Induction kettle

Patent metadata

Field	Value
Publication number	US-12150584-B2
Application number	US-202017435858-A
Country	US
Kind code	B2
Filing date	Mar 9, 2020
Priority date	Mar 7, 2019
Publication date	Nov 26, 2024
Grant date	Nov 26, 2024

Abstract

An appliance including: a vessel to receive a liquid, the vessel having a longitudinal axis, a bottom wall, and a side wall at least partly enclosing a chamber within which the liquid is heated, the chamber having an upper region axially spaced from the bottom wall, and a lower region located between the bottom wall and the upper region; a heating element within the chamber; a heater base including at least a portion of an induction coil; connections to deliver an alternating current to the induction coil to deliver a magnetic field to the lower region; the element being movable relative to the coil between an operative position at which the element is located within the lower region to be energised by the magnetic field to cause heating of the element, and an inoperative position at which the element is located in the upper region to not energize the element.

First claim

The invention claimed is:

1. An appliance to heat a liquid, the appliance including:
a vessel to receive the liquid to be heated, the vessel having a generally central upright longitudinal axis, a bottom wall, and a side wall extending upwardly from the bottom wall, with the bottom wall and side wall at least partly enclosing a chamber within which the liquid is heated, with the chamber having an upper region axially spaced from the bottom wall, and a lower region located between the bottom wall and the upper region;
a heating element located within the chamber for relative movement therewithin, with the heating element at least partly formed of ferromagnetic material;
a heater base to be positioned relative to the bottom wall of the vessel, the heater base including at least a portion of an induction coil; and
connections to deliver an alternating current to the induction coil so as to deliver a magnetic field to the lower region, wherein
the heating element is movable relative to the coil between an operative position at which the heating element is located within the lower region so as to be energised by the magnetic field to cause heating of the heating element so that heat generated by the heating element can be delivered to the liquid via conduction, and an inoperative position at which the heating element is located in the upper region so as to no longer place an operative load on the induction coil,
wherein the heating element is in the form of a plate centrally located on the axis, and
wherein the plate includes at least one bimetallic member located on an underside of the plate, with the member possessing at least two positions of stability, with each of the positions responsive to a threshold temperature.

2. The appliance of claim 1 , further including a cover attached to the vessel so as to enclose, with the bottom wall and the side wall, the chamber, with the cover including:
an opening extending through the cover and generally centrally located on the axis; and
a stopper at least partly sealingly located within the opening for movement relative thereto along the axis between a retracted position and an extended position at which the stopper is spaced upwardly along the axis from the retracted position, wherein
the heating element is connected to the stopper so as to move therewith, with the retracted position corresponding to the operative position, and with the extended position corresponding to the inoperative position, and wherein
the stopper is urged to move from the retracted position to the extended position when the chamber is subjected to a positive pressure relative to outside the chamber so as to move the heating element from the operative position to the inoperative position.

3. The appliance of claim 2 , further including a shaft generally aligned with the axis, with one end of the shaft attached to the heating element, and with the other end of the shaft attached to the stopper.

4. The appliance of claim 3 , wherein the shaft has a predetermined length so as to locate the heating element in the lower region when the heating element is in the operative position and so as to locate the heating element in the upper region when the heating element is in the inoperative position.

5. The appliance of claim 1 , wherein, when the member is at a temperature below the threshold temperature, the member is in one of the stable positions in which the member is generally coplanar with the underside of the plate, and wherein, when the member is at a temperature above the threshold temperature, the member is configured to actuate to the second position of stability in which at least a portion of the member engages the bottom wall to move the plate into the upper region.

6. The appliance of claim 1 , wherein the plate is perforated.

7. A vessel to receive liquid to be heated by a heater base, the heater base having an induction coil and connections to deliver an alternating current to the induction coil so as to deliver a magnetic field to the vessel, the vessel having a generally central upright longitudinal axis, a bottom wall, and a side wall extending upwardly from the bottom wall, with the bottom wall and side wall at least partly enclosing a chamber within which the liquid is heated, with the chamber having an upper region axially spaced from the bottom wall, and a lower region located between the bottom wall and the upper region; and
a heating element located within the chamber for relative movement therewithin, with the heating element at least partly formed of ferromagnetic material,
wherein the heating element is movable relative to the bottom wall between an operative position, at which the heating element is located within the lower region so as to be energised by the magnetic field to cause heating of the heating element so that heat generated by the heating element can be delivered to the liquid via conduction, and an inoperative position, at which the heating element is located in the upper region, so as to no longer place an operative load on the induction coil,
wherein the heating element is in the form of a plate centrally located on the axis, and
wherein the plate includes at least one bimetallic member located on an underside of the plate, with the member possessing at least two positions of stability, with each of the positions responsive to a threshold temperature.

8. The vessel of claim 7 , further including a cover so as to enclose, with the bottom wall and the side wall, the chamber, with the cover including:
an opening extending through the cover and generally centrally located on the axis; and
a stopper at least partly sealingly located within the opening for movement relative thereto along the axis between a retracted position and an extended position at which the stopper is spaced upwardly along the axis from the retracted position, wherein
the heating element is connected to the stopper so as to move therewith, with the retracted position corresponding to the operative position, and with the extended position corresponding to the inoperative position, and wherein
the stopper is urged to move from the retracted position to the extended position when the chamber is subjected to a positive pressure relative to outside the chamber so as to move the heating element from the operative position to the inoperative position.

9. The vessel of claim 8 , further including a shaft generally aligned with the axis, with one end of the shaft attached to the heating element, and with the other end of the shaft attached to the stopper.

10. The vessel of claim 9 , wherein the shaft has a predetermined length so as to locate the heating element in the lower region when the heating element is in the operative position and so as to locate the heating element in the upper region when the heating element is in the inoperative position.

11. The vessel of claim 7 , wherein, when the member is at a temperature below the threshold temperature, the member is in one of the stable positions in which the member is generally coplanar with the underside of the plate, and wherein, when the member is at a temperature above the threshold temperature, the member is configured to actuate to the second position of stability in which at least a portion of the member engages the bottom wall to move the plate into the upper region.

12. The vessel of claim 7 , wherein the plate is perforated.

Assignees

• Breville R & D Pty Ltd

Inventors

• Hellmers Duncan Bruce
• Mcclean Stephen John
• Thie Johnson
• Hoare Richard

Classifications

• H05B6/12

  Cooking devices · CPC title

• H05B6/108

  for heating a fluid · CPC title

• H05B6/06

  Control, e.g. of temperature, of power · CPC title

• A47J27/21175

  Covers · CPC title

• A47J27/21108

  using a bimetallic element · CPC title