom of the funnel 30 and conducts the liquid collected by the latter to a recuperator 55 located below a recovery nozzle 54 and communicating with the latter , the tip on which is connected the exhaust pipe 39. The funnel 30 being raised relative to the recuperator 55, the liquid collected by the funnel 30 flows quickly to the recuperator 55.

The recuperator 55 is in common with a recovery tank 56 which it is an extension gutter. The recovery tank 56 is advantageously mounted removably with respect to the body 1 of the machine and for this it has a re-entrant shape under the base 2. The recovery tank 56 also has a flange 57 on which the cup support 11 is installed. coffee, support which is in the form of a grid for harvesting in the same tank 56 possible flows resulting from the infusion of coffee.

In operation, when the coffee maker arrives at the end of the coffee extraction cycle, the user returns the distributor 7 to the rest position, so that the flow of pressurized hot water which is still in the hydraulic circuit at the outlet of the thermoblock 6, is sent by an expansion pipe 37 to the reservoir 4. In its path, this turbulent hot water flow is broken by the fins 52 of the jet-jet assembly 50 and is channeled to a zone provided for in FIG. this effect. This zone may be the tank 4 when the latter is properly positioned so that it communicates in a sealed manner with the bore 29 of the funnel 30.

On the other hand, if during the return of the flow of hot water to the tank 4, the user inadvertently removes the tank 4, or also if he lifts it slightly so that its valve 23 pushed by the spring return 24 closes the communication tank 4 with the funnel 30, the return flow will be channeled by the device of the invention to the peripheral zone of the funnel 30. This channeling is through the cutouts located between the crenellations 46 of the plate 45 for a slightly turbulent jet calmed by the fins 52 of the jet jet 50. In the case where the return flow or expansion is not sufficiently braked by the jet breaker assembly 50,it arrives on the upper face of the plate 45 and the overflows are channeled again by the channel ribs 47 of the plate 45 to the opening 48 and from here to the funnel 30. From the funnel 30, the overflows arrive by the evacuation pipe

39 in the recovery tank 56 where they are stored before emptying the tray.

Other embodiments of the invention may be envisaged without departing from the scope of its claims.

Thus, one can imagine that the O-ring 43 is held by a groove formed in the inner wall of the bore 29, the passage between the bore 29 and the funnel 30 in the absence of the reservoir 4 can be done by a space between the upper edge of the bore 29 and the inner face of the plate 45.

In another variant it is possible to imagine that the O-ring 43 is held by the wall of the column 22 of the tank 4. It is also possible to envisage a frontal seal between the base of the column 22 of the tank 4 and a corresponding surface of the connection device. 28.

In yet another variant, it is possible to envisage the use of other expansion means, in particular in the form of flexible fins coming from a peripheral wall installed in the expansion pipe or fins installed in the communication orifice with the detent pipe of the tank connection device.