GB2422293A

GB2422293A - Toaster with overheating protection function

Info

Publication number: GB2422293A
Application number: GB0604705A
Authority: GB
Inventors: Changling Huang
Original assignee: GUANGDONG YILONG ELECTRICAL AP
Current assignee: GUANGDONG YILONG ELECTRICAL AP
Priority date: 2003-08-11
Filing date: 2004-08-10
Publication date: 2006-07-26
Anticipated expiration: 2024-08-10
Also published as: CN1473537B; GB0604705D0; GB2422293B; WO2005013786A1; CN1473537A

Abstract

A toaster with overheating protection function, comprises a bread support which may be moved between a toast position and a reset position, an armature fixed on a carriage, a spring switch, an electromagnet unit and a base. The electromagnet unit includes an electromagnet element and a main body. At least one branch extended laterally and at least one hook element extended longitudinally is located on the main body. The base includes a top board. The top board has at least one hole. The hook of the electromagnet unit is mounted on the base movably through the hole. The spring switch is located between the branch and the armature on the main body. The branch may prevent the spring arm of the spring switch from moving down. The electromagnet element is turned on and grips the armature while the carriage moves down. When the electromagnet is cut off, the electromagnet unit slides from the position of the armature to the position of the base under it's gravity, thus the spring switch is flicked away and cuts off the heating circuit.

Description

6iL!cEaDEFINmvgcQp,r Toaster Having Overheating Protection Function

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a toaster, and more particularly, to a toaster having overheating protection function. The present invention belongs to the field of toasting devices.

BACKGROUND OF THE INVENTION

A toaster is a small household appliance used to toast bread or other food. The.

conventional toaster comprises a housing, a heating element, a toast rack, an electromagnet, a control rod, and a control circuit board. The toast rack, which is connected to the control rod, can be movably mounted within a toasting chamber formed within the housing and be moved between a toasting position and an ejection position within th toasting chamber. When the toast rack is at the toasting position, the electromagnet located at a bottom of the toasting chamber is activated and the toast rack is retained at the toasting position through a ferrous piece. The toast IS rack is moved to the ejection position after bread is toasted by the heating element for a predetermined period. However, if bread is suddenly jammed within the toast rack or bread having a larger size than the toast rack is positioned into the toast rack, the toast rack may be blockedatthetoastingposition.Thus, thetoastrackmaybejammedandfailtobemovedup after a predetermined period, but the heating element is still powered, which may cause bread to burn. This is too dangerous.

SUMMARY OF THE INVENTION

It is an object of the present invention to overcome the above-mentioned problems in the prior art by providing a toaster having overheating protection function. If a toast rack in the toaster is jammed, current in an electric heating element can be powered off to stop toasting after a predetermined time.

In order to flillill the above object, the present invention can employ the following technical solutions. A toaster having overheating protection function comprises: a housing within which a heating element is provided; a toast rack; a bracket a base; and a timer circuit, the timer circuit being configured to control a power on/off, the toast rack being able to move between a toasting position qid an ejection position and being fixed on the bracket, wherein the toaster further comprises an overheating protection device including a ferrous piece, an elastic switch, and an electromagnetic assembly, the elastic switch is disposed between the ferrous piece and the electromagnetic assembly, a power input port of the electromagnetic assembly is coupled to an output port of the timer circuit, the electromagnetic assembly is interlinked with the elastic switch, the electromagnetic assembly is movably mounted on the base, the base has a space within which the electromagnetic assembly can slide, and the elastic switch can he turned on or off by a movement of the electromagnetic assembly within the base.

Normally, the toast rack is retained at the toasting position according to an interaction between the electromagnetic assembly and the ferrous piece, a power circuit is turned on through the elastic switch, and the heating element is provided with power and then generates heat. Usually, current in the electromagnetic assembly is automatically cut off under a control of the timer circuit after a predetermined period, which causes an electromagnet in the assembly to release the ferrous piece as the attracting force therebetween disappears. The bracket then drives the toast rack to return up to the ejection position, which permits a user to take the toasted bread.

If the toasted bread is jammed within the toast rack, the toast rack may fail to be pulled up, but the current in the electromagnet will be cut off to make the attracting f6rce disappear after a predetermined period. As a result, the electromagnetic assembly can vertically fall down under its gravity, which causes the elastic switch to be turned off In this case, the heating circuit is cut off and the heating element stops toasting bread. Consequently, the toaster is really secure by avoiding continuously toasting which may cause bread to burn or even damage the electric element of the toaster.

The object of the present invention can also be achieved by employing the following teclrnical solutions.

The bracket comprises at least one arm, and a bulge is integrally formed on the bottom of the arm. At least one contact part is integrally formed at the elastic switch, The electromagnetic assembly comprises an electromagnet and a body both of which are tightly jointed together as a whole. The body provides at least one side arm extended laterally and at least one side step extended longitudinally. The base comprises a top board having at least one opening thereon. The electromagnetic assembly can be movably mounted on the base through the opening.

