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Title:
DISPENSER
Document Type and Number:
WIPO Patent Application WO/2017/171622
Kind Code:
A1
Abstract:
A dispenser (1) for filling a receptacle (R) with viscous material (30), said dispenser (1) comprising, a cylinder (2, 22), a main piston (4), a driving device, an auxiliary piston (5) and a space (S). The cylinder (2, 22) is arranged to be connected to a container (3) for the viscous material (30), and the main piston (4) is axially movable in the cylinder (2, 22) and arranged for both sucking and discharge the viscous material (30) from the cylinder (2, 22) through the outlet port (23). The driving device is arranged for moving the main piston (4). The main piston (4) and the auxiliary piston (5) are axially movable in the cylinder (2, 22). The space (S) being formed between the pistons (4, 5) and constituting a dosing chamber arranged for receiving viscous material (30) from the inlet port (21) and the pistons (4, 5) are further arranged to discharge viscous material (30) from the dosing chamber (S) through the outlet port (23).

Inventors:
NISS, Andreas (Bärstigen 37, MALUNG, 782 34, SE)
Application Number:
SE2017/050312
Publication Date:
October 05, 2017
Filing Date:
March 31, 2017
Export Citation:
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Assignee:
NISS, Andreas (Bärstigen 37, MALUNG, 782 34, SE)
International Classes:
A23G9/28; B65B3/32
Foreign References:
GB976068A1964-11-25
US5494194A1996-02-27
EP2269469A22011-01-05
US5816455A1998-10-06
US5494194A1996-02-27
Attorney, Agent or Firm:
BERGENSTRÅHLE & PARTNERS GÖTEBORG AB (Lindholmspiren 5A, Göteborg, SE-417 56, SE)
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Claims:
CLAIMS

1. A dispenser (1) for filling a receptacle (R) with viscous material (30), said dispenser (1) including:

- a cylinder (2, 22) having an inner surface (20, 220) and a side inlet port

(21) arranged to be connected to a container (3) for the viscous material (30), and an outlet port (23) axially spaced from the inlet port (21);

- a main piston (4) axially movable in the cylinder (2, 22) and arranged for sucking the viscous material (30) from the container (3) through the inlet port (21) into the cylinder (2, 22) and arranged for discharging the viscous material (30) from the cylinder (2, 22) through the outlet port (23), said main piston (4) sealing against the inner surface (20, 220) of the cylinder (2, 22); and

- a driving device for moving the main piston (4);

characterized in that

- the outlet port (23) is a cylinder side outlet port (24) having an orifice (25) directed downward;

- the main piston (4) is movable between a main piston front end position (Υ') and a main piston rear end position (Χ') positioned on each side of the inlet port (21);

- an auxiliary piston (5) is axially movable in the cylinder (2, 22), said auxiliary piston (5) sealing against the inner surface (20, 220) of the cylinder (2, 22) and being movable between an auxiliary piston front end position (Y) and an auxiliary piston rear end position (X), positioned on each side of the outlet port (23); and

- a space (S) of varying size in dependence of the movements of the main piston (4) and the auxiliary piston (5) being formed between the pistons (4, 5) and constituting a dosing chamber (S) arranged for receiving viscous material (30) from the inlet port (21) when the auxiliary piston (5) has reached its auxiliary piston rear end position (X) but the main piston (4) is continuing toward its main piston rear end position (Χ'), further arranged to discharge viscous material (30) from the dosing chamber (S) through the outlet port (23) when the auxiliary piston (5) has reached its auxiliary piston front end position (Y) but the main piston (4) is continuing toward its main piston front end position (Υ').

2. A dispenser as claimed in claim 1, wherein the dispenser is arranged such that the viscous material (30) in the dosing chamber (S) interconnects the two pistons

(4, 5), so that a movement of the main piston (4) causes a corresponding movement of the auxiliary piston (5), unless the movement of the auxiliary piston (5) is stopped by the auxiliary piston arriving at an associated one of the end positions (X, Y).

3. A dispenser as claimed in claim 1 or 2, wherein the main piston front end (Υ') is located between the two end positions (X, Y) of the auxiliary piston (5), such that the main piston (4) when in its main piston front end position (Υ') almost covering the outlet port (23), the main piston rear end position (Χ') being located at such a distance from the inlet port (23) that the dosing chamber (S) is of a sufficient size to receive a predetermined amount of viscous material (30), and the auxiliary piston rear end position (X) is located between the inlet port (21) and the outlet port (23) and close to the inlet port (21).

