GB2381436A

GB2381436A - Forming a plastics component such as a water gauge onto a metal body of a kettle

Info

Publication number: GB2381436A
Application number: GB0126399A
Authority: GB
Inventors: Tat Chan
Original assignee: BETTER ELECTRICAL PRODUCTS
Current assignee: BETTER ELECTRICAL PRODUCTS
Priority date: 2001-11-02
Filing date: 2001-11-02
Publication date: 2003-05-07
Also published as: GB0126399D0; CN1416769A

Abstract

A method of forming a plastics component onto a metal body of a kettle comprises the steps of providing a metal kettle body member 12 and moulding a plastics material thereto. Preferably the plastics material is moulded to an opening in the kettle body 12 which may have an inner edge 22 with at least one cavity therein for receiving at least part of the plastics material. The method may further comprise the steps of providing a plastics component, moulding plastics material onto the kettle body 12 in order to secure the plastics component to the said metal kettle body 12 and positioning a sealing ring 20 around the opening so that the opening is watertight. The kettle body 12 is preferably made of stainless steel while the plastics component is preferably a water gauge 14 made from polycarbonate or polypropylene. The moulding of the plastics material to the kettle body 12 is preferably carried out using insert moulding techniques.

Description

A Method of Forming a Plastics Component on a Kettle Body and a Kettle Formed of Such a Method This invention relates to a method of forming a plastics component on a kettle body and a kettle formed of such a method and, in particular, a method of forming a plastics water gauge on a kettle body made at least principally of metal.

There are in existence a large variety of electric and non-electric kettles. It is found desirable to form the body of the kettle at least principally of metal, and to have a non-opaque, e. g. transparent or translucent, water gauge communicating with the interior of the kettle body, so as to enable a user to be aware of the amount of water in the kettle. The water gauge is thus usually made of a plastics material. Various methods have been proposed for securing such a plastics water gauge onto the metal kettle body. However, as the kettle may be heated up and cooled down a number of times a day, many existing securing methods are found wanting in ensuring the secured and water-tight engagement between the water gauge and kettle body.

It is thus an object of the present invention to provide a method of forming a plastics component, e. g. a water gauge, on a kettle body in which the aforesaid shortcomings are mitigated, or at least to provide a useful alternative to the public.

It is also an object of the present invention to provide a kettle made by such a method.

According to a first aspect of the present invention, there is provided a method of forming a plastics component on a kettle body, including steps (a) of providing a metal kettle body member; and (b) of moulding plastics material onto said kettle body member.

According to a second aspect of the present invention, there is provided a kettle with a metal kettle body and a plastics gauge formed by (a) providing a metal kettle body member; and (b) moulding plastics material onto said kettle body member to form a water gauge.

Embodiments of the present invention will now be described, by way of examples of only, and with reference to the accompanying drawings, in which: Fig. 1 is a side view of a kettle formed of a method according to the present invention; Fig. 2 is a sectional view taken along the line X-X in Fig. 1, showing the structure of a kettle formed of a first embodiment of the present invention; Fig. 3 is a sectional view taken along the line X-X in Fig. 1, showing the structure of a kettle formed of a second embodiment of the present invention; Fig. 4 is a sectional view taken along the line X-X in Fig. 1, showing the structure of a kettle formed of a third embodiment of the present invention ; Fig. 5 is a sectional view taken along the line X-X in Fig. 1, showing the structure of a kettle formed of a fourth embodiment of the present invention; Figs. 6A and 68 are sectional views showing the procedure whereby a water gauge is moulded onto a kettle body according to a fifth embodiment of the present invention; Fig. 7 is a sectional view taken along the line X-X in Fig. 1, showing the structure of a kettle formed of a sixth embodiment of the present invention; Fig. 8A is a sectional view taken along the line X-X in Fig. 1, showing the structure of a kettle formed of a seventh embodiment of the present invention;

Fig. 8B is an enlarged view of the encircled part in Fig. 8A; Fig. 8C is a sectional view taken along the line Y-Y in Fig. 8B, according to a first example of the seventh embodiment; Fig. 8D is a sectional view taken along the line Y-Y in Fig. 8B, according to a second example of the seventh embodiment; Figs. 9A and 9B show the insertion of a kettle body into a moulding machine for moulding a plastics component thereon, according to the present invention; Fig. 9C shows a sectional view of the mould and kettle body shown in Fig. 9B when carrying out the method according to the first embodiment of the present invention; Fig. 9D is an enlarged view of the part marked as"A"in Fig. 9C; Fig. 9E is a corresponding enlarged view of the part marked as"A" in Fig. 9C when carrying out the method according to the fifth embodiment of the present invention shown in Figs. 6A and 6B; Figs. lOA and lOB are enlarged views of the part marked as"B"in Fig. 9E, showing the process whereby the sealing ring in Fig. 9E is kept under a compression pressure after moulding; and Figs. llA to 11F show generally the process whereby a plastics water gauge is formed on a metal kettle body by a method according to the present invention.

