Abstract:
The invention discloses a plunger-filter beverage-making machine with a lid which can be closed by a valve. The beverage-making machine has a vessel ( 2 ), a lid ( 3 ) and a filter piston ( 4 ) which can be vertically displaced in the vessel and has a piston rod ( 41 ). The lid ( 3 ) contains a pouring opening ( 37 ) which can be closed by means of an elongate lever ( 33 ) which extends transverse to the piston rod. To this end, the lever is mounted on the lid such that it can pivot about a horizontal axis. The lever has, in the region of its front end, a closure body ( 36 ) in order to close the pouring opening and, in the region of its rear end, an operating region ( 331 ) in order to pivot the lever by virtue of pressure exerted by a finger of a user.

Description:
TECHNICAL FIELD 
     The present invention relates to a beverage-maker having an upwardly open vessel and a filter piston arranged displaceably therein. Beverage-makers of this type are generally referred to as plunger-filter beverage-makers or as “French Press” beverage-makers. Beverage-makers of this type can be used to prepare coffee, tea, etc. or to froth up milk, for example. 
     PRIOR ART 
     “French Press” coffee makers have long been known from the prior art. These normally comprise a cylindrical glass vessel, in which a filter piston is displaceably arranged. The filter piston comprises a piston rod, to whose lower end a plunger-filter having a fine wire or plastics mesh is attached. The piston rod is passed through a lid which covers the vessel in the upward direction. 
     In order to prepare coffee, for instance, ground coffee beans are poured into the vessel and poured over with hot water. The mixture is left to stand for a few minutes. Next the filter piston is inserted into the vessel and pressed down. The plunger-filter hereupon separates the ready-to-drink coffee from the spent coffee powder. 
     For the pouring of the coffee, a beak-like spout is normally configured on the upper rim of the vessel. The lid generally has as spray protection a circumferential skirt, which extends inside the vessel. In the skirt (generally slit-shaped) apertures are present to enable the coffee to be poured out through the apertures by means of the spout. 
     In order to avoid a situation in which a user, when pressing down the plunger-filter, can be scalded by spurting hot liquid, the apertures of the skirt are normally turned away from the spout as the filter piston is pressed down and are only brought into the region of the spout immediately before pouring. However, a user can easily forget this. There is therefore always a certain danger that either hot liquid spurts out because the user has forgotten to turn the apertures away from the spout before pressing down, or that the ready coffee is spilt because the user, after pressing down, forgets to bring the apertures back into overlap with the spout and the coffee therefore escapes unchecked between the vessel wall and the lid. 
     U.S. Pat. No. 6,295,920 discloses a plunger-filter beverage-maker, the spout of which is covered with a pivotable flap. This pivots upward during pouring by virtue of the pressure of the escaping coffee and thus frees the spout. Such a flap is unsatisfactory, however, since the flap, during the pouring, is necessarily wetted by the coffee and the flow of the coffee thereupon changes, so that there is a danger of coffee dripping down from the spout during pouring, or subsequently. 
     REPRESENTATION OF THE INVENTION 
     An object of the present invention is thus to define a plunger-filter beverage-maker in which these problems are avoided, which thus ensures spray protection as the plunger-filter is pressed down, combined with high operating safety, without the risk of subsequent dripping. A further object of the invention is to define a beverage-maker of this type in which heat losses through the lid are minimized. 
     This object is achieved by a beverage-maker having the features of claim  1 . Advantageous embodiments are defined in the dependent claims. 
     The present invention thus provides a beverage-maker having the following features:
         an upwardly open, substantially cylindrical vessel made of a heat-resistant material, in particular glass, having a vessel bottom and a circumferential side wall;   a filter piston vertically displaceable in the vessel, having a piston rod to whose upper end an actuating element, for example in the form of a knob, is attached, and to whose lower end a plunger-filter is attached, which latter is suitable for allowing the passage of liquid and, at the same time, for retaining solids; and   a lid, which is passed through by the piston rod and has a top wall which at least partially covers the vessel in the upward direction and which, jointly with the vessel, delimits a vessel interior.       

