NL2008223C2

NL2008223C2 - Moulding food products from a pumpable foodstuff mass.

Info

Publication number: NL2008223C2
Application number: NL2008223A
Authority: NL
Inventors: Johannes Martinus Meulendijks; Thomas Willem Dekker; Martinus Johannes Willebrordus Zoelen; Jeroen Robert Willemsen
Original assignee: Marel Townsend Further Proc Bv
Priority date: 2012-02-03
Filing date: 2012-02-03
Publication date: 2013-08-06

Description

P31039NL00

MOULDING FOOD PRODUCTS FROM A PUMPABLE FOODSTUFF MASS

The present invention relates to a method and installation for moulding food products from a pumpable foodstuff mass. The invention is advantageously employed for the manufacture of meat products from a pumpable ground meat mass, e.g. a ground beef mass, for the manufacture of meat patties.

5 A known method for manufacture of e.g. meat patties involves the use of an installation having a frame and a mould drum with an outer circumferential drum surface and a longitudinal drum rotation axis, often a horizontal axis. The drum is rotatably supported by the frame to revolve about the drum rotation axis. The drum has in the drum surface multiple 10 mould cavities, each having a fill opening for the introduction of foodstuff mass, e.g. ground beef mass, into the mould cavity. A mould drum drive is coupled to the drum to drive the drum in a rotation direction. A mass feed member is stationary arranged at a fill position relative to the drum surface. This mass feed member has a single chamber with an inlet for the foodstuff mass to introduce foodstuff mass into the chamber and with a mouth facing the 15 drum surface that is provided with the mould cavities. The mass feed member is adapted to transfer mass from the chamber into the passing mould cavities of the rotating mould drum when the filling opening of a mould cavity is in communication with the mouth at said fill position. The mass that has been filled into a mould cavity remains in said cavity for a while, commonly the installation has a closure member that extends in downstream direction from 20 the mass feed member at the fill position and temporarily keeps the filled mould cavities closed downstream of the fill position, e.g. to allow the mass to become a more coherent food product. The mass in the mould cavity forms the food product, e.g. the meat patty. The installation comprises a pump that is connected to the inlet of the mass feed member and is adapted to feed foodstuff mass under pressure into the chamber of the mass feed member. 25 A food products release or removal mechanism is provided, e.g. associated with the mould drum, and is adapted to cause or facilitate removal of the food product at a product removal position that is downstream of the fill position. It is for example known to provide air channels in the drum that extend to the cavities and allow to selectively introduce air that has been supplied from a manifold at a head end of the drum via said channels to between the drum 30 and the product in order to facilitate the release thereof from the mould cavity. Other release or removal mechanisms, e.g. using a mechanical ejector, are also known in the art.

-2-

The production of moulded food products, e.g. meat patties, with such installations generally includes: - driving the drum in its rotation direction in a continuous, non-interrupted manner; - operating the pump so as to feed foodstuff mass to the mass feed member and establish a 5 foodstuff mass pressure in the chamber of said mass feed member, - transfer of pressurized foodstuff mass via the mouth into each passing mould cavity, - release of the moulded products from the mould cavities.

Some small capacity prior art moulding devices of the design mentioned above have a drum 10 of minimal axial length that is only provided with a single circumferential array of mould cavities that are arranged at different circumferential positions on the drum surface. An example thereof is shown in US 3137029.

It is also known to increase the capacity by lengthening the drum so that the drum has 15 multiple of such groups in axial direction of the drum, or in general to have the mould cavities arranged in the drum surface in a mould cavities pattern with cavities at multiple, e.g. two, or four or more, longitudinal positions when seen in longitudinal direction of the drum and at multiple circumferential positions when seen in circumferential position of the drum.

It is common in prior art mould drums for these installations to arrange the mould cavities in 20 straight or rectilinear rows of multiple mould cavities, said rows being parallel to the drum axis with the rows being offset from one another in circumferential direction. It is also common in such prior art mould drums that all mould cavities are of identical dimensions, e.g. circular contoured cavities, although other embodiments with non-identical cavities are known as well. Examples of known high capacity food product moulding installations and 25 methods are found in e.g. WO 0030458 and W02004002229.

In general drum type moulding installations allow for a high production capacity compared to well known slide-plate moulding devices, wherein a cyclically driven mould plate with a row of mould cavities is cycled back and forth between a fill position and a release position. At the 30 fill position the row of mould cavities in the reciprocating plate is filled with foodstuff mass. It is common for these plate type devices to fill the mould cavities with foodstuff mass, e.g. ground meat mass, at a high fill pressure, said fill pressure being significantly relieved by suitable operation of the pump in the period when the plate starts to move away from the fill position. This is for example illustrated in US 4356595.

In WO 2011005099 the issue of non-uniformity of the finally obtained food products is addressed, e.g. with regard to their appearance and shape. For instance in practical use of a 35 -3- high capacity drum mould device it is observed that in a batch of circular meat patties that are made of ground meat there are visible deviations from the circular contour of the mould cavities. These shape deviations are also non consistent within the batch. In WO 2011005099 it is amongst others proposed to embody each mould cavity with walls so as to 5 define a plurality of moulding cells within each mould cavity in order to alleviate this problem.

Whilst measures like the ones proposed in WO 2011005099 enhance moulded food product uniformity, the uniformity problem still remains present, in particular at a high production speed of drum moulding installation. For example stringent demands are placed on meat 10 patties that are supplied to fast food chains, e.g. with regard to shape uniformity.

The present invention aims to provide measures that resolve, or at least reduce, undesirable non-uniformity of the moulded food products that have been obtained with a high capacity drum moulding installation of the type discussed above. The non-uniformity may relate to the 15 shape but also to other aspects of the product, e.g. the composition, such as the density, which may influence other aspects like the later cooking or frying, or the taste in general.

The present invention achieves the above aim by providing a method according to claim 1.