A kettle formed of a method according to the present invention is shown in Fig. 1, and generally designated as 10. The kettle 10, which may be electric or non-electric, includes a body 12 made of a metal, e. g. stainless steel, secured with an oval transparent plastics water gauge 14, which may be made of polycarbonate or polypropylene. The water gauge 14 allows the interior of the body 12 to be observed from the outside, so that a user may become aware of the level of water in the body 12. The water gauge 14 may be provided with a scale to assist the user in better assessing the amount of water in the body 12. Before formation of the water gauge

14 on the body 12, the body 12 has a generally oval opening.

Fig. 2 shows the structure of a kettle lOa in which a plastics water gauge 14a is moulded on the kettle body 12a by way of a method according to a first embodiment of the present invention. It can be seen that the water gauge 14a is engaged with and enfolds an inner edge 16a of a stepped portion of the oval opening of the body 12a.

In Figs. 9A and 9B, a part of a moulding machine is shown. This part of the moulding machine includes and upper mould base 100 and a lower mould base 102. Provided on an upper end of the lower mould base 102 is a lower mould 104. A corresponding mould recess (not shown in Figs. 9A and 9B) is formed in the lower part of the upper mould base to complement the lower mould 104.

The kettle body 12a on which the plastics water gauge 14a is to be moulded is positioned on the lower mould 104. A bolster 106 is positioned at the rear end of the body 12a so as to securely position the body 12a relative to the moulding machine, and to support the lower mould 104 during moulding. The upper mould base 100 is then lowered to secure the body 12a between the upper mould base 100 and the lower mould base 102. When the upper mould base 100 is so lowered, the upper mould (to be discussed below) and the lower mould 104 collectively form a channel 108 leading to an oval opening 110 of the body 12a. The channel 108 allows molten plastics material from other parts of the moulding machine to flow to the opening 110 of the body 12a.

Figs. 9C and 90 show in more detail the position of the kettle body 12a relative to an upper mould 101 of the upper mould base 100 and the lower mould 104 of the lower mould base 102. As shown

in particular in Fig. 9D, a space 111 is formed between the upper mould 101 and the lower mould 104, and around an inner edge 112 of the opening 110 of the body 12a. Molten plastics material, e. g. polycarbonate or polypropylene, may then be introduced, e. g. injected, by the moulding machine to fill this space 111 via the channel 108. When the plastics material cools down, a non-opaque water gauge 14a will be formed on the kettle body 12a, in particular around and over the generally oval opening of the kettle body 12a.

Turning to Fig. 3, such shows the structure of a kettle lOb in which a plastics water gauge 14b is moulded on the kettle body 12b by way of a method according to a second embodiment of the present invention. An endless rubber sealing ring 20 of a generally circular cross-section is provided along an inner edge 22 of an opening of the kettle body 12b. This serves the purpose of further ensuring that the engagement between the water gauge 14b and the kettle body 12b is water-tight.

Fig. 4 shows the structure of a kettle 10c in which a plastics water gauge 14c is moulded on the kettle body 12c by way of a method according to a third embodiment of the present invention. In this embodiment, for achieving better water-tight effect, an endless sealing ring 24 surrounds and enfolds a stepped portion 26 of an inner edge of an opening of the kettle body 12c before the water gauge 14c is moulded thereon.

Fig. 5 shows the structure of a kettle 10d in which a plastics water gauge 14d is moulded on the kettle body 12d by way of a method according to a fourth embodiment of the present invention. It can be seen that an endless sealing ring 26 also surrounds and enfolds a stepped portion of an inner edge of an opening of the kettle body 12d before the water gauge 14d is moulded thereon. A major

modification in this embodiment is that the area of plastics on the outer surface of the kettle body 12d is increased to cover a larger area of the kettle body 12d. This enhances the outward appearance of the kettle lOd as, e. g. the plastics material may be of different colours, and different graphics may be provided on the plastics component. In addition, the plastics cover also prevents the possibly very hot stainless steel body 12d to be accidentally touched by a user, e. g. a child.

