| 1. | A method of volumetrically filling moulds with a flowable mass, such as ice cream, whereby a first pressure cylinder (9, 10) associated with a filling valve (1 ) is alternately filled with a predetermined volume of the flowable mass and emptied into a mould through the outlet (1 1 ) of the filling valve (1 ), c h a r a c t e r i s e d in that a second pressure cylinder (9, 10) associated with the filling valve (1 ) is filled with a predetermined volume of flowable mass while the contents of the first pressure cylinder (9, 10) is being emptied, and that the second pressure cylinder (9, 10) is emptied through the same outlet (1 1 ) while the first pressure cylinder is being filled again, the emptying period of each pressure cylinder (9, 10) being shorter than or equal to the filling period of each pressure cylinder (9, 10). |
| 2. | An apparatus for carrying out the method as claimed in claim 1 , said apparatus comprising a plurality of filling valves (1 ) with their respective inlet (6) for the feeding of the flowable mass under pressure, and their respective outlet (1 1 ) for volumetrically measured amounts of the mass in question, whereby each filling valve (1 ) is associated with a pressure cylinder (9, 10), which through the valve body (3) of the filling valve (1 ) is adapted to alternately be connected to the inlet (6) and the outlet (1 1 ), c h a r a c t e r i s e d in that each filling valve is associated with at least two pressure cylinders (9, 10), which by means of the valve body (3) of the filling valve (1 ) alternately is connected to the associated inlet (6) and outlet (1 1 ). |
| 3. | An apparatus as claimed in claim 2, and where the filling valves (1 ) comprise a substantially cylindrical housing (2) with a cylindrical valve body (3) pivotally journalled around the axis of said housing (2), said valve body (3) comprising a recess (4, 5) associated with each filling valve (1 ) for establishing either the connection between the inlet (6) and a pressure cylinder (9, 10) or between a pressure cylinder (9, 10) and an outlet (11) by turning the valve body (3) around its central axis, ch a racter i s e d in that two identical pressure cylinders (9, 10) are connected in a symmetrical manner to the valve housing (2) of each filling valve on each side of the inlet (6) thereof, and that the valve body (3) of each filling valve (1) comprises symmetrically shaped recesses (4, 5) on each side of a radial central plane including the axis of rotation, said recesses (4, 5) being adapted by a rotation of the valve body (3) to alternately establish a connection between an inlet (6) and the one pressure cylinder (9, 10) associated therewith and simultaneously a connection between the corresponding second pressure cylinder (9, 10) and the associated outlet (11). |
| 4. | An apparatus as claimed in claim 2 or 3, characterised in that the pressure cylinders (9, 10) are pneumatically driven pistoncylinder units. |
Technical Field
The invention relates to a method of volumetrically filling moulds with a flowable mass, such as ice cream, whereby a first pressure cylinder associated with a filling valve is alternately filled with a predetermined volume of the flowable mass and emptied into the mould through the nozzle of the filling valve. The invention relates furthermore to an apparatus for carrying out the method.
Background Art
It is known to fill moulds accommodated for instance in a rotating mould table with ice cream through filling valves. The ice cream is fed to the filling valves through a piping system extending between a freezer and the mould table. Such filling valves can comprise a pipe with a cylindrical valve body, and a diametrically through opening is provided in said valve body for each filling valve. A 90° reciprocating turning of the valve body about its axis of rotation is controlled by the movement of the mould table and alternately opens and closes for the passage of ice cream to the mould machine. Thus the opened period is mechanically determined by the movement of the mould table and can cause a varying degree of filling in response to the pressure inside the piping system. Another possibility is to allow the passing period to be determined by a weighing of each mould. Both solutions involve unsatisfactory variations in the ice mass in question. The time-controlled opening of the filling valves can involve a varying degree of compression of particulate ingredients in an ice mass, and the necessary interruption of the flow of ice can have the effect that particulate ingredients are compressed into lumps, which occasionally causes a clogging of the piping system. The problems are increasing in
proportion to an increasing particulate size and an increasing amount of the particles.
Attempts have been made at solving these problems by volumetrically filling the ice cream into the moulds. Thus it is known inter alia from Danish printed accepted application No. 161 ,243 to associate each filling valve with a cylinder-piston unit in short referred to as a pressure cylinder below. This pressure cylinder is initially filled with a predetermined volume of the ice mass, whereafter the resulting measured volume of ice mass is pressed out of the pressure cylinder again and fed into the mould. Such a so-called volumetric filling valve solves most of the above problems, but is still, however, encumbered with draw-backs making it unsuited for use in connection with ice cream. All the known volumetric filling valves operate on the basis of a cycle including a filling period and an emptying period, said two periods being clearly separated. The filling is performed in the period including the steps of conveying the cup or the mould to be filled forwards to the filling position, and the emptying is performed in the period where the cup is placed below the nozzle of the filling valve.