20 In the inventive method the drum is driven in its rotation direction in a continuous, non-interrupted manner. This is preferably at a constant rotational speed during a revolution of the drum, but one can also envisage a drum drive that causes a periodic variation of the drum rotational speed during a revolution, e.g. increasing the drum speed in an approach period when a cavity to be filled nears the mouth or is already in first communication 25 therewith and slowing down the drum speed when the major portion of the filling event takes place, e.g. when the effective filling opening formed by the overlap of the mouth and the filling opening of the mould cavity is the greatest.

The pump is operated so as to feed foodstuff mass to the mass feed member and establish a foodstuff mass pressure in the chamber of said mass feed member. The pump preferably is 30 a positive displacement pump, e.g. a rotor pump having a rotor with vanes that revolves in a pump chamber having an inlet and an outlet.

The pump may be connected at its inlet to a hopper that is adapted to receive therein a batch of pumpable foodstuff mass, e.g. ground meat. The hopper may be evacuated to reduce the inclusion of air in the mass.

35 The transfer of pressurized foodstuff mass via the mouth of the mass feed member into each passing mould cavity takes place in a corresponding mould cavity filling event that is defined - with regard to the duration thereof - by the moment of first flow of foodstuff mass into the -4- individual mould cavity and the moment wherein the individual mould cavity has been fully filled and flow of foodstuff mass therein is terminated. Later, e.g. as explained above with reference to the prior art, the release of moulded products from the mould cavities is performed.

5 In the invention the operation of the pump and the rotation of the mould drum are controlled in combination with the design of the mould cavities pattern on the drum and of the mouth of the mass feed member in such a manner that during the production of moulded food products all mould cavity filling events during a revolution of the mould drum are performed in a sequential order, preferably with a pause between each pair of successive filling events 10 wherein effectively no flow of foodstuff mass out of the mouth takes place.

The invention is based on the insight that uniformity of the food products, in particular of the shape and composition, is greatly enhanced if the actual filling process of all the mould cavities is also highly uniform. To obtain such uniformity of the filling it has been found that 15 this can be achieved if all filling events take place in sequential order, or in other words such that “only one mould cavity is filled at a time”. This means that the outflow of foodstuff mass from the chamber of the mass feed member is focussed on one mould cavity only, which outflow stops when the cavity has been filled. It is noted that this moment of the outflow effectively coming to an end is commonly while the filling opening of the mould cavity is still 20 in communication with the mouth. In the practice of manufacturing hamburger meat patties this may e.g. be when about half of the filling opening has passed the mouth of the mass feed member or even earlier. Only then, and possibly and preferably with an intermediate pause (without stopping the drum rotation), does another mould cavity arrive at the filling position such that the mouth and the filling opening of said new cavity come into 25 communication and the outflow of foodstuff mass into this successive one mould cavity starts. As expressed above, this may mean that the mouth still is in communication with the previously filled mould cavity, but as that filling event has been completed there is only the new mould cavity that is effectively filled from the chamber of the mass feed member.

30 With regard to the pattern of mould cavities this invention excludes the presently most common design of mould drums for high capacity moulding devices, which drums have a pattern of rectilinear rows of mould cavities, which rows are parallel to the drum rotation axis, in combination with a mouth of the mass feed member that is parallel to the rotation axis.

This design is excluded as this entails that in each row the multiple mould cavities come into 35 communication with the mouth of the chamber of the mass feed member at the same time and the filling events take place in parallel. With the benefit of the knowledge of the present invention, one will now appreciate that in this arrangement the foodstuff mass will nearly -5- always tend to flow into one cavity of the row first. The immediate result is a pressure drop of the mass in the chamber of the mass feed member, as well as a flow distribution of the mass within the chamber, such that the slightly later starting flows into the other mould cavities of the row are slightly different. These small differences in filling events, which happen very 5 quickly, are now determined to be at the root of the non-uniformity of the food products that are moulded in these high capacity drum moulding installations.

The invention is preferably performed with the mass feed member having a mouth that is embodied as a closed contoured singular straight slot that is arranged parallel to the 10 longitudinal axis of the drum. As indicated above, this is a known embodiment of the mouth for these moulding installations. In this embodiment, the drum may not have rectilinear rows of mould cavities that are parallel to the drum rotation axis, as then multiple filling events would start and take place simultaneously or at least in overlapping manner. Therefore one can envisage that in the method of the invention the mould cavities of a drum are arranged in 15 a pattern of helically extending rows, with one cavity being offset in circumferential direction with regard to the axially neighbouring cavity. It is noted that such an embodiment of the mould drum is disclosed in W00030458 in combination with a method that envisages a continuous filling of the mould cavities of the drum, so with overlap between the filling events of the mould cavities.

20 One can also envisage other patterns of the mould cavities than said helically extending rows, e.g. with mould cavities in staggered rows, e.g. at equal axial spacing yet at differing circumferential positions. One can envisage that mould cavities that are to be filled in direct succession are not directly in adjacent axial positions on the drum surface, but are separated further with a mould cavity at an intermediate axial position on the drum surface being filled 25 at a later filling event during the revolution of the drum. All sorts of variations of the pattern are possible within the scope of the inventive method.

As expressed above, a preferred embodiment envisages that there is an actual pause in between successive filling events such that as one filling event is terminated it takes a short 30 while before the next filling event starts. This approach, even though in real terms the pause is very short, effectively guarantees in practice the existence of only one filling event at each moment during the revolution of the drum. The pause can also be advantageously used to allow the pump to make up or restore the pressure within the chamber of the mass feed member, preferably to a predetermined target pressure or target pressure range. This 35 approach allows to avoid the use of a high filling pressure of the mass, which is in particular advantageous for ground meat mass, as a high filling pressure in practice requires the pump to supply mass at a rate well above the average rate wherein mass is filled into the mould -6- cavities. By letting the pump supply mass at a lower rate one can observe in an embodiment of the inventive method that as a consequence of mass flowing into the mould cavity the mass pressure in the chamber drops as the outflow effectively exceeds the inflow. The pause between filling events then allows the pump to restore the mass pressure in the chamber.

