GB2144208A - Device for making frozen confections - Google Patents

Abstract

A device for making frozen confections such as ice cream comprises a double-walled hermetically sealed cylindrical vessel (1) having an upper open end and a closed bottom. The space between the walls of the vessel is partially filled with a freezable cold-keeping agent (6). An outer receptacle (12) receives and supports the vessel (1) therein. A cover member (11) engages a ring (13) attached firmly to the upper edge of the double-walled vessel (1) so as to prevent relative rotational movement therebetween. A rotatable stirring means (18) extends into the interior of the vessel through a bearing hole formed at the centre of the cover member (11). The ring (13) is made of a pliant deformable material and has an outer receptacle supporting shoulder formed at its periphery and a vessel engaging annular groove formed at its lower side. A means is provided for preventing relative rotational movement between the ring (13) and the cover member (11) or between the outer receptacle (12) and the cover member (11). <IMAGE>

Description

SPECIFICATION Device for making frozen confections The present invention relates to a device for making frozen confections such as ice cream and sherbet, mainly for use in a home.

Heretofore, a conventional device for making handmade frozen confections such as ice cream comprises an outer vessel and an inner vessel located in the outer vessel with a certain clearance held therebetween, the clearance being filled with a plurality of broken pieces of ice with a certain amount of salt added thereto so that the inner vessel is cooled by the ice thereby permitting the material for making the frozen confections contained in the inner vessel to be frozen while the material is held in stirred condition.

With such a method as described above, the temperature of the broken pieces of ice of the size of about several cm with 15% of salt added thereto reaches theoretically -15 C, but the actual temperature reaches only about -5 C at the lowest and, since the outer surface of the inner vessel is merely held substantially in point contact with the respective broken pieces of ice, the material contained in the inner vessel can not be cooled and frozen rapidly, and, therefore, it takes a fairly long time until the desired frozen confections are completed.

Further, water resulting from the melting of ice during the making of frozen confections makes the place where the frozen confections are being made unclean, thereby making it unpleasant for the people attending to the making of frozen confection.

A device for making frozen confections has also been developed in which, instead of using ice, a double-walled hermetically sealed vessel located in a receptacle is used for containing in the vessel the material for making frozen confections and an appropriate amount of cold-retaining agent fills the space between the inner and outer vessel members constituting the vessel. In use, the vessel is cooled in a separate refrigerator so as to freeze the cold-retaining agent to an appropriate temperature and then the cooled vessel is placed in the receptacle and the material for making frozen confections is supplied into the vessel and it is stirred by appropriate stirring means thereby permitting frozen confections to be completed.

In such a device having a double-walled vessel, however, since the cold-retaining agent commences freezing from the upper portion thereof downwards so that local concentration of expansion of the coldretaining agent will take place at the lower end of the vessel due to the expansion of the cold-retaining agent occurring during the freezing of the cold-retaining agent, the vessel can be deformed or damaged.

Heretofore, in such a device for making frozen confections, the operator's fingers might be subjected to frostbite when he actuates the stirring means by holding the outer vessel stationarily by the fingers so as to mix up the material contained in the inner vessel for making frozen confections, because the outer vessel is held under a very cold state, thereby making the handling of the device very inconvenient.

The present invention aims at avoiding the above described disadvantages of the prior art device for making frozen confections.

It is, therefore, an object of the present invention to provide a device for making frozen confections such as ice cream and sherbet which is simple in construction and inexpensive to manufacture and is capable of easily and quickly making frozen confections of a high quality without causing any harmful frostbite to the operator and without causing any damage or deformation of the inner vessel of the device which contains the frozen confections.

