FR2766346A1 - Filter carrier for expresso-type coffee making machine - Google Patents

Abstract

The filter holder includes a scoop (1) with a handle (2) designed to hold a filter (3). The filter consists of a housing (4) and a perforated bottom wall (5), the bottom wall being movably mounted in the spaced defined within the housing by means of a height adjustment device (6). The adjustment device (6) includes a stack consisting of several rings (8) adjacent to the bottom wall (5), and an opposed ring (9) coaxial with the upper rings. The respective side surfaces of the rings include an alternating series of staggered angled and horizontal surfaces. An actuating element (16) is mounted on the cup (1) for causing relative movement of the first and second rings (8,9).

Description

FILTER HOLDER FOR COFFEE MACHINE OF THE "ESPRESSO" TYPE
The present invention relates to a filter holder intended to be mounted on a head of a coffee machine of the "espresso" type, and comprising a cup provided with a side handle and adapted to receive a filter formed by a cage with cylindrical side wall and a perforated bottom.

 The invention relates, more specifically, to a filter holder, the perforated bottom of the filter is mounted movable in the space delimited by the cage by means of a height adjustment device thus making it possible to obtain various dosages of coffee. to prepare one or more cups of infusion.

 In filter holders of this kind, the height adjustment device generally comprises a complicated linkage requiring locks on different heights so as to define precise positions of the perforated bottom in the cage of the cup. Indeed, in these machines of the "espresso" type, the pressure of the hot water supplied by the pump of the machine being located in the vicinity of 15 bars, it is imperative that the perforated bottom is kept locked at different heights throughout of the brewing operation so as to guarantee the choice of brewing selected by the user, and to avoid any sudden decompression which would cause the destruction of the filter holder and the risks of projection of vapor and hot brewing outside the filtered.

 In addition, we have imagined locking devices by screw-nut, but as will be understood the height adjustment proves to be long, tedious and without any precision during the passage of an infusion operation according to a choice of cup. to another brewing operation according to another choice of cup.

 The invention particularly aims to simplify the height adjustment device by eliminating the drawbacks described above.

 According to the invention, the height adjustment device comprises, between the perforated bottom and the bottom of the cup, a stack of at least one crown mounted adjacent to the bottom and a counter-crown coaxial with said clolurlonne which respectively have on their face lateral opposite an alternating succession of stepped ramps and ranges and staged counter-ramps and counter-ranges, as well as an actuating member mounted movably on the cup and adapted to generate a relative rotational movement between the crown and counter crown to make the perforated bottom occupy different height positions in the cage.

 Thanks to the invention, a filter holder is obtained which is very easy to use, guaranteeing not only precise and identical settings over time for each grinding dosage selection, but also great operational safety since all the mechanical stresses due to the water pressure are located on the ranges and counter-ranges which are opposite and which thus define stable bearing surfaces.

 According to another particularly advantageous characteristic of the invention, the counter-crown is formed by two distant upper and lower rings connected in rotation by anchoring means and between which are interposed elastic members, so that the upper ring bearing the counter ramps and counter pads is mounted movable in translation relative to the lower ring.

 Thus, this construction of the counter-crown in two pieces mounted elastic between them makes it possible to obtain, during and at the end of the brewing operation, a self-tamping of the coffee grounds which ensures, on the one hand , a complete extraction of the taste and aromatic constituents of the coffee, and on the other hand the preparation of a practically dry and easily disposable cake.

The characteristics and advantages of the invention will become apparent from the description which follows, by way of nonlimiting example, with reference to the accompanying drawings in which
- Figure 1 is a partial vertical section of a filter holder according to the invention, mounted on a coffee machine head and illustrating the bottom of the filter in position "a cup
- Figure 2 is a sectional diagram of a partial development of a height adjustment device according to the invention and illustrated in a position corresponding to that of Figure 1;
- Figure 3 is a view similar to that of Figure 1, but in which the bottom of the filter is in position "two cups"
- Figure 4 is a representation similar to that of Figure 2, but for which the position of the height adjustment device corresponds to that of Figure 3
- Figure 5 is a partial vertical section of the filter holder illustrated in Figure 1 and in which the bottom of the filter occupies an ejection position.

 The filter holder illustrated in FIGS. 1, 3 and 5 is intended to be mounted on a head T (shown in broken lines) of a coffee machine of the espresso type operating generally with an electric pump capable of supplying hot water under pressure, for example, of the order of 15 bars. As is known per se, the filter holder is mounted on the head T by means of a bayonet system and for this purpose comprises a cup 1 provided with a part of the bayonet and with a side handle 2. The cup 1 is adapted to receive a filter 3 formed by a cage 4 with a cylindrical side wall anchored in the cup 1, and a perforated bottom 5 made of metal.

 In order to obtain various dosages of ground coffee to prepare one or more coffee cups, the bottom 5 is mounted movably in the space delimited by the cage 4, along a vertical axis V coinciding with the axis of said cage , by means of a height adjustment device 6.