4. A dispenser as claimed in any one of claims 1-3, wherein the auxiliary piston (5) includes a disk member (50) sealing against the inner surface (20, 220) of the cylinder (2, 22), and a central shaft (51) extending axially therefrom, and the main piston (4) includes an axial central bore (40) for receiving the shaft (51) and preventing the disk member (50) from getting upset in the cylinder.

5. A dispenser as claimed in any one of claims 1-4, wherein the driving device includes a motor (60) and a device (62) for sensing when the receptacle (R) is filled to a predetermined degree.

6. A dispenser as claimed in claim 5, wherein the sensor senses the weight of the receptacle (R) during filling.

7. A dispenser as claimed in claim 5, wherein the sensor includes a pivotal control lever (7) for controlling when to start and when to stop the filling of the receptacle (R), said pivotal control lever (7) having a free end (70) located at a level of an orifice (25) of an outlet chute or immediately below said orifice (25), a lifting of said free end (70) of the pivotal control lever (7) starting the drive motor (60) to dispense viscous material (30) into said receptacle (R), and a returning of the free end (70) to its start position or to a position just above said start position stopping the dispensing.

8. A dispenser as claimed in any one of claims 1-7, wherein the container (3) has an inner surface (31) and includes a movable plate (32) sealing against the inner surface (31) to protect the viscous material (30) from air, said movable plate (32) resting on the viscous material (30) and following downward by vacuum force as the viscous material (30) is being sucked into the dosing chamber (S).

9. A dispenser as claimed in claim 8, wherein the movable plate (32) comprises an upper pressure plate (33), a lower pressure plate (34) and a silicon membrane (35) there between and the lower pressure plate (34) is arranged with an air pipe (36).

10. A method of filling a receptacle (R) with a viscous material (30) from a dispenser (1) comprising:

- sucking a portion of the viscous material (30) from a container (3) through an inlet port (21) into a dosing chamber (S) defined by a cylinder (2, 22), a main piston (4) and an auxiliary piston (5) axially movable in the cylinder;

- moving said portion inside the dosing chamber (S) while closing the inlet port (21) by positioning the main piston (4) in the inlet port (21) and opening an outlet port (23) in the dosing chamber (S) by letting the auxiliary piston (5) pass said outlet port (23), said outlet port (23) having an orifice (25) directed downward;

- providing a pivotal control lever (7) having a free end (70) located immediately below the orifice (25) for controlling when to start and when to stop the filling of the receptacle (R);

- placing the receptacle (R) under the orifice (25) and lifting the receptacle (R) to position the orifice (25) inside the receptacle (R) and simultaneously lifting the free end (70) of the pivotal control lever (7) by a brim of the receptacle (R) to start the filling of the receptacle (R);

- lowering the receptacle (R) as it is being filled; and

- when the receptacle (R) is filled to a desired degree, removing the receptacle (R) from the orifice (25), thereby letting the free end (70) of the pivotal control lever (7) return to its position at a level of an orifice of an outlet chute or immediately below said orifice (25) to stop the filling.

Description:
DISPENSER

TECHNICAL FIELD

The present invention relates to a dispenser for filling a receptacle with viscous material, said dispenser including a cylinder having an inner surface and a side inlet port arranged to be connected to a container for the viscous material, and an outlet port axially spaced from the inlet port, a main piston axially movable in the cylinder and arranged for sucking the viscous material from the container through the inlet port into the cylinder and arranged for discharging the viscous material from the cylinder through the outlet port, said main piston sealing against the inner surface of the cylinder, and a driving device for moving the main piston. The invention also relates to a method of filling a receptacle with a viscous material from such a dispenser. BACKGROUND ART

The present invention relates to a dispenser for filling a receptacle with viscous material, primarily soft ice cream but also other viscous food such as sauces, purees, mash etc. are suitable for use in the machine. Frozen food such as ice cream, frozen yogurt or sorbet often have a viscosity that will enable it to flow through a dispensing nozzle into a receptacle or similar. Traditionally, dispenser machines operates by compressed air to squeeze in/out the ice cream and this may create air bubbles which becomes ice crystals in the ice cream which degrades the taste and texture of the ice cream. To use compressed air to squeeze in/out the ice cream also results in that the ice cream is compacted, resulting in a lower quality of the soft ice cream. Traditionally dispensers also bases the amount of ice cream that is to be dispensed on its weight.

