Patent Publication Number: US-2019191659-A1

Title: Press cover

Description:
FIELD OF THE INVENTION 
     The invention concerns a press cover that corresponds with a cheese mould, in particular a cheese mould that is arranged in a cassette press or similar. 
     BACKGROUND 
     A device for the industrial production of cheeses is of known art, for example, from EP-A-350777. This comprises a cheese press with a rectangular tray open at the top for the reception of moulds, a pillar frame for the arrangement of a compression head that can be raised and lowered, and a distribution head for the supply and metering of the curds into the moulds, and a portal carriage that can travel on the tray for purposes of guiding the distribution head and manipulating a turning mechanism for the moulds. Here the distribution head and the turning mechanism must be provided or changed manually. The wall of the mould consists of a perforated plate, and a plurality of moulds can be arranged in sets. The end surfaces of a set are provided with cylindrical pins for purposes of docking a manipulation device. 
     EP-A-406899 shows a development of such a device, in which the moulds are accommodated in cassettes, which in turn are arranged compactly in rows in the tray. Above the moulds a compression head is provided, with compression plungers aligned with the moulds for purposes of compressing the curds. 
     Here the actual press mould is surrounded by a cup-shaped casing with an air supply passage (EP-B-1269832). By this means an air passage is formed, and the air supplied can loosen the cheese mass adhering to the sieve holes of the perforated plate of the mould from the pressing hoop side after compression. 
     According to EP-B-543185, a mould or press cover can be connected to the compression plunger via a tilting device (self-centring), so that the mould cover is prevented from being sucked into the cheese mass as a consequence of any tilting movements. The mould itself is round or square and can consist of an outer container and an inner perforated casing. 
     BR 9300409 discloses a double-walled mould, which is provided with ribs crossing on its floor. However, these ribs serve only as a stop for a floor plate and are unsuitable as stiffening elements, and also are not intended for this purpose. 
     U.S. Pat. No. 3,838,955A discloses a mould for the production of cheddar, which has a mould and a press cover. The mould, and in particular the press cover, are of a solid design. The press cover and the floor of the mould are provided with a few holes  5  for the outflow of whey. The press cover is constructed in the form of a plate and consists of PP or PE. It provided with a raised solid flange, which has eyelets for purposes of suspension. The plate-form press cover is provided with a second, significantly thinner perforated plate facing the mould for the removal of whey from the cheese mass. 
     In order to achieve the required dimensional stability when pressing out the whey, such plate-form plastic press covers have a thickness of approx. 10 mm. 
     Another cheese mould with a perforated metal mould wall is disclosed in DE-B-1030612. The internal surface of this mould wall has evenly distributed, low elevations and depressions of up to approx. 1 mm, which are designed so as not to damage the rind when the cheese wheel is removed, even if the cheese is knocked out of the mould. 
     According to DE-C-2823182, such a cheese mould with perforated walls can also consist of plastic, the internal face of which is provided with parallel grooves with a triangular cross-section. In the transition region and one-piece floor region, the grooves are separated by ribs with interruptions. Mould walls or double floors of this type are time-consuming to clean. 
     SUMMARY 
     One aspect of the invention relates to a press cover that corresponds to a cheese mould, and which is suitable for arrangement on the compression head of a cassette press or similar, is simply constructed, withstands a compression pressure, and also satisfies high hygienic standards. 
     In one embodiment of the invention, the press cover essentially comprises a one-piece perforated plate, whose cross-section corresponds to the internal cross-section of a cheese mould, with which the press cover corresponds in normal use, with a ribbed structure integrally formed thereon, which imparts the necessary dimensional stability and rigidity to the press cover. 
     The press cover is manufactured in one piece, for example by milling out of a plate, or by 3D printing. 
     On the one hand the inventive press cover enables a good whey outflow, and on the other hand can be easily and completely cleaned on both sides. 
     The inventive press cover is produced in one piece in one operation from a food-approved plastic, for example from PE or PP. 
     Preferred embodiments are also disclosed. 
     The perforated plate preferably has a thickness of approx. 3-5 mm and is provided with a perforation pattern, except for the regions below the ribbed structure, which remain non-perforated. The hole diameter of the perforation pattern is preferably 0.4-1.0 mm. Smaller hole diameters are less easy to clean. The individual holes are arranged at a distance of 2-5 mm from each other. 
     In the case of round cheese moulds, individual ribs in the form of struts extend over the centre of the press cover, preferably radially from the longitudinal axis of the cheese mould over the perforated plate to the circumference. They thereby cross annular transverse ribs and are connected to the latter, wherein a plurality of rings with different diameters can be provided, spaced apart from each other. In the case of polygonal cheese moulds, struts parallel to the outer edges are also possible instead of the rings. 
     The ribbed structure also has upwardly directed eyelets or similar, which enable the press cover to be arranged, for example, on a compression plunger. 
     The inventive press cover can be embodied with any cross-section, in particular a round or square cross-section. However, special shapes, such as a heart-shaped cross-section, would also be possible. 
     The ribbed structure can also accordingly be applied to shapes of any cross-section, in particular to round and rectangular shapes, with appropriate adaptations. 
     The ribs are dimensioned such that the external dimensions of existing cassettes can remain unchanged for the accommodation of cheese moulds. 
     Such shaping, choice of materials and production methods do not obviously ensue from the prior art. Press covers of previous known art, on the other hand, consist, for example, of a rigid cover plate made of steel or plastic, the shape and dimensions of which correspond to the internal cross-section of a cheese mould, and a thin perforated plate arranged on the underside of the cover plate. The cover plate also has a number of larger openings for the outflow of whey when pressing the curds. 
     In the non-perforated regions of the cover plate of the prior art, whey and cheese residues or other impurities can accumulate, which are invisible and can only be removed with difficulty. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In what follows the invention will be described in more detail in an example of embodiment. In the figures: 
         FIG. 1 : shows an inventive press cover; 
         FIG. 2 : shows the press cover from  FIG. 1  in a side view, and 
         FIG. 3 : shows the press cover from  FIG. 1  in a plan view. 
     