     On the lid or on the vessel, outside the vessel interior, a spout is configured. The lid has a pouring opening, which is disposed between the piston rod and the spout and breaches the top wall and which forms a connection between the vessel interior and the spout in order to pour liquid out of the vessel through the pouring opening by means of the spout. An elongated lever, extending above the top wall transversely to the piston rod, is attached to the lid pivotably about a horizontal axis. The lever has a closure body in the region of its front end for closing the pouring opening, and the lever has an actuating region in the region of its rear end for pivoting the lever, by virtue of pressure exerted by a finger of the user, from a first position, in which the closure body closes the pouring opening, into a second position, in which the closure body frees the pouring opening. 
     In this way, a valve, which can be opened and closed very easily in a purposeful manner, is configured in the lid. The vessel interior is completely closed, as long as the user does not deliberately actuate the lever in order to open the valve. An operating error, which could lead to splashing of the drink as the filer piston is pushed down, is thereby practically precluded. It is ensured, moreover, that heat is not unnecessarily lost through the pouring opening. 
     Heat-insulated coffee pots, whose lid contains a valve which can be opened by means of a lever mechanism by pressure onto an actuating element located above the handle of the pot, are known from U.S. Pat. No. 6,755,120 or U.S. Pat. No. 6,997,104. However, these coffee pots are intended for filter coffee machines, in which coffee powder is filled into a filter disposed above the pot and is poured over with hot water which extracts the coffee and makes its way through the filter into the below-situated coffee pot as the finished drink. The valve must here fulfill a dual function, namely, on the one hand, to ensure the inflow as the coffee is brewed and, on the other hand, to enable the finished drink to be poured. These valves are consequently of relatively complicated design, while the valve of the present invention, in comparison thereto, is very simply constructed. Moreover, these solutions are not transferable to plunger-filter coffee pots, since the valve, in the known pots, is arranged centrally and would not allow a central piston rod to pass through. 
     By the term “substantially cylindrical vessel” is meant that the vessel, over a considerable part of its length, has a cylindrical basic shape. The vessel can widen, however, for example in its upper rim region. The spout is preferably configured on the lid. If the top wall of the lid is disposed sufficiently far within the vessel, however, it is also conceivable to configure the spout on the vessel itself. The vessel can optionally be held in a holder which at least partially encompasses the vessel and has a handle, as has long been known per se in a wide variety of variants. However, the vessel can also itself have an integrated handle, which can be produced, for example, integrally with the glass or plastics vessel. 
     Preferably, the lever is spring-loaded in the direction of its first position in order to ensure that the pouring opening is closed as long as the lever is not deliberately actuated. Instead, the lever can also be configured, however, such that the pouring opening is closed solely due to the weight of the lever and of the closure body, as long as no pressure is applied to the actuating region. 
     Preferentially, for the generation of the spring force, a compression spring is present. This is preferably disposed in a rear region of the lid, facing away from the spout, between the lever and the below-situated top wall in order to subject the lever to a spring force in the direction of its first position. However, such a spring can also be disposed in a region of the lever, adjacent to the spout, between the lever and a lid region disposed above the lever. 
     Insofar as the compression spring is disposed in the rear lid region, a cup-shaped depression (spring seat), extending towards the vessel interior, is preferably configured in the top wall, into which depression the compression spring extends. In this way, the compression spring is secured against lateral displacements or even against falling out, and a sufficiently large spring length for the required spring travel is enabled. 
     In order to pass the piston rod through the lid, the lever preferably has a through opening, through which the piston rod extends. The lever can instead, however, be led around the side of the piston rod. 
