GB2274802A

GB2274802A - Machine for extruding comestible materials

Info

Publication number: GB2274802A
Application number: GB9302060A
Authority: GB
Inventors: Leslie Neville Reeves
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-02-03
Filing date: 1993-02-03
Publication date: 1994-08-10
Anticipated expiration: 2013-02-03
Also published as: GB2274802B; GB9302060D0

Abstract

A machine for extruding edible material comprises a vessel 10, with an agitator 12, which directs material towards the periphery of the bottom of the vessel. Worms 17, 18 disposed diametrically opposite each other direct the material down into outlets 13, 14. The outlets are branched to lead to four pumps 25, 26, 27, 28 and to nozzles 33, 34, 35, 36. The shafts of the worms 17, 18 and the agitator 12 extend out above the vessel, and are connectable by self engaging and disengaging clutches to an arm or head 37, which can be swung into and out of position over the vessel, to allow access to the vessel. The entire machine is mounted on a weigh-bed 47 which is compensated to cancel out the weight of the machine, so that only the weight of the contents of the vessel is recorded, and may be connected to monitoring means for sampling the weight readings and displaying results, or controlling pump delivery rates. <IMAGE>

Description

IMPROVEMENTS IN MACHINES FOR EXTRUDING COMESTIBLE MATERIALS This invention relates to improvements in machines for extruding comestible materials.

In the bulk manufacture of food products and confectionery, comestible materials are extruded as continuous or semi-continuous lengths or discrete portions of the material for subsequent coating.

The comestible materials may be for example chocolate, or fruit jams for example, for coating in pastry shells, or shells of an uncooked pastry precursor, or the like.

It is known to extrude such comestible materials from one or more nozzle, usually two, each powered by a pump, and fed by an outlet from a vat or hopper of such material. The material in the hopper is stirred by a rotated agitator which has blades profiled to direct the material outwards to the periphery of the vat. An outlet is provided for the material, extending tangentially horizontally from the periphery of the base region of the vat, in a direction such that the agitator tends to impel material into the outlet. The outlet may be fed by a rotating screw feeder worm, and branches to connect to the outlet to each of a pair of pumps, which each deliver the material to a respective extrusion nozzle.The nozzles may be manipulated as desired to produce continuous or discontinuous lengths or portions of the material on a conveyor which is disposed to receive the material dispensed from the nozzles.

It is desirable, from the point of view of increasing output, to increase the number of nozzles which extrude onto the conveyor.

However, simply further dividing the flow from the outlet will not suffice, and will merely reduce each flow in volume terms. Taking a second outlet from the diametrically opposite side of the vat also gives rise to problems, as the most efficient outlet feed is in the direction of rotation of the mixture imparted by the agitator, and not against it, so that such a second outlet must extend in the direction opposite the first outlet, so that extra pipe connections are required to connect such a second outlet to nozzles disposed alongside the nozzles fed from the first outlet.

The rotary parts in the vat, such as the agitator and the feed worm are driven from below, and whilst this enables easy access to the vat from above for cleaning and maintenance, there are problems with sealing due to seepage of comestible material under pressure seeping from the vat through shaft seals and capilliary joints, leading to considerable wastage.

Such known extruders are also not effectively thermally insulated or jacketed, to maintain the temperature and thus viscosity of the material therein, and monitoring of the throughput is not possible, to ensure the production of a consistent end product particularly in terms of fillingicoating ratios, except by estimations based on refilling rates, and the skill of the operator, which is complicated -by factors such as leakage of the product.

A main object of this. invention is to provide a food product extruding machine which is able to operate twice as many nozzles as the said known machine, and objects which are preferably attained by the invention or some embodiments of it include a construction which makes possible a reliable leak-proof sealing against seepage of product, and which enables continuous monitoring of throughput to enable product quality and consistency to be ensured.

According to the invention, a machine for extruding comestible material comprises a vessel for containing a supply of extrudible material, stirring means provided in the vessel and rotatable to stir the material and direct a flow of the material towards the periphery of the base of the vessel, two outlets provided at diametrically opposed sides of the vessel, each having a respective feed worm with a vertical axis to feed material downward through each outlet, each outlet being connected by a bifurcated conduit to

respective

outlet nozzles via respective pumps, the nozzles all opening in the same direction.

