GB2324978A

GB2324978A - Method and apparatus for producing food products

Info

Publication number: GB2324978A
Application number: GB9709017A
Authority: GB
Inventors: Michael John Paul Mason
Original assignee: United Biscuits Ltd
Current assignee: United Biscuits Ltd
Priority date: 1997-05-03
Filing date: 1997-05-03
Publication date: 1998-11-11
Anticipated expiration: 2017-05-03
Also published as: GB9709017D0; GB2324978B

Abstract

A filled food product produced as a continuous length of tubular casing of dough with a soft filling is passed through apparatus comprising at least two cooperating curved surface tools (35) operably mounted in a drive mechanism (10) and located on either side of the intended path of the continuous length, the drive mechanism being operated to bring the curved surface tools together periodically whereby said filled food product is pinched therebetween to cause both separation of predetermined short lengths of the food product and sealing of the ends thereof. The resulting sealed product retains the desired shape and, amongst other advantages, can be baked without the soft filling bursting out the ends.

Description

Method and apparatus for producing food products The present invention relates to a method and apparatus for automatically and consistently manufacturing filled extruded food products and is concerned particularly, though not exclusively, with co-extruded products formed from an outer tubular casing of dough with a soft filling such as jam. It will be understood that such forming operations are conducted before the product is baked or otherwise finally cooked or subjected to other desired finishing treatments such as glazing.

A filled food product of the type noted above may be co-extruded using a process wherein the casing is extruded through an annular die while simultaneously the filling is extruded through a central mandrel. This process produces a continuous filled tube which, in order to produce the desired individual food product, needs to be cut and the cut ends sealed at regular intervals. There are cutter mechanisms available in the art for achieving this purpose which are located at or near the point at which the filled tube leaves the extruder. An example of such a mechanism relies on cutter means which operates in a manner rather similar to an iris diaphragm in a camera with the ability to close to zero aperture so as to completely cut through the food product to form a separated product. The intended operation of that mechanism is that if a filled tube is fed into the iris as it closes then it will be cut evenly on all sides. It is observed that during this cutting operation sealing of the cut ends of the food product can be obtained to a certain degree.

After the resulting individual products are cut they are conveyed away from the extruder/cutter apparatus usually by a belt conveyor. For best performance of the manufacturing process and minimal labour input it is highly desirable that the products to be conveyed away remain in an orderly predictable regular array. This enables subsequent process steps to be conducted upon the products in a predetermined way without for example needless waste of coating materials. Furthermore a random presentation of product would make it impossible to accurately apply physical treatments such as slitting to the product.

Problems exist when the above described apparatus is used in conjunction with tubular food products where the casing is to be made from a sticky material e.g. a dough with a low fat content. With such a product the stickiness of the casing leads to undesirable results in that the sticky casing often adheres to the cutter mechanism, fails to cut and release cleanly, and does not seal at the ends adequately. It is observed that the poorly cut product is often dragged out of line to either drop under the machinery or become trapped in the mechanism. If the product is not cut successfully then further processing of the still connected products is wasteful because they cannot be sold.

Where the product is not sealed adequately then at later stages e.g. during baking in the oven the soft filling comes out the ends again resulting in a product which is not desirable for the market. Therefore losses in marketable product arise due to these deformed products. Obviously where product becomes lodged in the mechanism or falls under the machinery then this also involves economic losses due to delay whilst the mechanism is cleaned, interruption in production, waste of materials in product which cannot be finished for sale and higher labour input than is predictable from theoretical optimum performance of the process. Such problems frustrate manufacture of consistent product in terms of quality, even weight distribution, filling to casing ratio control and low wastage.

It is an object of the present invention to obviate or at least mitigate the aforementioned disadvantages.

According to a first aspect of the present invention there is provided apparatus to separate and seal a filled food product from a continuous length thereof to be passed therethrough the apparatus comprising at least two cooperating curved surface tools mounted in a drive mechanism and located on either side of the intended path of the continuous length, the arrangement being such that the drive mechanism is operated to bring the curved surface tools together periodically whereby said filled food product is pinched therebetween to cause separation of predetermined lengths of the food product with sealing of the ends thereof.

Preferably the drive mechanism operates such that the curved surface tools cooperate together by motion following respective curved paths. Such paths may be circular and are preferably paired in opposite directions, i.e. the drive mechanism operates in a contra-rotary manner.

Preferably also the drive mechanism operates multiple pairs of tools in an array allowing a plurality of continuous lengths of tubular food product to be processed in parallel.

The curved surface tools may be conveniently provided in the form of pins each of which is preferably provided with a tapering lobe to thereby provide a working curved surface of a substantially tear-drop configuration when viewed in plan. Thus each such preferred pin has essentially a head surface and a tail surface with a gradual taper therebetween. Such a configuration, which applies essentially blunt surfaces to the casing instead of cutter blades as in the known apparatus, surprisingly improves the separation and sealing of the product length in the desired manner. Thus by a single operational step both product separation and end sealing is achieved efficiently.

