GB2149640A - Improvements in cheese manufacture - Google Patents

Abstract

A cheese mould (1) has sides hinged to its bottom and is held within a frame (2). Guide rods on the frame cause the walls to pivot outwards as the mould is pressed partially out of the frame. The mould may be used in a processing plan incorporating a turntable capable of being indexed about a vertical axis. The turntable has vertical stacks of horizontal cylinders in which the moulds are stored under vacuum and mechanically applied pressure to promote setting of the cheese. Also disclosed are apparatus for filling the mould with curd, cheese cutting apparatus (fig. 14) and a mould lid application device. <IMAGE>

Description

SPECIFICATION Improvements in cheese manufacture In the conventional manufacture of cheese, a box-like mould is filled with curd, pressed and allowed to stand. Afterthe cheese has set, the mould is inverted and the cheese ejected, possibly by applying pressuretoa separate bottom ofthe mould. The mould is necessarily provided with drain holesforthe whey. In between successive moulding operations it is necessary to clean the mould. The known constructions of mould are difficultto clean. One attempted solution is that described in British patent number 1 421 528, in which the drain holes open into large diameter bores in the outer surface ofthe mould wall.

Even so, it is difficult to clear accumulations of whey from these bores, from the internal corners of the mould, particularly around the separate bottom, and from between the mould and itssupportframework.

In order to automate the production process to the maximum, it is necessaryforthe mould to be so designed that it may be cleaned efficiently and quickly.

The solution to this problem herein proposed is for the sides of the mould to be hinged to its base and to be partially extractable from the mould supportframe.

In this position the sides move apartto facilitate removal of the cheese and cleaning.

It is known from WO Pu blication N u m ber A82/01 976 to leave a group of moulds within a horizontal tube-like chamber of rectangular cross-section while the cheese is allowed to set. The chamber may be evacuated and pressure applied to the mould to promote the setting ofthe cheese. A plurality of such chambers may be mounted on the arms of a star wheel. As the star wheel is rotated about a horizontal axis, each chamber in turn is brought into a loading station in which it is charged with moulds. Following repeated indexing of the starwheel, each chamber come into an unloading station atwhich the moulds are removed. A problem with this arrangement isthat the loading applied bythefull chambers to the star wheel tends to distortthe shaft on which it rotates.As a resu It, the capacity ofthe star wheel is very limited compared with the spacewhich it occupies.

A second, and indepedent, proposal made herein is to usethe mould described above, or any other suitable mould, in a cheese manufacturing plant in which the filled moulds are supplied to, and stored in, horizontally extending chambers mounted on a turntable which is indexed about a vertical axis while the cheese sets. The advantage ofthis arrangement is the considerable quantity of cheese which may be pressed and subjected to vacuum compared with the known arrangement.

In order to produce finished cheeses of constant size and weight, it is necessary to fill each mould with a very accurate quantity of curd. The need to meterthe flow of curd accurately into each mould while it remains stationary at a filling station leads to delays in the production process.

This problem is overcome by a third, and independent, proposal made herein. Two moulds are disposed simultaneously at the filling station and curd is fed at a high rate into a first hopper until the weight of curd dispensed is slightly less than the desired weight.

Curd is then fed to a second hopper at a high rate while curd is fed at a much lower rate into the first hopper to bring its weight exactly upto that desired. A door is then opened in the first hopper to dump the curd into the mould beneath it. When the second hopper is nearlyfull, the rate of feed to it is reduced and curd is fed at a high rate into the first hopper.

These and other proposals will appear more clearly from the following description to be read in conjunction with the diagrammatic drawings, in which: Figure lisa perspective, exploded view of the proposed mould and its frame, Figure 2 is a vertical section through the assembled mould and frame, Figure 3 is a sectioned plan view of a corner of the mould, Figure 4 is a plan view of a cheese processing plant in which the mould may be used, the plant utilising a turntable on which mould storage chambers are mounted, Figures 5 is a side view ofthe plant, looking in the directionofarrowVin Figure4, Figure 6 is a side view ofthe plant looking in the direction of arrow Vl in Figure 4, Figure 7 is an end view of the mould filling apparatus, Figure8showsthe mould lid application apparatus, Figure 9 shows the apparatus for loading moulds into the chambers of the turntable, Figure loins a detail of the turntable in Figure 4 showing a group of chambers, Figure 11 shows a vertical row of chambers, Figure 12showsthe lid removal apparatus, Figure 13 shows the cheese removal apparatus, and Figure 14shows a cheese destacker.

