NL1009931C2 - Device for heating liquids, especially kettle, contains seal radially clamped between inner wall of liquid vessel and peripheral wall of base - Google Patents

Abstract

The seal (4) between the inner wall of the liquid vessel (2) and the base (3) are clamped under radial pressure between this inner wall and the peripheral wall of the base. Independent claims are also included for (a) a method for making the device, by placing the seal around the base periphery and then placing the base inside the vessel, and (b) an auxiliary piece for assisting the assembly of the device by this method.

Description

R CL / SvW / Ferro- LIQUID HEATING APPARATUS, METHOD FOR MANUFACTURING THE APPARATUS AND AN APPARATUS FOR APPLICATION TO THE METHOD.

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The invention relates to a device for heating liquid, which device is provided with: | 5 a container for the liquid; I a heating element, which is attached to the! bottom of the container; and sealing means for liquid-tightly sealing the space between the inner wall of the 10 holder and bottom.

Such a device is known from GB 2291325. In the known device sealing means are arranged on the top of the bottom near the edge thereof, with which the bottom is pressed against the bottom side of an edge protruding from the inner wall of the container. The bottom is held in this position by a flexible collar, which is deformed to push the bottom upwards from the bottom.

The known device has a number of drawbacks. One of them is that part of the surface of the bottom cannot be used for the heat transfer to the liquid. Another drawback is that high clamping forces are required for fixing the bottom in the container, in particular for bending the collar, which entails a heavy load on the container. As a result, high demands are placed on the material used for the container, which in turn leads to higher material costs.

The object of the invention is to provide an apparatus of the type mentioned at the outset, which obviates the above drawbacks.

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To this end, the device according to the invention is characterized in that the sealing means are clamped under radial pressure between the inner wall of the container and the peripheral edge of the bottom.

The device according to the invention also has the advantage that the sealing means now form a sufficiently high thermal resistance to the surrounding container, so that it can be made of cheaper materials if desired. In addition, this leads to a more efficient use of energy.

In a first preferred embodiment, the sealing means comprise elastomers. By using these heat-resistant materials, the thermal resistance can be increased even further.

The invention also relates to a method for manufacturing a device according to the invention, which method comprises the following steps: 1) Applying the sealing means around the peripheral edge of the bottom; 2) Placing the assembly formed in step 1 in the container such that the sealing means is clamped under radial pressure - between the inner wall of the container and the peripheral edge of the bottom.

In a first preferred embodiment, step 1 of the method according to the invention comprises the following steps: a) arranging the sealing means around a first fitting; b) placing the bottom on the first aid; c) sliding the sealing means over the first fitting to the peripheral edge of the bottom.

In a further preferred embodiment, step c of the method according to the invention comprises the following steps: 100993 (3 cl) arranging a second attachment around the first attachment; c2) shifting the sealing means 5 to the peripheral edge of the bottom by means of the second attachment over the first attachment.

Preferably, the method of the invention further comprises the step of removing one or more of the attachments.

With the aid of the method according to the invention, the device according to the invention can be manufactured in a quick, simple and therefore inexpensive manner. By using one or more attachments as a mounting tool, the different parts of the device according to the invention can be designed as simply as possible, which allows for further cost savings. Partly due to the aforementioned aspects, the method according to the invention lends itself perfectly to (automated) mass production.

In a further preferred embodiment of the method according to the invention, the second fitting has an at least partly conically extending outer wall for cooperation with the at least partly conically extending inner wall of the holder for clamping the sealing means under radial pressure. In an alternative further preferred embodiment, step 1 of the method according to the invention further comprises the step of: d) arranging a third fitting around the sealing means and the second fitting, the third fitting having an at least partly conical inner wall for the clamping the sealing means under radial pressure. Both methods make it possible to effect the radial clamping of the sealing means in a number of simple, rapid steps. Although the alternative embodiment requires an extra fitting and an extra operation, it has the advantage that the holder without conical inner wall can be simpler and thus cheaper.

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Preferably, the fittings comprise collars, the general shape of at least the outer collar corresponding to the shape of the inner wall of the container.