The document US 5494194 describes a dispenser with a reciprocating piston with an integral valve that moves in a first direction within a cylinder to pressurize viscous material contained therein, such as ice cream or the like, thereby pushing it out of a dispensing nozzle located at one end of the cylinder while simultaneously extracting viscous material from a collapsible container into the other end of the cylinder by suctioning the material from the container. When the piston moves in a second direction, the integral valve opens to allow the piston to pass through the previously suctioned viscous material within the cylinder. The dispensing nozzle includes a normally closed, spring-biased valve opened by the force of the pressurized material, closing of the valve being assisted by a transient suction force occurring as the valved piston begins to move in the second direction through the material. SUMMARY OF THE INVENTION

It is an object of the present invention to provide a dispenser for viscous material, primarily soft ice cream, which will eliminate or at least minimize repeated compression or pressurization of the viscous material to avoid or at least minimize the above noted problems associated therewith. This is accomplished by a dispenser for viscous material wherein the outlet port is a cylinder side outlet port having an orifice directed downward,

the main piston is movable between a main piston front end position and a main piston rear end position positioned on each side of the inlet port, an auxiliary piston is axially movable in the cylinder, said auxiliary piston sealing against the inner surface of the cylinder and being movable between an auxiliary piston front end position and an auxiliary piston rear end position, positioned on each side of the outlet port, and a space of varying size in dependence of the movements of the main piston and the auxiliary piston being formed between the pistons and constituting a dosing chamber arranged for receiving viscous material from the inlet port when the auxiliary piston has reached its auxiliary piston rear end position but the main piston is continuing toward its main piston rear end position, further arranged to discharge viscous material from the dosing chamber through the outlet port when the auxiliary piston has reached its auxiliary piston front end position but the main piston is continuing toward its main piston front end position.

Thanks to the invention a dispenser is provided which dispense a certain volume of ice cream by carefully avoiding the problem that soft ice may contain big bubbles of air in the dispensing operation.

According to another aspect of the invention the dispenser is arranged such that the viscous material in the dosing chamber interconnects the two pistons, so that a movement of the main piston causes a corresponding movement of the auxiliary piston, unless the movement of the auxiliary piston is stopped by the auxiliary piston arriving at an associated one of the end positions.

According to yet another aspect of the invention the main piston front end is located between the two end positions of the auxiliary piston, such that the main piston when in its main piston front end position almost covering the outlet port, the main piston rear end position being located at such a distance from the inlet port that the dosing chamber is of a sufficient size to receive a predetermined amount of viscous material, and the auxiliary piston rear end position is located between the inlet port and the outlet port and close to the inlet port.

According to yet another aspect of the invention the auxiliary piston includes a disk member sealing against the inner surface of the cylinder, and a central shaft extending axially therefrom, and the main piston includes an axial central bore for receiving the shaft and preventing the disk member from getting upset in the cylinder.

According to yet another aspect of the invention the driving device includes a motor and a device for sensing when the receptacle is filled to a predetermined degree so that dispensing of the desired amount of soft ice cream is secured.

According to yet another aspect of the invention the sensor includes a pivotal control lever for controlling when to start and when to stop the filling of the receptacle, said pivotal control lever having a free end located at a level of an orifice of an outlet chute or immediately below said orifice, a lifting of said free end of the pivotal control lever starting the drive motor to dispense viscous material into said receptacle, and a returning of the free end to its start position or to a position just above said start position stopping the dispensing so that dispensing of the desired amount of soft ice cream is secured.

According to yet another aspect of the invention the container has an inner surface and includes a movable plate sealing against the inner surface to protect the viscous material from air, said movable plate resting on the viscous material and following downward by vacuum force as the viscous material is being sucked into the dosing chamber.

