FR2744615A3 - IMPROVED ELECTRIC KETTLE - Google Patents

Abstract

An electric plastic kettle has a hollow body (10) and an integrally molded steam chamber (16) leading steam to a steam detector (28); the lower end of the chamber (16) is covered by a ventilation plate (22) being controllable by the vapor detector between a closed position in which current is supplied to a heating element (11) and an open position in which the heating element (38) is not supplied with current, and the vapor chamber is ventilated to the atmosphere.

Description

This invention relates to electric kettles which can be either

  in the form of a conventional kettle having a very approximately cylindrical shape, i.e. a pouring kettle

  having a height greater than its diameter.

  Both types of kettles have a hollow body to hold a liquid to be heated; an electric resistance heating element located inside the body; a temperature sensitive switch, often a bimetallic element, arranged to disconnect the heating element from an electrical supply when it reaches a predetermined temperature; and a steam chamber arranged to conduct steam from the body to the temperature sensitive element, the temperature sensitive element providing a

  automatic activation when boiling.

  Several vapor chamber arrangements are known. For example, in a pouring kettle in which the body is made from plastic material, a channel can be embedded in the side of the jug which adjoins the handle to conduct steam to a temperature sensitive element arranged so as to extend towards the

base of the kettle.

  A common factor in all of the arrangements is that the vapor in the chamber adjacent to the temperature sensitive element must cool and condense before the element can be reset. This is why it can be irritating for a user that the kettle cannot be switched on and brought to the boil again immediately after automatic activation, and that a short delay is inevitable. In addition, there may be a large

  amount of vapor to condense and drain from the base.

  One method of reducing the amount of condensation is to shrink the vapor chamber, but this requires a small diameter insertion into the molding die in which a kettle body is molded.

made of plastic.

  We know other arrangements in which the route is modified

  of steam extending to the bimetallic element.

  In Great Britain's patent application 2,252,875 Strix Ltd. a steam opening between the boiling vessel and the steam channel is provided with a valve which closes the opening when the water boils, but the reset delay is not

  this fact neither reduced nor the amount of vapor which must condense.

  In British Patent Application 2,282,957, Fast Forward Design Ltd., the boiling period before automatic activation can be adjusted by placing a bellows in the vapor path having a variable opening to provide a variable impedance on steam passage, but the reset delay is not

  thus not reduced nor the volume of vapor which must condense.

  According to the invention an improved electric kettle has a hollow body for containing a liquid to be heated; an electric resistance heating element located inside the body being contiguous with its base; an electric control unit connected to the heating element and fixed to the kettle outside the hollow body and contiguous to its base, said electric control unit incorporating a movable switch member, sensitive to temperature, arranged so as to establish and interrupting a power supply to the heating element; a steam chamber for conducting steam from the hollow body to the vicinity of the switch member; and a controllable ventilation device with the switch member situated between a first position in which the steam chamber is closed and the heating element is supplied with current and a second position in which the combustion chamber

  steam is open and the heating element is not supplied with current.

  Advantageously, the ventilation device comprises a hinged valve arranged so as to cover an opening present in the

steam channel.

  Advantageously, the switching member is a bimetallic disc forming part of a rocker mechanism and the hinged valve is

  mechanically connected to the rocker mechanism.

  Advantageously, the steam chamber is integrally molded with the hollow body and it optionally extends above the switching member substantially towards the upper side of the container, the chamber having a first opening at its upper end connecting the chamber to the body. hollow and a second opening at its lower end on its side opposite the hollow body, said second

  opening is covered by the ventilation device.

  The invention will be described in more detail with reference to the accompanying drawings in which: FIG. 1 is a partial view of a pouring kettle having a ventilation device in the closed position; Figure 2 is a partial view of a pouring kettle having a ventilation device in the open position; FIG. 3 illustrates a standard bimetallic disc and a rocker mechanism cooperating with the ventilation device; Figures 4 and 5 illustrate in front view respectively in side view the ventilation device illustrated more

  detailed in Figures 1 to 3.