In most volumetric filling valves the pressure cylinder is filled from a hopper or a vat by the ice cream being sucked in during the return stroke of the piston of the pressure cylinder, the resulting vacuum causing a sucking of the product into the volumetric pressure cylinder. When an ice cream-mixture is subjected to vacuum, the solid particles contained therein have a tendency to be separated from the fluid with the effect that the mixture is destroyed. The use of a hopper or a vat requires a relatively soft ice cream because it must be capable of freely flowing into the cavity resulting from the retraction of the piston of the pressure cylinder. The required use of a hopper or a vat only increases the problems caused by the vacuum effect on the ice cream.
The removal of the heat from the ice cream is one of the most expensive
steps of the manufacturing process, and said removal is most efficiently performed in the ordinarily used continuously operating freezer. The continuous freezer is one of the most important machines used by the manufacturing process of ice cream because it not only removes most of the heat, but also produces the ideal ice crystal structure. The colder the ice cream is when it leaves the continuous freezer, the less it costs to produce the ice products in question and the better the quality thereof is. Accordingly, it is rather disadvantageous to temporarily store the ice in a hopper or a vat in order to ensure the volumetric filling of the moulds before said ice passes through the filling valves.
Brief Description of the Invention.
The object of the invention is to provide a filling valve allowing a continuous flow of ice cream directly from the freezer through the piping system thereof and to the filling valves.
This object is according to the invention obtained by a second pressure cylinder associated with each filling valve being filled with a predetermined volume of flowable mass while the contents of the first pressure cylinder is being emptied, and by the second pressure cylinder being emptied through the same outlet while the first pressure cylinder is being filled again, the period of the emptying of each pressure cylinder being shorter than or equal to the period of the filling of each pressure cylinder. In this manner a pressure cylinder is always ready to be filled with the flowable mass, such as ice cream, with the result that said ice cream can pass in an uninterrupted continuous flow to the filling valve. The utilization of the continuous movement of the ice cream directly from the freezer has the effect that the pressure in the piping system can be used for retracting the pistons of the pressure cylinders in such a manner that said ice cream is not subjected to a vacuum. Thus the use of a vat or a hopper for a temporary storing of the flowable mass is avoided. The filling valve only
subjects the flowable mass to a pressure when the measured amount is to be emptied into the mould or the cup in question, and this pressure can be set so as not to exceed the pressure which the mass is subjected to in the piping system from the freezer. As the flow of mass is never stopped in the piping system, the pressure remains substantially constant in said piping system.
As a result, a relatively accurate volumetric filling of the moulds is obtained. In addition, the product present in said moulds is of a relatively homogeneous quality even though it is a question of mixtures containing relatively high percentages of large particles.
An apparatus for carrying out the method comprises a plurality of filling valves with their respective inlet for the feeding of the flowable mass under pressure and their respective outlet for volumetrically measured amounts of the mass in question, said outlet being associated with a pressure cylinder which is adapted through the valve body of the filling valve to alternately be connected to the inlet and the outlet. This apparatus is according to the invention characterised in that each filling valve is associated with at least two pressure cylinders, which alternately are connected to the inlet and the outlet by means of the valve body of the filling valve.
In this manner an advantageous apparatus for carrying out the method is obtained.
According to a further advantageous apparatus the filling valves comprise a substantially cylindrical housing with a cylindrical valve body, which is pivotally journalled around the axis of said housing and provided with a recess associated with each filling valve so as to establish a connection either between the inlet and a pressure cylinder or between a pressure cylinder and an outlet by turning the valve body around its central axis.
This advantageous apparatus is characterised in that two identical pressure cylinders are connected in a symmetrical manner to the valve housing of each filling valve on each side of the inlet thereof, and that the valve body comprises recesses symmetrically shaped for each filling valve on each side of a radial central plane including the axis of rotation, said recesses being adapted by way of turning the valve body to alternately establish a connection between an inlet and the one pressure cylinder associated with said inlet simultaneously with establishing a connection between the corresponding second pressure cylinder and the associated outlet.
In this manner a very simple apparatus is obtained for carrying out the method according to the invention.
The pressure cylinders may advantageously be pneumatically driven piston-cylinder units.
Brief Description of the Drawings.
