GB1594092A - Electric water heater container closure arrangement - Google Patents

Description

(54) ELECTRIC WATER HEATER CONTAINER CLOSURE ARRANGEMENT (71) We, P. & R. ELECTRICAL (LON DON) LIMITED, a British Company, of Pearl House, 1 Berrymead Gardens, London W.3., do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to electric water heaters and their water container closure arrangements and is particularly, but not exclusively, applicable to electrically heated continuous flow water heaters.

Continuous flow water heaters, having particularly advantageous forms of control by means of temperature sensitive switches, are described and illustrated in the Specifications of our Patent No. 1363842 and our Application No. 20728/76, Serial No.

1594091. As described and illustrated in the Specification of that Patent and in the Provisional Specification of that Application, these water heaters comprise a copper cannister which is enclosed in a high density type plastics jacket. The jacket provides a degree of thermal insulation and also protects the cannister from damage and the user from contact with the hot cannister.

Electric kettles have recently been introduced, having bodies made of a plastics material of good strength and very low thermal conductivity, so that one can put a hand on the body of the kettle with little discomfort even when the water in the kettle is boiling. This material is known as NORYL (Registered Trade Mark). We have found that it can readily be moulded to form the body of a continuous flow water heater which does not need an outer jacket.

However, the use of this material has presented a considerable problem in respect of the closure of the top of the water container with the necessary sealing.

An object of the present invention is to provide a closure arrangement which can be successfully employed to solve the above mentioned problem.

According to one aspect of the present invention there is provided a water heater comprising an electric heating element in a water container having water inlet and outlet connections and a neck with a closure arrangement in which a metallic disc is clamped in sealing engagement with a resilient sealing ring on an end face of the neck by means of a clamping ring cooperating with the neck. Apertures may be provided in the said disc for the upper ends of heating element(s), thermostatic switch probe(s) or any other component(s) which have to pass through the closure. Each such aperture may be surrounded by a ferrule having a clamping nut for squeezing a resilient sealing ring against an end face of the ferrule and inwardly against the component passing through it.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawling, which shows a part-sectional view of a continuous flow water heater.

Referring to the drawing, the continuous flow water heater comprises a mineral insulated, sheathed wire, heating element 2 disposed within a water container 4 which is moulded from NORYL material to include a cold water inlet 6 and a hot water outlet 8 at the bottom, each with an up-standing internal portion 6A, 8A. A stand pipe 10, inserted in the internal portion 8A of the hot water outlet, extends upwards to maintain the water level near the top of the container 4, and a probe 12 of a temperature sensitive switch (not shown) extends into the upstanding portion 6A of the cold water inlet. It will be appreciated that, since the invention is concerned with the closure arrangement, the specifically described and illustrated configuratlon of water container and components may be varied.The specifications of our aforesaid Patent and Application should be referred to for a description of some possible variations and of the way in which the electrical connections may be maae and the water heater operated.

The water container 4 is provided with a neck 14 which is also moulded from NORYL material in a shape which is apparent from the drawing. The neck 14 is sealed to the rim of the container 4 at 16 as shown.

The neck 14 is externally threaded and the closure arrangement includes an internally threaded clamping ring 18 which screws onto the neck, the ring being moulded with upstanding studs 20 around the edge of its upper surface to enable it to be screwed down tightly and unscrewed.

The closure arrangement is completed by a metallic disc 22, which may be of copper and is preferably dished slightly as shown.

The disc 22 is clamped by the ring 18 against a resilient sealing ring 24 on an end face of the neck 14. The disc 22 has apertures such as 26 for components which pass through it such as the ends of the heating element 2, one of which is shown at 28, and the upper part (not shown) of the temperature sensitive probe 12. The necessary sealing is provided at each of these points by means of a ferrule 30, secured to the upper surface of the disc 22 as by brazing or welding at 32, a clamping nut 34 and a resilient sealing ring 36 which is squeezed inwardly against the element portion 28 or other component.

The body of the water heater is completed by a cap portion 40 and a lid 42, both of NORYL material. The cap 40 is moulded with a terminal block platform 44 (not fully shown) and has a cable entry cut-out in the rear Part of its wall immediately below the lid 42. The cap 40 sits in an annular recess 50 at the outer edge of the neck 14 and is held in position by a nut on a threaded upper part of a central stud (not shown in the drawing) preferably with a locking washer and a wired seal. The stud is attached to the centre of the disc 22 and extends upwards therefrom. The threaded upper end goes through a receiving hole in the platform 44. With the disc of copper the stud may be solid brass.