     The lever is preferably mounted on the lid, such that it can be pivoted horizontally, by means of bearing elements directly connected to the top wall. The lever preferably has a bearing shaft extending transversely to the longitudinal direction of the lever, for example in the form of a continuous pin, or two coaxially arranged, bearing journals extending outward transversely to the longitudinal direction of the lever. For fastening, the lid then preferably has two mutually opposing, jaw-shaped bearing elements for the reception of the bearing shaft or bearing journals, and the bearing shaft or bearing journals, in surmounting an elastic spring force, can be clicked into the bearing elements. Simple manufacture and maintenance is thereby ensured. However, the lever can also be pivotably mounted on the lid in another way, for example via a shaft which is arranged centrally in an opening in the lever and is inserted in a single, central bearing element, as is known per se. 
     In order to ensure an effective sealing of the pouring opening, the closure body is preferably made of a material which is softer (on the Shore A scale) than the material of the rest of the lever. In particular, the closure body can consist of silicone plastic. It is preferably inserted in an opening or recess in the region of the front end of the lever, but can also, for example, be produced jointly with the rest of the lever in a two-component injection molding process. Where appropriate, the closure body can also consist of the same material as the rest of the lever and be produced integrally therewith, particularly when, by the shaping of closure body and opening, an adequate seal is already ensured. 
     The lid preferably has a circumferential skirt, which extends vertically downward and extends into the vessel interior, as is already at present generally the case with the lids of commercially available plunger-filter coffee pots. In order to create an effective seal between the vessel and the lid, on the outer side of the skirt there is preferably disposed a circumferential sealing element, which bears sealingly against the inner side of the side wall of the vessel. The sealing element can assume, in particular, the shape of a ring made of a softer material, for example silicone plastic, than the rest of the lid material, and can have a sealing lip extending radially outward. In order to facilitate the insertion of the sealing element, the vessel can widen slightly at the upper rim. 
     The top wall of the lid, which delimits the vessel in the upward direction, is preferably configured substantially flat. In order to retain in the region of the pouring opening liquid running back from the spout, in a region surrounding the pouring opening there can be configured an upwardly protruding retaining web, which, starting from the spout, extends partially around the pouring opening. 
     The lid is preferably of two-part construction, i.e. the lid preferably comprises a lid bottom part, which forms the top wall delimiting the vessel interior, and a separately configured lid top part, which at least partially covers the lid bottom part and the lever. In order to guide the piston rod in as precise and vertically stable a manner as possible, on one of the lid parts, selected from lid bottom part and lid top part, there is then preferably configured a cylindrical guide sleeve, which is held in the other lid part such that the guide sleeve is secured against a lateral tilting motion. The guide sleeve can be latched, in particular, to the other lid part. 
     A simple design results if the guide sleeve is configured integrally with the lid top part and extends vertically downward into the vessel interior through the top wall delimiting the vessel interior, and if a releasable latching connection, for example in the form of latching cams configured on the outer side of the guide sleeve and reaching under the top wall of the lid bottom part, is configured between the guide sleeve and the top wall. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred embodiments of the invention are described below with reference to the drawings, in which: 
         FIG. 1  shows a perspective view of a “French Press” beverage-maker; 
         FIG. 2  shows a perspective view of the lid (in part) and of the filter piston of the beverage-maker of  FIG. 1 ; 
         FIG. 3  shows a central longitudinal section in the plane A-A through the beverage-maker of  FIG. 1 ; 
         FIG. 4  shows a central longitudinal section in the plane A-A through lid of the beverage-maker of  FIG. 1 ; 
         FIG. 5  shows a non-central longitudinal section in the plane B-B through lid of the beverage-maker of  FIG. 1 ; and 
         FIG. 6  shows a side view of the lid of  FIGS. 4 and 5 . 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     In  FIGS. 1 to 6 , a preferred illustrative embodiment of a beverage-maker according to the invention, in the form of a plunger-filter coffee pot, is shown in various representations. 
