Soft ice cream machine

Abstract

The invention relates to a soft-serve ice cream machine for producing soft-serve ice cream (13) with consistently uniform quality. It features a controllable peristaltic pump (2) that maintains a constant pressure in a conveying section leading to a ready-made ice cream mix (12) and an ice cream cylinder (6). The soft-serve ice cream machine is particularly suitable for installation in self-service vending machines, but also for professional use by operators in ice cream parlors or at stationary or mobile soft-serve ice cream stands.

Description

[0001] The invention relates to a soft-serve ice cream machine for producing soft-serve ice cream from a stored ice cream mix. It is particularly suitable for installation in self-service vending machines, but can also be used professionally by operating personnel, for example in ice cream parlors or at stationary or mobile soft-serve ice cream stands.

[0002] Conventional soft serve ice cream machines usually include an ice cream mix reservoir, which holds a pre-made ice cream mix (also called ice cream base) used for making soft serve ice cream, a pump, and an ice cylinder.

[0003] The ice cream mix is ​​pumped to the ice cylinder, and air is typically added to the mix to produce soft serve ice cream with a particularly soft consistency. The ice cream mix pumped to the ice cylinder, and optionally enriched with air, is referred to below as the finished ice cream mix. The finished ice cream mix is ​​then processed into soft serve ice cream by cooling in the ice cylinder, using a generally known method. Finally, the soft serve ice cream is dispensed from the ice cylinder, ready to eat.

[0004] The pumps conventionally used in soft-serve ice cream machines are gear pumps, which are also used to mix in the air. With this technology, an air overrun of typically 50% to 60% can be achieved. The overrun is defined as the difference between the mass of the base ice cream and the mass of the finished soft-serve ice cream; overrun figures are usually given as percentages. However, soft-serve ice cream machines with gear pumps have the disadvantage that cleaning the gear pumps is very time-consuming and therefore expensive.

[0005] Another disadvantage of common soft-serve ice cream machines is that during (longer) breaks between servings, such as with self-service machines or in ice cream parlors with low customer traffic, the premixed ice cream blend introduced into the ice cream cylinder after such a break is sometimes processed into soft-serve ice cream with an insufficient consistency. The desired consistency is usually restored after a few servings are dispensed. In ice cream parlors, this problem can be managed by dispensing portions of ice cream that have been lost. However, this is not possible with self-service machines; the customer then receives soft-serve ice cream with an inadequate, or even substandard, consistency or quality.

[0006] DE 24 26 166 A1 discloses a device for ice cream or soft serve ice cream machines for the production and dispensing of iced drinks. The device comprises a mixing device connected to a valve device, as well as a storage container arrangement for liquid flavoring additives. These additives can be added to the ice cream in a controlled manner by a special feed device, thus enabling individual flavor combinations. Furthermore, the described soft serve ice cream machine has a gear pump controllable by means of a control and regulation device, as well as a non-return valve integrated in the delivery line before it enters the ice cream cylinder, wherein the gear pump is controlled to maintain a constant pressure in the delivery line.

[0007] DE 23 31 744 A describes a method and a device for feeding ice cream or soft serve ice cream machines with liquid or powdered ingredients. The device is equipped with an agitator assembly to ensure uniform mixing. The device also includes a system for controlling the liquid level and dosage to increase the efficiency and precision of the mixing. This device also features a pump controllable by means of a control and regulating device, as well as a non-return valve integrated in the delivery line before it enters the ice cream cylinder, the pump being controlled to maintain a constant pressure in the delivery line.

[0008] The object of the invention is to provide a soft-serve ice cream machine that overcomes these disadvantages, that is, to produce soft-serve ice cream with consistently uniform quality and consistency even after periods of inactivity. Furthermore, the soft-serve ice cream machine should be capable of producing soft-serve ice cream with increased air content.

[0009] This problem is solved by a soft-serve ice cream machine with the features according to claim 1. Advantageous further developments of the invention are listed in claims 2 to 10.