5 For example the pump is slowed down or switched off once the pressure of the mass has reached the target pressure or target pressure range during this pause.

It will be appreciated that operation of the pump is a factor in the invention as the rate of supply of foodstuff mass to the mass feed member has significant impact on the outflow of 10 the mass from the mouth and thereby on the duration of each filling event. The invention envisages that in an advantageous situation the pump would be operated at a constant output rate during the revolution of the mould drum as this is beneficial for the lifetime of the pump and may be beneficial for the quality of the pumped mass.

15 In an embodiment the moulding installation comprises a foodstuff mass pressure sensor that is adapted to sense the actual pressure of the foodstuff mass in the chamber of the mass feed member, preferably the sensor being arranged directly on or in the chamber. The installation comprises a pump control unit that is connected to said foodstuff mass pressure sensor, preferably an electronic control unit. An embodiment of the method comprises 20 selecting a target pressure or target pressure range for the foodstuff mass in the chamber, e.g. based on test runs performed with such foodstuff mass on the device, or based on historical data (e.g. from the manufacturer of the device or other food product manufacturers). In this embodiment it is envisaged that the pump control unit stops or at least slows the pump when the measured foodstuff pressure exceeds the target pressure or 25 the target pressure range and that the pump control unit activates or accelerates the pump when the measured foodstuff pressure drops below the target pressure or target pressure range.

In combination with a pump output such that during a filling event the foodstuff mass pressure in the chamber drops due to outflow into the mould cavity, this approach results in 30 the pump having a periodic variation of the pump output, the frequency per revolution of the drum effectively corresponding to the number of filling events and thus to the number of mould cavities that are filled by the mass feed member to which the pump is connected. In graphical form during a revolution of the drum, the mass pressure in the chamber may show a wave pattern with peaks and valleys at said frequency. In a preferred embodiment for 35 ground meat the pressure amplitude of the mass pressure lies between 0.3 and 1.0 bar, with an average pressure of the mass in the range between 3 and 6 bars.

-7-

In an embodiment the invention envisages the use of an installation that is also provided with a pump timing mechanism that causes activation or acceleration of the pump during intervals that take place periodically during a revolution of the mould drum, each of said intervals being in timed relation to a corresponding filling event of a single mould cavity, an interval at 5 least partly being in timed overlap with said single filling event, said activation or acceleration causing a temporary increase of flow of foodstuff mass to the mass feed member during said interval and said flow being relatively reduced in between successive intervals. In a preferred embodiment the timing mechanism determines the actual position of the first to be filled mould cavity relative to the mouth, e.g. by detecting the actual angular position of the drum 10 (and thereby of the mould cavities) during operation of the device. It will be appreciated that such pump timing may be used as an alternative for the pump controlled based on actual mass pressure in the chamber, or can even be combined therewith to obtain a further enhanced control of the pump output and thereby enhanced filling of the mould cavities. With regard to the pump timing mechanism reference is made to applicants non-prepublished and 15 co-pending patent application NL2006841 which is incorporated herein by reference, in particular with respect to the embodiments of the device and method as listed in the claims thereof.

In a practically preferred embodiment of the invention the mass feed member comprises a 20 funnel body that delimits the single chamber for the mass in the mass feed member. The funnel body has main walls of substantially triangular shape that are connected along their sides, with a mouth side thereof formed by a wall containing the mouth and with the inlet to the chamber being arranged at an apex of said main walls that is located opposite said wall containing said mouth. Due to this funnel shape the effective cross section of the chamber 25 increases from the inlet towards the opposite side wall containing the outflow mouth. As is preferred the mass feed member has a single slot mouth that spans the length of the drum surface provided with mould cavities, so that all said cavities pass along said single slot.

It is envisaged that the chamber of the mass feed member is a closed chamber that allows 30 for pressure of the mass during the method at a level or levels above atmospheric pressure, with the mouth being the only outlet for the mass from the chamber. The closed chamber also shields the mass from the atmosphere, e.g. to avoid inclusion of air into the mass, as it only has the inlet that is connected to the pump and the mouth that is directly adjacent the outer surface of the revolving drum.

In a practically preferred embodiment, as is known from prior art drum moulding installations, the mouth is a closed contoured singular straight slot that is arranged parallel to the 35 -8- longitudinal axis of the drum. Most preferably the slot has rectilinear and parallel leading and trailing edges, e.g. with the trailing edge embodied as or provided with a knife formation to cut fibres in the mass, e.g. fibrous elements in a ground meat mass. In an alternative, yet less preferred, embodiment the mouth is composed of an array of mouth openings, e.g.

5 slotted openings along a common line parallel to the axis of the drum. Such a design with an array of mouth openings in the mass feed member is regarded as less versatile in combination with various drums having different mould cavities patterns that can be commonly exchanged for one another in these devices without having the need to exchange the mass feed member as well.

10

In another embodiment the mouth is a closed contoured singular slot that is helically shaped so as to extend as a helix segment in longitudinal direction and circumferential direction relative to the mould drum surface. So instead of the well known straight slot shaped mouth that extends parallel to the drum axis this design requires that said mouth extends in a helix 15 closely adjacent the curved outer drum surface. In the scope of the present invention such a helix design of the mouth may allow for the mould cavities in the drum surface to be arranged in rectilinear rows, parallel or possibly nearly parallel, to the drum axis and the rows offset from one another in circumferential direction. It will be appreciated that whilst this helical mass feed member may be more complex than an embodiment with a straight slot, the 20 design of the drum may be less complicated due to a simpler pattern of the mould cavities therein. The actual shape of the mouth of the mass feed member and the layout of the mould cavity pattern, in combination with the operation of the pump and the rotary drive of the mould drum, is still governed by the inventive requirement that all filling events are performed in succession during a revolution of the drum, preferably with a pause between successive 25 filling events. An advantage of such a helix design of the mouth may also lie in the release of the food products from the mould cavities when these are arranged in rectilinear rows parallel to the drum axis, as this release can then be effected with less complexity or more efficiently than with mould cavities arranged in another pattern.