The invention also relates to an accessory for use in the method according to the invention.

The invention will be described in more detail below with reference to the appended drawing, in which:

Figure 1 shows a schematic view of a kettle according to the invention, partly worked open, partly in section;

Figures 2A to 2F show step by step a first preferred embodiment of the method according to the invention; and

Figures 3A to 3G show stepwise a second preferred embodiment of a method according to the invention.

Figure 1 shows, as an example of a device according to the invention, a kettle 1. Kettle 1 is provided with all parts known in the art, which as standard belong to a kettle. In the following description, only those parts which are important for the understanding of the invention are further described. The other parts are assumed to be known.

The kettle 1 comprises a container 2 for the liquid to be heated (not shown). Holder 2 is provided with a bottom 3 on which a heating element 5 is arranged. In the shown preferred embodiment, heating element 5 is integrated in the bottom 3 by techniques known in the art. Preferably bottom 3 is a PEMS element (PEMS = Porcelain Enamelled 35 Metal Substrates). PEMS elements are known in the art and generally comprise a metal base plate of steel, stainless steel or copper. On this base plate is a dielectric, for example a layer of glass-ceramic, 1 0 0 9 9 cl; 5 applied. Circuits are subsequently applied to this by means of thick-film techniques, which can for instance be composed of conductive pastes and / or resistance pastes. Optionally, a covering layer is applied over the whole. A method for manufacturing such a PEMS element is described, for example, in EP 0 201 967 of applicant.

The PEMS element described above serves as a bottom and as a heating element. Within the scope of the invention, however, it is also conceivable for a separate heating element to be arranged on top or bottom of bottom 3.

15 sealing means 4 are arranged on the peripheral edge of bottom 3. Sealing means 4 are radially clamped between this circumferential edge or cutting edge and the inner wall of container 2. The material of the sealing means should be waterproof, resistant to high temperatures (preferably 20 to approximately 200 ° C) and this material should also have a suitable, permanent elasticity and hardness. An example of a suitable material is an elastomeric material, preferably extruded silicone material. In view of the cylindrical shape of container 2 and the circular shape of bottom 3, a contiguous ring of extruded silicone material has been used in the shown preferred embodiment. A suitable material for the holder and the collars is plastic. The bottom is preferably of a suitable metal type, such as stainless steel, aluminum, etc.

Figures 2A to 2F show the steps of a first preferred embodiment of a method according to the invention on the basis of a cross-section of a part of the kettle.

In the first step, a ring of elastomeric material 4 is placed around a first collar 6. The general shape of collar 6 corresponds to the general shape of the inner wall of container 2. In the preferred embodiments shown, this shape is cylindrical. Then bottom 3 is applied to collar 6.

By means of a second collar 7, sealing ring 4 is shifted over the first collar 6 to a position in which this ring surrounds the peripheral edge of bottom 3. The general shape of collar 7 again corresponds to the general shape of the inner wall of container 2. Collars 6 and 7 have dimensions such that they can be slid over each other closely.

Subsequently, the assembly 13 thus formed is introduced into holder 2 in the next step. For this purpose holder 2 is provided on the inner wall with a conical tapering part 9 which cooperates with the top side of collar 7, which also tapers. The dimensions of the collars 6 and 7 and the holder 2 are such that the assembly 13 can be slid tightly into holder 2.

On the inside, holder 2 is provided with a first shoulder 8, against which the sealing ring 4 rests after placing the assembly in the holder.

Finally, collars 6 and 7 are removed from holder 2. The sealing ring 4 is now radially clamped between the peripheral edge of bottom 3 and the inner wall of holder 2 at the location of shoulder 8. The conical tapering shape of the inner wall of holder 2 at location of shoulder 8 ensures that sealing ring 4 becomes radial pressed.

Optionally, holder 2 can be provided with an overhanging edge adjoining shoulder 8, whereby sealing ring 4 is clamped on three sides in its final position. Preferably, this overhanging edge has such dimensions that it ends at some distance above bottom 3.

Figures 3A through 3G show a second preferred embodiment of the method according to the invention. Steps 3A through 3C are identical to steps 2A through 2C and are therefore not discussed in more detail here.

