Abstract:
The invention concerns a unit ( 1 ) for automatically preparing espresso coffee from prepackaged coffee pods containing one or two coffee pods and comprising a mechanism for individually detecting the presence of each pod in its location. It comprises a drawer ( 5 ) movable between a position for extracting, a position for loading and a position for discharging pods and an injection unit ( 6 ) closing the support of the preparation unit ( 1 ) in its front part above the drawer ( 5 ) in its extracting position and entirely mobile to be brought closer to the drawer through the cams ( 29 ) of the camshaft ( 7 ) driven by a single motor ( 8 ), being automatically returned away from the injection unit ( 6 ) through a return force. The invention is of interest to professional coffee machine manufacturers.

Description:
[0001]    This is a national stage completion of PCT/FR2005/001781 filed Jul. 8, 2005 which claims priority from French Application Serial No. 0407906 filed Jul. 16, 2004. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention concerns an automatic unit for preparing at least one cup of espresso-type coffee with a professional coffee maker using at least one single prepackaged unit called a pod. 
         [0003]    More generally, the present invention concerns a device for preparing a hot beverage using pressurized hot water and at least one pod containing the amount of product to be extracted by the amount of hot water used for one serving of beverage. 
       BACKGROUND OF THE INVENTION 
       [0004]    Usually such coffee machines utilize one or more preparation units, with the user attaching to each unit a detachable filter holder comprising a strainer previously filled with one serving of coffee. After the user has pressed the coffee selection keypad, an internal pump in the machine is set in motion and the water is subjected to pressure before passing through a flow meter that circulates the amount of water determined by the type of coffee selected towards a heating element. This measured amount of heated water reaches and then is discharged through a spray head, then passes through the coffee in the strainer inside the filter holder. The only remaining step is to collect the hot coffee flowing through the spout of the filter holder in a cup placed beneath it. 
         [0005]    In general, commercial restaurant or bar machines comprise filter holders with two spouts so two cups can be filled simultaneously. The number of preparation units varies according to the size of the machine. 
         [0006]    The traditional method for making espresso using these machines, before the advent of pods, consisted of using ground coffee packed into a filter holder using a flat device to tamp it down. However, this is a relatively long and messy, labor-intensive process. 
         [0007]    For this reason, the use of a prepackaged pod of ground coffee for each cup has developed gradually and is now common. The method has proven to be more practical, faster, cleaner and more hygienic, in addition to offering precise and consistent control over the amount and grind of coffee and preserving the coffee aroma when the pods are packaged in individual hermetically sealed units. It also allows a great variety of coffees to be offered, such as mixtures or blends that do not require an establishment to stock a large number of packages of coffee corresponding to the selections offered. In any event, this problem existed previously with regular and decaffeinated coffee. 
         [0008]    In this context, coffee roasters and manufacturers of coffee makers have developed a standard type serving containing seven grams of coffee and shaped like two saucers joined along their peripheral rims. These pods are designated by the name “ESE pods” (Easy Serving Espresso) and can be used in most single serving coffee machines, even if other coffee roasters have preferred to create their own pod format. 
         [0009]    These units may be manually introduced directly into the machine and positioned in the place provided, which can be awkward when the location is difficult to access and/or even dangerous if the user must stick his hand into the machine, or they may be introduced through a slot. In the latter case they may be introduced vertically on a slide along which each unit moves to the place provided, or there may be a horizontal drawer with placements for the pods. 
         [0010]    The use of such a drawer offers several advantages: in particular, it is extremely easy and quick to place the pods on it, with this procedure taking place outside the machine and posing no danger to the user&#39;s hands. For this reason, the invention concerns a preparation unit that uses this loading method. 
         [0011]    Thus, several devices have been proposed for infusion beverage preparation machines to automatically manipulate and load prepackaged beverage pods using a drawer. 
         [0012]    For example, Application No. WO 00/49926 in the name of SIMAC VETRELLA discloses an automatic loading and preparation device with a translationally movable drawer for one or more pods that are ejected in two stages just before the next serving is made. 