The inventors envisage that such a mass feed member design of the moulding device can 30 also be advantageous in methods and devices wherein the filling events are not necessarily in sequential order.

In another embodiment the mouth is composed of multiple staggered slot sections with one section being offset from the one or more adjacent slot sections in the circumferential 35 direction of the mould drum. This mimics a helical design of the mouth and provides the same effects yet with less complexity of the mass feed member itself as to its structure. The inventors envisage that such a mass feed member design of the moulding device can also -9- be advantageous in methods and devices wherein the filling events are not necessarily in sequential order.

As explained above the mould drum devices are predominantly chosen for their high 5 capacity. This capacity can amongst others be enhanced by increasing the length of the drum so as to mould more food products with a single drum or at least to eject food products along a greater length of the drum. This is seen as beneficial for large capacity food producing installations, e.g. as the moulded food products may be received on a conveyor of significant width, e.g. of 0.8 or 1.0 meter that passes into a further treatment device, e.g. into 10 an oven or a fryer.

In view of increasing length of the drum the invention, in an embodiment thereof, envisages a installation comprising not just a single mass feed member at the fill position, but with at least a first and a second mass feed member that are arranged at the fill position in side by side arrangement. Herein each mass feed chamber has a chamber therein for the mass that is 15 separated from the chamber of the other mass feed member, preferably with a first and a second pump respectively connected to the first and second mass feed member. The installation has a single mould drum with a first section of the drum surface passing along the first mass feed member and a second section passing along the second mass feed member during revolution of the drum. The mould cavities of said single drum are filled by said first 20 and second mass feed members, wherein each of the first section and the second section of the drum surface have multiple mould cavities that are arranged in a mould cavities pattern for each drum surface section with cavities at multiple (at least two, e.g. four or more) longitudinal positions when seen in longitudinal direction of the drum and at multiple circumferential position when seen in circumferential position of the drum. In the invention 25 the requirement is applied that for each mass feed member and corresponding drum surface section all filling events are performed in sequential order.

The inventors envisage that such dual or multiple mass feed member design of the moulding installation can also be advantageous in methods wherein the filling events are not necessarily in sequential order.

30

In a practical embodiment the mould cavity pattern is composed of mould cavities of identical dimensions, e.g. to mould meat patties with circular contour.

The present invention also relates to an installation that is adapted to perform the inventive 35 method, e.g. with the installation having a computer control for the drum rotation and operation of the pump, said control being programmed to perform the inventive method, e.g.

-10- with a memory containing predetermined routines that make the installation perform the inventive method for selected foodstuff masses.

The invention will be explained below with reference to the drawings. In the drawings: 5 Fig. 1 shows schematically a moulding installation for moulding food products from a pumpable foodstuff mass; fig. 2 an exemplary embodiment of a moulding installation for moulding food products from a pumpable foodstuff mass; fig. 3 the installation of figure 2 in a different view 10 fig. 4 a part of the mass feed member and the mould drum of the moulding device in figures 2 and 3; figs 5a-c different patterns of mould cavities on the outer drum surface of a mould drum; fig. 6a an example of mass pressure in the mass feed member measured in a method according to the prior art; 15 fig. 6b an example of mass pressure in the mass feed member measured in a method according to the invention; fig. 7 an example of a mass feed member and the mould drum of the moulding device; fig. 8 another example of a mass feed member and the mould drum of the moulding device.

20 Figure 1 schematically depicts a high capacity installation for the moulding of three dimensional products from a mass of pumpable foodstuff material, for example from a ground meat mass, e.g. for the production of hamburger patties.

A batch of ground meat mass, e.g. of beef, pork, or poultry meat, is commonly prepared with 25 a meat grinding device or a mixer/grinding device. A batch is e.g. loaded into a (wheeled) bin and then transported to the installation. Instead of loading a hopper of the installation with bins, the loading may be conducted via a pipe connecting to the installation, e.g. to a hopper thereof.

30 In this example it is illustrated that the installation may comprise a hopper 1 that is adapted to receive one or more batches of the mass of pumpable foodstuff material, e.g. ground meat.

In this example it is illustrated that an optional feeder assembly 2 is associated with the hopper 1 to assist in discharging the mass from the hopper 1. In this example one or more motor driven augers 3 are mounted at the bottom of the hopper 1.

The installation comprises a pump, as is preferred a positive displacement pump 5, having an inlet 6 receiving the mass from the hopper 1, here via the auger 3.

35 -11-

The pump 5 further has an outlet 7 for outputting the mass.

The pump 5 shown is (as is preferred in the invention) a vane pump with a rotor having multiples vanes disposed in a pump cavity of a pump housing. Such rotor pumps, e.g.

5 supplied by Risco (Italy), are known for pumping ground meat and other pumpable foodstuff masses.

A pump drive motor (e.g. electric, shown at M in figure 2) is provided for driving the pump. The pump 5 forms pump chambers, in the figure shown between neighbouring vanes, that 10 each are successively in communication with the pump inlet 6 for the introduction of mass into the pump chamber and with the pump outlet 7 for the discharge of mass from the pump chamber. The effective volume of the pump chamber reduces from the position thereof at the pump inlet to the position thereof at the pump outlet, so that the mass is effectively expelled from the pump chamber when the pump is in operation. An example of such a pump is 15 disclosed in US4761121.

The pump 5 may instead of a vane pump also be embodied as a different type of pump, e.g. as a piston pump having one or more reciprocating pistons.

20 A pumped mass supply tube 10 is connected to the outlet 7 of the pump 5. This tube 10 extends from the pump outlet to an inlet 17 of a mass feed member 15 of a food products moulding device 20 of the installation and serves to convey the outputted mass to the mass feed member 15.