Referring to Figures 1 to 3, a cheese mould 1 is normally housed within a frame 2, both parts being shown inverted. The mould has a lide, not shown in these Figures. In Figure 1, the mould is shown separated from the frame for the purposes of illustration. The mould has a bottom la and side walls 1 b which are moulded from plastics and have rows of drain holes passing throughthem.The bottom and walls may have rows of grooves throughout the area oftheirinnersurfaces.

The vertical edges of the side walls are castellated, the projections 1 on one edge interfitting with those an the other when the edges are broughttogether from the exploded position in Figure 1. The edges of the bottom are likewise castellated, the projections 1 d passing through slots 1 e in the side walls. The bottom is fitted with vertical brackets 1f having bores for pivotal hook-like links 1 g.

The frame 2 is constructed from interwelded components and has upper and lower rim members 2a, 2b joined together by struts 2c, which are themselves interconnected by braces 2d. Welded to the lower rim 2b is a base member 2e, opposite sides of which arejoined by cross pieces 2f having slots 29 for receiving the links 1 g. In the assembled structure, the mould bottom is suspended from the frame base memberbythe links so asto be movable between a retracted position wholly enclosed with in the frame member and the partially extracted position shown in Figure 2. At each of the corners oftheframe are guides formed by rods 2h.The rods at each corner arse inclined slightly outwards from the vertical centre line ofthe mould and define a groove which receives the castellated edges of the mould walls, the rods thereby holding the sidewalls of the mould in slightly inclined positions. During movement ofthe mould from the retracted to the partially extracted position, the castellated edges of the mould slide in the inclined grooves defined bythe rods, and the side walls are spread apart, thereby promoting the removal ofthe cheese. Thorough cleaning of the mould is also possible because the mating edges ofthe mould are seperated and the mould is partly clear of its frame.

The drain holes in the side walls and bottom taper towards the outer side ofthe wall or bottom as the case may be. The angle of taper may be so small as not to be discernableto the naked eye, and the holes may be formed either by passing the mould panels through an industrial sewing machine or by laser punching.

Conventional moulds may be provided with drain holes formed in this way. Tapering drain holes may be cleaned readily and may be produced more cheaply than the stepped holes disclosed in British Patent No.

1 421 528.

Moulds ofthis construction may be used in the plant shown in Figures 4,5 and 6. Considering briefly each ofthe stations indicated in the Figure, the plant comprises a washer 10 from which the moulds (each supported by its frame) are supplied to a lower conveyor 11, and from which separate mould lids are supplied to an upper conveyor 12. The moulds are initially in their inverted positions, projecting from the frames as shown in Figure 2. The moulds and frames are turned upright in a rotator 13, pushed fully home into theirframes in a tamping station 14, and filled with curd in a filling station 15. In the following, a mould and frame assembly will be referred to for convenience as a mould.Afterthe curd has been subjected to pressing operations in the pressing stations 16, a lid is applied in station 17 and pressed down inthestations 18. During the various pressing operations, the whey escapes through the drain holes.

Thefilled moulds are transported bya conveyor 19 to a loading station 20which introduces each mould into one of a number of separate, horizontal chambers 21a of a turntable 21. Each chamber is capable of being hermetically sealed and is equipped with rams for applying pressureto the moulds within it. The chambers are arranged in vertical rows and the turntable is indexed each timethat a vertical row is filled with moulds. As the row of chambers mobes out ofthe loading staton the chambers are evacuated and the rams actuated. Atmospheric pressure is restored and the rams retracted before the row of chambers enters an unloading station atwhich the moulds are extracted.

The moulds leaving the turntable are conveyed along a conveyor 23 to a station 24 at which the lids are removed and fed by conveyor 25 to the washer. Each mould is inverted in rotator 26 and pressed downwards relativeto its frame in a pressing station 27 so as to ejectthe cheese, which is conveyed away by a slat band conveyor 28. The mould, partially extended from its frame is fed by the conveyor 29 to the washer.

As well as or instead of being washed, the moulds may be vibrated ultrasonically in the washerto improve their cleaning.

Considering now certain ofthe individual stations: the mould filling station is shown in Figures 5 and 6 and in more detail in Figure 7, which is a view looking along the conveyor in the direction of mould travel.

Two tubes 15a, 15b extend parallel to each other and generally perpendicularto the conveyor 11. Each tube houses a feed screwformed buy a ribbonlike metal flight 1 sic spaced from and extending helically around a shaft 15e, being supported therefrom by radial struts 15d. An outlet 15f at the downstream end of each tube opens above a respective hopper 15g or 1 Sh, the bottom ofwhich is closed bydoors controlled by piston and cylinder units. Below the hoppers are frusto-pyramidal guide 15i, 15j respectively, each of which is movable under the action of a respective cylinder 15k between the upper position shown and a lower position for guiding curd into a mould 1.

