CA1249947A - Method and apparatus for manufacturing a confection, depositor for use in such a method, and depositing apparatus - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
The present invention provides an apparatus for depositing a material from a multiplicity of outlets into respective rows of moulds, said apparatus comprising at least one depositor containing a multiplicity of outlets and res-pective valves for controlling the flow of material through said outlets; a conveyor for conveying rows of moulds past said depositor; means for supplying material under pressure to said at least one depositor; and control means for periodi-cally opening and closing said valves in a sequence such that, in use, the number of valves which are open and the number of valves which are closed in said at least one depositor does not vary as well as a method of depositing a material from a multiplicity of outlets into respective rows of moulds, com-prising the steps of supplying material under pressure to at least one depositor containing a multiplicity of outlets and respective valves for controlling the flow of material through said outlets, depositing said material into said moulds thorugh said orifices, and periodically opening and closing the valves in a sequence such that the number of valves which are open and the number of valves which are closed does not vary.

Description

~Z~9~47 This invention relates to a method of manufacturing confectionery and is more particularly concerned with a method of manufacturing confectionery in which a confection, e.g.
chocolate, in a liquid phase is thoroughly mixed with gas under pressure and is then passed through a depositor into a zone of lower pressure so that gas expansion occurs to produce an expanded product which requires further cooling for more rapid s~lidification. The invention also relates to a deposi-tor for use in such a metnod.
This application is a divisional application of copending Canadian application No. 438,803 filed October 12, 1983.
We have found, in the manufacture of an expanded confection, that, for volume production, it is difficult to produce a product which is evenly expanded to the desired extent. We have also found that the manner in which the mix-ture of liquid confection and gas is discharged through the depositor has a substantial effect on the quality of the expanded product insofar as cell uniformity and size are con-cerned.
The present invention provides an improved process whereby by cell uniformity and size can be strictly con-trolled.
According to a first aspect of the present invention as disclosed and claimed in copending Canadian application No.
438,803, there is provided a method of manufacturing a confec-tion comprising the steps of thoroughly mixing a confection in liquid phase form with gas under pressure, passing the mixture of liquid phase confection and gas through a depositor into a zone of lower pressure s~ as to allow the confection to expand, and allowing the expanded confection to solidify to produce a solid expanded confection, wherein the depositor ~L~499~7 includes at least one annular orifice through which said mix-ture is discharged, the annular orifice discharging into said region of lower pressure and having a length which is not greater than its diameter, and wherein the depositor includes a valve for controlling flow of said mixture to said annular outlet orifice, said valve including an annular valve seat and a valve member movable into and out of engagement with the valve seat.
~ccording to a second aspect of the present inven-tion as disclosed and claimed in copending Canadian applica-tion No. 438,803, there is provided apparatus for carrying out the method of the invention, said apparatus comprising means for mixing a confection in liquid phase form with gas under pressure, a depositor for receiving the mixture and for dis-charging said mixture to a lower pressure zone, and means for receiving said mixture from the depositor and allowing said mixture to cool to form an expanded confection, wherein the depositor includes at least one annular orifice through which said mixture is discharged, the annular orifice discharging into said region of lower pressure and having a length which is not greater than its diameter, and a valve associated with said at least one annular orifice, said valve including an annular valve seat surrounding said annular orifice and a valve member movable into and out of engagement with the valve seat.
Preferably, the inner peripheral wall of the annular orifice is defined by an extension of the valve member.
In one embodiment, the valve seat is defined by a frusto conical surface which merges with an upstream end o~
the outer peripheral wall of the annular orifice, and the mov-able valve member has a valve seat-engaging edge which is rounded.

~2~9947 In another embodiment, the valve seat is defined by a rounded surface which merges with an upstream end of ~2~'9~7 the outer peripheral wall of the annular oriEice, and the valve member has a frusto conical surface engageable with the valve seat.

Typically, in either embodiment, the rounding on the valve mem~er or the valve seat, as the case may be, is of a radius of 0.5 to 2 mm, peeferably 1 mm.

It is preferred for the diameter of the inner peripheral wall of the annular orifice to be 1/2 to 2/3 that of the annular contact line between the valve member and the valve seat.