In accordance with the present invention there is provided a device for making frozen confections, such as ice cream, comprising a double-walled cylindrical vessel having an upper open end and a closed bottom, said vessel consisting of an inner vessel member and an outer vessel member, the space between said inner vessel member and said outer vessel member being hermetically sealed from the exterior with a predetermined amount of freezable cold-keeping agent disposed within said space, an outer receptacle adapted to receive and support said double-walled vessel therein with the aid of a ring mounted on the upper edge of said vessel and closely fitted therewith so as to prevent relative rotational movement therebetween, a cover member adapted to engage at its periphery with said ring attached to said upper edge of said vessel or with the upper edge of said outer receptacle, and stirring means extending into the interior of said vessel through a bearing hole formed at the centre of said cover member.

The ring is preferably made of a pliant deformable material, such as a plastics material or rubber, and has such a cross-section that an outer receptacle supporting shoulder is formed at its outer periphery and a vessel engaging annular groove is formed at its lower side.

With the above described construction, the device of the present invention can be easily and quickly assembled and disassembled, frozen confections can be made by first cooling the double-walled vessel in a refrigerator for several hours so as to freeze the cold-keeping agent to a predetermined low temperature, locating the vessel in the outer receptacle, feeding a predetermined amount of the material for making confection in the vessel, and attaching the cover member onto the vessel and the receptacle with the ring interposed therebetween with the stirring means located in position in the vessel, thereby permitting the frozen confections to be completed by actuating the stirring means while holding the outer receptacle stationarily by the operator's fingers.This is achieved by virtue of the fact that the material is quickly and sufficiently cooled and frozen by the frozen cold-keeping agent which contacts with the material through the entire area of the inner vessel member.

Further, by the provision of heat transmitting fin means in the space between the double walls of the double-walled vessel, even or uniform heat transmitting action over the entire height of the doublewalled vessel can be ensured, thereby positively prohibiting the freezing of the cold-keeping agent occurring first at the upper portion thereof and proceeding successively downwards so that local concentration of expansion of the cold-keeping agent at the lower portion of the vessel during the freezing of the cold keeping agent is positively prevented, thereby to avoid damage or deformation of the vessel.

The device of the present invention does not require troublesome handling of pieces of ice and can be operated in clean conditions in comparison with the prior art device which involves melting of ice and causes unpleasant contamination at the place where the frozen confections are being made.

The device of the present invention may include a means for preventing relative rotational movement between the ring and the cover member or between the outer receptacle and the cover member so that the handling of the device during the making of frozen confection is greatly facilitated.

The inner vessel member and the outer vessel member are preferably formed by thin aluminium plates with alumilite process applied thereto or a plastics coating applied thereon, and the upper edges of the members are sealingly curled tightly together after the cold-keeping agent is introduced into the space between the outer vessel member and the inner vessel member. This makes it possible to improve the transmission of cold through the inner vessel member and the high durability of the device.

The outer receptacle is preferably made of an integrally moulded plastics material with a plurality of supporting lugs provided on the bottom adjacent to the periphery thereof, and the receptacle is preferably provided with a manipulating grip so as to facilitate the holding of the receptacle stationarily during the making of frozen confections. This makes it possible to manufacture the receptacle at a low cost while the cold dissipation from the outer vessel member outwardly through the receptacle is reduced to the minimum by virtue of the provision of the supporting lugs contacting the bottom of the vessel in very small areas, in addition to the provision of the clearance or the heat insulating material provided between the vessel and the receptacle.

The cold-keeping agent preferably comprises water or carbonated water as the base medium with organic or inorganic salts such as alcohol, glycol, ethylene glycol, polypropylene glycol, urea, NaCI and the like added thereto so as to set the melting point of the agent to the range between about -5oC and -25 C, preferably between about -7 C and about -17 C. An organic viscosity increasing agent may be added to obtain an appropriate viscosity of the cold-keeping agent.