     The beverage-maker comprises a holder  1  made of plastic, a substantially cylindrical vessel  2  held therein, a lid  3 , and a filter piston  4 . In  FIG. 1 , the vessel is represented as transparent and consists, in particular, of heat-resistant glass; however, it can also consist of plastic or metal, for example. 
     The holder  1  comprises an upper holding ring  12 , encompassing the side wall  21  of the vessel, and a lower holding ring  11 , which merges into a base breached in the downward direction by a circular central opening. The holding rings are connected to each other by two longitudinal struts  13  extending in the longitudinal direction of the vessel. Likewise connected to the holding rings  11 ,  12  is a handle  15  for grasping of the beverage-maker. 
     The upwardly open vessel  2  consists of a slightly upwardly arched bottom  22  and a circumferential side wall  21  of cylindrical basic shape. Unlike in most coffee makers of the prior art, there is no spout configured in the side wall. The side wall ends approximately flush with the upper holding ring  12  of the holder  1 . 
     Inserted in the vessel  2  is the lid  3 . This is constructed in two parts and comprises a lid bottom part  32  and a lid top part  31 . In  FIG. 2 , the lid top part is not represented. The lid bottom part  32  has a substantially flat top wall  321 , which largely covers the upper vessel opening and, together with the vessel  2 , delimits a vessel interior  23 . Configured in the top wall  321  is a pouring opening  37 , which is discernible in  FIGS. 2 ,  3  and  4  and is there sealingly closed by a closure body  36 . To the rear, the pouring opening  37  is surrounded by a retaining web  322 , which on both sides ends at a beak-like spout  328  and thus prevents liquid which might run back from the spout in the direction of the pouring opening from getting into the rest of the lid region. 
     Starting from the top wall  321 , extending upward on the outer margin thereof, is a cylindrical side wall  327 , which is interrupted by the spout  328  and by a recess for a lever  33 . Likewise starting from the top wall  321 , a circumferential, cylindrical skirt  325  of somewhat smaller diameter extends downward into the vessel. Extending outward from the skirt is a pair of annular, mutually spaced webs, which form a seat  326  for a circumferential, annular seal  35  having a radially outwardly protruding sealing lip. Hence, on the one hand, the lid  3 , having been inserted, is held relatively firmly in the vessel  2  and, on the other hand, a seal is formed between the vessel and the lid, which seal prevents liquid from possibly escaping between the vessel and the lid. 
     The elongated lever  33  is fastened pivotably to the lid bottom part  32 . To this end, it has on a central main portion  332  two laterally protruding, coaxial, horizontal bearing journals  336 , which are clicked into two jaw-shaped bearing elements  329 , which are open to the fore, i.e. in the direction of the spout  328 . The bearing elements  329  are configured integrally with the lid bottom part. The jaw opening is at the front end somewhat smaller than the journal diameter, and the bearing elements are of slightly elastic configuration in order to allow the clicking engagement. 
     In the direction of its front, spout-facing end, the lever  33  first has a contour which is pre-arched upward in the style of an arc in order to surmount the retaining web  322 . In the following, front end region of the lever there is configured a round opening, in which the closure body  37  is inserted. While the lever  33  itself, just like the rest of the lid, is made of an impact-resistant and relatively hard plastic such as, for example, polypropylene, the closure body  37  consists of a relatively soft material, for example silicone plastic, in order to obtain a good sealing effect. 
     At its rear end facing away from the spout, the lever  33  projects with an actuating region  331  from the lid bottom part  32  and can be pivoted slightly about its horizontal pivot axis by virtue of downward pressure exerted by the thumb of the user, so that the closure body  36  is raised from the pouring opening  37  and frees the pouring opening. 
     By means of a pressure-operated helical spring  34 , the lever is preloaded into the closing position. The helical spring  34  is disposed in the rear region of the lever, facing away from the spout, but still within the side wall  327  of the lid bottom part. It is accommodated in a cup-shaped depression  324  in the top wall  331 , which depression allows a greater spring travel than would be possible without such a depression. In the upward direction, it reaches into an annular spring seat  333  on the bottom side of the lever  33 . By virtue of the depression  324  and the spring seat  333 , the spring is secured against lateral displacements or even against jumping out. 
