Abstract:
Device for instant, automatic, pressurized percolation of food liquids provided with a horizontal mechanical assembly including as main elements functional sections, especially a stationary rail, an infusion chamber with a movable bottom and a movable part carrying the compression piston sliding on the rail, and a filling chamber linked to the movable bottom by a rod whose position and section is adapted to control the movement of a scraper pivoting on a horizontal pivot. The invention is used for preparing espresso coffees.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is related to a device for instant, automatic, pressurized percolation of food liquids, and especially of hot beverages such as coffee. 
     The invention is intended to enable the preparation, under entirely automated conditions and without human intervention except for sending an initial command signal, of a hot beverage such as an &#34;espresso&#34; type of coffee, i.e., delivered and made available to the consumer immediately upon exiting the percolation phase. 
     2. Discussion of Background Information 
     Devices disclosed up until now, and especially the device described in FR 86 02636 by the same inventor, are most often based on the use of a vertical cylinder constituting the infusion chamber into which is poured a certain quantity of ground coffee retained by a mesh constituting the base of the cylinder. A vertically displacing piston compresses the coffee powder, through which hot water is injected and then removed. The hot water generally gets into the cylinder by passing through the mobile compression piston, thereby necessitating flexible tubing which is generally fragile. The base of the cylinder is mobile and can rise within the latter so as to enable the extraction of the powder which is removed by means of a mobile scraper. The assembly is activated by means of generally complex and expensive mechanisms, comprising mechanical or other latching systems, and are controlled by electro-mechanical or electronic devices, attached to a series of micro-contacts, that often break down. The presence of the mobile piston above the cylinder renders the pouring action of the coffee powder therein clumsy, by requiring a complicated progression and mobile guide means. Finally, the hot water supply and removal of the infused coffee is done by a network of conduits that lead to loss of heat. 
     FR 90 00 820 and PCT/FR91/00030, by the same inventor, partially resolve these faults. They describe a device equipped with a mechanical group arranged horizontally in which the movements of the mobile elements are all caused by two racks with inverted horizontal displacements driving a series of cross-pieces sliding along columns, the infusion chamber with the horizontal axis, through which the hot water passes vertically, being extended by a horizontal, mobile filling chamber directly receiving the poured coffee powder, which is later removed by a scraper, also having a horizontal movement and moved by a rotational lever. A heater located immediately below the mechanical group is directly connected to the infusion chamber by quick connectors for the injection of water and removal of the infused coffee, without tubing, the infused coffee recrossing the body of the heater. The infusion chamber has a mobile base with a magnetic latching driving system. Finally, the mechanical group is driven by virtue of a quick coupling by a motor whose stoppage and reverse motion are directly controlled by an electronic torque sensor that controls the pressure and suppresses the microcontacts. 
     The machining of this device, however, is relatively complex and expensive, especially insofar as the cross-pieces, columns and scraper are concerned. In addition, magnetic latching is not completely reliable due to the risk of the accumulation of coffee powder on the magnetized elements. 
     The device as per the present invention, that brings a series of improvements to the devices of FR 90 00 820 and PCT/FR91/00030, overcomes all these disadvantages. In fact, it enables an automatic, pressurized percolation machine to be obtained that comprises a small number of elements that are extremely reliable, especially easy to maintain, having excellent heat yield and a competitive manufacturing price. 
     SUMMARY OF THE INVENTION 
     The present invention is constituted by the combination of a removable, horizontal mechanical group, equipped with an infusion chamber having a mobile base, extended by a filling chamber that is displaced in conjunction with the mobile base, a heater located below the mechanical group, equipped with a removable pouring element and connected to the infusion chamber, and a drive unit activating all the mobile members of the mechanical group, the main members thereof being obtained from functional sections, especially a fixed rail, the infusion chamber as well as a mobile element sliding along said fixed rail and bearing the compression piston as well a main rack driving a secondary rack by means of a fixed pinion, the filling chamber and the mobile base also sliding along such fixed rail and being rendered affixed by a rod whose position and section are determined in order to check the movement of scraper pivoting about a horizontal pivot borne by the infusion chamber. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     In the annexed drawings, provided as non-limiting examples of an embodiment of the aim of the invention: 
     FIGS. 1 through 3 represent, in a front view, the mechanical group at three different stages of the functioning cycle, respectively, in the stand-by position, before the coffee powder has been poured, at the end of the compression period and after ejection of the infused powder by the scraper. 