[0010] According to the invention, the soft serve ice cream machine has the basic structure of conventional soft serve ice cream machines, with an ice cream mix reservoir for receiving and storing a stock ice cream mix, as well as at least one ice cream cylinder and a pump. Within the machine, the stock ice cream mix is ​​transformed into a ready-to-serve ice cream mix, from which the soft serve ice cream is produced in the ice cream cylinder. The ready-to-serve soft serve ice cream can be dispensed from the ice cream cylinder. The pump draws the stock ice cream mix from the reservoir and delivers it as a ready-to-serve ice cream mix to the ice cream cylinder.

[0011] According to the invention, the pump is a peristaltic pump; it is also referred to as a hose pump or hose squeeze pump. The peristaltic pump draws the ice cream mix from the ice cream mix reservoir via a suction line and pumps it as finished ice cream mix to the ice cream cylinder via a delivery line. The delivery line and the ice cream cylinder together form a delivery section, i.e., the inner area of ​​the soft serve ice cream machine, through which the finished ice cream mix is ​​conveyed to the dispensing point of the ice cream cylinder. The suction line and the delivery line are typically designed as (flexible) hoses.

[0012] The proposed soft-serve ice cream machine also features a control and regulation device for the peristaltic pump. Furthermore, a pressure sensor is integrated into the conveying line to measure the pressure within the line. The pressure sensor can be located in the conveying line or in the ice cream cylinder. The pressure sensor is designed to Signal transmission – preferably wired, but possibly also wireless – is connected to the control unit for controlling the peristaltic pump. The control unit is configured to control the peristaltic pump in such a way that – apart from brief moments of soft ice cream dispensing from the ice cream cylinder – a constant pressure, for example 1 bar, is maintained in the delivery line.

[0013] Furthermore, the soft-serve ice cream machine has a non-return valve in the dispensing line before it enters the ice cream cylinder. This non-return valve is, for example, a one-way or check valve. It prevents the ready-mixed ice cream from flowing back from the ice cream cylinder into the dispensing line. The non-return valve typically closes when no ready-mixed ice cream is being dispensed, i.e., when the pump is inactive. Due to the dispensing elements in the ice cream cylinder that are used to pump the soft-serve ice cream, and which exert pressure on the ready-mixed ice cream or the soft-serve itself, an overpressure is created—at least during soft-serve dispensing—that is sufficient to close a non-return valve, such as a one-way valve.

[0014] The peristaltic pump, controlled by the pressure sensor and the control and regulation device, keeps the pressure in the conveying line constant, so that when pressure is released in the ice cylinder, i.e. when the soft ice cream is removed, ready-made ice cream mix is ​​fed into the ice cylinder in a defined manner.

[0015] This ensures that the filling of the ice cylinder with ready-made ice cream mix is ​​always carried out in a consistent manner and quality, so that the consistency of the soft serve ice cream remains the same even after pauses in dispensing.

[0016] According to one embodiment of the soft-serve ice cream machine, a mixing valve may be provided in the intake line for adding air to the incoming ice cream mix. Within the mixing valve, the mixing of the ice cream mix with the supplied air creates the finished ice cream mix in the form of an ice cream mix-air mixture. The mixing valve is preferably designed to adjust the air content in the finished ice cream mix, i.e., it is adjustable, controllable, or regulating, so that the proportion of air in the finished ice cream mix or in the ice cream mix-air mixture can be precisely varied. For visualization and easier adjustment, the mixing valve may have a scale for setting a fixed, predetermined air content in the finished ice cream mix. The displayed value on the scale represents a specific ice cream mix-air composition.

[0017] Unlike gear pumps, the peristaltic pump combined with the mixing valve allows for the addition of air with a significantly higher air content, or overrun, in the soft serve ice cream. Compared to soft serve machines with gear pumps, an overrun of approximately 100% can be achieved.

