Abstract:
An apparatus for preparing coffee includes a holder provided with an access opening for placing a pouch filled with a product to be extracted into the holder; a cover for closing and releasing the access opening; a clamping arrangement for pressing the holder and cover towards each other when the cover closes off the access opening of the holder; and a closing arrangement for retaining the cover and the clamping arrangement in position when the cover closes off the access opening of the holder. The closing arrangement is mechanically coupled to the clamping arrangement for bringing the clamping arrangement from a non-clamping condition into a clamping condition by manually operating the closing arrangement from a first defined position to a second defined position.

Description:
BACKGROUND 
   The invention relates to an apparatus for preparing coffee, comprising a holder provided with an access opening for placing a product to be extracted into said holder; a cover for closing and releasing the access opening; clamping means for pressing the holder and cover towards each other when the cover closes off the access opening of the holder and closing means for retaining the cover and the clamping means in position when the cover closes off the access opening of the holder. 
   Such an apparatus is known from EP 0 904 718. In this known apparatus the holder is mounted in a first housing part and the cover is spring adjustably mounted in a second housing part. To close the apparatus, the second housing part is pivoted towards the first housing part, whereupon the spring will adjust the orientation of the cover so that it can properly engage the holder. Due to this adjustment, clamping means at the inner side of the second housing part engage clamping means at the outer side of the cover, thus establishing a clamping force which presses the cover onto the holder. Subsequently, a clip on the second housing part can be hooked behind a protrusion of the first housing part, to retain the cover and clamping means in the closed position. 
   A disadvantage of this known apparatus is that the spring and clamping means allow the cover to become misaligned during closure, without a user noticing. The misalignment can for instance be prompted due to a pouch or other filter structure or coffee granulate being misplaced and getting caught between the edges of the cover and the holder or due to too many pouches having been placed in the holder. Due to such misalignment no proper seal will be attained between the holder and cover and consequently, in use, the pressure in the holder will be too low, affecting the quality of the brew. 
   SUMMARY 
   It is an object of the invention to provide an apparatus of the above-described type, wherein the risk of operation with the cover not properly aligned is reduced. 
   To that end, in an apparatus according to the invention the closing means are mechanically coupled to the clamping means for bringing the clamping means from a non-clamping condition into a clamping condition by manually operating the closing means from a first defined position to a second defined position. Such a configuration offers the advantage that a user obtains immediate tactile and visual feedback regarding the state of the clamping means, and hence the state of the cover, from operating the closing means. If, for instance, a force for operating the closing means is considerably lower or higher than usual, this will signal the user that the cover is positioned incorrectly, or at least that something is not working properly. The user may then take appropriate action to remedy the cause. Furthermore, as long as the closing means have not reached one of their two defined end positions, the user is informed that the clamping means have not reached their end position either and the cover is not, or not yet, properly engaged. 
   The clamping means can for instance comprise one or more cams and mating recesses, which can be brought into and out of engagement with each other by operating the closing means. Preferably the configuration of the cams and recesses is such that they can only be engaged when the cover is properly closing off the holder. Thus, if for whatever reason the cover is not properly aligned, the closing means will not be operable to the closed end position, thereby sending a clear message to the user, both tactile and visual, that something is the matter. 
   Preferably the cams are at least partly wedge-shaped. This offers the advantage that the clamping force can be gradually built up, while advancing the cams in the recesses, thus facilitating the operation of the closing means. 
   According to an advantageous embodiment of an apparatus according to the invention, part of the clamping means is statically mounted in a first housing part to which the holder is connected, whereas the mating clamping means are movably mounted in a second housing part to which the cover is connected. Preferably, said movable clamping means are mounted on a single slider, which slider is movably connected to the second housing part. In that way, by displacing, e.g. rotating and/or translating the slider, all movable clamping means can be simultaneously brought into engagement with the static clamping means. Since only a single slider will have to be operated, the closing means can be of a simple, robust construction and will be easy to operate. Furthermore, the construction will have a high sensitivity to detecting misalignment of the cover, for if only one pair of co-operating clamping means cannot be properly engaged, the complete slider will not attain its engaged position, which again will be communicated to the user by the position of the closing means. 