         [0013]    Application No. EP 1050258 in the name of EUROMATIK describes an automatic loading and preparation device with a translationally movable drawer for a single pod that is ejected in two stages just before the serving cup is made. 
         [0014]    Another solution is divulged in application WO No. 02/38016 in the name of SMILE COFFEE which describes an automatic loading and preparation device using several actuators, with a pivoting drawer used for a single pod. 
         [0015]    Application No. EP 1153561 in the name of NESTLE describes an automatic loading and preparation device with a translationally movable drawer for a single non-ESE pod that is ejected just before the next serving is made. 
         [0016]    Finally, Application No. EP 1219216 in the name of NESTLE describes an automatic loading and preparation device with a translationally movable drawer for two non-ESE type pods only that are ejected just before the next serving is made. 
         [0017]    However, these automatic pod loading and coffee preparation devices do not allow two pods to be positioned and used simultaneously, and even in that case, it is still not possible to utilize one at a time to prepare a single cup of coffee. Moreover, none of the devices described above can detect whether or not a pod is present, meaning that when only one of the pod placement areas is in use, it is the user who must inform the machine. It would be much more advantageous if the automatic loading and preparation device could be supplied with two pods simultaneously and had an individual means of detecting the presence of each pod. 
         [0018]    Furthermore, these devices do not always discharge the pod at the end of the cycle; the pod is often ejected just before the next cup of coffee is prepared. Thus, the moist pod remaining in position or on an intermediate support that is often inaccessible constitutes a significant disadvantage when the machine is stopped for long periods of time. It can deteriorate quickly and become infested with germs or mold proliferating in the receptacles and the circuit, which is detrimental to coffee quality and even dangerous to the health of the consumer. Therefore, it is important for the pod to be ejected automatically once used up and immediately after use. 
         [0019]    Moreover, certain of these devices do not use ESE format pods, but pods of a specific format which are often more costly. Therefore it would be highly advantageous if the device could use ESE format pods, or even other types of prepackaged pods or all existing types. 
         [0020]    Consequently, the object of the invention is to provide a complete unit for automatically preparing espresso-type coffee or other beverages from prepackaged pods that is equipped with a drawer for a beverage device accommodating at least one and at the most two pods, and comprising an individual means of detecting the presence of each pod in its placement. Advantageously this device would be capable of using numerous types of prepackaged pods, particularly ESE format pods, and these should be ejected automatically at the end of the cycle. 
         [0021]    Preferably this device would be designed to be dependable and economical, simple and quick to use, and safe for both the user and the consumer. 
       SUMMARY OF THE INVENTION 
       [0022]    To resolve this technical problem, the unit for automatically supplying and preparing beverages from prepackaged pods according to the invention is composed of a fixed mechanical support designed to be mounted in a coffee or beverage preparation machine, especially for hot beverages. The machine comprising the additional elements necessary for the unit to operate, specifically, a pressurized heating unit, one or more hot water outlets, one or more steam outlets, and a control panel for controlling the unit. 
         [0023]    The preparation unit of the invention comprises in the lower portion a drawer moving in horizontal translation which comprises a tilting receiving platform equipped with two strainers housed on a filter holder attached to its upper surface and which forms, along with its support, a hatch tilting on a horizontal axis located in the front portion of the receiving platform. It is kept closed with the help of a locking mechanism. This receiving platform communicates at the lower portion with several elements that conduct the prepared beverage downward into a suitable receptacle, for example, a mug or a cup. 
         [0024]    In its upper portion the unit of the invention includes an injection block movable in vertical translation, comprising on its lower surface two spray heads movable in vertical translation like a piston within a protective sleeve and affixed tightly to the lower surface of the injection block. These spray heads are provided for connection to the hydraulic circuit of the machine. 
         [0025]    The movable injection block is displaced in vertical translation by a single motor mechanism using a mechanical transmission to drive several movable elements of the unit, one of which is the injection block, using a cam shaft that always turns in the same direction for the entire cycle without the need for any course recovery system related to wear. Preferably this cam shaft also controls the opening of the system that locks the tilting receiving platform in order to automatically eject pods at the end of the cycle. 