There has been thus described a continuous flow water heater having NORYL body portions and a suitable sealing closure. The use of NORYL material instead of metal for the water vessel permits the elimination of the outer jacket hitherto required and the material is more adaptable than metal to shaping and the inclusion of integral parts by moulding.

A particular advantage of the construction described is that it can readily be dismantled "on the kitchen table" for servicing or replacement of parts, thus considerably reducing the cost of any maintenance that may be required.

WHAT WE CLAIM IS: 1. A water heater comprising an electric heating element in a water container having water inlet and outlet connections and a neck with a closure arrangement in which a metallic disc is clamped in sealing engagement with a resilient sealing ring on an end face of the neck by means of a clamping ring cooperating with the neck.

2. A water heater as claimed in claim 1, wherein apertures are provided in the said disc for components which extend through the closure.

3. A water heater as claimed in claim 2, wherein each such aperture is surrounded by a ferrule having a clamping nut for squeezing a resilient sealing ring against an end face of the ferrule and inwardly against the component passing through it.

4. A water heater as claimed in any one of claims 1 to 3 in which the water container is moulded from plastics material.

5. A water heater as claimed in claim 4, wherein the said neck is also moulded from the same plastics material.

6. A water heater as claimed in any one of claims 1 to 5, wherein the metallic disc is dished slightly.

7. A water heater as claimed in any one of claims 1 to 6, wherein the metallic disc is of copper.

8. A water heater comprising an electric heating element in a water container having water inlet and outlet connections and a neck with a closure arrangement substantially as herein described with reference to the accompanying drawing.

9. A continuous flow water heater constructed substantially as herein described with reference to the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (9)

**WARNING** start of CLMS field may overlap end of DESC **. The neck 14 is externally threaded and the closure arrangement includes an internally threaded clamping ring 18 which screws onto the neck, the ring being moulded with upstanding studs 20 around the edge of its upper surface to enable it to be screwed down tightly and unscrewed. The closure arrangement is completed by a metallic disc 22, which may be of copper and is preferably dished slightly as shown. The disc 22 is clamped by the ring 18 against a resilient sealing ring 24 on an end face of the neck 14. The disc 22 has apertures such as 26 for components which pass through it such as the ends of the heating element 2, one of which is shown at 28, and the upper part (not shown) of the temperature sensitive probe 12. The necessary sealing is provided at each of these points by means of a ferrule 30, secured to the upper surface of the disc 22 as by brazing or welding at 32, a clamping nut 34 and a resilient sealing ring 36 which is squeezed inwardly against the element portion 28 or other component. The body of the water heater is completed by a cap portion 40 and a lid 42, both of NORYL material. The cap 40 is moulded with a terminal block platform 44 (not fully shown) and has a cable entry cut-out in the rear Part of its wall immediately below the lid 42. The cap 40 sits in an annular recess 50 at the outer edge of the neck 14 and is held in position by a nut on a threaded upper part of a central stud (not shown in the drawing) preferably with a locking washer and a wired seal. The stud is attached to the centre of the disc 22 and extends upwards therefrom. The threaded upper end goes through a receiving hole in the platform 44. With the disc of copper the stud may be solid brass. There has been thus described a continuous flow water heater having NORYL body portions and a suitable sealing closure. The use of NORYL material instead of metal for the water vessel permits the elimination of the outer jacket hitherto required and the material is more adaptable than metal to shaping and the inclusion of integral parts by moulding. A particular advantage of the construction described is that it can readily be dismantled "on the kitchen table" for servicing or replacement of parts, thus considerably reducing the cost of any maintenance that may be required. WHAT WE CLAIM IS:

1. A water heater comprising an electric heating element in a water container having water inlet and outlet connections and a neck with a closure arrangement in which a metallic disc is clamped in sealing engagement with a resilient sealing ring on an end face of the neck by means of a clamping ring cooperating with the neck.

2. A water heater as claimed in claim 1, wherein apertures are provided in the said disc for components which extend through the closure.

3. A water heater as claimed in claim 2, wherein each such aperture is surrounded by a ferrule having a clamping nut for squeezing a resilient sealing ring against an end face of the ferrule and inwardly against the component passing through it.

4. A water heater as claimed in any one of claims 1 to 3 in which the water container is moulded from plastics material.

5. A water heater as claimed in claim 4, wherein the said neck is also moulded from the same plastics material.

6. A water heater as claimed in any one of claims 1 to 5, wherein the metallic disc is dished slightly.

7. A water heater as claimed in any one of claims 1 to 6, wherein the metallic disc is of copper.

8. A water heater comprising an electric heating element in a water container having water inlet and outlet connections and a neck with a closure arrangement substantially as herein described with reference to the accompanying drawing.

9. A continuous flow water heater constructed substantially as herein described with reference to the accompanying drawing.