In a highly preferred embodiment, a multiplicity of such annular orifices and associated valves are provided in the depositor, and the valves are so controlled that they are opened and closed in sequence so that at any one time during operation of the process, the same number of valves are open, the number being such as is required to give the period of switch off during the cycle to produce the desired length of deposit.

Preferably also, more than one depositor is fed with said mixture of liquid phase confection and gas.

~ith such a construction of annular outlet orifice, we have found that the shear which is imparted to the mixture as it is expanding during passage through the orifice is minimised because of the short length of the passage through which the mixture is constrained to pass and, for a given throughput, produces less of a velocity profile across the passage than an outlet orifice of circular cross-section. Large velocity profiles across the outlet orifice have been found to give uneven expans~on of the confection.

According to a third aspect of the present inven-tion, there is provided a depositor for use in a method of manufacturing confectionary according to the present inven-tion, said depositor comprising a body for receiving a mixture of a confection in liquid phase forrn and gas, said body having at least one outle-t orifice through which said mixture is dis-charged, in use, the annular orifice having a length which is not greater than its diameter, and a depositor further includ-ing a valve having an annular valve seat surrounding said annular orifice and a valve member movable into and out of engagement with the valve seat.
Where a material is to be deposited into a multi-plicity of moulds from a series of orifices in one or more depositors, problems can arise in obtaining products of con-sistent quality with existing depositors if the material to be deposited is pressure sensitive. An example of such a mate-rial is a foamed confection such as foamed chocolate. Fluctu-ations in the pressure of the supply causes pressure varia-tions in the material being moulded and undesirable variations in the density and cell size of the foamed product as well as inconsistencies in the weight of material deposited in the moulds.
~ In a fourth aspect of the present invention this disadvantage is obviated or mitigated.
According to the present invention, there is pro-vided apparatus for depositing a material from a multiplicity of outlets into respective rows of moulds, said apparatus com-prising at least one depositor containing a multiplicity of outlets and respective valves for controlling the flow of material through said outlets; a conveyor for conveying rows of lZ49947 moulds past the depositor; means for supplying material under pressure to said at least one depositor; and control means for periodically opening and closing the valves in a sequence such that, in use, the number of valves which are open and the number of valves which are closed in said at least one depositor does not vary.

~ith such an arrangement, pressure fluctuations in the supplying means caused by more valves being open at some times than at other times in the operating cycle are obviated.

In a preferrred embodiment, the periodic valve opening and closing means is arranged so that, at any time only one valve in the or each depositor is closed whilst the remaining valves in the or each depositor are open.

Preferably, the conveyor is continuously movable, the moulds associated with the or each depositor are arranged in rows which extend longitudinally of the direction of travel of khe conveyor with the moulds in the respective rows being aligned in a direction at right angles to said direction of travel; said at least one depositor is inclined at an acute angle to the direction of alignment oE the rows; and said valve opening and closing means is controlled so as to cause material to be discharged from said depositor into a respective one of the sets of aligned moulds during each cycle of operation.

Preferably, also a plurality of depositors is provided, and the valve opening and closing means is arranged to cause a respective one of the valves in every head to be periodically opened and closed simultaneously. ~th such an arrangement, it is ~Z~99~7 convenient to provide a separate control valve for controlling operation of each set of valves in the heads which are to be opened and closed simultaneously. Preferably, each control valve is arranged to be operated by a respective cam, the cams being mounted on a common shaft driven from the conveyor and being equi-angularly staggered around the shaft.
The pres~nt invention further provides a method of depositing a material from a multiplicity of outlets into respective rows of moulds, comprising the steps of supplying material under pressure to at least one depositor containiny a multiplicity of outlets and respective valves for controlling the flow of material through said outlets, depositing said material into said moulds through said orifices, and periodi-cally opening and closing the valves in a sequence such that the number of valves which are open and the number of valves which are closed does not vary. Suitably the valves are opened and closed such that, at any time, only one valve in the or each depositor is closed whilst the remaining valves in the or each depositor are open. Desirably said material being deposited is a foamed confection. More desirably the method includes the step of mixing gas under pressure with a confection, and supplying the resultant mixture to said at least one depositor so that foaming of the confection occurs as a result of pressure releases upon discharge through said outlets.
An embodiment of the present invention will now be described, by way of example, with reference to the accompany-ing drawing, in which:-Fig. 1 is a schematic illustration of apparatus for manufacturing aerated chocolate according to the presentinvention to illustrate the principles of the present inven-tion;