         [0026]    In addition, the movable injection block comprises an individual means for automatically detecting the presence of a pod in either or both strainers in the lower platform. This detection means consequently activates the hydraulic system in the machine for either or both individual pod positions. 
         [0027]    Thus, the preparation unit according to the invention offers numerous advantages, among which are the following: 
         [0028]    the drawer principle; 
         [0029]    automatic ejection at the end of each coffee preparation cycle; 
         [0030]    automatic and individual detection of the presence of each pod; 
         [0031]    simultaneous but individual processing of two pods at once; 
         [0032]    a single motor for the entire preparation cycle always turning in the same direction; 
         [0033]    absence of any course recovery system associated with wear; 
         [0034]    decompression of the chamber prior to the opening of the tilting receiving platform; 
         [0035]    synchronized control of catches locking the tilting receiving platform; 
         [0036]    the use of a force to remove used pods; and 
         [0037]    automatic closing of the tilting receiving platform when the drawer opens. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0038]    Other characteristics and features of the invention will be apparent from reading the following detailed description, with reference to the attached drawings, in which: 
           [0039]      FIG. 1  is an overhead perspective view of an entire conventional coffee machine equipped with two groups of automatic pod loading and preparation units according to the invention in the open position; 
           [0040]      FIG. 2  is side view of the entire unit of the conventional coffee machine of  FIG. 1  with a cup positioned in it and with the two units according to the invention in the extraction position; 
           [0041]      FIG. 3  is a perspective view of an automatic pod loading and preparation unit according to the invention with the drawer in open position; 
           [0042]      FIG. 4  is a perspective view of an automatic pod loading and preparation unit according to the invention with the drawer in closed position; 
           [0043]      FIG. 5  is an exploded perspective view of an automatic pod loading and preparation unit according to the invention; 
           [0044]      FIG. 6  is an overhead perspective view of the drawer of the automatic pod loading and preparation unit according to the invention with the tilting receiving platform in closed position; 
           [0045]      FIG. 7  is a perspective view from below of the drawer of the automatic pod loading and preparation unit according to the invention with the tilting receiving platform in open position; 
           [0046]      FIG. 8  is an exploded view of the drawer of the automatic pod loading and preparation unit according to the invention; 
           [0047]      FIG. 9  is an overhead perspective of the tilting receiving platform on the drawer according to the invention; 
           [0048]      FIG. 10  is a perspective from below of the tilting receiving platform on the drawer according to the invention; 
           [0049]      FIG. 11  is an exploded perspective of the tilting receiving platform of the drawer according to the invention; 
           [0050]      FIG. 12  is an overhead perspective of the entire injection block according to the invention; 
           [0051]      FIG. 13  is a perspective from below of the entire injection block according to the invention; 
           [0052]      FIG. 14  is an exploded view of the entire injection block according to the invention; 
           [0053]      FIG. 15  is a simplified vertical transverse cross-sections of a unit according to the invention showing a first principal stage of one operating cycle. 
           [0054]      FIG. 16  is a simplified vertical transverse cross-sections of a unit according to the invention showing a second principal stage of one operating cycle. 
           [0055]      FIG. 17  is a simplified vertical transverse cross-sections of a unit according to the invention showing a third principal stages of one operating cycle. 
           [0056]      FIG. 18  is a simplified vertical transverse cross-sections of a unit according to the invention showing a fourth principal stage of one operating cycle. 
           [0057]      FIG. 19  is a simplified vertical transverse cross-sections of a unit according to the invention showing a fifth principal stage of one operating cycle. 
           [0058]      FIG. 20  is a simplified vertical transverse cross-sections of a unit according to the invention showing a sixth principal stage of one operating cycle. 
           [0059]      FIG. 21  is a simplified vertical transverse cross-sections of a unit according to the invention showing a seventh principal stage of one operating cycle. 