   The cover can either be connected to the slider and, together with the slider and the clamping means, be slid into the closing position, or it can be connected to the second housing part, separately from the slider. In the latter case, the cover can be clamped onto the holder by means of the slider pressing directly onto the cover, or indirectly, by means of the second housing part, which itself is being clamped onto the first housing part. 
   In a further advantageous embodiment, the clamping means are spaced evenly along the access opening of the holder, at least in the clamped condition. As a result, the clamping force will be evenly distributed over the cover, in particularly around its periphery, resulting in a good, reliable seal. The clamping means can for instance be arranged around the access opening in a triangle, preferably an equilateral triangle. If so, the widest part of the triangle, that is the base thereof, preferably faces a front side of the apparatus so that the accessibility of the holder is not hampered. 
   According to yet a further preferred embodiment, the closing means for operating the clamping means include a toggle joint lever. By applying such a toggle joint lever the force needed for operating the slider and bringing the clamping means into engagement can be kept relatively low. Although the operating force will be low, this will still contain sufficient information regarding the state of the clamping means and cover. Hence, ease of operation can be increased, without compromising the feedback function of the closing means. 
   In a highly preferred embodiment, the closing means furthermore comprise a spring, which helps return the closing means to either one of its two defined end positions, thereby communicating to the user whether the closure of the holder has been successful or not. Preferably, the design of the toggle joint lever and spring action is chosen such that the movement of the closing means between said two defined positions corresponds to a natural sense for opening and closing the apparatus. 
   The above and other advantageous embodiments of the invention are set forth in the dependent claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     To explain the invention, exemplary embodiments thereof will hereinafter be described with reference to the accompanying drawings, wherein: 
       FIG. 1  shows a cross section of the apparatus according to the invention, in the closed condition; 
       FIG. 2  shows a cross section of the apparatus according to  FIG. 1 , in the partly opened condition; 
       FIG. 3  shows a cross section of the apparatus according to  FIG. 1 , in the completely opened condition; 
       FIG. 4  shows schematically, in cross section, in four subsequent steps the working of the closing and clamping means according to the invention, during opening and closing of an apparatus according to  FIG. 1 ; 
       FIG. 5  shows in a plan view a preferred embodiment of a slider according to the invention; and 
       FIG. 6  shows in an exploded and assembled view the various parts of a closing and clamping configuration according to an embodiment of the present invention. 
   

   DETAILED DESCRIPTION 
   In this description, the same or corresponding parts have the same or corresponding reference numerals. 
     FIGS. 1–3  show an apparatus  1  for preparing coffee, comprising a first housing part  2 , in which a holder  4  has been mounted and a second housing part  44 , in which a cover  34  has been mounted. 
   The holder  4  is of a cup-shaped design, comprising a bottom  16  and an upright, circumferential sidewall  18 , connected to the bottom  16 . At its upper end, the holder  4  is provided with an access opening  24 , for receiving a product to be extracted, for instance a pouch, made of filter material and filled with for instance ground coffee. Provided in the bottom  16  of the holder  4  is at least one outflow opening (not visible in the Figures) for discharging extracted liquid. 
   The cover  34  is designed to accurately close off the access opening  24  of the holder  4 . At its upper side, an inflow opening is provided through which water is passed into the holder  4 , and onto the product to be extracted. To that end, the inflow opening is connected to a hot water supply  42  (not shown), via a liquid duct  40 . Furthermore, the side of the cover  34  facing the holder  4  can be equipped with a sealing ring, which in use co-operates with the holder  4  to ensure a proper liquid seal between the holder  4  and the cover  34 . 
   The second housing part  44  is adjacent one end connected to the first housing part  2  for rotation around a rotation axis  50  between a first position, in which the access opening  24  is closed off by the cover  34  (as illustrated in  FIGS. 1 and 2 ) and a second position in which the access opening  24  of the holder  4  is cleared (as shown in  FIG. 3 ). 