     FIG. 4 is an end view of the mechanical group, along arrow A of FIG. 1, with the removable pouring element in position, 
     FIGS. 5 and 6 are transverse sections of the mechanical group, respectively, along arrows B--B and C--C of FIGS. 2 and 3, 
     and FIG. 7 is a top, splintered view of the device assembly, showing the mechanical group, the heater, the drive unit in a partial horizontal section and the pouring element. 
    
    
     DETAILED DESCRIPTION 
     The device, FIGS. 1 through 7, is constituted by a horizontal mechanical group, removable without tools, by a heater 2 for the production of hot water located immediately below mechanical group 1 and connected to infusion chamber 5 by quick connectors 15 for the injection of water and removal of the infused coffee, by a drive unit 3, motorized with automatic reversal of motion, and finally, a removable pouring element 20 mounted on the front of heater 2 and whose placement latches mechanical group 1 on the latter. 
     Mechanical group 1 comprises a compression piston 7 that is displaced horizontally in a cylindrical infusion chamber 5, having a mobile base 11 in which the passage of hot water occurs via two peripheral meshes transversely with respect to the axis of the compression piston, the infusion chamber being extended by a filling chamber 12, mobile horizontally, in conjunction with mobile base 11, and provided with an upper opening 13 enabling the direct pouring of the coffee powder to be received, such powder being removed by a scraper 14 after percolation. 
     The passage of hot water can also be done by two series of peripheral perforations, each distributed at 360 degrees in infusion chamber 5 and off-set axially so as to cause the water to move in parallel to the axis of the infusion chamber. 
     The assembly of the mobile members is activated by drive unit 3, motorized by virtue of a quick coupling causing the displacement of a main rack 8 and of a secondary rack 9 in opposite directions, the latter acting on filling chamber 12 and mobile base 11, so as to successively enable the filling of infusion chamber 5, the compression of the coffee powder therein, and its removal after percolation. 
     Mechanical group 1 is obtained from functional sections respectively forming a fixed rail 4, the infusion chamber 5 as well as a mobile element 6 sliding along the fixed rail in parallel to the axis of infusion chamber 5. This mobile element bears compression piston 7, main rack 8 and a journaled hook 21 latching onto a snug 23 of a mobile abutment 22 that slides along fixed rail 4, behind the infusion chamber, and on which are mounted the axis of mobile base 11 as well as a rod 17 affixed to filling chamber 12, and whose position and section are determined so as to check the movement of scraper 14, the latter pivoting in a perpendicular plane with respect to the axis of infusion chamber 5 about a horizontal pivot 18 borne by such chamber. Main rack 8, by means of a pinion 10 rotating about an axis affixed to fixed rail 4, activates the secondary rack 9, the latter acting on mobile abutment 22 to bring filling chamber 12 in contact with infusion chamber 5 and to make mobile base 11 enter therein. 
     The drive unit 3 is constituted of a motor 24 driving, by means of a regulator 25, a screw 26 bearing a threaded catch 27 that engages in a housing 28 provided to this end in the mobile element 6 of mechanical group 1. Screw 26 can be displaced axially in both directions and is normally maintained in the intermediate position by two springs 29 pressing against a bearing mounted in a block 30 affixed to the frame of the drive unit and located at one end of the screw. Such screw bears at its other end the mobile element of a proximity sensor 31. When catch 27 comes to the end of its path, it causes an axial displacement of screw 26 that is detected by the proximity sensor, which engenders an electrical safety information used to command the reversal of motion or stoppage of the motor in case of an anomaly. 
     The motion control of motor 24, as well as the other functions of the apparatus, heater, pump, coffee grinder, etc., are ensured by an electro-mechanical or electronic programmer associated to a sensor measuring the torque of the motor. 