           [0060]      FIG. 22  is a simplified vertical transverse cross-sections of a unit according to the invention showing an eighth principal stage of one operating cycle. 
           [0061]      FIG. 23  is a simplified vertical transverse cross-sections of a unit according to the invention showing a ninth principal stage of one operating cycle. 
           [0062]      FIG. 24  is a simplified vertical transverse cross-sections of a unit according to the invention showing a tenth principal stage of one operating cycle. 
           [0063]      FIG. 25  is a simplified vertical transverse cross-sections of a unit according to the invention showing an eleventh principal stage of one operating cycle. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0064]    The coffee preparation unit according to the present invention will now be described in a detailed fashion with reference to  FIGS. 1-25 . Equivalent elements shown in different drawings will bear the same reference numerals. 
         [0065]    The term coffee should hereafter be understood as denoting any beverage, particularly a hot beverage, made by hydraulic extraction of a product contained in a prepackaged pod, whether it is coffee, tea, or any other product or mixture of products for preparing a beverage. Similarly, the term coffee machine here means any automatic, semi-automatic, or public vending machine operated with coins or tokens for the preparation of beverages by extraction using a prepackaged pod. 
         [0066]    The unit according to the invention for the preparation of espresso coffee from at least one pod, such as those shown in  FIGS. 1 and 2 ), principally designed to be mounted on a professional coffee machine of the type that exists in bars, restaurants, communal gathering places, and other places where beverages are consumed. These machines supposedly prepare espresso in the best way possible because they utlilize optimal espresso coffee preparation conditions insofar as water temperature, pressure, quantity, and speed of execution are concerned. 
         [0067]    These machines, with one or more preparation units, generally comprise a water inlet, a pressurized heating unit, a hydraulic system, one or more hot water outlets, and one or more steam outlets. 
         [0068]    Unit  1  according to the invention, as shown in  FIGS. 3-5 , consists of a functional unit for mounting on the frame  2  of coffee machine  3 . Each machine  3  can accommodate one, two, three, or even four or more units depending on its capacity. 
         [0069]    The functional unit is a mechanical support  4  that contains all the components forming the functional unit of preparation unit  1  according to the invention. 
         [0070]    It includes the following elements: 
         [0071]    a drawer  5  movable between an extraction position, a loading position, and a position for the evacuation of one or more pods; 
         [0072]    an injection block  6  closing support  4  in its upper front portion above drawer  5  in its extraction position, movable in its entirety toward and away from drawer  5 ; 
         [0073]    a cam shaft  7  activating the injection block  6  to move towards the drawer  5 , while its return movement away from the drawer  5  is effected automatically by a recall force; 
         [0074]    a single drive motor  8  for the entire operating cycle and all the elements; and 
         [0075]    a means  9  for transmitting movement from the output of the single motor to the elements it controls. 
         [0076]    Now the various general elements outlined above will be set forth in detail. 
         [0077]    Movable drawer  5 , shown in  FIGS. 6-8 , is a unit moving in horizontal translation, for example on rollers  10 , between and extended position and a return position. It may optionally be equipped with a motorized activator using a separate auxiliary motorized device  11  and with a pinion mechanism  12  engaging a rack  13  attached to one of the edges of drawer  5 . Motor  11  which activates opening and closing of the drawer  5  is advantageously designed to minimize the risk of pinched fingers, for example, by using a small connection such as in a CD drive. 
         [0078]    In the manually activated version, this drawer comprises a gripping handle  14  on the front surface. 
         [0079]    In a preferred version, drawer  5  moves to an extreme position that is stopped by a block comprising a sensor to ensure that drawer  5  is completely closed. 
         [0080]    Drawer  5  is formed of a support frame  15  holding a tilting receiving platform  16 . This receiving platform  16 , shown in  FIGS. 9-11 , has a groove  17  in which a filter holder  18  engages, that is, a plate comprising two receptor cavities  19  each serving as a housing for a perforated cupel  20 . 