In accordance with a preferred embodiment of the invention, the feed worms and stirring means are all driven from overhead, to thereby substantially eliminate leakage of material via the seals of rotary connections effected from below. In order to allow access to the vessel for cleaning and maintenance, the drive connections are preferably mounted on a pivotable arm or head, which can be stvlln about a vertical pivot at one side of the vessel over, and clear of the vessel to allow access thereto, or to be connected, via suitable clutches or other self-locating connections, to drive shafts for the stirring means and feed worms.

The vessel is preferably provided with a water-jacket, so that water at a desired temperature (e.g. above the setting temperature of chocolate), can be fed through the water jacket to maintain material in the vessel at a desired temperature, to thereby maintain a desired state of viscosity.

In accordance with a further feature of the invention, means are provided whereby the weight of material in the vessel can be continuously, or periodically, determined, so that the feed rate of material from the machine can be monitored and controlled, and the vessel replenished when required.

In a preferred embodiment, the machine, including the vessel, pumps and nozzles and drive motors for the pumps and other rotating parts, is carried on a weigh-bed, which is compensated so that the weight of the machine is cancelled out, and only the weight of material on the machine is registered. A monitoring device, e.g.

an electronic computer, may be set up to sample the weight at prescribed intervals, for example as frequently as the timer on each 5 seconds of time, and the samples taken in each five second period averaged to produce a nearly instantaneous display. The frequency, or integration period for weight samplings may of course be greater, or much less, and may be selectable as part of the operation of the computer. The computer may only provide a visual numerical display of the total weight of the material in the machine, and /our a calculated feed rate, in grammes or Kg per minute, allowing an operator to operate controls to alter the delivery rate of the pumps. Alternatively, the computer may control the pumps in order to maintain the delivery rate at a prescribed level, with operator intervention only being needed to alter the prescribed delivery rate.

A preferred embodiment of machine for extruding comestible products according to the invention will now be described, by way of example, with reference to the accompanying drawings, wherein: Fig. 1 is a frontal elevation of a machine according to the invention; Fig. 2 is a side elevation of the machine shown in Fig. 1; Fig. 3 is an overhead view of the machine of Figs. 1 and 2; Fig. 4 is a sectional view, on line IV-IV in Figs. 1 and 2; and Fig. 5 is a diagrammatic view of a control panel associated with the machine.

A machine for extrusion of comestible materials, such as jams, chocolate, cream or the like, in the manufacture of confectionery, biscuits and other bakery products, comprises a vessel 10, which is of generally cylindrical shape. The vessel contains an axial drive shaft 11, connected to a rotor 12, located adjacent the floor of the vessel 10, which is configured to keep material in the vessel stirred, and to direct a flow of the material outwardly towards the sides of the vessel.

Two outlets, 13, 14 are disposed on axially opposite sides of the vessel, in the floor of the vessel, and each outlet is connected to an outlet pipe 15, 16, and has an associated helical feed worm screw 17, 18, which is driven by a respective shaft 19, 20. Each outlet pipe 15, 16 is curved to a generally horizontal orientation and bifurcated into branch pipes 21, 22 and 23, 24 connected to respective pumps 25, 26 and 27, 28 which are each driven by respective motors 29, 30 and 31, 32 and debouch through nozzles 33, 34 and 35, 36.

Due to the vertical orientation of the axes of outlets 13, 14 and worms 17, 18, the outlet pipes of both outlets can be curved around so that the nozzles 33-36 can face in the same direction, onto for example a single conveyor for receiving extruded material.

The drives for the vertical shafts 11, 19 and 20 are contained in a pivotable beam or head 37, which can be swung between alternative positions about an axis coincident with that of shaft 19, worm 13 and outlet 15.

A motor 38 drives the centre shaft 11, by means of a suitable gear arrangement, and drive is taken by means of sprocket and chain arrangements 39, 40, to respectively the worm shafts 19 and 20. The beam 37 is latched by a mechanism 41 into the closed (over the vessel) position by a lever 42, and can be swung into an alternative position (Fig. 3) wherein the vessel is clear for removal of a lid 43 for access to the interior of the vessel for cleaning and maintenance.

The beam 37 pivots on the drive shaft 19, and the other drive shafts 11 and 20 are arranged so that they are automatically connected to the drive when the beam is moved into the working position over the vessel. A proximity switch is provided adjacent the free end of the beam 37 so that the machine can only be switched on when the beam is in the working position.