The present invention will be described in detail hereinbelow, by way of example only, with reference to the accompanying drawings illustrating several preferred embodiments of the present invention, in which like reference numerals designate like components throughout the drawings, and in which: Figure 1 is a longitudinal cross-sectional elevation showing the construction of one embodiment of a device in accordance with the present invention; Figure 2A is a longitudinal cross-sectional elevation similar to Figure 1 but showing another embodiment; Figure 2B is a fragmentary cross-sectional view showing the construction of the modified form of the ring; Figure 3 is a fragmentary longitudinal cross-sectional view showing the double-walled vessel provided with one form of the heat transmitting fin means;; Figure 4 is a fragmentary longitudinal cross-sectional view similar to Figure 3 but showing another form of the heat transmitting fin means; Figure 5 is a perspective view with a portion broken away for the clear showing of the construction of the double-walled vessel having the heat transmitting fin means shown in Figure 4; Figure 6 is a perspective view showing the heat transmitting fin means shown in Figures 4 and 5; Figure 7 is a perspective view similar to Figure 6 but showing another form of the heat transmitting fin means; Figure 8 is a fragmentary cross-sectional view showing the construction of aluminium brazing sheet suitable for use in making the inner vessel member of the double-walled vessel for facilitating soldering of the fin piece to the outer surface of the inner vessel member;; Figures 9 to 11 are perspective views showing further various forms of the heat transmitting fin piece; Figure 12 is a fragmentary longitudinal sectional view showing the double-walled vessel having a further form of heat transmitting fin means; Figure 13 is a sectional longitudinal cross-sectional view showing the double-walled vessel having heat transmitting fin means provided on the outer surface of the bottom of the inner vessel member of the double-walled vessel; and Figure 14 is a perspective view showing one form of the heat transmitting fin means provided on the outer surface of the bottom of the inner vessel member.

With reference to Figure 1, the first embodiment comprises a double-walled cylindrical vessel 1 consisting of an inner vessel member 2 and an outer vessel member 3 each having an upper open end and a closed bottom end made of a thin aluminium plate with an alumilite process applied thereto. The open upper ends of the inner and outer vessel members 2, 3 are hermetically sealed by curling the upper ends tightly together to form a curled seam 4, wherein an appropriate clearance is held between the cylindrical wall portions as well as the bottoms of the inner vessel member 2 and the outer vessel member 3 so that a space 5 is formed between the two vessel members 2,3.

An appropriate amount of freezable cold-keeping agent 6 is introduced into the space 5 with a certain amount of void or air space 5a being left at the top of the space 5 in order to prevent the vessel members 2,3 from being deformed due to the expansion of the volume of the cold-keeping agent 6 when it is frozen.

The cold-keeping agent 6 tends to begin to be frozen from the upper portion of the agent 6 downwardly. The local concentration of expansion of the cold-keeping agent 6 during the freezing thereof will thus take place in the lower portion of the agent 6 as the frozen portion increases so that local concentration of compression force will be generated in the lower portion of the agent 6.

A heat transmitting fin means 8 made of aluminium having a high heat conductivity is provided in the space between the cylindrical peripheral walls of the inner and outer vessel members 2, 3 extending substantially over the entire height thereof, the fin means 8 abutting against or contacting with at least the outer surface of the inner vessel member 2 so that the uniform transmitting action is obtained over the entire height of the cylindrical peripheral surface of the inner vessel member 2.

The provision of the heat transmitting fin means 8 greatly reduces the temperature gradient occurring from the upper portion of the inner vessel member 2 downwards, thereby preventing local concentration of expansion of the cold-keeping agent 6 at the lower end of the inner vessel member 2 during the freezing thereof so that local concentration of the compressive force at the lower end of the inner vessel member 2 is positively prevented so as to avoid the deformation or damage of the inner vessel member 2.

The heat transmitting fin means 2a shown in Figure 1 comprises a plurality of fins equally spaced around the outer surface of the inner vessel member 2 and radially extending from the outer surface, with the inner edge joined to the outer surface, respectively, while the outer edges are spaced a short radial distance from the inner surface of the outer vessel member 3.