A curd supply duct is bifurcated and has its limbs 151,1 sum connected to the inlets ofthetubes 1 5a, 1 5b respectively. Avalve at the point of bifurcation is movable to connect one or other ofthe duct limbs to a source of curd. Each ofthefeed screws is drivable at a higher speed for coarse filling and at a lower speed for fine filling ofthe associated hopper.

Moulds are conveyed along thetrackthrough the station by reciprocating pawls. In operation, two moulds indicated A and B are advanced simultaneously into the positions shown in broken lines in Figure 6 and the guides 15i, 15j lowered. The curd supply valve is positioned to divert curd to one of the feed tubes, saytothetube 15a,thescrewofwhich is driven at the higher speed. A load cell associated with the hopper 159 generates a signal when the quantity of curd received is slightly below that needed to fill the mould to the desired level. The coarsefilling operation of this hopper having now been completed,thevalve is reset and the speed of the feed screw oftube 1 5b reduced.

Simultaneously, the speed of the screw of tube 1 5b is increased and coarse filling ofthe second hopper 1 5h begins. The residue of curd within tube 1 5a is fed slowly into the hopper 1 sag until the load cell generates a signal indicating that the hopper is full.The hopper doors are now opened to discharge the curd byway af the lowered guide 15i. The hopper 15h now receives a coarse quantity of curd, whereupon the valve is reset, and the screw speeds re-adjusted, so thattheflrst hopper 15g begins to receive its coarse quantity of curd. Following fine filling of the second hopper, its contents are discharged,the guides are raised and the filled moulds moved on, and replaced by empty ones.

Referring nowto Figure 8,themould lid application station 17 comprises a shaft 17a, movable vertically by a piston and cylinder unit. Projecting from the shaft are arms 17b which carry channel sectioned guides 17cfromwhich pins 17d project into slots 17eofframe members 17f. A plunger 179 is mounted atthe lower end oftheshaft. In preparationforapplying a lid, the piston and cylinder unit is retracted to raise the shaft 17a. A lid is pushed by a ram from the conveyor 12 (which is at a higher level than conveyor 11) into the channel section guides 17c. With a mould in place in the station, the shaft 17a is made to descend.The pins 1 7d slide in the slots 17e until they reach the lower ends ofthe slots whereupon they are compelled to halt, causing the guides to swivel apart and release the lid, which is pressed bythe plunger into the the mould.

Optionally, a cylinder 15A may be used to move a stationary cutter into a position at the end ofthe screw in orderto breakdown orshred the curd.

Theturntable loading station 20 shown in Figure 9 comprises vertically extending endless chains 20a provided with mould support brackets 20b. The chains are circulated by sprockets mounted in frame members 20c (Figure 5). Atthe level of each chamber 21 a in the turntable is a trackway 20c pivoted about an axis 20d and suspended by inclined rods 20e which permit the trackway section some vertical freedom of movementto permit fine adjustment of the section relative to the chambers of the turntable, as will be described later. A ram 20f servestotransfer mouldsfrom the vertical conveyor onto the track and into the mould.

The construction ofthe unloading station 22 is similar to that of the loading station, eceptthatthe ram 20f is replaced byan arm provided with a hook capable of retracting each mould from the chamber. The moulds may have interlocking fitments, and the track leading from the chamberto thevertical conveyor may have a hump (depicted at 22a in Figure 9) to effect disengagement of one mould from the next as it is drawn out of the chamber.

The tu rntable 27 hasa latticeframework21e supported on wheels guided on a circulartrackway.

The framework defines locations fortwentyfour vertical rows of six cylindrical chambers 21 a each with a door 21 b.To makethe maximum use of space, the chambers are alternately long and short, each long chamber being paired with an adjacent short one with regard to the ducting arrangement illustrated in Figure 11. Theverticalframe members accommodate or serve as ducts, members 21f serving to connectthe chambers alternatively to a vacuum pump dedicated to one long and one short row, orto a source of cleaning fluid, and members 21 g serving to connect the same chambers to drain. Each long chamber accommodates six moulds, and each short chamber accommodatesthree moulds.

Each chamber 21 a is a thin walled metal cylinder, having ribs 21 cformed by swaging. An internal guide rack 21 h forms a continuation of the external track 20c atthe loading station. A pneumatic cylinder located above each position to be occupied by a mould operates to press down on to the mould whilst the pressure within the chamber is reduced to a desired level.

Located at each ofthevarious levels of chambers is a cam 209 in the form of an arcuate rod which slopes upwards atthe entry to the unloading station and slopes downwards atthe exittothe loading station.