    
    
     DETAILED DESCRIPTION 
     An inventive press cover  1  ( FIG. 1 ) made of PE, in the example of a round cheese mould, comprises a single-walled, circular perforated plate  10 , the cross-section of which corresponds to the internal cross-section of the cheese mould (also circular). 
     On the perforated plate  10 , on the side facing away from the cheese mould, a stiffening ribbed structure  12 ,  13  is integrally formed, which gives the press cover  1  the necessary stiffness for pressing out the whey. The ribbed structure  12 ,  13  comprises webs  13  (longitudinal ribs) and rings  12  (transverse ribs) arranged annularly. The webs  13  extend over the centre of the press cover, preferably radially from the centre or longitudinal axis of the cheese mould over the perforated plate  10  to the circumference of the perforated plate  10 . They thereby cross the annularly arranged rings  12  and are connected to the latter at the crossing points, wherein a plurality of rings  12  with different diameters can be provided, spaced apart from each other. 
     In the example, the perforated plate has a wall thickness (thickness) of approx. 3 mm and is provided on the circumference with a rim  14  facing towards the cheese mould ( FIG. 2 ). In the example, the said rim  14  is flexible and fits closely against the internal wall of the cheese mould when the whey is being pressed out. With the exception of the ribbed structure  12 ,  13 , the perforated plate  10  is provided with a perforation pattern  11  (shown in an exemplary form in  FIGS. 1 and 3 ). The regions below the ribbed structure  12 ,  13  remain non-perforated. The hole diameter is 0.4-1.0 mm. Smaller hole diameters can cause problems during cleaning; hole diameters larger than 1 mm are not necessary for a good whey outflow. 
     The rings  12  are provided with openings  16  between two webs  13  for the outflow of liquids. 
     In the example, three hooks  15  are also welded to the webs  13  for arrangement on a compression plunger. 
     The inventive press cover  1  is produced in one piece; in the example it is milled out of the solid from a plate of PE (or another food-approved plastic). The perforated plate  10  and the ribbed structure  12 ,  13  are thus connected to each other in a materially-bonded and form-fit manner, inseparably and without connecting elements. This ensures on the one hand a high dimensional stability, and on the other hand a very good cleanability. There are no gaps or similar in which cheese mass or dirt could collect. 
     No perforation pattern  11  is provided in the vicinity of the ribbed structures  12 ,  13 , which further improves the hygiene of the press cover  1 . 
     Instead of production of the press cover  1  by machining, the latter could also be produced in a 3D-printer from a plastic in one piece. However, the perforation pattern  11  would have to be introduced subsequently. 
     A round cheese mould, with which the inventive press cover  1  corresponds, and as disclosed by the applicant, for example, in EP 2845469 A1, comprises a cylindrical casing with an upper basket and a floor. 
     For cheese that is to be highly pressed, i.e. hard cheese, the casing wall and, if necessary, also the floor are made of Conidur® fine perforated sheet. As a result of the specific perforation pattern, the formation of “hairs”, such as occurs with plastic moulds, or normal, thicker perforated sheets, can be avoided. 
     When pressing soft cheese or semi-hard cheese, however, a conventional perforation pattern can be sufficient. The perforated plate below the basket can have a whey rim with a coarser perforation pattern than the rest of the casing, in particular for the production of hard cheese. In the case of softer cheese, a different perforation pattern for the casing is not mandatory. 
     The cheese moulds can in principle also consist of plastic. 
     The cheese moulds are used in cassette presses of known art, which are not shown. Such a cassette press serves, in a manner known per se, for the compression of curds with the reduction of liquid content, and comprises in particular:
         a tray that is rectangular in plan view and open at the top, with cassettes that are rectangular in plan view and open at the top, arranged side by side in rows transverse to the longitudinal direction of the tray,   cheese moulds for the accommodation of the curds to be compressed; these are arranged in the cassettes and have at least a floor and a casing with at least one outlet for the liquid to be pressed out, wherein a cassette comprises at least one cheese mould, and at least the floor of the cheese mould can be provided with a ribbed structure, and wherein the cheese mould can be part of the cassette,   a compression head mounted on end pillars and having a plurality of compression plungers aligned with the cheese moulds, with a press cover  1  located thereon, for compressing the curds, e.g. designed in accordance with the disclosure of EP 543899 B1, and, if required, hold-down means for releasing the compression head from the cassette,   a pipe distribution system or a filling device for filling the curds into the cheese moulds,   at least one manipulation device, which can be traversed along the longitudinal sides of the tray, for purposes of lifting, moving and depositing a cassette onto a conveyor device outside the tray,   a device for rotating/turning the cassette, or row of cassettes, about its longitudinal axis.       

     The cassette press can also preferably be assigned a vibrator in the form of a clamping frame for the accommodation of a cassette; this is arranged horizontally above the conveyor device and is spring-mounted, and is provided with unbalance motors. The cheeses are only emptied onto the conveyor device after being vibrated. 
     LIST OF REFERENCE SYMBOLS 
     
         
           1  Press cover 
           10  Perforated plate 
           11  Perforation pattern 
           12  Transverse rib, ring 
           13  Longitudinal rib, web 
           14  Rim 
           15  Hook, eyelet 
           16  Opening