According to yet another aspect of the invention the movable plate comprises an upper pressure plate, a lower pressure plate and a silicon membrane there between and the lower pressure plate is arranged with an air pipe in order to function as an air valve.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the invention will be described in more detail with reference to preferred embodiments and the appended drawings. Fig. 1 is a perspective view of a dispenser according to the invention,

Fig. 2 is a partly exploded view of a dispenser according to the invention, Fig. 3 is an exploded view of a container according to the invention,

Fig. 4 is an exploded view of a movable plate according to the invention, Fig. 5 is a cross sectional view across the line A-A in figure 6, of a dispenser according to the invention,

Fig. 6 is a dispenser according to the invention, seen from above, and

Fig. 7-10 is a cross sectional view across the line A-A in figure 6, of a dispenser according to the invention during different stages of the filling and dispensing operation.

DETAILED DESCRIPTION OF FIGURES

The following detailed description, and the examples contained therein, are provided for the purpose of describing and illustrating certain embodiments of the invention only and are not intended to limit the scope of the invention in any way. In the description is referred to viscous material 30, hereinafter referred to as ice cream although the skilled person realize that it could be other than that, such as sorbet, sauces, mashed potatoes, purees etc.

Figure 1 illustrates a perspective view of a dispenser 1 according to the invention. The dispenser 1 is arranged to fill a receptacle R with ice cream 30, such as soft ice cream. The dispenser 1 comprises a casing 100, a dispensing arm 200 and a container 3 for the ice cream 30. The casing 100 comprises driving means and electronic devices and it also acts as a stand with sufficient weight to balance the container 3 which is placed upon a horizontally extending dispensing arm 200. It has a height which enable the filling of any desired size of receptacle R without disturbance from the

surface/foundation it is placed on. The receptacle R is not part of the invention but can be any receptacle suitable for the purpose.

Figure 2 illustrates a partly exploded view of the dispenser 1. The casing 100 comprises an outer display 101 arranged at one of the side walls. At an upper part of the front of the casing, two parallel slots 103 are arranged in a vertical section of a mounting plate 104 which extends at the inside of the casing and is formed as an angled iron. A piston bracket 102 for attachment of a main piston 4 of the dispensing arm 200 is arranged between the slots 103. The piston bracket 102 is horizontally movable in the axial direction of the dispensing arm 200 by a guide 55 engaged with the motor 60 inside the casing 100 (see fig. 5) via an opening (not shown) in the mounting plate. The dispenser 1 also comprises an outer pivotal control lever 7 which extends under the dispensing arm 200 and is pivotally engaged with the driving means and electronic devices inside the casing 100 through an opening in one of the side walls of the casing 100.