25 The moulding device 20 comprises a frame 21 (depicted in figs. 2 and 3) and a rotating or revolving mould drum 22, the drum 22 being rotatably supported by the frame 2, e.g. on a cantilevered shaft of the device 20. Preferably the device 20 and drum 22 are designed to allow for an easy exchange of one drum for another drum having a different pattern and shape of mould cavities so as to allow the production of different food products with the 30 installation.

The mould drum 22 has an outer circumferential drum surface 23 and a longitudinal drum rotation axis 24. The drum 22 is rotatably supported by the frame 21 to revolve about the drum rotation axis, here - as is preferred - a horizontal axis.

The mould drum 22 has in the drum surface 23 multiple mould cavities 25, each cavity 25 having a fill opening in the plane of the surface 23 for the introduction of foodstuff mass into 35 -12- the mould cavity and for the later removal or release of the product from the cavity 25. The cavities 25 are embodied as individual recesses in the outer surface 23 of the drum body, having a bottom opposite the filling opening of the cavity.

5 The mass feed member 25 is arranged at a fill position adjacent the drum surface 23. Here, as is preferred, the fill position is a stationary fill position.

A mould member drive 26 is provided for rotating, preferably an electric drive allowing for a variable and controllable drum rotation speed. In use of the installation it is envisaged that 10 the drum 22 is driven in a continuous, non-interrupted manner, so without starting and stopping during a revolution of the drum in order to achieve a high production capacity. As explained it is preferred that the drum 22 is driven at a constant speed during normal production (e.g. with an acceleration when starting production). It may also be that the speed of the drum 22 is periodically varied during a revolution of the drum e.g. as explained herein, 15 yet without stopping and starting.

In general a cavity 25 is filled with foodstuff mass if the filling opening thereof comes into communication that allows the pressurized mass in the mass feed member to flow via a mouth 18 of the mass feed member 15 into the cavity 25.

20

An example of the mass feed member 15 is depicted in more detail in figure 4.

The mass feed member 15 has a single internal chamber 16 with an inlet 17 for foodstuff mass that is connected, e.g. via a releasable coupling, to tube 10 and thereby to the pump 5 25 in order to introduce foodstuff mass into the chamber 16. The member 15 has a mouth 18 facing or directly adjacent the drum surface 23 with cavities 25. The mouth 18, as is generally preferred in the context of the present invention, is preferably a non-valved, continuously open mouth. The member 15 is adapted to transfer mass into passing mould cavities 25 of the rotating mould drum 22 when the filling opening of a mould cavity 25 is in 30 communication with the mouth 18 at the fill position, the mass forming a food product in the mould cavity.

As is preferred the mass feed member 15 sealingly engages the surface 23 of the drum 22 in which the cavities are formed, so that substantially no mass may escape between the mass 35 feed member and the mould drum.

-13-

As is preferred the mass feed member 15 is integrated with a closure member 19a that extends in downstream direction from the mouth 18 of the mass feed member to keep the filled cavities closed for a while as the filled cavities move away from the fill position. This allows the mass to become a more coherent food product. The mass in the mould cavity 5 forms the food product, e.g. the meat patty. As shown a closure member 19b is preferably provided to extend from the mouth 18 in upstream direction, in order to closure the cavity as it is in communication with the mouth 18.

Optional details of a mould drum, mass feed member, and closure member, are e.g.

10 disclosed in WO00/30548 and in W02004/002229.

For example, the one or more closure members 19a, b may each comprise a semi-circular plate member, preferably of flexible design, that is urged in sealing contact with the surface 23 by one or more actuators, e.g. pneumatic actuators, e.g. with transverse lamellae 15 between the plate member and the one or more actuators.

The pump 5 urges the foodstuff mass through the tube 10 towards the mass feed member 15 and into the single chamber 16 thereof. By suitable control of the pump 5, e.g. of the pump rotor speed, e.g. using a controllable electric pump drive motor M, the output of mass by the 20 pump and thereby the pressure of the mass in the chamber 16 of mass feed member 15 can be controlled. As will be explained below in more detail this pressure control may include the sensing of the actual pressure of the mass in the chamber 16 by a pressure sensor, said signal acting as a feedback signal for a pump control unit.

25 The figures 1 and 4 illustrate the preferred feature that the device comprises a foodstuff mass pressure sensor 55 that is adapted to sense pressure of the foodstuff mass in the chamber 16 of the mass feed member 15.

The device comprises a control unit 60, at least for the pump 5 but as is preferred also for the 30 drum rotation drive 26, which unit 60 is preferably connected to the foodstuff mass pressure sensor 55 to control operation of the pump amongst others on the basis of the sensed actual mass pressure in the chamber 16.

At a release position that is downstream of the fill position the formed product, here meat 35 product 40, is released from the mould cavity 25, e.g. to be transported onward on a conveyor 45, e.g. to other downstream equipment, e.g. an oven, a fryer, etc. The release from the mould cavity 25 may be assisted by pneumatic pressure, e.g. as the wall of the -14- mould cavity comprises one or more sections of porous material through which pressurized air or gas is forced thereby assisting the release of the product. A mechanical ejector member may also be provided to perform or assist in the release of the product from the mould drum 22. For example the bottom of the mould cavity in the drum may be formed by a 5 mobile piston member, that allows to eject the formed product from the cavity, possibly the piston being porous to allow for the use of air to release the product from the piston.

The installation may comprise a controllable vacuum assembly 50, here integrated with the pump 5 as is known in the art. This vacuum assembly 50 is adapted to cause controlled 10 evacuation of air from the mass at one or more locations in the trajectory of the mass from the hopper 1 to and including the pump chamber at a position where it is in communication with the pump inlet 6 of the positive displacement pump. As is preferred, this vacuum assembly comprises a vacuum pump 51, e.g. an electrically operated vacuum pump.

As is preferred, a vacuum port 52 is arranged in the pump 5 so as to be effective in 15 establishing a vacuum in the pump chamber that is in communication with the inlet 6 during operation of the pump 5. This vacuum assists in the complete filling of the pump chamber with a portion of the mass.