[0018] The non-return valve is preferably designed as a one-way valve with a ball that selectively either blocks or allows the flow of the ready-mix ice cream. The one-way valve has a sieve-like or filter-type passage plate with multiple openings for the ready-mix ice cream to pass into the ice cream cylinder. When the one-way valve is open, the ball rests on the passage plate. The openings are dimensioned so that the ball cannot pass through, but the flow of the ready-mix ice cream is still permitted. The ball can rest on the passage plate by gravity or be pressed against it by spring force. When closed, the ball lifts off the passage plate and is pressed against a ring element, thus closing or blocking the delivery line. The ring element is preferably fixed within the pipe section of the one-way valve.An additional elastic ring seal, such as a ring disc, installed on the ring element improves the sealing effect. Release or closure is primarily achieved by a pressure differential between the delivery line and the ice cylinder. When the ice cylinder is installed vertically below the one-way valve, release is further assisted by the force of gravity acting on the ball.

[0019] To minimize pumping power, the ice cylinder, according to an advantageous design of the soft-serve ice cream machine, is installed below the ice cream mix reservoir. Furthermore, the ice cream mix reservoir and the peristaltic pump are positioned so that the peristaltic pump's delivery line connection is located above the maximum ice cream mix level in the reservoir. The peristaltic pump draws ice cream mix from the reservoir and pumps the finished ice cream mix downwards, i.e., by gravity, into the ice cylinder. This arrangement prevents backflow of finished ice cream mix even in the event of a pump failure.

[0020] According to the soft-serve ice cream machine design described above, the ice cream mix reservoir is preferably trough-shaped (for example, made of stainless steel); it has a reservoir base and a side wall that encloses the reservoir laterally. A bottom opening is provided in the reservoir base through which the delivery line passes, with the ice cream cylinder being connected to the delivery line immediately after the delivery line exits the bottom opening. The backflow preventer is preferably located within the delivery line in the area of ​​the bottom opening in the ice cream mix reservoir; that is, the backflow preventer is located directly outside after the bottom opening, directly inside before the bottom opening, or within the passage through the bottom opening. The backflow preventer can, in particular, form the connection to the ice cream cylinder.

[0021] Furthermore, according to this design, the soft-serve ice cream machine can have an inlet opening in the side wall of the storage container, through which the suction line from the ice cream mix storage container to the peristaltic pump passes, and an outlet opening through which the delivery line from the peristaltic pump passes through the ice cream mix storage container to the ice cream cylinder. The mixing valve is preferably located in a section of the suction line within the ice cream mix storage container. The pressure sensor is located, for example, in the delivery line outside the ice cream mix storage container, between the side wall of the storage container and the peristaltic pump.

[0022] The invention is explained in more detail below with reference to an exemplary embodiment and to the schematic drawing, wherein identical or similar features are provided with the same reference numerals; for this purpose, the drawing shows Fig. 1. The basic structure of the soft ice cream machine in a cutaway view.

[0023] The soft ice cream machine according to Fig. 1 has an upwardly open, trough-shaped ice mix storage container 1 for receiving the storage ice mix 10.

[0024] The peristaltic pump 2 draws in the storage ice cream mix 10 via the suction line 4. Air 11 is mixed into the storage ice cream mix 10 via the mixing valve 9 integrated into the suction line 4, resulting in the finished ice cream mix 12 as an ice cream mix-air mixture. The finished ice cream mix 12 is then forced by the peristaltic pump 2 into the delivery line 5 leading to the ice cream cylinder 6. The delivery line 5 and the ice cream cylinder 6 together form the delivery system.

[0025] The soft ice cream 13 is produced in the ice cylinder 6, which can then be taken out of the ice cylinder 6 ready to eat in the usual way.

[0026] The pressure sensor 7 is integrated into the delivery line 5 – near the delivery line connection of the peristaltic pump 2 – and measures the pressure in the delivery section. The measured pressure is transmitted via a signal line to the control unit 3, which regulates the peristaltic pump 2 to maintain a constant pressure in the delivery section. Alternatively, the pressure sensor 7 can also be installed in the ice cylinder 6 (not shown); the non-return valve 8 does not play a role in maintaining a constant pressure in the delivery section.