~Z4~47 Fig. 2 is a cross-sectional view through a depositor used in the apparatus of Fig. 1, and showing schematically a control for such deposi-tor;
Fig. 3 is a plan view of four depositors forrning part of a practical embodiment of apparatus for manufacturing aerated chocolate according to the present invention;
Fig. 4 is a schematlc circuit diagram showing a typ-ical pneumatic control circuit, for a respective pneumatically operated valve in each of the four depositors of Fig. 3;
Fig. 5 is a front view of a mechanism for operating control valves in six pneumatic circuits of the type illus-trated in Fig. 4; and - 7a -~2~4~

Fig. 6 is an end view of the mechanism of Fig. 5.

RefeLring now to Fig. 1, the apparatus comprises a pump 1 whl~h a~d~ tempe~ed Ghoaolate along line 2 to a mlxar ~ o ~ pr3~ ~ b~own ~yp~ ~a~ ~smple ~ m1xer sold under the code E or G by rlONDO~IIX). Carbon dloxlde under pressure is fed via a line 4 into the line 2 and is intimately mixed with the tempered chocolate in the mixer 3. It will be appreciated that the tempered ~
chocolate is maintained at an elevated temperature such that it is in a liquid state. The mixture of liquid chocolate and dissolved carbon dioxide is discharged from the mixer and is passed via line 5 to a depositor 6 from which it is discharged into moulds 7 which are arranged in six parallel rows extending longitudinally of a COnVQyOr 8 which moves the moulds 7 under the depositor 6. The depositor 6 has six outlets which discharge into the respective rows of moulds 7.
Discharge is arranged to occur such that, at any one time, five of the outlets are open whilst the other is closed, the outlets being closed in turn, as will be described hereinafter. In order to maintain the required pressure conditions within the system, a pressure relie valve 3 controls flow of the mixture through a return bypass 10. In this way, the amount of deposit is controlled. In the arrangement according to Fig. 1, only one depositor 6 has been shown. In practice, four such depositors will be provided, each discharging into an arrangement of six rows of moulds on a respective conveyor, as will be apparent later.

In accordance with usual practice, the lines through which the liquid chocolate is passed and the depositor itself are jacketed and supplied with warm water to maintain the chocolate in a liquid phase up to the depositor 6. ~\

~9947 Referring now to Flg. 2, the depositor 6 inc~udes a body 12 in which six outlet passages or orifices 13 and associated valves 14 are provided. The outlet orifices 13 and associated valves 14 are identical and, for the sake of convenience, only one such outlet orifice 13 and associated v~lve will be described. The outle~
orifice 13 is of annular shape, the outer peripheral wall of the orifice 13 being defined by a hardened insert 15 which is disposed with its upper end in a circular recess 16 in the body 12 and with its lower end screw fitted into the body 12. The inner peripheral wall of the annular orifice 13 is defined by a cylindrical projection 18 of circular cross-section which extends from the lower end of a valve member 19 which is vertically slidable in the bod-y 12. The upper end of the valve member 19 is formed as a piston 20 which is slidable in a further recess 21 in the body 12. The further recess 21 defines a cylinder which is arranged to be supplied with air for piston controlling purposes via one or other of ports 22, 23 disposed on opposite sides of the piston 20. In this embodiment, the further recess 21 has a smooth bore and the piston 20 is fitted with annular sliding seals 24. At its lower end, in the region of the projection 18, the valve member 19 has an annular shoulder which is rounded to 1.0 mm radius. This shoulder 25 is engageable with a frusto-conical valve seat 26. The valve seat 26 is downwardly ta~oering and is provided in the insert 15 so that its lower, smaller diameter end merges with the upper end of that portion oE the insert 15 defining the outer 2eripheral wall oE
the annular orifice 13. A manually adjustable screw 27 3L2~99~L7 and associated locking nut 2B are provided at the upper end of the body 12, the screw 27 e~tending into the further recess 21 so as to define an abutment 29 for limiting upward movement of the valve member 19 away from the valve seat 26. A sealing ring 30 surrounds the screw 27 to prevent unwanted escape of air from the further recess 21. The intermediate portion of the valve member 19 is machined so as to be a sliding fit in a bore 31 extending between the recess 16 and the Eurther recess 21. Sealing rings 32 are provided in the bore 31 to prevent escape of air downwardly and escape of material being deposited upwardly and into the recess 21. The body 12 is slotted at 50 so that the region of the bore 31 between the sealing rings 32 is e~posed to atmosphere. This allows material being deposited to leak to atmosphere rather than to leak into the recess 21 in the event of failure oE the lower sealing ring 32.