   The apparatus  1  furthermore comprises clamping means  70  for pressing the cover  34  against the holder  4  when it closes off the access opening  24  of the holder  4 , and closing means  80  for maintaining the cover  34  and the clamping means  70  in the aforementioned position. 
   As is best seen in  FIGS. 2 ,  4  and  5 , the clamping means  70  comprise three sets of recesses  72  and mating cams  74 . The recesses  72  are provided in the first housing part  2 , spaced in a triangle around the access opening  24  of the holder  4 . The cams  74  are provided on a substantially triangular slider  75  (see  FIGS. 4 and 5 ), adjacent the three corners thereof. The slider  75  is movably mounted in the second housing part  44 , and can be operated by the closing means  80 , in a way to be described in more detail below, between a first and a second position, in which the cams  74  are respectively in and out of engagement with the recesses  72 . 
   Thanks to the triangular configuration the clamping means  70  are spaced at more or less regular angles along the periphery of the access opening  24 . Consequently, the clamping force will be evenly distributed along the edge of the cover  34 , resulting in a reliable seal. Of course, more cams and mating recesses can be applied within the scope of the invention. These cams and recesses may be spaced differently around the access opening. Also, the position of the cams and recesses can be interchanged, that is the cams  74  can be mounted in the first housing part  2 , whereas the recesses  72  can be provided in the slider  75 . 
   In case the triangular configuration is applied, the triangle is preferably oriented in such a way that the widest part thereof, that is base B, faces the front side of the apparatus  1  via which products are placed into or removed from the holder  4 , as indicated by arrow A in  FIG. 5 . In this way, the accessibility of the holder  4  need hardly be affected. 
   Preferably, the cams  74  are of a wedge-shaped design (as illustrated in  FIGS. 1 and 2 ). This facilitates introducing the cams  74  into the recesses  72  and enables the clamping force to be built up gradually while the cams  74  enter the recesses  72 . Of course, other shapes are possible and understood to fall within the scope of protection. 
   The closing means  80  for operating the slider  75  comprise a lever  82 , a push rod  84 , and a spring  86 . The lever  82  has an angular shape and, near its angle, is rotatably connected to the second housing part  44 , for rotation around a first rotation axis  90 . A first end  82 A of the lever  82  extends from the rotation axis  90  to outside the second housing part  44 , through an opening  45  (see  FIG. 6 ). The second end  82 B of the lever  82  is connected to the push rod  84 , i.e. to a first end  88  thereof, for rotation around a second rotation axis  92 . This second rotation axis  92  extends substantially parallel to the first rotation axis  90 . The push rod  84  is connected, near its other end  89 , to the slider  75 , more specifically to two mounting brackets  78  extending upward from the slider  75 , for rotation around a third rotation axis  94 . This third rotation axis  94  extends substantially parallel to the first and the second rotation axis  90 ,  92 . In the push rod  84  a slot  87  is provided, which extends from the second end  89 , between the mounting brackets  78 , in the longitudinal direction. This slot  87  provides a passage for the liquid duct  40  of the cover  34 , which extends at least partially below the slider  75  and can be connected either to said slider  75  or to the second housing part  44 . 
   The lever  82  and push rod  84  together form a toggle joint lever assembly  85 , with which the slider  75  can be operated from a non-clamping to a clamping position, with a relatively low operating force. The closing means  80  furthermore comprise a spring  86 , which at one end is connected to the slider  75  or the push rod  84 , near the third rotation axis  94 , and at an opposite end is connected to the second housing part  44 . The spring  86  turns the toggle joint into a snap mechanism, and helps a user operate the lever  82  between its defined end positions I, II. 