[0027] The non-return valve 8, integrated at the delivery line outlet into the delivery line 5 and designed in the form of a one-way valve, prevents the ready-made ice cream mix 12 or the soft ice cream 13 from flowing back into the delivery line 5 above the non-return valve 8. Reference symbol list 1 ice cream mix storage container 2 Peristaltic pump 3 Control and regulating device 4 Intake pipe 5 Conveyor line 6 ice cylinders 7 Pressure sensor 8 Backflow preventer 9 Mixing valve 10 Stock Ice Cream Mix 11 Air 12 Ready-made ice cream mixes 13 soft serve ice creams

Claims

[1] Soft serve ice cream machine comprising an ice cream mix storage container (1) for receiving and storing a stock ice cream mix (10), an ice cream cylinder (6) for producing ready-to-eat soft serve ice cream (13), a control and regulating device (3), and a pump for drawing the stock ice cream mix (10) from the ice cream mix storage container (1) and for conveying a finished ice cream mix (12) to the ice cream cylinder (6), wherein the ice cream mix storage container (1) is connected to the pump by a suction line (4) for drawing the stock ice cream mix (10) from the ice cream mix storage container (1), and the pump is connected to the ice cream cylinder (6) by a delivery line (5) for conveying the finished ice cream mix (12) into the ice cream cylinder (6), and wherein the delivery line (5) and the ice cream cylinder (6) form a conveying path for the finished ice cream mix (12), characterized by, that the pump is a peristaltic pump (2) controllable by means of the control and regulating device (3), wherein the soft ice cream machine further comprises a pressure sensor (7) integrated into the conveying section, designed to detect the pressure in the conveying section and connected to the control and regulating device (3) for signal transmission, as well as a non-return valve (8) integrated in the conveying line (5) before the entry into the ice cylinder (6), and wherein the control and regulating device (3) is configured, on the basis of the pressure prevailing in the conveying section detected by means of the pressure sensor (7), to control the peristaltic pump (2) so that a constant pressure is maintained in the conveying section. [2] Soft ice cream machine according to claim 1, characterized by, that the soft ice cream machine further comprises a mixing valve (9) in the intake line (4) for adding air (11) to the stock ice cream mix (10) drawn in via the intake line (4) and for forming the finished ice cream mix (12) in the form of an ice cream mix-air mixture from the stock ice cream mix (10) and the added air (11). [3] Soft ice cream machine according to claim 2, characterized by , that the mixing valve (9) is designed to adjust the air content in the ready-made ice cream mix (12). [4] Soft ice cream machine according to claim 3, characterized by , that the mixing valve (9) has a scale for fixing a predetermined air content in the finished ice cream mix (12). [5] Soft ice cream machine according to any one of claims 1 to 4, characterized by , that the backflow preventer (8) in the delivery line (5) is designed as a one-way valve. [6] Soft ice cream machine according to claim 5, characterized bythat the one-way valve has a ring element and a ball that blocks backflow through the system at the ring element. [7] Soft ice cream machine according to any one of claims 1 to 6, characterized by , that the ice mix storage container (1) is designed in a trough-like form, wherein the ice mix storage container (1) has a storage container base and a laterally enclosing storage container side wall, wherein a bottom opening is provided in the storage container base through which the conveying line (5) is passed, and wherein the ice cylinder (6) is connected to the conveying line (5) immediately after the conveying line (5) exits the bottom opening. [8] Soft ice cream machine according to claim 7, characterized by , that the backflow preventer (8) is located within the conveying line (5) in the area of ​​the floor penetration introduced in the ice mix storage container (1). [9] Soft ice cream machine according to claim 7 or 8, characterized by, that the ice mix storage container (1) has an inlet opening in the side wall of the storage container through which the suction line (4) from the ice mix storage container (1) to the peristaltic pump (2) is passed, and an outlet opening through which the delivery line (5) from the peristaltic pump (2) is passed through the ice mix storage container (1) to the ice cylinder (6), wherein the pressure sensor (7) is arranged in the delivery line (5) outside the ice mix storage container (1) between the side wall of the storage container and the peristaltic pump (2). [10] Soft ice cream machine according to claim 9, characterized by that the soft ice cream machine has a mixing valve (9) according to claim 2, wherein the mixing valve (9) is arranged in a section of the suction line (4) located within the ice cream mix storage container (1).

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