         [0081]    These cavities  19  that form housings each have an evacuation channel on the upper surface. Each of the evacuation channels communicates through a passageway extending into an evacuation conduit  21  by a flow device  22  serving as a dispenser for the cup  23  or mug. 
         [0082]    Each cavity  19  forms a base for a perforated cupel  20  usually referred to as a strainer. A pod  24  containing the serving of coffee to be extracted is placed in either or both cavities for each usage. 
         [0083]    Each strainer  20  is attached in a filter-holding cavity  18  with one or more pins. In a variation of the embodiment, it is also possible to construct filter-holding plate  18  with receptor cavities from the same piece as strainers  20 . 
         [0084]    Receiving platform  16  tilts on a front transverse axle and is blocked in the rear during the entire coffee preparation process by a locking mechanism, for example, two locking catches such as catches  25 . Receiving platform  16  tilts partly due to gravity at the end of the preparation phase between a horizontal operating position and an inclined ejection position toward the base of the pod or pods  24 , which in the ejection position it reaches after being freed from locking catches  25 . It can also be pushed as far as the beginning of the opening by springs for detecting pods  24 , with the initial force being adjusted by modifying the point of opening. 
         [0085]    The frame  15  forming the mechanical support for drawer  5  comprises stops at the level of the axle on which receiving platform  16  tilts, such as, for example, two buffer stops made of flexible material producing a shock at the same time that platform  16  tilts downward that is sufficient to quickly and systematically eject pods  24  from their receptacle with making any unpleasant metallic sounds. 
         [0086]    A hopper  26  guides empty pods  24  as they fall into a used pod receptacle located at the bottom of machine  3  or beneath it (not shown). 
         [0087]    The unit is enclosed at the top by injection block  6  shown in its entirety in  FIGS. 12-14 . It is formed of a movable metal support plate  27  which can be elastically recalled to the top by means of symmetrical elastic forces, for example, two springs such as springs  28  provided in the lateral walls of metal support  4  of preparation unit  1  of the invention. Injection block  6  is activated to descend by contact with the projections on several cams, for example, three cams  29  held by or formed on cam shaft  7  driven in rotation by single central drive motor  8  through a pinion type reduction transmission  9 . 
         [0088]    Movable metal plate  27  on injection block  6  holds two spray heads such as spray heads  30 , each attached to move like a piston in a corresponding protective cylinder  31  or protective sleeve, projecting from the lower surface. 
         [0089]    In a preferred embodiment, injection block  6  is attached to the mechanical support of the unit using connecting elements  32  with a cone shaped attachment. This allows it to be correctly positioned above tilting receiving platform  16  during its descent. 
         [0090]    Injection block  6  actually descends in such a way that the lower rim of the protective sleeve  31  of each spray head  30  comes into close contact with the upper rim of filter-holder plate  18  in drawer  5 , forming a sealed extraction chamber essentially shaped like pod  24 . 
         [0091]    In order to form this seal, the lower portion of protective sleeves  31  on injection block  6  comprise a sealing element, for example, a toric gasket  33  housed in a circular groove  34 . 
         [0092]    In order to conform perfectly to the shape of pod  24 , the lower edge of protective sleeve  31  on each spray head  30  has a concave beveled portion  35  with a rounded profile whose curve generally corresponds to the curved edges of pods  24 . 
         [0093]    Each spray head  30  is hydraulically connected at its upper extremity by a connector  36 , for example, a beveled connector, to a hot water inlet conduit. 
         [0094]    Each spray head  30  takes the form of a water diffusion head with a flat perforated front surface and a rear inlet connected to the pressurized hot water intake circuit on the machine through various control and safety devices. 
         [0095]    Each spray head  30  is associated with a device  37  for detecting the presence of a pod  24 , for example, a device based on abutting contact of its front portion with the upper surface of pod  24 . 
         [0096]    Presence detector  37  may take the form of a micro-switch or contact activated to close by the internal extremity of the body of spray head  30  or to open when the front surface of spray head  30  abuts the upper surface of pod  24 . Detection can occur by forming or breaking contact. This operation will be explained more fully in the portion devoted to operation. 