The elastic switch is located between the side arm of the body and the ferrous piece.

The side arm may prevent an elastic arm of the elastic switch from falling. When the bracket is moved downwards, the bulge presses the contact part which further presses another elastic arm of the elastic switch to turn on the switch. As a result, the electromagnet is magnetized to attract the ferrous piece. When the switch is cut off, the electromagnet releases the ferrous piece and the electromagnetic assembly falls vertically under its gravity to make the elastic switch turn off and the heating circuit disconnect.

The toaster of the present invention has the following prominent advantages: By using the above-mentioned technical solutions, if bread is jammed within the toasting chamber to cause the toast rack failing to spring up, current in the electromagnetic assembly may be cut off to make the heating circuit turn off through the elastic switch after a predetermined period Therefore, the toaster is safe by avoiding continuously toasting which may cause bread to burn or even damage the electric element of the toaster.

BRiEF DESCRIPTION OF THE DRAWINGS

Fig. I is a structural cross-sectional view of a toaster of the present invention; Fig. 2 is a perspective view showing a security device of the toaster; Fig. 3A and 3B are enlarged perspective views showing an electromagnetic assembly of the toaster; Fig. 4 is a cross-sectional view showing a security device of the toaster; Fig. 5 is a cross-sectional view showing a security device of the toaster when the toaster is started to work; Fig. 6 is a cross-sectional view showing a security device of' the toaster when the toaster is working normally; and Fig. 7 is a crosssectional view showing a security device of the toaster after the security device is activated.

DETAILED DESCRIPTION OF THE iNVENTION

As shown in Figs. I and 2, a toaster of the present invention comprises a toast rack I that is inserted into mounting holes provided at two opposite arms 12 of a bracket 3. A control rod 2 is inserted into a fastening hole 31 located on an upper portion of the bracket 3 so that the control rod 2 and the toast rack I are jointed together as a whole. A bulge 121 is integrally formed on each bottom of the two arms 12 of the bracket 3. The bracket 3 can move vertically along a guide pillar 4. The bracket 3 provides a horizontally protruded part at a lower portion thereof under the fastening hole 31, which provides a groove receiving a ferrous piece 11 and allowing the same vertically and horizontally movable therein so that the ferrous piece can always attract an electromagnet 110 in a good position. A hollow portion 32 is provided at a side of the fastening hole 31, through which a reset spring 15 is disposed and fixed (to the inner of the toaster).

As shown in Figs. 2, 3A, and 3B, a security device of the toaster mainly comprises a base 1 40 Located at a bottom portion of the toaster, the electromagnet 110 and a body 1 30. The electromagnet 110 comprises an Eshaped arm 111 which is formed by silicon steel sheets. The body 130 has a hollow portion for enclosing the center of the E-shaped arm 111. A winding is wound around a portion of the body 130 between an upper flat and a lower flat of the body 130 and embraced by the two arms of the Eshaped arm 111. An electromagnetic assembly 10 is thereby provided by the electromagnet 11 0 and the body 130, which may be powered off by an independentS control circuit after a predetermined period. Two side arms I 20 are oppositely extended out from each side of the body 1 30 in a direction perpendicular to the E-shaped ann 111. Two side steps 150 are extended downwardly from the body 130 which are perpendicular to the extending directions of the side arms 120, respectively. Two rectangular openings 141 which are in a loose fit with the side steps 150 are provided at a top board 143 of the base l50 In this manner, tile electromagnetic assembly 10 including the electromagnet 110 and the body 1 30 can be movably mounted on the base 1 40 through the loose fit between the side steps 1 50 and the openings 141. The base 140 is fixed to a bottom board of the toaster. The electromagnet together with the body 130 can be moved upward until the side elements 150 are stopped by a lower surface of the top board 143 of the base 140. When the current of the winding is cut off, the electromagnetic assembly 1 0 will fall downwards under the gravity of the electromagnet 110 and the body 130 until the lower surface of the electromagnetic assembly 10 contacts the upper surface of the top board 143 of the base 140.

Referring to Figs. 2 and 4, two support boards 16 which are symmetrical with respect to the electromagnetic assembly 10 are disposed. Two switches 19 made of elastic materials are mounted on the support boards 16, respectively. Each switch 19 comprises an elastic arm 191, two contact parts 1 71 and 1 72 made of elastic materials and disposed vertically opposite to each other, and two argental contacts 181 and 1 82. The contacts 18 1 and 182 can be pressed down by exerting a pressure at the end of the contact parts 1 71 and 1 72. The elastic switches 19 are electrically communicated with a heating circuit of the toaster. When the switches 19 turn on the heating circuit, a heating element begins to work and the heating element stops toasting as the circuit is cut off. When the elastic switches 19 are in an open state, the undersurface of a curving portion of each of the contact parts 172 can contact the upper surface of each of the side arms 120. The contact parts 172 is limited to vertically move by the side arms 120, while the contact parts 1 7 1 can stretch up freely under the elasticity.