The body 12 is provided with an inlet passage 33 leading to each recess 16, each inlet passage 33 being connected with a common manifold 34 fitted with a water jacicet 35 for maintaining material being passed to the depositor 6 at the required temperature. The manifold 34 is connected with the line 5.

Each of the ports 22, 23 is connected via a respective air line 36, 37 and all of the`air lines 36, 37 lead to a multiway distributor and sequencing valve assembly 38 connected with an air supply via line 39. The valve assembly 38 is controlled by an electrical or pneumatic control unit 40 to perform the aforesaid sequencing of the valves 14 in each depositor 6 so that, at any one time, one of the valves 14 in each depositor 6 is closed whilst the others remain open. In the condition shown in Fig. 2, the val\'ve 14 is shown closed. When it is the ~L~z~94~7 turll o[ the illustratecl valve to be opened, a signal is passed Erom the control unit 40 to the valve assembly 3~3 which causes line 39 to be connected with line 37 and line 36 to be exhausted to atmosphere. This causes the piston 20 and thereby the valve member 19 to be lifted until the upper end of the valve mernber 19 engages against the abutment 29. Liquid chocolate and dissolved carbon dioxide which has been fed to the manifold 34 by the line 5 and which fills the inlet passage 33 and the recess 16 is then permitted to flow through the outlet orifice 13 to be discharged into a mould 7 which is passing thereunder. Because of the relatively limited axial extent of the outlet oriEice 13 relative to its diameter (not greater than 100~ of the outer diameter of the orifice 13), the material being deposited is subjected to a relatively even shear across the cross-section of the orifice 13. As it passes throuyh the orifice 13 and discharges externally of the depositor 6, the material is exposed to atmospheric pressure and so experiences a pressure release which causes carbon dioxide dissolved in the chocolate to come out of solution and thereby expand the material as it is being deposited in the mould 7.
Even expansion of the material occurs in view of the relatively limited axial extent of the orifice 13. In the embodiment illustrated, the axial extent of the orifice 13 is only 50~ of its outer diameter so that substantially parallel flow of the material through the orifice 13 is only just established. It will be appreciated that the material passing into the outlet orifice 13 via the valve seat 26 will have a radially inward component of movement as a result of passage from the larger diameter recess 13. This radially inward component of movement of the material stops upon flowing through the orifice 13. The annular nature of the orifice 13 al~ws relatively high flow rates to be ~Zq~9947 obtained without incurring an undue di~ference in velocity profile across the cross-section of the orifice 13. Eligh velocity profiles are to be avoided because the Applicants have found that this leads to uneven expansion oE the material.

The material issues from the orifice 13 into chocolate shells in the moulds 7 and subsequent cooling of the material until it solidifies is eEfected in the moulds 7 which are vibrated in a manner known per se to ensure filling oE the moulds. ~fter solidifying, the resultant expanded chocolate confection can then be demoulded and subsequently packed.