The invention is explained in greater detail below with reference to the accompanying drawing, in which
Fig. 1 is a diagrammatic, sectional view through a filling valve according to the invention, seen in three different situations A, B and C during an operating cycle,
Fig. 2 is a side view of parts of a filling station for filling ice cream and comprising two filling valves,
Best Mode for Carrying Out the Invention
Fig. 1 illustrates an apparatus according to the invention, where a
sectional view is shown through a filling valve designated the general reference numeral 1. This filling valve is one of a plurality of filling valves formed by a cylindrical housing 2, in which a valve body 3 is accommodated and sealingly abuts the inner side of the housing in a conventionally known manner.
The valve body 3 is preferably made of a rod-shaped body of plastics, such as neoprene, and is common to all the filling valves. Opposite each filling valve, the valve body 3 comprises a symmetrically shaped recess 4 and 5 on their respective side of a radial central plane including the axis of the valve body. These recesses are shaped such that alternately they can establish a free flow between an inlet 6 connected to the valve housing and one of two openings 7 and 8, respectively, into one of two pressure cylinders 9 and 10, respectively, connected thereto, and between the opening 7 and 8, respectively, of one of the pressure cylinders 9 and 10, respectively, and an outlet 1 1 associated with the housing 2.
Apart from the valve body 3, each filling valve 1 is symmetrically shaped about a vertical central plane. The two pressure cylinders 9 and 10 are therefore also completely identically shaped. The pressure cylinders 9 and 10 are diagrammatically and only partially sectionally shown, and they comprise their respective piston 12 and 13 and a piston rod 14 and 15, respectively. They are in a manner not described in greater detail connected to a compressed air source for pressing the pistons 12 and 13 forwards towards the openings 7, 8 into the valve body 3.
In use the inlet 6 of the filling valve 1 is in a manner not described in greater detail connected to a piping system, in which ice cream is fed under pressure from a continuously operating freezer. By a setting of the valve body 3 in the position shown in Figure A, the ice cream is fed from the inlet 6 directly into the pressure cylinder 9 accommodated to the right as indicated by the arrow 16. The entering ice cream 16 has the effect
that the piston of the pressure cylinder 9 is pressed backwards until a desired volume of ice cream is present in the interior of the pressure cylinder.
As soon as the pressure cylinder 9 has been filled, the valve body 3 is turned approximately 90°clockwise in such a manner that the flow of ice cream is now carried from the freezer and directly into the interior of the second pressure cylinder 10, cf. the arrow 17 in Figure B, while the piston 13 is being pressed backwards. At the same time, the piston 12 of the first pressure cylinder 9 is activated so as to force the volumetrically measured amount of ice cream out of the interior of the pressure cylinder 9 and out through the outlet 1 1 of the filling valve, cf . the arrow 18, and further downwards into a mould therebelow. As indicated in Figure C, this emptying movement must be terminated in the moment the second pressure cylinder has been filled with the result that the first pressure cylinder is immediately ready for receiving a new amount of ice cream when the valve body 3 has been turned 90° counterclockwise when the pressure cylinder 10 has been registered as being filled. Then the process is repeated with a filling of the first pressure cylinder 9 while the second pressure cylinder 10 is emptied through the outlet 1 1.
The emptying process is driven by compressed air and must, as mentioned, be completed when the filling of a pressure cylinder 9, 10 has been terminated. The emptying process can be performed at a higher speed, but it cannot be performed at a speed slower than the speed of the filling process. Therefore an empty pressure cylinder is always ready for receiving a fresh amount of ice cream when a pressure cylinder has been filled up. The turning of the valve body 3 must be performed relatively quickly in such a manner that no substantial, noticeable stopping of the flow of ice cream through the inlet occurs during the adjusting process.
The volume of the individual pressure cylinders is accurately adjusted in a
manner known per se by means of screws 20 and 21 and 22 and 23, respectively, at the ends. The pressure cylinders are besides of a conventionally known type.
Fig. 2 is a side view of an embodiment of an apparatus according to the invention which comprises two filling valves. As these filling valves are identically structured and both are similar to the one shown in Fig. 1 , the parts illustrated have been provided with the same reference numerals as in Fig. 1 and with a mark (') or double mark (") indicating whether they are associated with one filling valve 1 ' or the other 1 ". The outlets 1 1 ' and 1 1 " as well as one of the associated pressure cylinders 10' and 10" of these filling valves 1 ' and 1 " appear. The filling valves comprise a common housing 2 and a common valve body 3, the projecting end of which appears to the right. The valve body is driven by means of a compressed air cylinder 24 accommodated at the other end and comprising a downwardly projecting piston rod 25, of which only a portion appears from the drawing. This piston rod engages a pin not shown which is connected to the valve body 3. The filling valves with the associated pressure cylinders are mounted on a frame 26, only a portion of said frame appearing.
The invention has been described with reference to a preferred embodiment. Many modifications can be carried out without thereby deviating from the scope of the invention. The invention can also be used for other flowable masses than ice cream.