  In Figure 1 a pouring kettle has a hollow body 10 for containing water, the body being of plastic material, and in which a heating element 11 (see Figure 3) is arranged near the bottom of the body. Electric current is supplied to the element through a socket 12 to which a plug can be connected (not shown); the socket is connected to the element 11 via a control device

14.

  Above the control device 14 and the outlet 12 is located a steam chimney 16 in the form of a vertical tube having a rectangular cross section molded with the body 10 and located outside said body, and having at its upper end an opening 18 by means of which the chimney is connected inside the hollow body 10. The chimney 16 conducts steam passing through the opening 18 to the control device 14, as indicated by the arrows A. The inner end of the chimney 16 has on its outer face a ventilation opening 20 (see FIG. 2) covered

by a ventilation plate 22.

  The ventilation plate 22 is mounted on a horizontal articulation pin 24 and it is movable between the position illustrated in FIG. 1 in which the plate closes the steam chimney, and the position illustrated in FIG. 2 in which the plate rotates on the hinge pin and opens to allow the vapor from the chimney 16 to escape into the atmosphere. This allows the vapor detector forming part of the control device 14 to cool more quickly than before, which allows a very rapid reset of the detector and minimizes the delay between triggering.

  automatic and admissible boiling.

  FIG. 3 illustrates the control device 14, the ventilation plate 22 being removed; any control device

  conventional, such as that manufactured by Strix Ltd., can be used.

  The control device 14 has a bimetallic vapor detector element 28 disposed at the base of the vapor chimney 16. A rocker body 30 has a first upper arm 32 which can come into contact with the element 28 and a second lower arm 34 which can come into contact with a current disconnection device 36 of the known type. When the first arm 32 is in contact with the detector element 28, current flows to the heating element 38 until the water present in the kettle boils, then steam descends in the chimney 16 and the steam detector element 28 operates on the tumbling rocker body, so that the second arm 34 comes into contact with the disconnection device, the current is disconnected from the heating element 38. As the rocker arm moves, it drives the ventilation plate 22. FIG. 1 corresponds to the position of passage of the

  current and Figure 2 at the current interruption position.

  The advantages of an improved electric kettle according to the invention are that all the steam entering the steam chamber is directed towards the bimetallic switch, thereby causing the switch to operate more quickly with a reduced volume of condensation. The switch can be reset faster than before. A large steam chamber can be used which is integral with the body of the kettle, which allows easier manufacture than previously used steam tubes, and the cover can be designed to match any control device. standard, even with control devices with different sizes, which allows easy interchangeability of control devices. The invention can be implemented for a pouring kettle like that illustrated or for a kettle

  having a conventional shape.

Claims (5)

  1. An electric kettle comprising a hollow body (10) for containing a liquid to be heated; an electric resistance heating element (38) located inside the body (10) being contiguous with its base; an electric control unit (12) connected to the heating element and fixed to the kettle outside the hollow body and contiguous to its base, said electric control unit incorporating a movable temperature-sensitive switching member (28) arranged so as to establish and interrupt an electrical supply to the heating element (38); a steam chamber (16) for conducting steam from the hollow body to the vicinity of the switch member (28); and a ventilation device (22) controllable with the switch member situated between a first position in which the steam chamber (16) is closed and the heating element is supplied with current, and a second position in which the steam chamber (16) is open and the element   heater is not supplied with power.   2. Electric kettle according to claim 1, in which the ventilation device comprises a hinged valve (22) arranged so as to cover an opening (20) present in the steam chamber (16).   3. An electric kettle according to claim 2, in which the switching member is a bimetallic disc forming part of a rocker mechanism and in which the hinged valve (22) is   mechanically connected to the rocker mechanism.   4. Electric kettle according to any one of claims   previous, in which the steam chamber (16) is molded   integrally with the hollow body (10).   5. An electric kettle according to claim 4, in which the steam chamber (16) extends above the switch member substantially towards the upper side of the container, the chamber having a first opening (18) at its upper end. connecting the chamber to the hollow body (10) and a second opening (20) at its lower end on a side opposite the hollow body (10), said second opening being covered by the ventilation device (22).