In the above described embodiment, the pressure within the mixer 3 and line 5 is maintained at a fixed pressure between one and a half and two atmospheres (152-203kPa). The exact pressure will depend on the type of expansion that is required. The lift on each valve member 19 is controlled by the screw 27 so that up to about 8 kg per minute of material pass through each orifice 13, the amounts passing through each orifice 13 being controlled so as to be the same by appropriate adjustment of the lift of each valve member 19 using manually adjustable screw 27. Typically, the lift on each valve member is about 1.1 mm. In this embodiment, the length of each orifice 13 is 10 mm, the outer diameter thereof is 16 mm, the inner diameter of each outlet orifice 13 (ie the diameter of the projection 18) is 10 mm and the diameter of the annular contact line between the shoulder 25 and the frusto conical valve seat 26 is 19 mm. ~e have found that by using the aforesaid sequencing of the valves 14, it is relatively simple to keep the system pressure constant at one and a half atmospheres (152 kPa)or at any other clesirecl pressure up to 2 atmospheres (203 kPa) and this ~Z49910~7 also assists in obtaining even expansion of the material .

Referring now to Fig. 3, there is shown a four depositor head arrangement in which each depositor 6a, 6b, 6c and 6d i5 oE the type described with reference to Fig. ~. Each depositor 6a to 6d is arranged to file a respective set of 6 rows of moulds (not shown in Fig.
3) or conveyor 8. All the rows of moulds extend parallel to the direction of movement of the conveyor 8 and the moulds in each set are aligned in a direction perpendicular to the direction of extent of the rows (see Fig. l). In the embodiment of Fig. 4, the depositors 6a to 6b are inclined at an acute angle of about 30 relative to the aforesaid perpendicular direction so that, having regard to the speed of travel of the moulds and the sequencing of operation of the valves in each depositor, one set of aligned moulds is filled during each cycle of operation o each depositor and, at any instant, four moulds (one by each depcsitor) are being filled.

The control circuit for simultaneous opening and closing of respective valves in the four depositors 6a to 6d is illustrated in Fig. 4, it being understood that five other identical control circuits are provided, one for each of the remaining valves in the respective depositors 6a to 6d. The pneumatic circuit includes a pneumatic pressure supply line 00 from a pressure source 101 common to all the six control circuits. The line 100 is connected to two pneumatic YES gates 102 and ]03 and two pneumatic NOT gates 104 and 105. The line 100 is also connected to an pneumatic valve 106 which is normally closed ie biassed to a position in which pressure is not transmitted.
The valve 106 is p~ovided with an operating arm ~2~9~7 terminating in a roller-type cam follower 107 which engages a respective rotary cam 108. The valve 106 is connected with each of the gates 102 to 105 so as to transmit pressure thereto when the cam 108 is in a position in which it biasses the operating arm 107 to a position in which the valve 106 is open. ~'he form of the cam 108 is such that the valve 106 is open for 300 of the rotary movement of the cam ~08 but closed for the remaining 60 of rotary movement o the latter.
However, provision is made for adjustment of this angle. Cam 108 is driven from the conve~or 8 in a manner to be described.

~hen the valve 106 is opened (as shown in Fig. 4), pressure is transmitted to the gates 102 to 105. Under these conditions, the YES gates 102 and 103 permit flow of air through lines 37a to 37d to lift the four pistons 20a to 20d in the Eour depositors 6a to 6d simultaneously. This opens the valves of the associated nozzles. It will be appreciated that flow of air to the pistons 20 through lines 36 will not be permitted via the NOT gates 104 and 105 under these circumstances. ~hen the cam 108 has rotated to a position to release the cam follower 107, the pneumatic valve 106 is allowed to close. Under these conditions, the NOT gates 104 and 105 permit flow of air to the pistons 20a to 20d whilst the YES gates 102 and 103 no longer permit flow of air to the pistons 20a to 20d through the lines 37a to 37d. The result of this is that the pistons 20a to 20d are lowered to close the valves of the associated noæzles so that mould filling through such nozzles is terminated.

Referring now to Figs. 5 and 6, the six cams 108 respectively associated with the six pneumatic contro]
circuits are mounted on a common rotary shaft 109 in ~Z~47 equi-angularly staggered relationship. It will thus be appreciated that Eor each 60 angle of rotary movement oE the shaft 109, a respective one of the pistons 20 in each of the four depositors will be in a lowered position whilst the remaining ones will be in a lifted position. The four pistons 20a to 20b which are operated simultaneously are those which are provided at corresponding locations in the four depositors and the arrangement is such that during rotation of the shaft 109 the valves in each depositor are o~ened sequentially starting from the most upstream valves and ending at the most downstream valve before repeating the cycle.

