Abstract:
A compressor arrangement for automatically compressing ground coffee includes a housing having an inlet opening and an outlet opening with a retention flap which adjusts a bulk density of the ground coffee, conveying and compressing elements arranged in the housing which are driven by a first drive device, and an adjustment device which pre-adjusts the bulk density of the ground coffee. The adjustment device comprises a second drive device, a retention flap shaft, a retention flap arranged on the retention flap shaft, a transmission which is operatively connected to each of the second drive device and the retention flap shaft, and an automatic dynamic pressure adjustment apparatus which enlarges or reduce a preset of the opening angle dependent on a higher dynamic pressure or a lower dynamic pressure being exerted on the retention flap. The transmission comprises a transmission device which limits an opening angle of the retention flap.

Description:
CROSS REFERENCE TO PRIOR APPLICATIONS 
       [0001]    This application is a U.S. National Phase application under 35 U.S.C. §371 of International Application No. PCT/EP2015/055031, filed on Mar. 11, 2015 and which claims benefit to German Patent Application No. 10 2014 106 407.0, filed on May 7, 2014. The International Application was published in German on Nov. 12, 2015 as WO 2015/169483 A1 under PCT Article 21(2). 
     
    
     FIELD 
       [0002]    The present invention relates to a compressor arrangement for the automatic compressing of ground coffee, the compressor arrangement having a first housing which has an inlet opening and an outlet opening, wherein conveying and compressing elements are provided in the housing which are drivable by at least one first drive device, wherein the outlet opening has a retention flap which serves to adjust the bulk density of the ground coffee, wherein an adjustment device is provided via which a pre-adjustment of the bulk density can be adjusted. 
       BACKGROUND 
       [0003]    Compressor arrangements are well known from the prior art. DE 197 18 455 A1, for example, describes a compressor arrangement wherein the ground coffee from a grinder is compressed according to specifications regarding filling weight and filling volume. The ground coffee to be filled must thereby have a defined bulk density (gram per cm 3 ). For this purpose, the compressor arrangement of DE 197 18 455 A1 has a retention flap at an outlet opening of the compressor arrangement which can be adjusted with an opening angle from 0° to 90° depending on the desired bulk density. A measuring means for the bulk density or the degree of compaction is provided in the region of the outlet opening so that a regulation is possible via an adjustment of the retention flap. 
         [0004]    The above-described arrangement of the measuring device in the region of the outlet opening is complicated and is therefore costly and susceptible to failure. Sudden variations in the quantity of ground coffee in the compressor which are caused, for example, by ground coffee slipping from side walls of the compressor trough, cannot be further compensated for so that overload damage to the first drive device may result. 
       SUMMARY 
       [0005]    An aspect of the present invention is to provide a compressor arrangement for the automatic compression of ground coffee which avoids the above disadvantages in an economic and simple manner. 
         [0006]    In an embodiment, the present invention provides a compressor arrangement for automatically compressing ground coffee which includes a first housing comprising an inlet opening and an outlet opening which comprises a retention flap configured to adjust a bulk density of the ground coffee, a first drive device, conveying and compressing elements arranged in the first housing, the conveying and compressing elements being configured to be driven by the first drive device, and an adjustment device configured to provide a pre-adjustment of the bulk density of the ground coffee. The adjustment device comprises a second drive device, a retention flap shaft, a retention flap arranged on the retention flap shaft, a transmission which is operatively connected to each of the second drive device and the retention flap shaft, and an automatic dynamic pressure adjustment apparatus configured to enlarge or reduce a preset of the opening angle dependent on a higher dynamic pressure or a lower dynamic pressure being exerted on the retention flap. The transmission comprises a transmission device configured to limit an opening angle of the retention flap. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The present invention is described in greater detail below on the basis of embodiments and of the drawings in which: 
           [0008]      FIG. 1  shows a perspective arrangement of the compressor arrangement of the present invention; 
           [0009]      FIG. 2  shows is a partially cut side view of an adjustment device of the compressor arrangement of  FIG. 1  in a first adjustment position; and 
           [0010]      FIG. 3  shows the adjustment device of the compressor arrangement of  FIG. 1  in a second adjustment position. 