Figure 3 shows a modified form of the fin means 8a comprising a plurality of fins similar to those shown in Figure 1 and Figure 2, wherein, however, the outer edge of each fin is joined to the inner surface of the outer vessel member 3.

Figure 4 shows a further form of the fin means 8b. The fin means 8b comprises a corrugated aluminium plate having sharp bent ridges and located around the outer surface of the inner vessel member 2, with the inner ridges joined to the outer surface of the inner vessel member 2, as shown in Figures 5 and 6.

Figure 7 shows a still further form of the fin means 8c. The fin means 8c is similar to that shown in Figure 6, but the fin means 8c is so formed that the respective bent ridges are of rounded form.

In order to facilitate the joining of these fin means to the outer surface of the inner vessel member 2, the fin means or the inner vessel member 2 may be made of a brazing sheet 9 as shown in Figure 8 to which a sheet 10 of soldering material is cladded. In joining the fin means to the inner vessel 2, a soldering operation is effected by using soldering material containing flux of KF and AIR3. In this case no washing or cleaning operation of the portions to be joined to each other is required thereby avoiding errasion of the joined portions while the soldering operation is greatly facilitated.

Figures 9 to 11 show various modified forms of separately formed fin means 8d, 8e, 8f having a plurality of holes formed therein allowing the free flow of the cold-keeping agent for improving the heat or cold distribution over the entire height of the inner vessel member 2.

The flat portions 8g of the respective fin means shown in Figure 11 are adapted to be joined to the outer surface of the inner vessel member 2 thereby permitting the cooling effect to be further improved.

Figure 12 shows a further modified form of the fin means 8h formed by a heat transmitting plate of rectangularly meandering form in cross-section extending in the vertical direction and having a plurality of holes for improving the heat or cold distribution over the entire height of the inner vessel member 2.

As described previously, since the cold-keeping agent 7 tends to be frozen from the upper portion thereof downwardly, the local concentraion of expansion of the cold-keeping agent 6 will take place in the lower portion of the agent 6. Therefore, it is preferred to provide a flexible air bag sheet 7 as shown in Figure 12 in the bottom of the outer vessel member 3, which will absorb the local concentration of compression by virtue of the contraction of the air bags 7a.

Figures 13 and 14 show fin means 8i adapted to abut against the outer surface of the bottom of the inner vessel member 2 and formed by a heat transmitting plate in the form of a disc with a plurality of concentric annular ridges 8j. The shape of the ridges 8j may be in any desired form and, further, the fin means 8i may be replaced by a plurality of separate fin pieces. The fin means 8i serve to ensure uniform heat or cold distribution over the entire surface of the bottom of the inner vessel member 2.

As described above, the fin means and the fin pieces can greatly relieve the concentration of expansion of the cold-keeping agent 6 at the lower portion of the double-walled vessel 1 during the progress of freezing thereof and, hence, greatly relieves the concentration of compression force at the lower portion of the double-walled vessel 1 so that the deformation and the damage thereof which otherwise might occur can be positively avoided.

A non-adhesive resin coating 2a such as fluorine resin coating and silicone resin coating is provided on the inner surface of the inner vessel member 2. The non-adhesive resin coating 2a permits the completed frozen confections adhering to the inner surface of the inner vessel member 2 to be easily removed or scraped therefrom so that damage which might otherwise occur in the inner surface of the inner vessel member 2 during the scraping operation of the frozen confections is positively prevented.

The non-adhesive coating 2a is prepared by first coating or applying the non-adhesive material such as fluorine resin and silicone resin onto the inner surface of the inner vessel member 2 and then sintering same.

Alternatively, the non-adhesive resin coating 2a may be formed by first injecting molten alumina onto the inner surface of the inner vessel member 2 so as to form an alumina layer having a roughened surface, then applying the resin coating 2a onto the roughened surface fo the alumina layer and then effecting the sintering thereof.