In order to ensure synchronisation of the depositors 6 with the movement of the moulds 7 on the conveyor 8 the shaft 109 is driven from a lay shaft 119 of the conveyor, toothed pulleys 111 to 114 of which pulley 111 is mounted on layshaft 110 and pulley 114 is mounted a shaft 115, and a belt 116 passing around pulleys 111 to 114. The shaft 115 is operably connected to the shaft 109 via a single angularly engagement position electromagnetic clutch 117 (manufactured by Monning ~loff, of Germany) and a phase variator 118 in the form of a differential gearbox fitted with a rotary control knob 119 for advancing or retarding the deposits relative to the moulds in use.
This knob 119 alters the angular position of the shaft 109 relative to the shaft 115.

The clutch 117, variator 118, shaft 109, cams 108 and six plates 120 carrying the gates 102 to 105 and the valve 106 of the respective pneumatic circuits are all mounted in a housing 121 mounted on a support frame 122 above the conveyo~ 8 ~not shown) in Figs. 5 and 6).
~10unted on top of the housing 121 is an electric motor 122 which also drives the shaft 109 via a variable speed lZ~9g47, drive 123, a sprag clutch 124 and a belt 125. The motor 122 is not used ciuriny normal operation oE the apparatus and the sprag clutch 124 free which when the shaft 1~9 is driven by the shaft 115 to prevent power being transmitted to the drive 123. The motor 122 is, however, used for testing and setting up purposes when it is not desired to have the conveyor 8,running.

Claims (11)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An apparatus for depositing a material from a multiplicity of outlets into respective rows of moulds, said apparatus comprising at least one depositor containing a mul-tiplicity of outlets and respective valves for controlling the flow of material through said outlets; a conveyor for convey-ing rows of moulds past said depositor; means for supplying material under pressure to said at least one depositor; and control means for periodically opening and closing said valves in a sequence such that, in use, the number of valves which are open and the number of valves which are closed in said at least one depositor does not vary.

2. An apparatus as claimed in claim 1, wherein the periodic valve opening and closing means is arranged so that, at any time, only one valve in the or each depositor is closed whilst the remaining valves in said depositor are open.

3. An apparatus as claimed in claim 1 or 2, wherein the conveyor is continuously movable; the moulds associated with the or each depositor are arranged in rows which extend longitudinally of the direction of travel of the conveyor with the moulds in the respective rows being aligned in a direction at right angles to said direction of travel; said depositor is inclined at an acute angle to the direction of alignment of the rows; and said valve opening and closing means is con-trolled so as to cause material to be discharged from said depositor into a respective one of the sets of aligned moulds during each cycle of operation.

4. An apparatus as claimed in claim 1, wherein a plurality of said depositors is provided, and the valve open-ing and closing means is arranged to cause a respective one of the valve in every depositor to be periodically opened and closed simultaneously.

5. An apparatus as claimed in claim 4, wherein a separate control valve is provided for controlling operation of each set of valves in the depositors which are to be opened and closed simultaneously.

6. An apparatus as claimed in claim 5, wherein each control valve is arranged to be operated by a respective cam, the cams being mounted on a common shaft driven from the con-veyor and being equi-angularly staggered around the shaft.

7. A method of depositing a material from a multi-plicity of outlets into respective rows of moulds, comprising the steps of supplying material under pressure to at least one depositor containing a multiplicity of outlets and respective valves for controlling the flow of material through said out-lets, depositing said material into said moulds through said orifices, and periodically opening and closing the valves in a sequence such that the number of valves which are open and the number of valves which are closed does not vary.

8. A method as claimed in claim 7, wherein the valves are opened and closed such that, at any time, only one valve in the or each depositor is closed whilst the remaining valves in the or each depositor are closed.

9. A method as claimed in claim 7, wherein said material being deposited is a foamed confection.

10. A method as claimed in claim 9, wherein said foamed confection is foamed chocolate.

11. A method as claimed in claim 9 or 10, including the step of mixing gas under pressure with a confection, and supplying the resultant mixture to said at least one depositor so that foaming of the confection occurs as a result of pres-sure release upon discharge through said outlets.