The tools such as pins of the preferred type are operably mounted to cooperate in pairs such that as the drive mechanism brings the tools together the head which has a leading surface of a relatively large curvature makes first contact with the food product, pinching it, and as the tool continues to follow its curved approach towards its mutually approaching partner, the product is first separated and then the closing tail sweeps towards its opposite number neatly sealing both the cut product end and the leading end of the continuous length. The separation step is enhanced by the effect of conveying the separated product away at a rate which is faster than the feed rate of the continuous length of food product. Careful timing control of the conveying away step with the pinching action of the tools leads to a very satisfactory separation of the sealed product, avoiding the risks of deformed products and fouling of the mechanism. It will be understood that the tools whilst being brought together to perform the pinching action do not need to contact each other to complete separation.

The pinching action upon the product coupled with the conveying step has been found to achieve the objectives.

Preferably the pins are mounted upon two contrarotating spindles, said pins being supported upon intermediate members such that the pins are provided eccentric to the rotational axes of the spindles. This arrangement provides for an improved approach to separation of the product with the desired type of sealing without fouling of the mechanism.

Conveniently the intermediate members may take the form of circular plates.

A drive mechanism is provided for at least one of the spindles, and the rotational motion of the other cooperating spindle(s) may be synchronised by a drive train e.g. by means of meshing spur gears provided upon the spindles.

Whereas it seems preferable to have the cooperating tools arranged to be driven or activated in a similar fashion to obtain the desired pinching action, variants of the mechanism include the possibility of varying the path and distance to be travelled by one or both tools during that operational cycle provided always that the tools cooperate together at the required stage to achieve the necessary separation and sealing action. Thus one such tool may be located in a more confined or a fixed but functional position, for example beneath a flexible conveyor surface over which product is passed for processing, the complementary tool(s) being brought towards the confined or fixed tool to an extent appropriate to provide the desired result.

The apparatus is ideal for use with filled food products which are co-extruded, but filled tubular products made in other ways known per se in the food industry can also be processed in a similar way. Therefore it is not essential that the product is a co-extruded product.

The invention is most advantageous for low fat dough products or the like sticky doughs which are to be used as a casing for soft fillings especially fillings such as fruit based substances e.g. jam which is prone to burst through casings when baked in an oven.

According to a second aspect of the present invention there is provided apparatus to separate and seal a plurality of filled food products comprising a plurality of contrarotating spindle pairs, each spindle of said spindle pairs supporting at least one tool mounted eccentric to the rotational axis of said spindle and being located on either side of the intended path of the food product to be separated and sealed, wherein the rotational paths of said tools supported by each spindle pair coincide once per revolution to compress the filled food product passing therebetween The tools are preferably pins having a profile which applies a variable degree of pressure to the food product with respect to a predetermined period of contact time, said pressure being sufficient to firstly penetrate the casing of the food product and secondly tamp down the ends thereof to seal the product.

According to a third aspect of the invention the apparatus of the aforesaid novel type for separating and sealing the food product further comprises a slitter mechanism for applying at least one slit to the food product intermediate its ends. Such a slit is normally applied in the food industry to the top of a product and has the effect of acting as a vent during baking and also offers an aesthetic improvement to the final marketable product.

According to the invention the slitter mechanism is synchronised with the sealing and separation mechanism to provide a sealed, slit and separated food product. The slitter mechanism is preferably electronically controlled to precisely locate the slit between the ends of the product.

Thus the whole slitting, sealing and separation operation is easily controlled using a microprocessor thereby minimising labour input during the process.

A method of separating and sealing a filled food product comprising the steps of: feeding a tubular filled food product of indefinite but continuous length into a mechanism for separating and sealing short predetermined lengths of food product, providing at least two cooperating curved surface tools and a drive mechanism adapted to bring said tools together to develop a pinching action between surfaces of said tools, separating a short predetermined length of food product from the continuous length by said pinching action, whilst sealing the end of said separated short length of food product by the continued action of the tool surfaces following through said pinching action, and at the same time, supporting the separated short length of food product upon conveyor means and, conveying same away from the tools, preferably at a rate exceeding the feed rate of the continuous length of filled food product.

The step of bringing together of the tools is preferably conducted along a curved path.

The method of this invention thus provides for effective sealing and separation of short product lengths essentially by a single step in the operation of the mechanism provided by this invention.