If desired a vacuum may be created in the hopper 1 as is known in the art. A vacuum may 20 also be created in any passage between the hopper 1 and the pump inlet 6, e.g. in a duct into which one or more augers 3 of a feed assembly extend.

A vacuum assembly 50 allows the evacuation of the foodstuff mass, e.g. the ground meat mass, so as to reduce the presence of air in the mass. This e.g. increases the uniformity of 25 the products when it comes to the weight of mass that is effectively introduced into each of the mould cavities, among other advantages.

The drum 22 is provided with multiple mould cavities 25 which are arranged in the drum surface 23 in a mould cavities pattern with cavities at multiple (possibly two, preferably four 30 or more) longitudinal positions when seen in longitudinal direction of the drum 22 and at multiple circumferential positions when seen in circumferential position of the drum 22. So in general terms a 2-dimensional pattern of cavities in the surface 23 of the drum 22.

The production of the food products with the installation comprises: 35 - driving the drum 22 in a rotation direction in a continuous, non-interrupted manner; so without starting and stopping the drum in its revolution, -15- - operating the pump 5 so as to feed foodstuff mass to the mass feed member 15 and establish a foodstuff mass pressure in the chamber 16 of the mass feed member 15, - transfer of pressurized foodstuff mass via the mouth 18 into each passing mould cavity 25 in a corresponding mould cavity filling event that is defined by the moment of first flow of 5 foodstuff mass into the mould cavity 25 and the moment wherein the mould cavity 25 has been fully filled and flow of foodstuff mass therein is terminated, and - release of the moulded product from the mould cavity 25.

In the invention the operation of the pump 5 and the rotation of the mould drum 22 are 10 controlled in combination with the design of the mould cavities pattern on the drum 22 and of the mouth 18 of the mass feed member 15 such that in the method all mould cavity filling events during a revolution of the mould drum 22 are performed in sequential order. Thereby only one filling event takes place at any given moment.

15 As is preferred in the invention there is a short pause between each pair of successive filling events wherein effectively no flow of foodstuff mass out of the mouth 18 takes place.

In an embodiment the method comprises selecting a target pressure or target pressure range for the foodstuff mass in the chamber 16, and programming the pump control unit 60 such 20 that it stops or slows the pump 5 when the measured foodstuff pressure exceeds the target pressure or the target pressure range and such that the control unit 60 activates or accelerates the pump 5 when the measured foodstuff pressure drops below the target pressure or target pressure range.

25 As expressed above, a preferred embodiment envisages that there is an actual pause in between successive filling events such that as one filling event is terminated it takes a short while before the next filling event starts. This approach, even though in real terms the pause is very short, effectively guarantees in practice the existence of only one filling event at each moment during the revolution of the drum. The pause can also be advantageously used to 30 allow the pump 5 to make up or restore the pressure within the chamber 16 of the mass feed member 15, preferably to a predetermined target pressure or target pressure range which is monitored here by means of the pressure sensor 55. This approach allows to avoid the use of a high filling pressure of the mass, which is in particular advantageous for ground meat mass, as a high filling pressure in practice requires the pump to supply mass at a rate well 35 above the average rate wherein mass is filled into the mould cavities. By letting the pump 5 supply mass at a lower rate one can observe in an embodiment of the inventive method that as a consequence of mass flowing into the mould cavity the mass pressure in the chamber -16- 16 drops as the outflow effectively exceeds the inflow. The pause between filling events then allows the pump 5 to restore the mass pressure in the chamber 16. For example the pump 5 is slowed down or switched off once the pressure of the mass has reached the target pressure or target pressure range during this pause. Figure 6b illustrates by way of example 5 the mass pressure in the mass feed member chamber in such an operation.

Figure 4 illustrates a practical embodiment of the mass feed member 25 which comprises a funnel body 25a delimiting the chamber. The body 25a has main walls 25b of substantially triangular shape that are connected along a mouth side thereof by a wall containing the 10 mouth 18 and with the inlet 17 arranged at the apex of the main walls 25b that is located opposite the wall containing the mouth 18, such that the effective cross section of the chamber 16 increases from said inlet 17 towards said wall containing the mouth 18.

Figure 4 illustrates the embodiment wherein the mouth 18 of the mass feed member is a 15 closed contoured singular straight slot that is arranged parallel to the longitudinal axis of the drum 22. As is common and preferred, the mouth 18 is a non-valved, continuously open slot.

Figure 7 illustrates an embodiment wherein the mouth 18’ is a closed contoured singular slot that is helically shaped so as to extend as a helix segment in longitudinal direction and 20 circumferential direction relative to the mould drum 22. As is common and preferred, the mouth is a non-valved, continuously open slot.

Figure 8 illustrates an embodiment wherein the mouth 18” is composed of multiple staggered slot sections with one slot section being offset from the one or more adjacent slot sections in 25 the circumferential direction of the mould drum. As similar design can be obtained when the slot sections are interconnected to form a closed contoured singular slot.

The skilled person will appreciate that other shapes of the mouth 18 of the mass feed member that are non-straight and non-parallel to the drum axis are also possible, e.g. with 30 the mouth 18 having (seen from above) a semi-circular, sinoid, V, U, or other shape.

As explained above the common prior art approach is to make use of a drum with straight rows of cavities 25 that are circumferentially offset from one another. The prior art approach is to use such a drum in moulding device having a mass feed member with a mouth 18 that 35 is straight and parallel to the drum axis. This prior art approach is schematically illustrated in figure 5a, wherein a portion of the cavity pattern is shown (2 rows of five cavities) and the mouth 18. The drum moves in direction D towards the mouth 18. The lines parallel to the -17- mouth and at right angles thereto are merely shown as a grid in axial and circumferential direction of the drum surface.