The non-adhesive resin layer 2a may also be formed by first effecting roughening of the inner surface of the inner vessel member 2 by sandblasting same so as to form the roughened surface and then applying the resin layer and effecting the sintering thereof.

As described above, the non-adhesive resin layer 2a serves to greatly reduce the sticking force of the completed frozen confections to the inner surface of the inner vessel member 2 so that the handling or the removal of the completed frozen confections is made easy avoiding the damage to the inner surface of the inner vessel member 2 while the time needed for making frozen confections in the succeeding operation can be shortened, because the frozen confections can be completely removed from the inner surface of the inner vessel member 2 thereby permitting good heat or cold conduction from the doublewalled vessel 1 to the material supplied therein for making frozen confections to be ensured without being subject to deterioration by the sticking of the residual frozen confections having a low heat conductivity to the inner surface of the inner vessel member 2.

The detailed construction of a preferred form of the device of the present invention will now be described hereinafter with reference to Figure 1.

A part-spherical recess 2b is formed at the centre of the bottom of the inner vessel member 2 as shown in Figure 1, the purpose of which will be described later.

An inverted-cup shaped cover member 11 made of an integrally moulded transparent plastics material is provided which has a central bearing hole 11a, a central recess 11b for providing a manipulatable knob ill and a peripheral shoulder portion 11d, the purpose of which will be described later.

In order to appropriately support the double-walled vessel 1 during the operation of the device, an outer receptacle 12 made of an integrally moulded plastics material is provided which is adapted to receive and support the vessel 1 therein with an appropriate clearance held between the outer cylindrical wall of the outer vessel member 3 and the inner cylindrical wall of the receptacle 12 as well as between the bottom of the outer vessel member 3 and the bottom of the receptacle 12.

In order to support the vessel 1 in position in the receptacle 12, a plurality of thin supporting lugs 12a are integrally formed on the upper surface of the bottom of the receptacle 12 adjacent to the periphery thereof. Thus, the vessel 1 is held in the receptacle 12 in the most effective manner preventing dissipation of cold from the vessel 1 outwardly through the receptacle 12.

The space between the vessel 1 and the receptacle 12 may be filled with heat insulating material in order to enhance the heat insulating capacity.

In order to facilitate the handling of the receptacle 12, a hand grip 12b is provided integrally therewith.

A coupling ring 13 sealingly couples the receptacle 12, the double-walled vessel 1 and the cover member 11 together. The ring 13 is a soft flexible member made of a soft, flexible plastics material or rubber and has an inner peripheral shoulder portion 13a snugly mating with a peripheral shoulder portion 11d of the cover member 11, an outer peripheral shoulder porton 13b snugly engaging with the upper inner peripheral edge of the receptacle 12 and an annular groove 13c formed in the lower surface of the ring 13 for snugly receiving the curled seam 4 of the vessel 1 as shown.

In order to prevent relative rotation of the vessel 1 with respect to the receptacle 12 during the operation of the device, a rotation preventing depending lug 13d is formed on the lower surface of the ring 13 which is received in the rotation preventing recess 12c formed in the upper portion of the grip 12b. The ring 13 makes it possible to greatly facilitate the assembling and disassembling of the device.

Figure 2a shows a modified form of the outer receptacle 12' in the form of the double-walled configuration and a modified form of the coupling ring 13' wherein the cover member 11 is adapted to be fitted on the outer periphery of the outer receptacle 12' which is fitted on the outer peripery of the ring 13'.

Figure 2b shows the detailed construction of the ring 13'. The function of the ring 13' is the same as that of the ring 13.

In order to stir the material fed in the inner vessel member 2 for making frozen confections, a stirring means is provided which comprises an upper component 14 located above the cover member 11 and a lower component 15 located beneath the cover member 11 and in the inner vessel member 2.