An embodiment of the present invention will now be described with reference to the following drawings: Fig 1 is a partially sectioned front view of separation and sealing apparatus in accordance with the present invention for use in conjunction with ten co-extruded filled product tubes; Fig 2 is a side view of the apparatus of Fig 1; Fig 3 is a view from below of the apparatus of Fig 1; Fig 4 is a partial sectional front view of separation and sealing apparatus in accordance with the present invention intended for use in conjunction with a single line (one co-extruded tubular product); Figs 5A-5B are plan and side views respectively of a pair of pin tool separator devices according to an aspect of the present invention; Figs 6A-6F are plan views of the motion of a pair of pin tool separator devices according to an aspect of the present invention; and Fig 7 is a schematic representation of a control system for production apparatus embodying separation and sealing apparatus in accordance with the present invention.

Referring to firstly to figures 1 to 3 there is shown apparatus 5 for the cutting and sealing of ten co-extruded filled dough/jam tubes. The apparatus comprises a drive unit 10 and an arm 15 supporting ten pairs of spindles 20A20J. Upon a lower end of each spindle 25 is mounted a circular plate 30 which in turn supports a downwardly projecting tool in the form of pin 35. Each pin 35 is mounted at the edge of its circular plate 30, while the circular plates 30 are positioned concentrically with respect to the spindles 25. Thus rotation of the spindles 25 will result in the rotation of the pins 35 in an eccentric manner about the rotational axes of the spindles 25.

Each spindle 25 is rotatably mounted in the arm 15 by an upper 40 and a lower 45 bearing. Each spindle 25 is further provided with a spur gear 50 which meshes with the spur gear(s) 50 of the adjacent spindle(s) 25 of any given spindle 25. It will be apparent that this arrangement forms a cascade of meshing spur gears 50 and that rotation of any given spindle 25 either clockwise or anti-clockwise will result in the corresponding clockwise and anti-clockwise rotation of the other spindles 25. In the embodiment of the invention shown in figures 1 to 3 the drive unit 10 is provided with downwardly projecting drive shaft 55 upon which is mounted a spur gear 60. The drive unit 10 is positioned substantially centrally with respect to the arm 15 and thus the drive shaft spur gear 60 meshes with the spindle spur gear 50 present upon the tenth spindle 25 from a first end 65 of the arm 15.

It will be apparent that, in use, each of the ten spindle pairs 20A-20J comprises both a clockwise rotating spindle and an anti-clockwise rotating spindle. The pins 35 on each of the circular plates 30 are positioned such that they coincide along the axis A indicated on figure 3 once per revolution of the spindles 25.

Referring to figure 4 there is shown a spindle pair 68 according to an alternative embodiment of the present invention. For ease of reference components common to the embodiment described above are annotated with like numerals.

In this embodiment a first spindle 70 projects upwardly from a spindle housing 75 to engage drive means (not shown).

Furthermore the circular plates 30 are each provided with an additional downwardly projecting pin 80.

Referring now to figures 5A and 5B there are shown a pair of pins 35. The pins 35 are cam shaped with a substantially circular face 85 and a single lobe 90 projecting therefrom. Figures 6A to 6F show the relative motion of a pair pins 35 over a portion of a single revolution. The pins 35 are positioned at the edge of circular plates 30 such that when they coincide, as shown in figure 6C, their axes indicated B-B and C-C respectively are substantially parallel to one another. The pins 35 are positioned such that at the point at which they coincide they do not touch one another but that a gap of around 0.1 mm is left.

In use, apparatus 5, 68 in accordance with the present invention is provided above a conveyor , which serves to transport co-extruded filled dough/jam tubes from an extruder, such that a filled dough/jam tube passes between a pair of contra-rotating pins 35. Once per revolution of the spindles 25 and circular plates 30 the pins 35 coincide and both cut the filled dough/jam tube and seal the ends formed by the cut to prevent the jam filling escaping. It will be understood that repeated use of the apparatus 5, 68 will result in the filled dough/jam tube being cut into a plurality of individual sections which are sealed at both ends. The rate at which the filled dough/jam tubes are extruded, together with the conveyor speed and the rotational speed of the pins 35, may be varied and thus the length of the individual section produced may be varied to meet end product requirements. Depending upon these such requirements the circular plates 30 may be fitted with more than one pin 35 in order that more than one cutting and sealing operation may be undertaken per revolution.

It will be noted from figures 6C to 6F that, once the pins 35 have passed the point at which they coincide and hence begin to diverge, inner facing flanks 95 of the pins 35 continue to close towards one another. This has the effect of further compressing the portion of the filled dough/jam tube between the pins 35 and hence strengthens the seal provided at the leading edge of the filled dough/jam tube.

Referring to figure 7 there is shown a schematic representation of the components of a production apparatus 100 embodying cutting and sealing apparatus 105 in accordance with the present invention. The production apparatus 100 comprises an extruder 110 for producing at least one filled dough/jam tube (not shown), a first conveyor 115, apparatus 120 to place a slit in the top of the filled dough/jam tube(s), cutting and sealing apparatus 105 to produce individual sections from the filled dough/jam tubes, and a second conveyor 125 to transport the individual sections, for example, to an oven or for further processing.