The dispensing arm 200 comprises a cylinder for discharging of the ice cream 30. The piston is arranged inside a cabinet 205, 206 which is attached to the casing 100. The dispensing arm 200 comprises, from left to right, an end cap 201, a first O-ring 202, a forward cylinder section 22 having a downwardly directed dispensing chute 24 in its forward end, a fill ring 203 mounted at the mouth 25 of the discharge chute 24, an auxiliary piston 5 arranged to run inside the forward cylinder section 22, a second O- ring 204, a rearward cylinder section 20 having an upwardly directed filling chute 26 in its forward end, a main piston 4 arranged to run inside the rearward cylinder section 20, a third O-ring 207, an upper cylinder tray 205 and a lower cylinder tray 206. The auxiliary piston 5 comprises a piston plate 50, a piston rod 51. The upper cylinder tray 205 has an opening 209 for the dispensing opening 304 of the container 3 and a flat upper side suitable as a support for the container 3. In assembled state the opening 209 is arranged in connection to the filling chute 26 of the rearward cylinder section 20. The lower cylinder tray 206 comprises two hooks 208 at the end arranged against the casing 100. At assembling, the hooks 208 are inserted into the slots 103 in the vertical wall of the mounting plate 104 and the edge of the cylinder tray rests against the vertical wall and is directed perpendicularly forwards in relation to the wall. Thereafter the other parts of the dispensing arm 200 are assembled and mounted to the piston bracket 102 via the rear side of the main piston 4. As a last step, the upper cylinder tray 205 is attached to cover the dispensing part 200. The upper cylinder tray 205 comprises tongues/latches 210 at the end arranged against the casing 100 which is inserted into the grooves 103 in the mounting plate 104. At the forward end, the upper cylinder tray 205 comprises a mounting plate 211 provided with slots 212 for the fastening screws 213 of the lower cylinder tray 206. The cabinet 4, 5 fixes the dispensing arm 200 in axial direction. Figure 3 illustrates an exploded view of a container 3 according to the invention and comprises a cylindrical side wall 300, an upper filling opening 31 having the same diameter as the cylindrical side wall 300, a preferably flat bottom having a lower dispensing chute 304 provided with an external fourth O-ring 301 and a filling cap 303 with a fifth O-ring 302 for the chute 304. The container further comprises an upper lid 305 having two openings 306, 307 for cooperation with a movable sealing plate 32 inside the container (see fig. 4). Figure 4 illustrates an exploded view of a movable sealing plate 32 according to the invention. The movable sealing plate 32 is designed to be arranged inside the container 3 and seal against an inner surface 31 of the cylindrical side wall 300 to protect the ice cream 30 from air. The movable plate 32 comprises a locking bar 38, a pressure pin 37, a sixth O-ring (not shown) for the pressure pin 37, an upper pressure plate 33, a lower pressure plate 34 and a silicon membrane 35 arranged there between. The lower pressure plate 34 is provided with an air pipe 36 which extends upwards through the silicon membrane 35 and the upper pressure plate 33. The pressure pin 37 have a diameter that is smaller than the inner diameter of the air pipe 36 and has a length that is longer than the air pipe 36. The pressure pin has a head and the sixth O-ring (not shown) is arranged underneath the head. The air pipe 36 and pressure pin 37 act as a valve. During assembling, air is evacuated through the air pipe 36 when the movable sealing plate is inserted into the container 3 and placed on top of the ice cream 30. The pressure pin 36 and the O-ring at its top is pushed all the way into the pipe so that an airtight lock is obtained. As the movable plate 32 rests on the ice cream 30 it moves downwards by vacuum force as the ice cream 30 is sucked out of the container by the dispensing arm 200. When the movable plate 32 reach the bottom of the container 3, the pressure pin 37, which extends a short distance below the lower pressure plate 34, is pushed upwards so that air may again pass through the pipe 36. As the container 3 is mounted to the filling chute 26 in an airtight manner, which will be described in connection to fig. 5, the removal of the container would otherwise risk to harm the parts of the dispensing unit 200 or complicate the removal.

Figure 5 is a cross sectional view, across the line A-A in figure 6, of a dispenser 1 according to the invention. The container 3 is placed on the upper cylinder tray 205. The bottom of the cylinder rests on the upper side of the tray 205. In the present embodiment the bottom and the upper side of the tray are flat but the skilled person understands that they may be formed otherwise in order to provide a safe and steady mounting of the container 3. The dispensing chute 304 is inserted into the filling chute 26 of the rearward cylinder section 20. The filling chute 26 has an upper cylindrical section for mating with the dispensing chute 304. The connection is airtight by the aid of the external fourth O-ring 301. In order to reduce the axial extension of the inlet port 21 in the cylindrical wall of the rearward cylinder section 20, the form of the filling chute 304 below this upper cylindrical section pass/transform to conical with a transverse square opening at the lower end. The inlet port 21 has an extension in axial direction of the rearward cylinder section 20 of approximately 50% or less of the diameter of the upper cylindrical section. In figure 5, the position of the auxiliary piston 5 and the main piston 4 is shown after assembly. There is no ice cream 30 in the dispensing unit 200 in this start position. The auxiliary piston 5 is seen at an auxiliary piston rear end position X inside the forward cylinder section 22. The auxiliary piston rear end position X is positioned between the outlet port 23 and the inlet port 21, close to the forward rim of the inlet port 21. The second O-ring 204 is arranged in a groove in the inner wall at the auxiliary piston rear end position X and acts as a stop for the rearward movement of the piston plate 50 and prevents air from passing when viscous materiel 30 is sucked into the dispensing arm 200. The main piston 4 is positioned close to the auxiliary piston 5. Preferably, its forward wall is positioned in front of the inlet port 21. The main piston 4 is arranged in an airtight manner inside the rearward cylinder section 20 by the third O-ring 207 which is arranged outside the rear end of the main piston 4 and seals against the inside of the rearward cylinder section 20. The rear end wall 42 of the main piston 4 is attached to a piston rod 43 which is engaged with an electric motor 60 inside the casing 100 via a driving mechanism such as a toothed gear 61. During operation, ice cream 30 from the container 3 will be sucked into the dispensing unit 200 and discharged therefrom during a reciprocating movement of the main piston 4 and the auxiliary piston 5 which will be described in more detail below. The main piston 4 has an extension in axial direction that is adapted to the distance between the inlet port 21 and the outlet port 23 so that the main piston 4 covers the inlet port when in its front end position Y' .