         [0097]    In order to effectively coordinate the operational cycle, it is necessary to know the position of cam shaft  7  during the principal phases. To accomplish this, cam shaft  7 , driven by its drive motor  8  and motion transmission  9 , comprises, at one extremity, an angular position detector  38 , for example, a detector of the upper and lower neutral point of the cam shaft. In a preferred embodiment, these two positions are detected with the help of a projecting local zone formed on the perimeter of the extremity of the cam shaft, which when the cam shaft is rotating enters into contact during each rotation with one of several opposing sensors on the extremity of cam shaft  7 . It is the contact with these sensors that transmits information on the position of cam shaft  7 . It is in the upper neutral position when the projection is in contact with the first sensor, and in the lower neutral position when the projection is in contact with the second sensor. 
         [0098]    The pressing movement of cams  29  on plate  27  of injection block  6  takes place in the following way. The projecting portions of cams  29  come into contact with and press against injection block  27  movable along sliding contacts  39 . For this reason, the projections on the cams are shaped so that all the movements by the injection block take place during a single rotation of cam shaft  7 . 
         [0099]    It should be noted that a single electric drive motor  8  is used for the entire operational cycle, always turning in the same direction. It is not necessary to associate it with any kind of wear recovery system because the contact between cam  7  and injection block  6  preferably consists of rolling movement along a non-deformable stainless steel slide. Moreover, a single motor such as motor  8  operating regularly and always turning in the same direction is less susceptible to breakdown, considerably increasing the reliability of the unit. 
         [0100]    The system for transmitting movement  9  between the output of the single motor  8  and the elements it controls can take place in different ways. In the preferred embodiment, this transmission uses a pinion system attached to the extremity of the electric motor  8  and to the cam extremities. 
         [0101]    The preceding description shows a reliable preparation unit  1  that is economical to manufacture. This unit  1  accommodates at least one and at the most two pods  24 . It comprises an individual means for detecting the presence of each pod  24  for each pod placement location. 
         [0102]    With reference to  FIGS. 15-25 , we will now proceed with a detailed description of the operation of a preparation unit  1  according to the invention and its mode of use by describing in detail the different stages forming one complete cycle. 
         [0103]    In the embodiment described, the complete operating cycle takes place during a single rotation by cam shaft  7 . 
         [0104]    If several units  1  according to the invention are in use simultaneously, the mode of use is the same, as the units operate independently. 
         [0105]    FIG.  15 —Resting Position and Initial Position 
         [0106]    Drawer  5  is in closed position and tilting receiving platform  16  is freed from locking elements  25 . In the preferred embodiment the platform  16  is nearly vertical. It is empty and in the open air, ensuring that the device remains sanitary. 
         [0107]    FIG.  16 —Drawer Opening 
         [0108]    The operator grips handle  14  and pulls drawer  5  towards himself as far as the stopping device allows. Tilting receiving platform  16  comes into contact with a pivoting roller located below its pivot axle, causing it to tilt upwards and assume a horizontal position. It is maintained in closed position by locking catches  25 . 
         [0109]    In a variation, the opening and closing of drawer  5  may be motorized by a second motor  11  associated with drawer  5 , for example, with a rack system. In that case, engaging motor  11  is sufficient to place drawer  5  in position for loading. 
         [0110]    FIG.  17 —Depositing Pods and Positioning Cups 
         [0111]    The operator deposits a pod in one or both strainers  20  in the block. Since strainer  20  is shaped like a circular basin with a diameter generally equal to or slightly different from that of pods  24 , positioning pod  24  in strainer  20  is simple and quick. Because there is optimal access to strainers  20 , the placement of pod  24  is simple, quick, and free of danger. 
         [0112]    Simultaneously, the operator places a coffee cup  23  beneath the spout  22  corresponding to each strainer that contains a pod  24 , or one cup  23  beneath the two outlets. 
         [0113]    FIG.  18 —Drawer Closing 
         [0114]    The operator pushes drawer  5  in mechanical support  4  as far back as the blocking device allows. 