The upper component 14 consists of a handle arm 16 having a coupling portion 16a of non-circular cross-section integral with the handle arm 16 and extending downwardly from the proximal end of the arm 16 as well as a coupling portion 16b of circular cross-section integral with the handle arm 16 and extending upwardly from the distal end of the arm 16, and a manipulating knob 17 having a downwardly extending sleeve portion 17a rotatably engageable with the coupling portion 16b and a cap 17b removably attached to the top of the knob 17.In order to releasably engage with and hold the coupling portion 16b in the sleeve 17a, the upper portion of the coupling portion 16b is made hollow and an enlarged diameter portion 16c and a plurality of vertical slits 16d are formed at the hollow portion of the coupling member 16b so that the coupling portion 16b can be inserted into the sleeve 17a by contracting the diameter of the enlarged diameter portion 16c by virtue of the provision of the slits 16d and thereafter engaging the enlarged diameter portion 13c with the shoulder portion 17c of the knob 17 formed in the sleeve 17a.

The lower component 15 consists of a rotatable shaft 18 having an upper radially extending stirring blade 18a and a lower radially extending stirring blade 18b fixedly secured thereto at a position diametrically opposite to the position of the upper blade 18a, respectively, the blades 18a and 18b being slightly inclined with respect to the axis of the shaft 18 and arranged parallel to each other so as to ensure that the material in the vessel 1 for making frozen confections can be moved downwardly and upwardly alternately by the rotation of the shaft 18 thereby permitting the material to be sufficiently mixed.

The shaft 18 has a bearing portion 18c at its upper end rotatably fitting in the sleeve 11a of the cover member 11 and a lower end 18d of semi-spherical form rotatably fitting in the part-spherical recess 2b of the inner vessel member 2 so that the shaft 18 is rotatably supported vertically in the inner vessel member 2.

In order to prevent the shaft 18 from being moved excessively upwardly during operation, a flange 18e is formed in the shaft 18 at a position adjacent to the lower end of the sleeve 1 lea.

In order to rotate the lower component 15 by means of the upper component 14, the bearing portion 18c of the shaft 18 is formed with a recess 18f of complementary cross-section to the non-circular crosssection of the coupling portion 16a of the handle arm 16, the recess 18f being snugly fitted with the coupling portion 16a so that the shaft 18 can be rotated by rotating the handle arm 16 by means of the knob 17.

As described previously, since the blades 18a, 18b are secured to the shaft 18 at a slight angle with respect to the axis of the shaft 18 in parallel relationship to each other, the material or the content fed in the inner vessel member 2 is stirred downwardly by the upper blade 18a, while it is stirred upwardly by the lower blade 18b, when the shaft 18 is rotated in the predetermined direction thereby permitting the contents to be sufficiently mixed up to provide high quality frozen confections. The arrangement of the blades 18a, 18b is also effective to mix air bubbles in the material to make soft cream.

The operation of the above described device of the present invention will be described below.

The double-walled vessel 1 is first cooled in a separate refrigerator for several hours so as to cause freezing of the cold-keeping agent 6.

The vessel 1, the receptacle 12 and the cover member 11 are sealingly assembled by using the ring 13 after the lower component 15 is located in the inner vessel member 2 and a predetermined amount of the material for making frozen confections is fed therein. The upper component 14 is then coupled with the lower component 15.

The material begins to be frozen in a thin layer on the inner surface of the inner vessel member 2 which is scraped off by the blades 18a, 18b as the shaft 18 is rotated by driving the knob 17. After several minutes, the material is rendered to form well mixed frozen confections such as ice cream and sherbet.

It is also possible to couple an electric motor with the lower component 15 directly or through a reduction gear so as to dispense with manual handling of the stirring means.

After the frozen confections are completed, the stirring means is removed and the cap 17a is fitted in the bearing hole 11 a of the cover member 11 for sealing purpose.