A piston rod 51 of the auxiliary piston 5 is movably fitted in axial direction inside a pipe 40 which extends through the main piston 4. A fourth O-ring 52 is arranged to be positioned in a groove 53 (see fig. 2) at the rear part of the piston rod 51. The piston rod 51 has a length that is adapted to the maximum distance between the piston plate 50 and the forward wall 42 of the main piston 4 while still being supported inside the pipe 40. The maximum distance is the distance when, in case of malfunction, the auxiliary piston 5 remains in an auxiliary piston front end position Y and the main piston 5 is in a main piston rear end position X' .

The dispenser 1 comprises a sensor 700 which comprises the pivotal control lever 7 which extends from the side of the casing 100 (see fig. 6) and alongside and in under the dispensing arm 200. The motor 60 is arranged inside the casing 100 and connected to the sensor 700 and thereby to the control lever 7. A free end 70 of the control lever 7 is angled horizontally inwards and positioned in connection to the discharge chute 24. The filling ring 203 is arranged at a lower end of the dispensing chute 24 and attached thereto, preferably by a bayonet mount whereby the circumferential position of the filling ring 203 is controlled. The pivotal control lever 7 controls when to start and when to stop the filling of the receptacle R and thus the amount of dispensed ice cream 30 is controlled. A lifting of said free end 70 of the pivotal control lever 7 to a level above the filling ring 203 starts the dispensing of ice cream 30 into the receptacle R. A return, i.e. lowering, of the free end 70 to the level of the filling ring 203 stops the dispensing. During lifting and lowering of the receptacle R the angled free end 70 of the lever 7 rests on the brim of the receptacle R. Preferably, the angled free end 70 extends close to the wall of the dispensing chute 24 to avoid or at least minimize the risk that the free end 70 slips off the brim. A vertical slit in the filling ring 203 (see fig. 2) provides a passage for the free end 70 of the lever 7. The size of the filling ring 203 is adapted to the actual receptacle R so that, during filling, the filling ring 203 covers the main part of the area inside the receptacle. The filling ring 203 controls that the upper surface of the ice cream 30 becomes substantially flat during filling and it further controls the level of the upper surface of the ice cream 30 as the receptacle R is pushed gradually

downwards during the filling operation. However, a gap shall be allowed between the filling ring and the wall of the receptacle R for evacuation of air during the initial filling stage. When the receptacle R is brought up against the dispensing chute 24 the brim of the receptacle R pushes the free end 70 of the control lever 7 upwards. The pivotal control lever 7 is connected to the sensor 700 that registers the movement of the control lever 7 and sends a signal to a microprocessor (not shown). In this described example the sensor 700 is a potentiometer that registers the movement but the skilled person realizes that it may also be any kind of suitable sensor known in the art. The microprocessor sends a signal to a motor controller that drives the motor 60. The potentiometer is not rotatable, as is customary, but consists of a strip, in this case, with 125 points. This allows that a very precise dosage is obtained, the accuracy is about + 0.1 g, and the dosing of sauce and other small amounts is facilitated. The microprocessor can be programmed to provide the selection of different sized portions by regulating the required degree of rotation of the lever 7 and hence the start and stop position of the dispensing.

The dispensing operation will now be described in connection to figs. 5 - 10. As earlier described, figure 5 shows the dispenser 1 after assembly in a start position. In the start position the auxiliary piston 5 is positioned in an auxiliary piston rear end position X. When the brim of the receptacle R lifts the control lever 7 the dispensing operation starts at a given signal, i.e. when the free end 70 of the control lever 70 reaches a level above the filling ring 203. The motor 60 drives the main piston 4 axially backwards inside the rearward cylinder section 20, to a main piston rear end position X', see figure 7. The auxiliary piston 5 remains in its position where it is in airtight abutment with the O-ring 204. During the backward displacement of the main piston 4, ice cream 30 is sucked from the container 3, through the inlet port 21 and into a dosing chamber S in the rearward cylinder section 20. During this step, the operator continues to lift the receptacle R until lifting is stopped as the inside of the receptacle R, which normally is sloping, contacts the filling ring 203. Theoretically, the receptacle may be lifted until its brim touches the underside of the lower cylinder tray 206 although a design utilizing a filling ring which is adapted to the size of the receptacle is preferred.