         [0115]    Advantageously, this blocking device may comprise a sensor to detect whether drawer  5  is tightly closed. This safety feature ensures that the drawer is properly positioned. 
         [0116]    Not shown—Selecting the Quantity of Coffee 
         [0117]    The operator selects the quantity of coffee desired on the machine, which is generally referred to as a large or small coffee. For this purpose the operator has a choice of different volume selections for a corresponding unit. If a small coffee is selected and there is one pod, a small coffee is obtained. If a small coffee is selected and there are two pods, two small coffees are obtained. 
         [0118]    The operator does not need to question whether he has placed one or two pods ( 24 ) and if he has positioned only one, there is no need to question on which side. 
         [0119]    Once the selection has been made, the single motor  8  of the unit of to the invention is engaged in operation. 
         [0120]    FIG.  19 —Lowering Injection Block 
         [0121]    Single motor  8  drives cam shaft  7  in rotation which causes injection block  6  to descend through contact with the projection on the cams. 
         [0122]    FIG.  20 —Detecting Presence of a Pod 
         [0123]    During the descent of injection block  6 , each spray head  30  is in the lowered position and its lower surface is essentially flush with that of protective sleeve  31 . 
         [0124]    During this descent if a pod  24  is present in strainer  20 , the upper surface of the strainer comes into contact with the lower surface of spray head  30 . While injection block  6  continues to descend in order to contact filter-holding plate  18  in drawer  5 , spray head  30  remains immovable relative to mechanical support  4 , causing it to move up into its protective sleeve  31  to the level corresponding to the portion of pod  24  projecting beyond strainer  20 . 
         [0125]    Once it has reached the upper position in its protective sleeve  31 , the upper portion of the body of spray head  30  activates the pod presence detector  37 . 
         [0126]    During this descent, if a strainer  20  does not contain a pod  24 , the corresponding spray head  30  does not move up inside its protective sleeve  31  and the pod presence detector  37  is not activated. 
         [0127]    FIG.  21 —Sealing Extraction Chamber 
         [0128]    Injection block  6  continues to descend until the lower edge of the protective sleeve  31  of each spray head  30  tightly contacts the upper edge of filter-holding plate  18  in drawer  5  to form a sealed extraction chamber. 
         [0129]    This stage takes place simultaneously with the preceding stage. 
         [0130]    Not shown—Detecting Neutral Low Point of Cam Shaft 
         [0131]    When the extraction chamber is closed, that is, when injection block  6  is in the lowered position, angular position detector  38  detects the neutral low point of cam shaft  7 . 
         [0132]    As indicated in the preferred embodiment, this position is detected through the use of a projection formed on the perimeter of the extremity of cam shaft  7  which comes into contact with the neutral low position sensor. 
         [0133]    FIG.  22 —Preparation of Coffee 
         [0134]    The low neutral position sensor activates the hydraulic system that sends the quantity of water selected during the coffee quantity selection stage through each of spray heads  30  for which the presence of a pod  24  has been detected during the stage of pod  24  detection. 
         [0135]    The water, represented by white arrows, passes through the selected spray head  30 , then through pod  24 , strainer  20 , evacuation conduit  21 , and pour spout  22  associated with it, finally flowing into the coffee cup placed beneath the spout. 
         [0136]    The coffee extracted after the water has passed through pod  24  is shown by black arrows. 
         [0137]    FIG.  23 —Decompression of Extraction Chambers 
         [0138]    Several instants after extraction is complete, cam shaft  7  begins to turn again, gradually eliminating the contact by the projections on cams  29 . Symmetrical elastic forces in the form of two springs  28  recall injection block  6  upward. 
         [0139]    The pieces forming the extraction chambers disassociate, causing decompression to occur. 
         [0140]    This decompression may cause a certain amount of water and coffee to travel up through the hydraulic system of machine  3 , which dirties it over the course of time. 