       
    
    
     DETAILED DESCRIPTION 
       [0011]    In an embodiment of the present invention, the adjustment device comprises a second drive device operatively connected with a transmission which is operatively connected to a retention flap shaft on which the retention flap is arranged so that the transmission can enable a limiting of the opening angle of the retention flap, and wherein an automatic dynamic pressure adjustment apparatus is provided which, in the case of a higher or lower dynamic pressure being exerted on the retention flap, enables an enlarging or reducing of the preset opening angle. The retention flap is thus no longer preset to a defined angle but may be pivoted up to a certain predefined opening angle. A short-term exceeding or undershooting of the ground coffee quantity, and thus an increase or decrease in the dynamic pressure acting on the retention flap, can be compensated in a simple manner via the mechanical dynamic pressure adjustment apparatus. The retention flap may thereafter be pivoted back to the preset opening angle. A measuring device in the region of the outlet opening is therefore no longer required. 
         [0012]    In an embodiment of the present invention, the transmission can, for example, be a worm gear with a worm shaft and a worm wheel, wherein a transmission housing part is provided which is rotatably supported on the retention flap shaft and in which the worm shaft is supported on the retention flap shaft for rotation therewith so that a rotation of the worm shaft allows a rotation of the transmission housing part around the worm wheel, and wherein the transmission housing part has a defined weight assigned thereto that allows the pre-adjustment of the desired opening angle. A pre-adjustment of the maximum opening angle of the retention flap is thereby provided in a particularly simple manner, wherein the mechanical dynamic pressure adjustment apparatus is realized by the transmission and the transmission housing part with the associated weight so that, in case an adjustment of the preset opening angle is required, the retention flap shaft may pivot with the transmission housing part via the transmission. It is possible to obtain the desired bulk density due to the weight adjustment. It should be noted that the term “preset opening angle” is understood as the opening angle the retention flap assumes when a dynamic pressure is applied. The retention flap is thus closed in the deactivated state of the compressor arrangement. It is thereby of course possible, based on knowledge of the machine-specific data of the respective compressor arrangement, such as output, dimensions etc., to store weights as data in combination with a respective opening angle and thus a desired bulk density and to thereby provide a simple adjustment. 
         [0013]    In an embodiment of the present invention, a weight element can, for example, be provided that is connected with the transmission housing part via a lever arrangement. A different moment acts on the retention flap shaft via a simple turning of the lever, whereby a different force also acts on the retention flap shaft, whereby the retention flap opens wider or narrower due to the dynamic pressure prevailing. It is thereby conceivable to adjustably arrange the weight element at the lever arrangement so that the compressor arrangement has a greater flexibility and the adjustment range is enlarged. 
         [0014]    An inadvertent adjustment, for example, due to a malfunction of the second drive device, is prevented in a simple manner because the worm wheel may have a circular segment-shaped groove element into which a pin element engages which in turn is supported in the transmission housing part so that the rotation of the transmission housing part during the pre-adjustment is limited by a first and a second end of the groove element. 
         [0015]    In an embodiment of the present invention, the maximum opening angle of the retention flap can, for example, be limited by a stop element that cooperates with the retention flap shaft. 
         [0016]    In an embodiment of the present invention, the second drive device can, for example, be operatively connected with the transmission via a coupling which may, for example, be designed as a releasable coupling. 
         [0017]    In an embodiment of the present invention, the second drive device can, for example, be an electric machine, in particular a stepper motor. To allow a simple representation of the preset opening angle, for example, on a display, the adjustment device may comprise a sensor element to monitor the position of the retention flap shaft. This may be performed directly or indirectly, for example, by a phase shift of the transmission. 
         [0018]    The present invention will be explained in detail below with reference to the drawings. 
         [0019]      FIG. 1  is a perspective view of a compressor arrangement  2  of the present invention for the automatic compression of ground coffee. The compressor arrangement  2  has a housing  4  substantially comprised of a plurality of housing parts  6 ,  8 ,  10 , which may in turn be of a multi-part design. The first housing part  6  is trough-shaped and has an inlet opening  12  which, in a manner known per se, adjoins a grinder (which is not illustrated in detail herein). A screw conveyor (not illustrated in detail herein) may be arranged in the first housing part  6  to convey the ground coffee on to the second housing part  8  in which a turbo mixer (not illustrated in detail herein) is arranged to homogeneously distribute coffee skins and to compress the ground coffee. The screw conveyor and the turbo mixer are connected in a manner known per se with a first drive device (not illustrated in detail herein). The ground coffee is compressed by the turbo mixer in the direction of an outlet opening  14  provided in the second housing part  8 , the outlet opening  14  being adjoined by a retention flap  16 . The retention flap  16  is hinged to a retention flap shaft  18  which in turn is operatively connected with an adjustment device  20  which has a transmission housing part as the third housing part  10 . The retention flap  16  closes the outlet opening  14  in the non-actuated state of the compressor arrangement  2 . As will be explained in more detail hereinafter with reference to  FIGS. 2 and 3 , the adjustment device  20  allows a pre-adjustment of the opening angle of the retention flap  16 , whereby an adjustment of the bulk density of the ground coffee becomes possible. 