In a method according to a fifth embodiment of the present invention, and as shown in Figs. 6A, 6B, 9E, lOA and lOB, there is already pre-formed a plastics water gauge 14e. An inner edge 30 of an opening of a kettle body 12e is surrounded with an endless rubber sealing ring 32. The pre-formed water gauge 14e is then positioned above the sealing ring 32, and kept in this position by an upper mould lOla and a lower mould 104a so as to engage with both the sealing ring 32 and the kettle body 12e. Molten polycarbonate or polypropylene is then introduced into the cavity between the upper mould lOla and lower mould lO4a via a channel 108a. When the molten material cools down, the structure shown in Fig. 6B will form. It should be noted in particular that although the water gauge 14e and the plastics material introduced into the mould cavity are shown in different shadings in Fig. 6B, they cannot be separated and are not distinguishable from each other after the moulding and cooling process.

An advantage of the fifth embodiment discussed above is that, during moulding, and after moulding and cooling, of the introduced plastics material, the rubber sealing ring 32 is under a compression force. As can be seen in Fig. lOA, when the upper mould 101a is lowered towards the lower mould 104a, the pre-formed water gauge 14e is forced downwardly to bear on and compress the sealing

32, until the water gauge 14e assumes the position shown in Fig. lOB, in which it is flush with the outer surface of the kettle body 12e. After molten plastic material is introduced into the moulds lOla, 104a and subsequently allowed to cooled, the sealing ring 32 will be kept in this compressed state, which further enhances the water-tight feature of the engagement between the kettle body 12e and the water gauge 14e.

Fig. 7 shows the structure of a kettle 10f in which a plastics water gauge 14f is formed on a kettle body 12f by way of a method according to a sixth embodiment of the present invention. This embodiment is similar to the fifth embodiment discussed above, except that the area of the plastic material moulded onto the inner surface of the kettle body 12f is larger than that in the fifth embodiment, which can reduce the temperature of the steel kettle body 12f.

Fig. 8A shows the structure of a kettle 109 in which a plastics water gauge 14g is formed on a kettle body 12g by a method according to a seventh embodiment of the present invention. This embodiment is similar to the first embodiment in Fig. 2 and discussed above.

A major modification over the first embodiment is that along a first bent portion 30g (see Fig. 8B) of an inner edge 32g of the kettle body 12g is formed a bulging portion 34g and a corresponding dimple region 36g, which assist in more secure engagement between the kettle body 12g and the water gauge 14g.

To further enhance the engagement between the water gauge 14g and the kettle body 12g, along a second bent portion 38g of the inner edge 32g of the kettle body 12g are formed a number of through holes 40g, of which three are shown in Fig. 8C. Thus, when moulding, the plastics material introduced into the mould cavity will fill

up the through holes 40g. Alternatively, a number of cavities 42g, again of which three are shown in Fig. 8D, may be formed along the second bent portion 38g of the inner edge 32g of the kettle body 12g. Thus, when moulding, the plastics material introduced into the mould cavity will also fill up these cavities 42g.

Fig. 11A to 11F show generally a process whereby a plastics water gauge is formed on a metal kettle body by a method according to the present invention.

Starting from Fig. 11A, a kettle body 202 is inserted into a lower mould 204 of an insert moulding machine 200. A bolster 206 (see Fig. 11B) is then inserted at the rear end of the kettle body 202 to maintain the kettle body in the proper position in the machine 200, and to support the lower mould 204 during moulding. An upper mold 208 is then brought down to bear on the lower mould 204 (see Fig. 11C). Molten plastics material is then injected into the cavities between the moulds 204, 208 to form the water gauge. Upon sufficient cooling of the plastics material, the upper mould

208 is raised (see Fig. lid). The bolster 206 is then removed (see Fig. HE), whereupon the moulded kettle body 202 may then be lifted up and then pulled out from the lower mould 204. Excess and useless plastics material may be removed from the kettle body 202 (see Fig.

I1F).

It can be seen from the foregoing that the present invention provides ways in which a non-opaque plastics water gauge may be formed on a metal kettle body, while ensuring that the engagement therebetween is water-tight.