Example 1 Conditions Thickness of the inner and outer vessel members 2, 3 = 0.7 mm Volume of the space 5 between the inner and outer vessel members = 500 cc 2, 3 Volume of the cold-keeping agent 6 = 430 cc (filling rate 86%) Melting point of the cold-keeping agent 6 = -12 + 2"C Temperature of the refrigerator = -18 + 2"C Duration of refrigeration = 6 + 1 hours Material for frozen confections = raw cream 200 cc 2 raw eggs 130 g sugar 80 g Temperature of the material = 8 +1"C Results The time for completing the operation: Temperature Time Soft cream - 2"C 8 t 2 min.

Ice cream - 3.5"C 25 t 5 min.

It has been proved that the filling rate of the cold-keeping agent 6 in the space 5 must be equal to or greater than 75%. An inert gas may be filled in the space 5a in place of air.

It has also been proved that the melting point of the cold-keeping agent 6 is preferably set to the range of -7 C and -17"C in light of the temperature of the refrigerator of -18 C, while good results can not be obtained when the melting point is set to equal to or higher than -6 C.

As described above, the present invention provides a device for making frozen confections which requires a very short time for making the frozen confections and which is easy to handle and can be used repeatedly in cleanliness, and since the parts of the device can be easily disassembled, it is made com pact and easily transported. The ring effectively prevents the operator from being hurt by frostbite.

By virtue of the cold-keeping capacity of the cold-keeping agent, it is possible to maintain the com pleted frozen confections in the vessel at a constant low temperature for a long time period, and the frozen confections can maintain their taste until the cold-keeping agent loses its cold-keeping effect by dissipating cold therefrom during use.

Further, it is made possible to set the time period required for freezing the cold-keeping agent as well as the time period in which the completed frozen confections can be kept in the frozen state to any de sired value by merely adjusting the quantity of the cold-keeping agent provided in the space between the walls of the inner and outer vessel members of the double-walled vessel.

Claims (8)

1. A device for making frozen confections, such as ice cream, comprising a double-walled cylindrical vessel having an upper open end and a closed bottom, said vessel consisting of an inner vessel member and an outer vessel member, the space between said inner vessel member and said outer vessel mem ber being hermetically sealed from the exterior with a predetermined amount of freezable cold-keeping agent disposed within said space, an outer receptacle adapted to receive and support said double-walled vessel therein with the aid of a ring mounted on the upper edge of said vessel and closely fitted there with so as to prevent relative rotational movement therebetween, a cover member adapted to engage at its periphery with said ring attached to said upper edge of said vessel or with the upper edge of said outer receptacle, and stirring means extending into the interior of said vessel through a bearing hole formed at the centre of said cover member.

2. A device as claimed in claim 1, wherein said ring is made of a pliant deformable material, such as a plastics material or rubber, and has an outer receptacle supporting shoulder formed at its outer periphery and a vessel engaging annular groove formed at its lower side.

3. A device as claimed in claim 1, including means for preventing relative rotational movement between said ring and said cover member or between said outer receptacle and said cover member.

4. A device as claimed in claim 1, wherein either one of said rings mounted on the upper edge of said vessel and the upper edge of said outer receptacle is provided with a projection, while the other is provided with a recess adapted to receive and engage with said projection so that relative rotational movement between said vessel and said outer receptacle is prevented.

5. A device as claimed in claim 1, wherein either a clearance or a quantity of heat insulating material at least partially filling said clearance is provided between the peripheral surfaces as well as between the bottom surfaces of said vessel and said outer receptacle.

6. A device as claimed in claim 1, wherein a cover supporting shoulder is formed in the inner periphery of said ring.

7. A device as claimed in claim 1, further comprising heat or cold transmitting fin means arranged in the sapce between said inner vessel member of said double-walled cylindrical vessel and said outer vessel member, said fin means being held in contact with at least the outer peripheral surface of said inner vessel member so as to ensure substantially uniform distribution of heat or cold over the entire height of said double-walled cylindrical vessel.

8. A device for making frozen confections such as ice cream, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.