Referring to Fig. 4, the toast rack I of the toaster of the present invention is in an ejection position which permits a user to put bread into or take bread out of the toast rack 1, The electromagnetic assembly 10 closely contacts the top board 143 of the base 140 under the gravity. The elastic switches 19 are in an open state, and the curving portions of the contact parts 172 cannot move downward for the curving portions are stopped by the extended side arms 120, Referring to Fig. 5, the control rod 2 is pressed to render the bracket 3 to move downwards along the guide pillar 4 and then the reset spring ISis thereby kept in a tension state by a downward pressure. The bulges 121 disposed at the bottom of the two arms 12 of the bracket 3 push the contact parts 171 to move down, which in turn causes the elastic arms 191 bended and makes the contacts 1 81 move downwards, Since the contact parts 172 arc stopped by the side arms 1 20, the contacts 181 can contact the contacts 1 82 when the control rod 2 moves downwards for a certain distance, and the circuit is turned on through the elastic switches I 9 The electromagnet 11 0 generates a magnetic force due to current flowing through the winding so as to attract the ferrous piece ii. At this time, the ferrous piece 11 and the electromagnetic assembly 10 can be moved together as a whole.

Referring to Fig. 6, the control rod 2 is released when the toast rack I moves in the toasting position. The reset spring 1 5 generates an upward force, so that the ferrous piece 11 attracts the electromagnet 110 and the body 130 to move up, and the contact parts 172 are also forced to move upwards by the extended side arms 120 of the body 130. The contacts I 8 1 and the contacts 1 82 keep connected to drive the elastic switches 19 to move upwards until the side steps 150 are stopped by the lower surface of the top board 143 of the base 140. At this time, the security device of the toaster does not work, and the heating element of the toaster toasts bread inthetoastrack 1.

Normally, the control circuit will be automatically cut off after the toaster works for a predetermined period. As a result, the electromagnet 11 0 will lose a magnetic force and then release the ferrous piece 11. The bracket 3 drives the toast rack 1 to move up to the ejection position under a pulling force of the reset spring 1 5, which permits a user to take the toasted bread out of the toaster.

Referring to Fig. 7, if the toasted bread is jammed within the toast rack 1, the toast rack 1 cannot be pulled up by the reset spring 15. As stated above, the control circuit will be cut off after a predetermined period. The magnetic force in the electromagnet 110 will thereby disappear. As a result, the electromagnetic assembly 10 including the electromagnet 110 and the body 130 will fall downwards vertically under its gravity until the lower surface of the electromagnet 110 contacts the upper surface of the top board 143 of the base 140. That is, the electromagnet 110 closely contacts the top board 143 of the base 140. Because the side arms 120 of the body 130 fall down, the elastic arms 191 arid the contact parts 1 72 will also bounce down, which thereby provides a sufficient space to ensure that the contacts 1 82 can depart from the contacts 181. The heating circuit is then cut off and the heating element stops working.

Therefore, the toaster is really safe by avoiding the heating elements thereof from continuously working which may singe bread or even damage the electric elements of the toaster.

Claims

I. A toaster having overheating protection function, comprising a housing, within which a heating element is provided; a toast rack; a bracket; a base; and a timer circuit, the timer circuit being configured to control a power onloff, the toast rack being able to move between a toasting position and an ejection position and being fixed to the bracket, characterized in that the toaster further comprises an overheating protection device including a ferrous piece, an elastic switch and an electromagnetic assembly, the elastic switch is disposed between the ferrous piece and the electromagnetic assembly, a powe input port of the electromagnetic assembly is coupled to an output port of the timer circuit, the electromagnetic assembly is interconnected with the elastic switch, the electromagnetic assembly is movably mounted on the base, and the base provides a space within which the electromagnetic assembly can move so that the elastic switch can be turned on or off by a movement of the electromagnetic assembly.
2. l'he toaster according to Claim I, wherein the electromagnetic assembly comprises an electromagnet and a body both of which are tightly coirnected together as a whole.
3. The toaster according to Claim 2, wherein the body provides at least one side arm laterally extended and at least one side step longitudinally extended.
4. The toaster according to any of Claims l3, wherein the base comprises a top board having at least one opening thereon.
5. The toaster according to Claim 4, wherein the side step is matched with the opening on the top board of the base in a loose fit, so that the electromagnetic assembly can he movably mounted on the base.
6. The toaster according to any of Claims 1 -3, wherein the ferrous piece can be mounted to the bracket and be moved along with the toast rack.
7. The toaster according to any of Claims 1-3, wherein the elastic switch is located between the side arm of the body and the ferrous piece.
8. The toaster according to Claim 4, wherein the bracket comprises at least one arm, a bulge is integrally formed on the bottom of the arm, and at least one contact part is integrally formed at the elastic switch.