The operations of the above components are synchronised by a programmable multi-axis controller (PMAC) 130 which is provided with interface means 135 to allow operating parameters such as extrusion rate to be changed. Signals sent from the PMAC 130 to the slitting apparatus 120 and the cutting and sealing apparatus 105 pass through servo amplifiers 140, 145.

Claims

1. Apparatus for separating and sealing a filled food product from a continuous length thereof to be passed therethrough the apparatus comprising at least two cooperating curved surface tools mounted in a drive mechanism and located on either side of the intended path of the continuous length, the arrangement being such that the drive mechanism is operated to bring the curved surface tools together periodically whereby said filled food product is pinched therebetween to cause separation of predetermined lengths of the food product with sealing of the ends thereof.

2. Apparatus according to claim 1 wherein the drive mechanism operates such that the curved surface tools cooperate together by motion following respective curved paths.

3. Apparatus according to claim 2 wherein the paths are circular.

4. Apparatus according to claim 2 or claim 3 wherein the drive mechanism operates in a contra-rotary manner to drive paired tools in opposite directions.

5. Apparatus according to any one of the preceding claims wherein the drive mechanism operates multiple pairs of tools in an array allowing a plurality of continuous lengths of tubular food product to be processed in parallel.

6. Apparatus according to any one of the preceding claims wherein the curved surface tools are provided in the form of pins each of which is provided with a tapering lobe to thereby provide a working curved surface of a substantially tear-drop configuration when viewed in plan.

7. Apparatus according to any one of the preceding claims wherein the tools are mounted upon two contra-rotating spindles, said tools being supported upon intermediate members such that the tools are provided eccentric to the rotational axes of the spindles.

8. Apparatus according to claim 7 wherein the intermediate members are circular plates.

9. Apparatus according to claim 7 wherein the drive mechanism drives at least one of the spindles, and the rotational motion of the or all other spindles is synchronised by a drive train e.g. by means of meshing spur gears provided upon the spindles.

10. Apparatus to separate and seal a plurality of filled food products comprising a plurality of contra-rotating spindle pairs, each spindle of said spindle pairs supporting at least one tool mounted eccentric to the rotational axis of said spindle and being located on either side of the intended path of the food product to be separated and sealed, wherein the rotational paths of said tools supported by each spindle pair coincide once per revolution to compress the filled food product passing therebetween

11. Apparatus according to claim 10 wherein the tools are pins having a profile which applies a variable degree of pressure to the food product with respect to a predetermined period of contact time, said pressure being sufficient to firstly penetrate the casing of the food product and secondly tamp down the ends thereof to seal the product.

12. Apparatus according to any one of the preceding claims further comprising a slitter mechanism for applying at least one slit to the food product intermediate its ends.

13. Apparatus according to claim 12 wherein the slitter mechanism is synchronised with drive mechanism for the tools whereby a sealed, slit and separated food product is obtainable.

14. A method of separating and sealing a filled food product comprising the steps of: feeding a tubular filled food product of indefinite but continuous length into a mechanism for separating and sealing short predetermined lengths of food product, providing at least two cooperating curved surface tools and a drive mechanism adapted to bring said tools together to develop a pinching action between surfaces of said tools, separating a short predetermined length of food product from the continuous length by said pinching action, whilst sealing the end of said separated short length of food product by the continued action of the tool surfaces following through said pinching action, and at the same time, supporting the separated short length of food product upon conveyor means and, conveying same away from the tools, preferably at a rate exceeding the feed rate of the continuous length of filled food product.

15. A method according to claim 14 wherein the step of bringing together of the tools is conducted along a curved path.

16. A method according to claim 14 or claim 15 wherein the cooperating tools are provided in the form of pins mounted to cooperate in pairs such that as the drive mechanism brings the pins together a curved surface thereof makes first contact with the food product, pinching it, and as the pin continues to follow its curved approach towards its mutually approaching partner, an end of the product is separated and sealed.

17. A method according to any one of claims 14 to 16 wherein the separation step is enhanced by the effect of conveying the separated product away at a rate which is faster than the feed rate of the continuous length of food product.

18. A method of separating and sealing a filled food product utilising at least two cooperating curved surface tools substantially as hereinbefore described.

19. A filled food product whenever obtained by a method according to any one of claims 14 to 18.

20. Food processing plant for producing a filled food product wherein the required lengths of said product are automatically separated from a continuous length thereof and sealed at both ends, said plant comprising apparatus substantially as hereinbefore described with reference to and as shown in Figs. 1 to 7 of the accompanying drawings.