As a result of this prior art approach the cavities 25 in a row all reach the mouth 18 at the same time. As the invention now teaches, this prior art approach does not entail that all filling 5 events of the cavities in a single row are the same, as the mass will have a tendency to flow into one of the cavities 25 slightly ahead of the others in the row with resulting differences in the filling of these cavities and resulting non-uniformity of the produced food products. However, as all filling events have generally simultaneously, the outflow of mass via the mouth 18 is significant and the pressure drop in the chamber 16 of the mass feed member is 10 equally significant. This is depicted by way of example in figure 6a wherein the mass pressure in the mass feed member is shown during operation as is done in this prior art approach. One recognizes that the frequency of the mass pressure in chamber 16 versus time graph corresponds to the passage of entire rows of cavities underneath the mouth 18. Also the amplitude is significant (pressure in bar) as the outflow into a row of cavities of the 15 mould is not directly replenished by operation of the pump 5.

The skilled person will appreciate that filling a mould cavity can, and in practice normally is, completed well before the trailing edge of the cavity 25 reaches the mouth 18. The filling starts commonly as soon as there is such an overlap between the filling opening and the 20 mouth that the pressurized mass can flow through this overlap. The mass will then seek to fill the entire cavity, which is commonly completed ahead of the trailing edge of the cavity reaching the mouth 18. Once the cavity has been filled the flow into the cavity ceases and the filling event of the cavity is terminated.

25 When using a mass feed member with a mouth 18 that is straight and parallel to the drum axis, the invention will not allow for the use of a drum as shown in figure 5a as the filling events will then not be performed in sequential order. Figure 5b shows a possible pattern of mould cavities 25 in the drum that may then be appropriate to perform the inventive method, with the cavities 25 being arranged in rows that extend helically over the surface of the drum. 30 Again the lines in the figure depict the axial and circumferential direction of the drum. As explained the output of the pump 5 and rotational speed of the drum 22 can then be controlled to achieve the sequential filling events. For example suitable settings and/or design of the pattern of cavities can be determined by performing test runs with the foodstuff mass that one desires to fill into the cavities.

Figure 5c shows yet another design of the pattern of mould cavities of the drum. It is noted that in this design, the location where actual outflow of mass via the mouth takes place 35 -18- “jumps” from one axial section of the mouth to a remote axial section, with the intermediate section only seeing outflow of mass into a cavity at a later stage of the filling process. In the figure 5b pattern the cavities in a helical row are filled in succession when seen in helical direction of the drum.

5

In figure 5d it is illustrated that the mouth 18 and cavity 25 are in overlapping position and the cavity has already been completely filled with the mass, e.g. ground meat (shown by hatching). So the filling event of this individual cavity has been completed, clearly ahead of the trailing end of the cavity reaching the mouth 18. It can also be seen that from this 10 termination moment, it takes a little while before the mouth 18 comes into communication with the cavity 25b, which is the successive cavity to be filled with the mass.

In figure 5e the process is shown slightly later, with the mouth 18 now in overlap with cavity 25b also. The overlap with cavity 25a does not result at this moment into a flow of mass into 15 said cavity 25a as this cavity 25a had already been fully filled. So there is only one filling event, namely the filling of cavity 25b. This is shown by hatching and one can see the mass flowing into the cavity to fill the cavity.

Figure 6b illustrates an example of a measurement of the mass pressure in the mass feed 20 member during operation as is done in the inventive method. One recognizes that the frequency of the mass pressure in chamber 16 versus time graph corresponds to the individual filling events of the cavities, and thus effectively to the number of cavities that pass underneath the mouth 18. It can be easily recognized and understood that in this approach the amplitude of the pressure changes is far smaller than in the prior art approach as the 25 pressure drop due to the single filling event is limited and the pump is able to replenish the mass into the chamber relatively fast. As a result the invention allows for a more stable operation of the pump (meaning less wear and noise), and for a more stable pressure of the mass (which may be advantageous for the properties thereof).

Claims

Method for forming food products from a pumpable food mass, wherein use is made of a forming installation for forming food products from a pumpable food mass, which installation comprises: - a frame (21), 10. a forming drum (22) with an outer peripheral drum surface (23) and a longitudinal drum pivot axis (24), the drum being rotatably supported by the frame for pivoting about the drum pivot axis, wherein the mold drum in the drum surface has a plurality of mold cavities (25, 25a, 25b), each of which have a filling opening for introducing food mass into the mold cavity, - a mold drum drive (26) coupled to the drum (22) to drive the drum in a direction of rotation (D), - a mass feeder (15) mounted on a filling position with respect to the drum surface (23), which mass supply member has a single chamber (16) with an inlet (17) for food ssa for introducing the food mass into the chamber and with a mouth (18) directed toward the drum surface (23), which mass feeder is adapted to transfer the mass to passing mold cavities (25, 25a, 25b) of the rotating mold drum when the filling opening of a mold cavity is in communication with the mouth (18) at the filling position, the mass forming a food product in the mold cavity, 30. a pump (5) connected to the inlet (17) of the mass feeder (15) and is adapted to feed nutrient mass under pressure to the chamber (16) of the mass feeder, the mold cavities (25) in the drum surface (23) being arranged in a pattern 35 of mold cavities with cavities seen at several longitudinal positions in longitudinal direction of the drum and at a plurality of circumferential positions as seen in the circumferential direction of the drum, the method comprising: - driving the drum (22) in the direction of rotation (D) in a continuous, non- interrupted manner; - operating the pump (5) to supply food mass to the mass feeder (15) and effecting a food mass pressure in the chamber (16) of the mass feeder, - transferring pressurized food mass through the mouth (18) in each passing mold cavity (25, 25a, 25b) in an associated mold cavity filling event defined by the moment of first flow of food mass in the mold cavity (25, 25a, 25b) and the moment when the mold cavity is completely filled and the flow of food mass has been put therein, - the release of molded products from the mold cavities, and wherein the operation of the pump (5) and the rotation of the mold drum (22) are controlled in combination with the design of the mold cavity pattern on the drum (22) and of the mouth (18) of the mass feeder that in the method all mold cavity filling events during a revolution of the mold drum in sequential order be performed, preferably with a pause between each pair of consecutive filling events in which no flow of food mass from the mouth 20 effectively takes place.