 According to the invention, the height adjustment device 6 comprises, between the perforated bottom 5 and the bottom 7 of the cup 1; a stack of at least one crown 8 mounted adjacent to the perforated bottom 5, and a counter-crown 9 coaxial with said crown and comprising (see FIGS. 2 and 4) respectively on their lateral face 10 and 11 located opposite an alternating succession of ramps 12 and stepped tracks 13B-13H, and of counter-ramps 14 and stepped counter-tracks 15B-15H, as well as an actuating member 16 movably mounted on the cup 1 and adapted to generate a displacement in relative rotation between the crown 8 and the counter-crown 9 to make the perforated bottom occupy 5 different height positions in the cage 4.

 In a preferred embodiment and as illustrated, the crown 8 is integral with the base 5 and comprises a means of immobilization in rotation 17 relative to the cage 4, while the counter-crown 9 is mounted movable in rotation around an axis common to the stack and corresponding to the axis V, and is integral with the actuating member 16, so that the rotation against the crown 9 causes different coincidences between the pads 13B-13H and against pads 15B -15H, therefore dccasionnant different heights of the bottom 5 in the cage 4.

 As clearly shown in FIGS. 2 and 4, the ranges 13B-13H and counter-ranges 15B-15H are located at two different heights so as to define two precise and stable positions of the bottom 5 corresponding for example to a cup or two cups of coffee brew.

 Thus, thanks to the height adjustment device, the user can prepare at will and automatically one or two cups of coffee by simple action on the actuating member 16, between two predefined stops, which determines by rotation the superposition 13H ranges and 15H counter ranges (Figure 2) for one cup and 13B and 15H ranges (Figure 4) for two cups.

 In the embodiment as illustrated in FIGS. 1, 3 and 5, the perforated bottom 5 is mounted on a cylindrical support 18 whose peripheral edge 19 is adapted to slide in the cage 4, and whose lower face 20 carries, on the one hand, the crown 8, and on the other hand the immobilization means 17. In order to ensure a perfect seal between the bottom 5 and the cage 4, said bottom carries on its peripheral edge 21 an annular seal 22 for sealing which also rests on the peripheral edge 19 of the support 18.

 On the other hand, the support 18 has on its upper face 24 a bowl 25 which is covered by the perforated bottom 5 and which communicates with the outside of the cup 1 by at least one down pipe 26 for the flow of the infusion which passes for this purpose a light 27 formed in the bottom 7 of the cup. Preferably, the support 18 comprises two pipes 26, only one of which is shown, and which also passes through one at the light (not shown).

 II In order to obtain an inexpensive production and to facilitate the construction of the filter holder, the means of immobilization in rotation 17 is constituted by the pipe or pipes 26 which pass through the light or lights 27, the pipe or pipes with little play 26 having a length such that it allows the bottom 5 to be displaced in height over the height of the cage 4.

 Of course, the immobilizing means 17 could be made according to another equivalent construction such as, for example, lateral indexing between the side wall of the cup 1 and the crown 8.

 In order to apply the crown 8 and the counter crown 9 engaged with each other, the support 20 is recalled, towards the lower region of the cage 4, by means of a spring 28.

According to another important characteristic of the invention, the counter-crown 9 is formed by two distant rings: upper 30 and lower 31, connected in rotation by anchoring means 32, and between which elastic members 34 are interposed , so that the upper ring 30, carrying the counter-ramps 14 and counter-tracks 15B-15H, is mounted movable in translation relative to the lower ring 31. The guiding in translation is carried out by bosses 33 carried by the ring 31 and which penetrate with slight play in housings 33 ′ made in the upper ring 30. Preferably, the elastic members 34 are constituted by compression springs, and are preferably arranged under the various counter pads 15
H so as to equalize the pressures of areas 13B-13H on said counterholes 15H.

 As will be explained below, this construction of the counter-crown 9 in two rings separated by springs makes it possible to obtain, during the infusion under high pressure, a self-tamping function of the milling as and when its hot water intake.

 In addition to the height adjustment device 6, the filter holder is equipped with a grinder ejector device 37 comprising a lever 38 which is pivotally mounted on a pivot 39 arranged in the junction region of the handle 2 and the cup 1 , and which comprises at one end 40 a key 41 projecting from an opening 42 formed in the handle, and at the other end 43 a coupling member 44 with a pin 45 connected to the perforated bottom 5 and integral with the lower face 20 of the support 18, said lever 38 also being subjected to the return spring 28 of the support 20 in the lower region of the cage 4. As can be seen in the figures, the spring 28 is a compression spring and is arranged under the end 40, so that the hook always pulls the support towards the bottom 7 of the cup.

 According to a preferred embodiment, the pin 45 has a ring-shaped end while the coupling member 44 is formed by a hook which passes freely in the ring to follow the movement of the support 18.