The vessel 10 is supported on legs 44, 45 which also carry the weight of the pumps 25-28 and motor 29-32 and the beam 37, and the legs 44, 45 are supported on a weigh platform 46. This platform 46 forms part of a weighing apparatus in which the fixed weight of the vessel, beam, pumps and motors are compensated by balance weights or electronically, so that the weight of the contents can be determined from moment to moment.

The weighing platform 46 is carried on a bed 47, in turn carried on wheels or castors 48 so that the machine can easily be moved as required.

The weighing apparatus includes a pre-programmed semi-conductor device or computer, which determines the weight of the filling from moment to moment, and periodically produces values for the feed rate of the machine (derived from the weight reduction of the material over a given period, and expressed in standard units as Kg per hour, or grammes per minute). The computer can also be programmed to produce a display, andlor adjust the settings of the pumps from time to time to compensate for variations of e.g.

viscosity in the material, and demand and initiate periodic refillings of the vessel when the total weight has dropped below a pre-set value. Alternatively, a visual display only may be provided, and actual control left to the discretion of a human operator.

Refilling is effected through an inlet connection 49 into the vessel 10.

An example of a control panel for the machine is illustrated in Fig. 5. 50 is a control switch for the stirrer drive. 51, 52, 53 and 54 control a respective one of the pumps, and 55 is a common control for all the pumps. Each of these controls includes a variable resistance or potentiometer to control the rate of the respective drive motor. 56 is a trim control.

At the other side of the panel, a window 57 displays numerical digits denoting either the weight from moment to moment of the material in the machine, or the feed rate, as derived by the computer from input data. 58 is a stop switch, 59 is a lamp indicating whether the machine is on or off, or if the machine is being refilled, when the lamp flashes; 60 is a start switch, 61 a reset switch, and 62 a switch to initiate the weight or rate determining computer.

Using this, the pumps may first be adjusted to produce a balanced flow rate, then further adjustment of the pumps, using common control 55 may alter all the pumps together, after they have been balanced or equalised.

The overall throughput of the machine can be monitored by the weight or rate determining computer, so that for example the ratio of filling extruded by the machine can be optimally adjusted in relation to subsequently applied coating, to obtain the desired product recipe.

Modifications and variations are possible within the scope of the invention, and for example, the construction enabling four nozzle extrusion may be adapted for a range of products of different viscosity, and not restricted to the food industry. The continuous weighing facility may also be adapted for use with machines of otherwise known constructions. The machine may be adapted for use with other plastic extrudable substances, including clay, synthetic plastics resins and the like.

Claims

1. A machine for extruding comestible material comprising a vessel for containing a supply of extrudable material, stirring means provided in the vessel, said stirring means being rotatable to stir the material and to direct a flow of the material towards the periphery of the base of the vessel, two outlets being provided, each outlet being located diametrically opposite the other outlet, and each outlet having a respective feed worm with a vertical axis to feed material downward through each outlet, each outlet being connected by a bifurcated conduit to respective outlet nozzles via respective pumps, said outlet nozzles all opening in the same direction.

2. A machine according to claim 1 wherein said stirring means and said feed worms are all driven by drive means from overhead of the vessel.

3. A machine according to claim 2 wherein means for operatively connecting said stirring means and said feed worms to said drive means are mounted in a pivotable arm or head, which can be swung about a vertical pivot at one side of the vessel above and over, or clear of, the vessel to allow access to the vessel, or to be connected by self locating connection means to drive shafts for the stirring means and feed worms.

4. A machine according to claim 1, 2 or 3 wherein the vessel is provided with a water jacket, so that water at a desired temperature can be fed through the water jacket to maintain material in the vessel at a desired temperature and thereby maintain a desired state of viscosity.

5. A machine according to any preceding claim wherein means are provided whereby the weight of material in the vessel can be continuously, or periodically, determined so that the feed rate of material from the machine can be monitored and controlled, and the vessel replenished when required.

6. A machine according to claim 5 wherein said means comprises a weigh-bed upon which the machine is carried, the weigh-bed being compensated so that the weight of the machine is cancelled out, and only weight of material in the machine is registered.

7. A machine according to claim 6 wherein a monitoring device is set up to sample the weight registered by the weigh-bed at prescribed intervals of time.

8. A machine according to claim 7 wherein the monitoring device includes an electronic computer programmed to record the weight a plurality of times in a predetermined integration period, to calculate, and to display a mean weight value determined in said integration period.

9. A machine according to claim 8 wherein said electronic computer is also programmed to operate to control the pumps to maintain a predetermined delivery rate.

10. A machine for extruding comestible material, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.