         [0020]      FIG. 2  shows a sectional view of the adjustment device  20 . The adjustment device  20  has a second drive device  22  operatively connected with a worm shaft  26  of a worm gear  28  via a coupling  24 . In a manner known per se, the worm gear  28  comprises a worm wheel  30  supported on the retention flap shaft  18  for rotation therewith. The worm shaft  26  is rotatably supported in the transmission housing part  10 , wherein the transmission housing part  10  is rotatably supported on the retention flap shaft  18 . The worm wheel  30  also has a continuous, circular segment-shaped groove element  32  into or through which a pin element  34  engages that is fixedly connected with the transmission housing part  10 . The angle of the circular segment of the groove element  32  is chosen to be larger than the adjustment angle of the adjustment device  20  as explained below. In the present case, the angle of the circular segment is about 140°. The groove element  32  with the engaging pin element  34  prevents an inadvertent adjustment of the adjustment device  20  beyond the adjustment angle. The groove element  32  has a first end  36  and a second end  38  for this purpose. The transmission housing part  10  has a weight element  40  assigned thereto which is connected with the transmission housing part  10  via a lever arrangement  42  (see  FIG. 3 ). The maximum opening angle of the retention flap  16  is further limited by a stop element (not illustrated in detail herein) which cooperates with the retention flap shaft  18 . 
         [0021]    The second drive device  22  is actuated for pre-adjustment. At that moment, the retention flap  16  closes the outlet opening  14  and cannot deflect in this direction so that the retention flap shaft  18 , and thus the worm wheel  30 , do not move. The worm shaft  26  and thus the transmission housing part  10  consequently move in a clockwise direction about the worm shaft  26 , whereby the weight element  40  is adjusted on the circular path indicated. The weight force acting in the vertical downward direction is thereby associated with a variable lever which causes a variable moment to act on the retention flap shaft  18 , and thus causes a variable force to act on the retention flap  16 . In  FIG. 2 , the preset position is chosen so that a great lever acts on the weight element  40  and thus a great force acts on the retention flap  16 . A bulk density can thereby be achieved that is at about 90% of the maximum compression. 
         [0022]    When the first drive device of the compressor arrangement  2  is activated and the ground coffee is conveyed in a compressed state towards the outlet opening  14 , a dynamic pressure is built in the region of the outlet opening  14  which eventually causes the retention flap  16  to open, whereby the retention flap shaft  18  turns the worm wheel  30  and thereby the entire adjustment device  20 , formed by the transmission/worm gear  28 , the transmission housing part  10 , the weight element  40 , and the second drive device  22 , is turned counterclockwise. In case of short-term variations of the ground coffee quantity, the dynamic pressure on the retention flap  16  will increase or decrease, which is compensated by an automatic shifting of the weight element  40 . The entire adjustment device  20  forms the mechanical automatic dynamic pressure adjustment arrangement in the present embodiment. 
         [0023]    The adjustment device  20  will subsequently pivot back into the preset position due to the weight force of the weight element  40 . 
         [0024]      FIG. 3  illustrates the adjustment device  20  in a side view, wherein the adjustment device  20  is pivoted by an angle of about 45% and thus causes a compression of about 45% of the maximum compression. The lever element  42 , via which the weight element  40  is hinged to the transmission housing part  10 , is also clearly visible. Reference numeral  44  denotes a sensor element, for example, a Hall sensor, which detects the pivot angle of the retention flap shaft  18  and thus monitors the opening angle of the retention flap  16 . The second drive device  22  is designed as a stepper motor in the shown embodiment. 
         [0025]    It should be clear that a variety of possible embodiments are conceivable, in particular with regard to the design of the transmission, all of which fall within the scope of protection of the present invention. Reference should also be had to the appended claims.