         [0141]    The use of a triple track valve prevents the pod from being filled with water when it is ejected, thereby eliminating spattering and keeping the device clean. Such a device using a triple track valve is known in the art and will not be described in detail. 
         [0142]    After the extraction chamber is decompressed, any used pods  24  remain in strainers  20 . 
         [0143]    FIG.  24 —Tilting of Receiving Platform 
         [0144]    Cam shaft  7  continues to turn and the cam transmission system controls opening of catches  25  on the mechanism for locking tilting receiving platform  16 . The platform tilts partially by gravity on its pivot axle until it is nearly in the vertical position, striking the buffer stop blocks made of flexible material. 
         [0145]    The shock this causes produces a muffled sound. Its purpose is to eject used pods  24  from their receptacle  20 . Pods  24  then fall by gravity and are guided in their fall by hopper  26  to a used pod receptacle. 
         [0146]    During this stage, spray heads  30  are in free contact with pods  24 , and the force they exert on the pods helps pods  24  to dislodge from receptacle  20  by increasing the opening speed and thereby the impact at the end of the course. 
         [0147]    FIG.  25 —Assumption of Resting Position 
         [0148]    Cam shaft  7  continues to turn as the injection block  6  reaches the upper position. Angular position detector  38  then detects the upper neutral position of cam shaft  7  and cuts motor  8 . 
         [0149]    Drawer  5  remains in closed position and tilting receiving platform  16  is freed from locking elements  25 . It is empty and in the open air, which considerably reduces any sanitation risk for the device. Unit  1  is in the final position, which is also the initial position in  FIG. 15 . It is ready to recommence another cycle. 
         [0150]    A reading of the preceding description of a cycle makes it apparent that preparation unit  1  of the invention is simple to use, free of danger for the operator, and fully responsive to sanitation requirements. 
         [0151]    This automatic cycle requires electronic automation circuits that have not been described. Actually, the design for electronic circuits adapted to the specifics of the preparation unit is based upon simple studies of automation. 
         [0152]    In the preferred embodiment previously described, drawer  5  is manually activated. As indicated, however, it may be motorized using an auxiliary motor device, said motor  11  possibly being activated to close the drawer when the operator selects the quantity of coffee or through the use of a dedicated button, and to open it during the step of positioning pods  24  in which drawer  5  will be opened from the resting position in which it is closed. 
         [0153]    It is also possible to conceive of numerous variations of the preceding design and operating embodiments without departing from the scope of the invention. 
         [0154]    For example, the operating stages may be modified to adapt to the user&#39;s requirements, for example, by providing a resting position in which drawer  5  is open instead of closed. 
         [0155]    It is also possible to adapt unit  1  of the invention to other shapes of pods  24 . To do this, it is only necessary to adapt the shape of strainers  20  and pods  24 , without any need to modify the remainder of machine  3 . 
         [0156]    It is also possible to adapt unit  1  of the invention to machines  3  for household use rather than commercial use. 
         [0157]    Additionally, it is possible to adapt the automation system to make it possible to simultaneously prepare a small coffee from one pod and a large coffee from the other. 
         [0158]    A very interesting improvement also consists of providing an identification code on pods  24  that can be read by a device adapted to unit  1  of machine  3  for recognizing the type of pod  24  being used. This identification code might consist, for example, of a bar code, an electronic chip, a magnetic imprint, or a raised and/or recessed impression or other means, that is respectively read by an optical, magnetic, electronic, mechanical, or other reading device. 
         [0159]    It is also possible to differentiate the pods according to the type of coffee they contain so the machine can consequently adapt the amount of water, its temperature, pressure, and more generally, all the parameters of the machine according to these characteristics, with this process taking place individually for each pod and the unit of the invention incorporating an extraction chamber and an individual presence detector for each pod, as well as a specific hydraulic system for each strainer and thus for each pod. 
         [0160]    The device for reading pod identification codes to be provided on each strainer requires no description because it already exists in theory. 
         [0161]    In this embodiment, it would also be possible to replace the individual mechanical presence detectors for each pod by the identification code reader, adapting it for this purpose.