     The lid top part  31  covers with its upper top wall  311  the upper margin of the side wall  327  of the lid bottom part  32 . Extending vertically downward from a central opening in the upper top wall is a guide sleeve  312 , which is produced integrally with the upper top wall and in which the piston rod  41  of the filter piston  4  is guided. The lever  33  and the lower top wall  321  of the lid bottom part  32  respectively have a through opening, through which the guide sleeve  312  extends. The through opening in the lever  33  is here sufficiently large not to hinder the pivot motion of the lever. The through opening in the lower top wall  321 , by contrast, fits precisely with the guide sleeve  312 . In the region of the lower end of the guide sleeve, a plurality of flat, spherical-segment-shaped latching cams  315  are configured on the surface of the guide sleeve, which, following the insertion of the guide sleeve, form a releasable latching connection between the guide sleeve  312  and the lid bottom part  32 . The guide sleeve is thereby secured at two different vertical locations against lateral displacements, and thus against tilting motions. Hence, on the one hand, the vertical guidance of the piston rod  41  is improved, and, on the other hand, the risk of breaking of the connection between the upper top wall  311  and the guide sleeve  312  is reduced. 
     The filter piston has at the upper end of the piston rod  41  a knob  42  as the actuating element. At the lower end, a plunger-filter  43  of a construction which is known per se is attached to the piston rod. The plunger-filter comprises an upper perforated plate  431 , which at its upper margin is raised and is provided with a multiplicity of small openings. Through these openings, a toroidal wire coil  433  is threaded. A fine wire mesh  432  rests on the bottom side of the perforated plate and is drawn upward over the wire coil  433 . The wire mesh is fixed in the downward direction with a star-like or perforated-plate-like fixing plate  434  placed beneath the wire mesh parallel to the perforated plate. With a common fixing screw  435 , which engages in a check nut  436  (represented only in  FIG. 3 ), the perforated plate  431 , the wire mesh  432  and the fixing plate  434  are secured on the piston rod. 
     The invention is not, of course, restricted to the above example and a large number of modifications are possible. In particular, for instance, the lever can also be designed differently in terms of its shape and arrangement. For example, the actuating region does not need to be disposed radially outside the lid bottom part, but can also be situated within the lid bottom part and be accessible from above through a cutout or opening in the lid top part. Of course, the plunger-filter can be configured in a different manner than represented above, for example with a plastics mesh cast into a plastics frame, as is known per se from the prior art. Instead of the vessel holder represented in the drawings, any other holder may also be used, or the holder can be wholly dispensed with if, for example, the vessel has a molded-on handle. A large number of further modifications are possible. In particular, the above-described embodiments of the lever and of the piston guide can, self-evidently, advantageously be used independently of each other and independently of further features. 
     Reference Symbol Table 
     
         
           1  holder 
           11  lower ring 
           12  upper ring 
           13 ,  14  longitudinal strut 
           15  handle 
           2  glass vessel 
           21  side wall 
           22  bottom 
           3  lid 
           31  lid top part 
           311  top wall 
           312  guide sleeve 
           315  latching cam 
           32  lid bottom part 
           321  base 
           322  retaining web 
           323  opening 
           324  depression 
           325  skirt 
           326  seal seat 
           327  side wall 
           328  spout 
           329  shaft mount 
           33  closing lever 
           331  actuating region 
           332  main portion 
           333  spring seat 
           334  opening 
           335  curved region 
           336  shaft 
           34  compression spring 
           35  sealing ring 
           36  stopper 
           37  pouring opening 
           4  plunger filter 
           41  piston rod 
           42  actuating knob 
           43  filter plate 
           431  base plate 
           432  wire mesh 
           433  wire coil 
           434  fixing plate 
           435  fixing screw 
           436  check nut