 In order to clarify the overlapping of the various characteristics described above, we will now describe the operation of the filter holder according to the invention. During a first operation, the user holding with one hand the handle 2 of the filter holder, maneuver VL19, l with the other hand, the actuating member 16. In the present case, this member 16 is formed by a ring B mounted coaxially with the counter-crown 9 on the outside of the cup 1. This ring comprises a drive finger 46 which projects through an arc-shaped slot 47 formed in the bottom 7 of the cup 1 and which engages the counter-crown 9 so as to cause it to rotate at an angle defined by the ends of the lumen 7 forming stops. The ring B is held around the cup 1 by any means passing through the slot 47 and preferably by the finger 46 which for this purpose carries side tabs (not shown) which come into engagement with the internal edge of the slot 47.

If the user chooses to prepare a cup
(FIG. 1), the ring 8 brings the counter-crown 9 and the crown 8 into the position illustrated in FIG. 2 and in which the pads 13H are supported on the counterplates 15H. This position brings the support 18 and therefore the perforated bottom 5 in the upper part of the cage, leaving a small space between the bottom and the upper edge of the filter 3 to receive the ground coffee.

 In a second operation, the user fixes the filter holder to the head T of the machine by means of the bayonet device. Then, the machine sends hot water under pressure (15 bars) to swell the ground coffee and to make the infusion of coffee which then flows through the pipe or pipes 26.

 During this preparation of infusion, the swelling of the ground coffee exerts, in addition to the water pressure, a pressure on the perforated base 5 which is transmitted via the crown 8 to the ring 30 of the counter-crown 3 , and starting on the springs 34 which compress until the two rings 30 and 31 come into contact. During the flow of the infusion, the grinding mass decreases slowly allowing the bottom 5 to rise very slightly under the pressure springs 34.

 At the end of filling the cup with the infusion, the user stops the operation of the pump which cuts off the supply of pressurized water. From this moment the springs 34 strongly push the ring 30 upwards thus causing the bottom 5 towards the head T of the machine and causing a dewatering of the grounds until a rigid, practically dry cake is obtained.

 In a third operation, the user unlocks the filter holder from the head and can eject the ground coffee from the filter 3.

To do this, while holding the handle, he exerts, by his thumb, a pressure on the key 41 against the spring 28 causing the pivoting of the lever 38 whose hook, pressing on the pin 45, pushes the support 18 towards the top of the cage 4 until, as illustrated in FIG. 5, bring the perforated bottom 5 in the vicinity of the upper edge of the cage 4, and therefore the grindstone out of the filter 3. During this sliding in the cage, the support 18 and its crown 8 are well guided linearly by the pipe or pipes 26, so that the adjustment device always retains the chosen adjustment position.

 Thus, it will be understood that a simple reversal of the filter holder by means of the handle 2 will cause the grinding disc to fall out of the filter 3.

 As soon as the user releases the pressure on the key 41, the spring 28 rotates the lever in the 1QQnaire direction, causing the hook to pull on the ring and therefore the sliding of the support 18 and of the perforated bottom 5 in the direction of the bottom 7 from the cup to position the crown 8 and therefore the ranges 13H pressing on the counter-ranges 15H, starting position illustrated in FIG. 2.

 Now suppose the user wants to brew two cups of coffee. Starting from the position illustrated in FIGS. 1 and 2, the user grasps the ring B and by a counter-rotation movement according to the sheet F of FIG. 4, causes the counter-crown 9 to turn around the axis by the finger 46 V. This rotation slides the counter pads 15H on the pads 13H, the counter-ramps 14 on the ramps 12 until bringing the counter-pads 15H on the pads 13B, thus defining the position corresponding to two cups for which the perforated bottom 5 is located in the lower region of the cage 4 as illustrated in FIG. 3. As can be seen, in this position, the capacity of the filter 3 is clearly greater than the capacity shown in FIG. 1.

 The other operations for brewing and ejecting the ground coffee are done in the same manner as explained above for the preparation of a cup.

Claims (3)

 1. Filter holder intended to be mounted on a head  (T) of a coffee machine of the "espresso" type and comprising a cup (1) provided with a side handle (2) and adapted to receive a filter (3) formed by a cage (4) with side wall cylindrical and a perforated bottom (5) mounted movable in height in the space delimited by the cage (4), characterized in that, under the perforated bottom (5) and in connection therewith, are arranged in superposition two distant upper (30) and lower (31) rings, which are interconnected by anchoring means (32) and between which elastic members are interposed  (34), and the upper ring (30) is mounted movable in translation relative to the lower ring (31) by means of guide members (33, 33 ').  2. Filter holder according to claim 1, characterized in that the guide members include bosses (33) carried by the lower ring (31) and penetrating with a slight clearance in housings (33 ') made in the upper ring (30).  3. Filter holder according to claim 1 or 2, characterized in that the elastic members (34) are constituted by compression springs.