When the main piston 4 reaches the main piston rear end position X' a new signal is sent from the microprocessor to the motor controller to move the main piston 4 in the forward direction. As seen in figure 7, when the auxiliary piston 5 is in the auxiliary piston rear end position X and the main piston 4 has reached the main piston rear end position X' the ice cream 30 has been sucked into the dosing chamber S between the main piston 4 and the auxiliary piston 5. The ice cream 30 interconnects the main piston 4 and the auxiliary piston 5 hydraulically. Movement of the main piston 4 causes a corresponding movement of the auxiliary piston 5 due to hydraulic forces, see fig. 8, until the auxiliary piston 5 has passed the outlet port 23 which is the inlet to the dispensing chute 24 and arrived at an auxiliary piston front end position Y in the forward end of the forward cylindrical section 22 whereby the movement is stopped. While the auxiliary piston 5 is in the auxiliary piston front end position Y the main piston 4 continues its forward movement. This will gradually reduce the volume of the dosing chamber S which results in a discharge of the ice cream contained therein through the outlet port 23, see figure 9. The main piston 4 may continue its forward movement to a main piston front end position Y' almost covering the outlet port 23 in close proximity to the auxiliary piston front end position Y, see figure 10, which will result in a close to complete discharge of ice cream 30 from the dosing chamber S at the same time as an undesired stress on the discharge unit 200 is avoided due to an otherwise induced hydraulic pressure from captured ice cream 30. However, as will be explained below, a complete discharge is not desired. Alternatively, and more likely, the discharge of ice cream is stopped when the receptacle R is completely filled which is indicated by the free end 70 of the lever 7 returning to the level of the filling ring 203. As a final step, a new portion of ice cream is sucked into the dosing chamber S so that the dispenser 1 is prepared for quick dispensing of a new portion. As the microprocessor registers that the discharge is stopped it sends a signal to the motor controller to move the main piston 4 in the rearward direction. The hydraulic forces exerted by the remaining ice cream 30 between the main piston 4 and the auxiliary piston 5 result in that a rearward movement of the main piston 4 will generate a simultaneous movement of the auxiliary piston 5 until the auxiliary piston 5 reaches the auxiliary piston rear end position X where it is stopped and the procedure of sucking in ice cream 30 into the dosing chamber by rearward movement of the main cylinder 4 is repeated. However, when the main cylinder 4 reaches the main cylinder rear end position X' it will stay in that position until a new discharge signal is given by the lifting of the free end 70 of the lever 7 in the manner described earlier.

The main piston rear end position X' is located at such a distance from the inlet port 21 that the dosing chamber S is of a sufficient size to receive a predetermined amount of ice cream 30, and the auxiliary piston rear end position X is located between the inlet port 21 and the outlet port 23 and close to the inlet port 21.

As earlier described, the dosing chamber S is preferably designed to have a volume that is larger than the volume ice cream to be dispensed. This also gives the advantage that in case the ice cream in the dosing chamber S comprises air pockets the volume of ice cream is enough to fill the receptacle R. It is also preferable if the dispenser 1 comprises a preset option on the outer display 101 for selection of the volume of the ice cream portion, for example a small portion could be 250 ml and a big portion may be 500 ml, in order to reduce the amount of remaining ice cream between two portions as this may impair the quality of the ice cream.

The components in the dispensing arm 200 are preferably made of plastics, for example acrylic or polycarbonate since plastics has a lower thermal coefficient than stainless steel which is conventionally used in dispensers of this kind. The dispenser according to the invention will therefore more quickly obtain essentially the same temperature as the viscous material which is to be dispensed which improves the quality of the dispensed material. In the case soft ice cream is to be dispensed, a common problem is that some portions has to be wasted at startup, which now may be prevented or at least minimized.

The O-rings in the dispenser 1 are preferably made of silicone since these are smoother and functions better in cold environment.