After formation of assembly 13, in the second preferred embodiment of the method according to the 1009931 7, a third collar 10 is slid over the assembly, such that collar 10 surrounds sealing ring 4. For radially pressing sealing ring 4, collar 10 is provided with a partly conically tapering inner wall 11. The dimensions of collar 10 are such that it can be slid tightly over collar 7. The assembly 14 thus formed is placed in holder 2. The dimensions of container 2 and the collars are chosen such that assembly 14 can be slid snugly in container 2.

Assembly 14 is in the correct position when collar 10 rests against second shoulder 12 located on the inside of container 2. With the help of collars 6 and 7, sealing ring 15 4 and bottom 3 are respectively pushed into the correct position, in which sealing ring 4 rests against shoulder 8.

Finally, collars 6, 7 and 10 are removed from holder 2. The result is shown in Figure 3G. This preferred embodiment is also shown in Figure 1.

The difference between the two different embodiments of the method according to the invention lies in the use of third collar 10 for performing the function of radially pressing sealing ring 4 with the aid of a partially conical inner wall 11. Since this function is now no longer needs to be carried out by holder 2, holder 2 can be made simpler. Holder 2 can now also be shorter, as is apparent from the comparison of figures 3G and 2F, and it can comprise a larger volume of liquid 30.

Obviously, the invention is not limited to the preferred embodiments shown, which all relate to use with an electric kettle. Many other applications are conceivable for the invention described, including application in rice cookers, hot plates, cooking appliances, etc. Also larger-scale applications, for example in industry, are conceivable. After all, the invention generally relates to the liquid-tight attachment of a bottom and / or (plate-shaped) heating element by clamping at the circumferential wall in a container for liquid.

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Claims (14)

1. Device for heating liquid, which device comprises: a container for the liquid; a heating element attached to the bottom of the container; and sealing means for liquid-tightly sealing the space between the inner wall of the container and the bottom, characterized in that the sealing means are clamped under radial pressure between the inner wall of the container and the peripheral edge of the bottom. The device of claim 1, wherein the sealing means comprises elastomers. 3. Removing one or more of the fittings. Device as claimed in claim 1 or 2, wherein the heating element is integrated in the bottom. A method for manufacturing a device according to claim 1, 2 or 3, which method comprises the following steps: 1. applying the sealing means around the peripheral edge of the bottom; 2. placing the assembly formed in step 1 in the container in such a way that the sealing means are clamped under radial pressure between the inner wall of the container and the peripheral edge of the bottom. The method of claim 4, wherein step 1 comprises the following steps: a) applying the sealing means about a first fitting; b) placing the bottom on the first aid; 1009931 c) sliding the sealing means over the first fitting to the peripheral edge of the bottom. The method of claim 5, wherein step c comprises the following steps: cl) arranging a second attachment about the first attachment; c2) displacing the sealing means to the peripheral edge of the bottom by means of the second attachment over the first attachment. The method of claim 4, 5 or 6, the method further comprising the step of: 8. A method according to any one of the preceding claims 4 to 7, wherein a first shoulder is provided on the inner wall of the container against which the "sealing means rest against after performing step 2. A method according to any one of the preceding claims 6 to 8, wherein the second fitting has an at least partly conically extending outer wall for cooperation with the at least partly conically extending inner wall of the holder for clamping the radial pressure sealants. A method according to any one of the preceding claims 6 to 8, wherein step 1 further comprises the following step: d) arranging a third fitting around the sealing means and the second fitting, the third fitting having an at least partly conical inner wall has for clamping the sealing means under radial pressure. A method according to claim 10, wherein a second shoulder is provided on the inner wall of the holder, against which the third fitting rests after the execution of step 2. A method according to any one of the preceding I claims 6 to 11, wherein the fittings comprise collars i wherein the general shape of at least the I 1009931 outer collar corresponds to the shape of the inner wall of the container. The method of claim 12, wherein the thickness of the second collar and the thickness of the sealing means viewed in radial direction are substantially equal. Attachment, for use in the method according to any one of claims 4 to 13. 1009931