The lid of each mould has a roller21iwhich comes into contact with the cam and is lifted thereby to open the lid, and hold it open while the chamber is in or between the loading and unloading stations. The lid of each chamber (except the uppermost ones) has a second roller 21 j which engages the track section 20c of the next above chamber to position it correctly for alignmentwith the track 21 h, this action taking place in both the loading and unloading stations.

Between the loading and unloading stations is a cleaning station 30. The row of chambers in this station have cleaning liquid passed through them by way of the duct 21f, the liquid and any accumulated whey escaping through the duct 219.

The lid removal station 24 is shown in Figure 12. It comprises a shaft 24a carrying channel sectional receptacles 24b.The shaft is initially in a lowered position so that projecting flanges on a mould lid slide into the receptacles as the mould arrives at the station.

The shaft is then raised to the level of conveyor 25 and the lid ejected by a ram 24c. The mould is then inverted and propelled to the cheese removal station 26 shown in Figure 13. A vertically movable shaft 26a bears a receptacle 26b which receives the mould and raises it to the illustrated position. Piston and cylinder units 26e press the mould out of its frame (into the Figure 2 position) to ejectthe cheese onto the slat bank conveyor28.Themouldisthen raised onto the conveyor 29.

Referring to Figure 14thefinished blockofcheese may be subdivided into four pieces by cutting station 31 including a pusher31a advanced bya ram and having a group of four, vertically and laterally spaced piston and cylinder units 31 b. The pusher advances the blockthrough a cruciform cutter 31 cfollowed buy a support and guide 31 d likewise in the form of a cross having an upright 31 e and cross piece 31f. The support and cutter assembly is adjusted in height in dependence on thethickness ofthe block, using afeeler31g which raises or lowers the assembly byway of a linkage 31 h. A conveyor 31 c may be raised to receive thetwo upper pieces of cheese which are pushed onto it one afterthe other using the upper units 31 b, and then loweredto receive the lower pieces which are pushed onto it using the lower units. The piece are thustransported away on the conveyor31c ata convenient distance from each other.

Claims (12)

1. A cheese mould assembly comprising a box-like mould having sides hinged to a bottom, and a support frame within which the mould is movable between retracted and extended positions, the sides being pivoted outwards to promote removal of the moulded product as the mould moves towards its extended position.

2. A mould assembly as claimed in claim 1, wherein the sides ofthe mould have interfitting castellated edges received within guides which urge the sides outwards during such movement.

3. A mould assembly as claimed in claim 2, wherein the guides are formed by rods extending between upper and lower members of the frame, the rods being inclined relative to the normal.

4. A mould assembly as claimed in claim 1, wherein the walls of the mould have outwardly tapering drain holes.

5. A cheese moulding plant including a turntable rotatable about a vertical axis and provided with horizontal chambers, each equipped with a door, a loading conveyorforfeeding moulds into the cham bersata loading station, rams for applying pressure to each mould with the chambers, means for indexing the turntable, and an unloading conveyorforextracting moulds from the chambers at an unloading station.

6. A plant as claimed in claim 5, wherein long and short cylindrical chambers are arranged alternatingly around the circumference oftheturntable, in vertically extending rows.

7. A plant as claimed in claim 5, wherein cam members are arranged at the loading and unloading stations and engage followers on doors ofthe chambers for opening and closing the doors.

8. A plant as claimed in claim 7, wherein the positions of track sections along which moulds are fed to the chambers are adjusted in height by means on the doors.

9. A cheese moulding plant including a mould filling station comprising a conveyorfor positioning two moulds at locations within the station, a hopper at each location, feed means for feeding curd to each hopper, the feed means being alternately operable art a higher and a lower rate, and divertervalve means operable to supply curd to the feed means operating at the higher rate.

10. Acheesecutting apparatus comprising an assembly including a cutter and cruciform support, a pusherforadvancing a block of cheese into contact with the cutter such that the cut pieces pass onto the support, a conveyor movable vertically to receive pieces from the support at an upper and lower level, the pusher including individually operated ram means for displacing pieces from the support onto the conveyor.

11. A cheese processing plant including a mould lid application device comprising a vertical shaft, a pusheratthe lowerendoftheshaft,channel- sectioned lid suports supported from the shaft, means forlowering the shaftfrom a lid receiving position to a lid releasing position, and cam means operable to tilt the lid supports in the lower position.

12. A method of making cheese, comprising dispensing curd into a mould, feeding the mould into a horizontal, cylindrical chamberata loadingstaton, closing the chamber and evacuating air therefrom, applying mechanical pressure to the mould, opening the chamberand withdrawing the mould atan unloading staton, wherein the chamber is transported between the two stations on a turntable rotatable about a vertical axis.