Toaster

Patent metadata

Field	Value
Publication number	US-12011113-B2
Application number	US-202117322465-A
Country	US
Kind code	B2
Filing date	May 17, 2021
Priority date	Jun 19, 2020
Publication date	Jun 18, 2024
Grant date	Jun 18, 2024

Abstract

A toaster includes an activation element, a power circuit, a heating device and a control device. When the activation element is moved to turn on the power circuit, the control device is powered such that an electromagnet is activated to attract a retaining element to hold the activation element and to actuate a two-state switch, which allows passage of electrical power to the heating device. After a time interval has elapsed, the control device stops the electromagnet from attracting the retaining element such that the retaining element no longer actuates the two-state switch, which cuts off electric power provided to the heating device.

First claim

What is claimed is:

1. A toaster comprising:
an activation element configured to move between a turn-off position and a turn-on position;
an elastic element configured to provide a reaction force that drives said activation element to move from the turn-on position to the turn-off position;
a power circuit configured to connect to mains electricity to receive electrical power therefrom, said power circuit including a live wire, a neutral wire, a first switch connected with said live wire, and a second switch connected with said neutral wire, wherein said first switch and said second switch are configured to be turned on when said activation element is at the turn-on position;
a heating device; and
a control device electrically connected to said heating device and said power circuit, and configured to receive electrical power from said power circuit when said first switch and said second switch are turned on, said control device including:
an electromagnet;
a retaining element that is magnetically attractable and that is configured to move between a first position and a second position, to stay at the first position when not being magnetically attracted by said electromagnet, and to stay at the second position when being magnetically attracted by said electromagnet in order to hold said activation element at the turn-on position;
a timing element configured to count a time interval, and to control said electromagnet to continuously produce, only during the time interval, a magnetic force that attracts said retaining element to move to and be retained at the second position;
a two-state switch connected between said first switch of said power circuit and said heating device, and configured to be set at a first configuration and a second configuration when said retaining element is at the first position and the second position, respectively;
a first rectifier circuit connected between said two-state switch and a common node to which said electromagnet and said timing element are connected, and configured to, when said first switch and said second switch are turned on and when said two-state switch is at the first configuration where said two-state switch electrically connects said first switch and said first rectifier circuit, provide electrical power to said electromagnet and said timing element; and
a second rectifier circuit connected between said heating device and the common node, and configured to, when said first switch and said second switch are turned on and when said two-state switch is at the second configuration where said two-state switch electrically connects said first switch and said heating device, provide electrical power to said electromagnet and said timing element;

wherein said heating device is configured to, when said two-state switch is at the second configuration, convert electrical power received from said power circuit to thermal energy, and provide a fraction of the electrical power to said second rectifier circuit, and
wherein said timing element is further configured to:
in response to said activation element being moved to the turn-on position, be powered on by receiving electrical power from said first rectifier circuit, start counting the time interval, and control said electromagnet to produce the magnetic force to attract said retaining element to the second position, which in turn actuates said two-state switch to transition from the first configuration to the second configuration,
when said two-state switch is at the second configuration, receive electrical power from said second rectifier circuit, and control said electromagnet to continuously produce the magnetic force during the time interval, and
after the time interval has elapsed, control said electromagnet to stop producing the magnetic force, which in turn causes said retaining element to return from the second position to the first position, so that said activation element is released from the turn-on position and is moved to the turn-off position by the reaction force provided by said elastic element, and so that said two-state switch transitions from the second configuration to the first configuration to electrically disconnect said heating device from said first switch of said power circuit.

2. The toaster of claim 1 , wherein:
said electromagnet has an attractive side;
said retaining element is at the attractive side of said electromagnet; and
said retaining element includes:
a lock part that is configured to prevent said activation element at the turn-on position from moving toward the turn-off position;
a magnetic part that is to be magnetically attracted to the attractive side of said electromagnet;
an extension part that is configured to, when said retaining element is at the second position, press on said two-state switch in order to set said two-state switch at the second configuration; and
an elastic part that is configured to provide an elastic force that drives said retaining element to move from the second position to the first position.

3. The toaster of claim 2 , wherein said activation element includes:
a hook portion configured to engage with said lock part of said retaining element when said activation element is at the turn-on position, in order for said activation element to be held at the turn-on position;
a first press portion configured to press on said first switch of said power circuit when said activation element is at the turn-on position, in order to turn on said first switch; and
a second press portion configured to press on said second switch of said power circuit when said activation element is at the turn-on position, in order to turn on said second switch.

4. The toaster of claim 1 , wherein:
said two-state switch is a micro switch; and
said two-state switch is in the first configuration when said two-state switch is not being pressed, and is in the second configuration when being pressed.

5. The toaster of claim 1 , wherein each of said first switch and said second switch is a snap action switch.

6. The toaster of claim 1 , wherein said timing element includes:
a temperature sensor configured to measure a temperature of said heating device; and
a controller configured to count the time interval, to shorten the time interval when the temperature measured by said temperature sensor is above a threshold temperature, and to lengthen the time interval when the temperature is below the threshold temperature.

7. The toaster of claim 1 , wherein said heating device is configured to divide a voltage received from said power circuit to result in a voltage portion that is to be applied to said second rectifier circuit so as to provide the fraction of the electrical power to said second rectifier circuit, said second rectifier circuit being configured to perform rectification on the fraction of the electrical power thus received so as to provide electrical power to said electromagnet and said timing element.

Assignees

• Tsann Kuen Zhangzhou Entpr Co

Inventors

• Sun Xiaosen
• He Yangtai
• Wu Ziwang

Classifications

• H05B1/0225

  actuated by timers · CPC title

• H05B1/0261

  of food · CPC title

• A47J37/0842 Primary

  with electronic timers · CPC title

• A47J37/0814

  with automatic bread ejection or timing means (A47J37/0857 takes precedence) · CPC title

• A47J37/08 Primary

  Bread-toasters · CPC title