2. Method as claimed in claim 1, wherein the installation comprises a food mass pressure sensor (55) which is adapted to detect the pressure of the food mass in the chamber (16) of the mass feeder, and wherein the installation comprises a pump control unit (60) which is connected to the food mass pressure sensor (55), the method comprising selecting a target pressure or target pressure range for the food mass in the chamber (16), the pump control unit (60) stopping or slowing down the pump when the measured food pressure or said target pressure or exceeds said target pressure range and wherein the pump control unit activates or accelerates the pump when the measured food pressure falls below said target pressure or said target pressure preparation.

3. Method as claimed in claim 1 or 2, wherein the installation is provided with a pump timing mechanism which effects the activation or acceleration of the pump (5) during intervals that occur periodically during a revolution of the forming drum (22), each of said intervals is in a timed relationship to a corresponding filling event of a single mold cavity, an interval at least partially overlapping in time with that single filling event, which activation or acceleration causes a temporary increase in flow of food mass to the mass feeder (15) during that interval and wherein the flow is relatively reduced between successive intervals.

4. Method as claimed in one or more of the foregoing claims, wherein the mass supply member (15) comprises a funnel body which delimits the chamber (16), which body has main walls (15a) of substantially triangular shape which are connected along an mouth side thereof by a wall comprising the mouth (18) and the inlet (17) being arranged at a point of those main walls opposite the wall with the mouth, so that the effective cross-section of the chamber increases from the inlet to the wall with the mouth mouth.

A method according to any one of the preceding claims, wherein the mouth (18) is a single straight, closed contour slot parallel to the longitudinal axis of the drum (22).

6. Method as claimed in one or more of the claims 1-4, wherein the mouth (18 ') is a single slot with closed contour which is helically shaped to form a helical segment in the longitudinal direction and in the circumferential direction relative to the forming drum (22) to stretch out.

7. Method as claimed in one or more of the claims 1-4, wherein the mouth (18 ') is composed of a plurality of slot sections staggered relative to each other, wherein a section is offset in the circumferential direction of the forming drum relative to the one or more adjacent slot sections.

8. Method as claimed in any of the claims 1-7, wherein the installation comprises a first and a second mass feeder arranged at the filling position, wherein each mass feeder has a chamber which is separate from the chamber of the other mass feeder, preferably with a first and a second pump which are respectively connected to the first and the second mass feeder, and wherein the device has a single forming drum with a first part of the drum surface that passes along the first mass feeder and a second part that passes along the second mass feeder wherein the mold cavities of said single drum are filled by the first and second mass feed members, each of the first portion and the second portion of the drum surface having a plurality of mold cavities arranged in a pattern of mold cavities of each portion of the drum surface with cavities seen in multiple longitudinal positions in longitudinal direction of the drum and at a plurality of circumferential positions as viewed in the circumferential direction of the drum, and wherein for each mass feeder and associated part of the drum surface all filling events are carried out in sequential order.

9. Method according to any of the preceding claims, wherein the pattern of 10 mold cavities is composed of mold cavities of identical dimensions.

10. Method for forming meat products, for example hamburgers, from a pumpable ground meat mass, wherein use is made of a forming installation for forming meat products from a pumpable ground meat mass, which installation comprises: - a frame (21), - a frame (21), mold drum (22) with an outer circumferential drum surface (23) and a longitudinal drum pivot (24), the drum being rotatably supported by rotating the frame about the drum pivot axis, the mold drum in the drum surface having multiple mold cavities (25, 25a, 25b ), each of which has a filling opening for introducing meat mass into the mold cavity, - a mold drum drive (26) coupled to the drum (22) for driving the drum in a direction of rotation (D), - a mass feed member ( 15) disposed at a filling position with respect to the drum surface (23), which mass supply means has a single chamber (16) with an inlet (17) for vl a mass for introducing the meat mass into the chamber and with a mouth (18) directed toward the drum surface (23), which mass feeder is adapted to transfer the mass to passing mold cavities (25, 25a, 25b) of the rotating mold drum when the filling opening of a mold cavity is in communication with the mouth (18) at the filling position, the mass forming a meat product in the mold cavity, -23- a pump (5) connected to the inlet (17) of the mass feeder (15) and is adapted to feed meat mass under pressure into the chamber (16) of the mass feeder, the mold cavities (25) being arranged in the drum surface (23) in a pattern of mold cavities with cavities at several longitudinal positions viewed in longitudinal direction of the drum and at a plurality of circumferential positions viewed in circumferential direction of the drum, the method comprising: 10. driving the drum (22) in the direction of rotation (D) in a continuous, non-interrupted manner; - operating the pump (5) to supply meat mass to the mass feeder (15) and to effect a meat mass pressure in the chamber (16) of the mass feeder, 15. transferring pressurized meat mass through the mouth (18) in each passing mold cavity (25, 25a, 25b) in an associated mold cavity filling event defined by the moment of first flow of meat mass into the mold cavity (25, 25a, 25b) and the moment when the mold cavity is completely filled and the flow of meat mass 20. the unloading of molded products from the mold cavities, and wherein the operation of the pump (5) and the rotation of the mold drum (22) are controlled in combination with the design of the mold cavity pattern on the drum (22) ) and from the mouth (18) of the mass feeder that in the method all mold cavity filling events are performed in a sequential order during a revolution of the mold drum, preferably with a pause between each pair of consecutive filling events in which there is effectively no flow of meat from the mouth.

11. An installation adapted to carry out the method according to one or more of the preceding claims, for example wherein the installation has a computer control for the rotation of the drum and the operation of the pump, which control is programmed around the method according to the invention, for example with a memory containing predetermined routines which allows the installation to carry out the method according to the invention for selected food masses. 35