     At the start of the cycle (FIG. 1), mobile element 6 of the mechanical group is positioned at the end of fixed rail 4, on the side of filling chamber 12 and the mobile abutment 22 at the other end, the filling chamber is pressed against infusion chamber 5, mobile base 11 is located behind such infusion chamber and scraper 14 is raised. When the functioning command is given, first the coffee powder is poured into the filling chamber via opening 13, then catch 27 drives the mobile element towards the other end of the fixed rail. Compression piston 7 pushes the coffee powder towards the infusion chamber and finally compresses it in the latter (FIG. 2). The resistance encountered by the compression piston thus drives the axial displacement of screw 26 of the drive unit, which causes the stoppage, infusion then reversal of the movement. 
     At the moment when mobile element 6 starts in the reverse direction, journaled hook 21 has overtaken snug 23 of mobile abutment 22, which means that it will drive the latter and cause the displacement of mobile element 11 towards the front of infusion chamber 5, the distancing of filling chamber 12 and the displacement of rod 17. Such rod bears a contraction 32 that will enable scraper 14 to get lowered under the action of a spring (not represented) at the moment at which the mobile base reaches the front of the infusion chamber (FIG. 3). At this moment, journaled hook 21 is raised by virtue of a ramp 33 affixed to fixed rail 4 and no longer drives the mobile abutment. 
     Meanwhile, by its displacement, the latter has lowered a cam 34 mounted on heater 2 and activated a valve 35 to expose the hot water supply circuit to open air, in order to avoid moistening the infused coffee powder, and thus to facilitate its removal. 
     By continuing its movement, mobile element 6 brings secondary rack 9 into contact with mobile abutment 22 which will be pushed back towards its initial position at the same time as filling chamber 12, mobile base 11 and the repositioning of scraper 14. The cycle then ends, and a new cycle can start. 
     According to an embodiment variation, heater 2 is placed behind mechanical group 1 and is connected to infusion chamber 5 by a quick connector 15 for the injection of water, the removal of the infused coffee being done directly via a conduit directed towards the front. 
     Open air exposure will then be done by a longitudinal channel obtained in the driving rod of mobile base 11, extended so as to be able to penetrate into an adequate housing of a fixed abutment (not represented) affixed to fixed rail 4 and located beyond mobile abutment 22. When mobile base 11 is located behind infusion chamber 5, during percolation, the end of the rod is engaged in the fixed abutment and arranged so as to seal it. Conversely, when the mobile base is displaced to cause the expulsion of the infused powder, the end of the rod gets disengaged, enabling the passage of air. 
     According to a second embodiment variation, drive unit 3 is constituted by a double action jack activated by means of pressurized water that comes from the pump that also provides the water intended to infuse the coffee. In this case, the control of the jack position, as well as of the quantity of water to be infused, can advantageously be done by virtue of a single flow meter associated to a programmable system activating the solenoid valves. 
     It can also be envisioned that other elements are obtained such as filling chamber 12 or mobile abutment 22 by using the functional sections. On the other hand, if mobile element 6 is manufactured by extrusion, it would be interesting to obtain it from two functional sections assembled after cutting, with a view to reducing material scraps, one of such sections constituting the sliding portion and the other the support of compression piston 7. 
     The functional sections can be extruded from a light alloy or a reinforced synthetic material, or can be molded if they are to be manufactured in large quantities. 
     The elements sliding along fixed rail 4, for example filling chamber 12 and mobile element 22 will be advantageously obtained from a material having a low friction coefficient, such as polyamide, especially when said rail is metallic. If the rail and mobile element 6 are both made of a light alloy, slides 36 made of polyamide or similar, will be interposed between them. 
     The design of the system described hereinabove enables the manufacture of a machine that is very compact and capable of being obtained in large quantities, at reasonable prices, which means that both domestic and professional use can be envisaged for it. 
     The positioning of the various component elements provide the object of the invention with a maximum of useful effects that had not been, up until now, obtained by similar devices.