The moulding method used in the present invention may more appropriately be called"insert moulding". Such a moulding method

is typically, as in the examples discussed above, done using vertical clamp injection moulding machines, in which the mould halves are opened and closed vertically. The advantage of such an arrangement is that gravity assists in keeping components in location. Insert moulding may be done in multiples steps, which allows different plastics parts to be moulded onto the kettle body.

It should be understood that the above only illustrates examples whereby the present invention may be carried out, and that various modifications and/or alterations may be made thereto without departing from the spirit of the invention.

It should also be understood that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any appropriate sub-combinations.

Claims

CLAIMS :- 1. A method of forming a plastics component on a kettle body, including steps (a) of providing a metal kettle body member; and (b) of moulding plastics material onto said kettle body member.
2. A method according to Claim 1 wherein said plastics material is moulded onto said kettle body member by insert moulding.
3. A method according to Claim 1 or 2 wherein said plastics material is moulded onto said kettle body member to form at least part of said component.
4. A method according to any of the preceding claims further including steps (c) of providing said plastics component; and (d) of moulding plastics material onto said kettle body member to secure said plastics component with said kettle body member.
5. A method according to Claim 1 wherein said plastics material is moulded around and over an opening of said kettle body member.
6. A method according to Claim 5 wherein said plastics material is moulded onto an inner edge of said opening of said kettle body member.
7. A method according to Claim 6 further including a step (e) of providing at least one cavity in said inner edge for receiving at least part of said plastics material moulded thereon.
8. A method according to Claim 7 wherein said at least one cavity comprises a through-hole.
9. A method according to any one of Claims 5 to 8 wherein said plastics material is moulded onto an inner surface of said kettle body member.
10. A method according to any one of Claims 5 to 8 wherein said plastics material is moulded onto an outer surface of said kettle body member.
11. A method according to any one of Claims 5 to 10 further including

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a step (f) of positioning a sealing ring around said opening.
12. A method according to Claim 11 wherein said sealing ring enfolds at least part of an inner edge of said opening.
13. A method according to Claim 12 wherein said sealing ring enfolds at least part of a stepped portion of said opening.
14. A method according to Claim 11,12 or 13 wherein said sealing ring is endless.
15. A method according to any one of Claims 11 to 14 wherein said plastics material is moulded onto said sealing ring and said kettle body member.
16. A method according to Claim 15 wherein during moulding, said sealing ring is under a compression force.
17. A method according to Claim 15 and 16 wherein after moulding, said sealing ring is under a compression force.
18. A method according to any of the preceding claims wherein said kettle body member is made at least principally of stainless steel.
19. A method according to any of the preceding claims wherein said component is a water gauge.
20. A kettle including a metal kettle body and a plastics gauge formed by (a) providing a metal kettle body member; and (b) moulding plastics material onto said kettle body member to form a water gauge.
21. A kettle according to Claim 20 wherein said plastics material is moulded around and over an opening of said kettle body member.
22. A kettle according to Claim 21 wherein said plastics material is moulded onto an inner edge of said opening of said kettle body member.
23. A kettle according to Claim 22 wherein said inner edge includes at least one cavity receiving at least part of said plastics material moulded thereon.

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24. A kettle according to Claim 23 wherein said at least one cavity comprises a through-hole.
25. A kettle according to any one of Claims 21 to 24 wherein said plastics material is moulded onto an inner surface of said kettle body member.
26. A kettle according to any one of Claims 21 to 24 wherein said plastics material is moulded onto an outer surface of said kettle body member.
27. A kettle according to any one of Claims 21 to 26 further including a sealing ring around said opening.
28. A kettle according to Claim 27 wherein said sealing ring enfolds at least part of an inner edge of said opening.
29. A kettle according to Claim 27 wherein said sealing ring enfolds at least part of a stepped portion of said opening.
30. A kettle according to Claim 27,28 or 29 wherein said sealing ring is endless.
31. A kettle according to any one of Claims 27 to 30 wherein said plastics material is moulded onto said sealing ring and said kettle body member.
32. A kettle according to any one of Claims 27 to 31 wherein said sealing ring is under a compression force.
33. A kettle according to any of Claims 20 to 32 wherein said kettle body member is made at least principally of stainless steel.
34. A kettle substantially as herein described and with reference to the accompanying drawings.
35. A method substantially as herein described and with reference to the accompanying drawings.