   The operation of the closing and clamping means  80 ,  70  is as follows. In a closed position, illustrated in  FIG. 4A , the cover  34  closes off the opening  24  and is clamped onto the holder  4  by means of the slider  75 , which is engaged into the recesses  72  by means of the cams  74 . In this position, the spring  86  is slightly compressed and exerts a force on the push rod  84 , which tends to rotate the lever  82  counterclockwise, to a first defined end position I, in which the second end  82 B of the lever  82  abuts the inner side of the second housing part  44  and the first end of the lever  82 A extends downward, against part of the outer side of the second housing part  44  (see  FIG. 4A ). A user can see from this first lever position I that the cover  34  is properly closed. 
   To open the apparatus I and lift the cover  34  from the holder  4 , the first end  82 A of the lever  82  is rotated clockwise, around the first rotation axis  90  in the direction of arrow C (see  FIG. 4B ). Consequently, the push rod  84  is rotated counterclockwise around the third rotation axis  94 , against the force of the spring  86 . The spring  86  is compressed until the lever  82  passes the point where the second end  82 B and the push rod  84  are aligned. The spring  86  then recovers from compression and expands, thereby pushing the slider  75  sideward and disengaging the cams  74  from the recesses  72 . Simultaneously, the second end of the lever  82 B is rotated further downward around the first rotation axis  90  and the first end  82 A is rotated upward, away from the second housing part  44  to a second defined end position II (see  FIG. 4C ). In this position the push rod  84  extends about parallel to the slider  75  and the spring  86  is not compressed. In this position the upward extending lever  82  signals to the user that the cover  34  is now unclamped. For gaining access to the holder  4 , the user may proceed by rotating the second housing part  44  around its rotation axis  50 , away from the first housing part  2 , thus lifting the cover  34  from the holder  4  (as shown in  FIG. 4D ). After placing a product to be extracted into the holder  4 , the apparatus  1  can be closed by going through the above-described steps in reversed order. Thus, the lever end  82 A is rotated downwards, against the spring force, till the spring  86  snaps and rotates the lever  82  further till the second lever end  82 B abuts the inner side of the second housing part  44  and locks the lever  82  and slider  75  against further movement. 
   The closing and clamping means  80 ,  70  as described offer several advantages. For instance, because the clamping means  70  are brought into a clamping condition by the user himself instead of by a spring, the user obtains immediate feedback on the status of the cover  34  from the force needed to operate the closing means. Preferably the clamping means  72 ,  74  are dimensioned such that if the cover  34  is near its closed position but does not properly seal the holder  4 , the cams  74  cannot be brought into engagement with the recesses  72 . The lever  82  will then retain its second end position II or at least not reach its first end position I, thus indicating to the user that no proper closure could be achieved. The user may then take appropriate action to remedy the cause, for instance by reopening the second housing part  44  and rearranging the pouch. 
   Furthermore, the toggle joint design of the closing means allows the clamping means to be operated with relatively little effort, without undoing the feedback function of the closing means. Thanks to the snap mechanism the first lever end  82 A will at all times be returned to one of its two defined end positions I, II, to provide the user with reliable visual information about the state of the cover  34 . Preferably, the design of the snap mechanism is such that the movement between the first and second position of the lever corresponds to a natural movement for opening or closing the apparatus  1 . 
   Although not shown, the slider  75  and second housing part  44  can be equipped with co-operating guiding means, for guiding the slider  75  during its movement between the clamping and non-clamping position and support the slider  75  in retaining a preferred orientation with regard to the access opening  24 . 
   The invention is not in any way limited to the embodiments described hereinbefore. 
   For instance, the slider can be designed to surround the cover or overlap the cover, at least partly, in the clamped condition. Also, the cover and the slider can be connected to the second housing part jointly or separately. The slider and the closing means can be arranged for rotating the slider around a rotation axis extending substantially perpendicularly to the plane of the slider or extending substantially parallel to said plane. Furthermore, the engaging movement of the slider can be a combination of a rotational and a linear movement. The cams and recesses may differ in number, shape and position from the ones shown in the accompanying drawing. 
   Such variants are understood to fall within the scope of the invention.