Anti-surge structure built in switches
First Claim
1. An anti-surge structure built in switches, comprising:
- a housing;
a first metal-oxide varistor, a second metal-oxide varistor, a third metal-oxide varistor, each having a first surface at a side thereof and a second surface at an opposite side thereof, said metal-oxide varistors partially overlapped in stair-like arrangement, the first surface of the first metal-oxide varistor and the second surface of the third metal-oxide varistor being left completely exposed, the second surface of the first metal-oxide varistor partially overlapped with the second surface of the second metal-oxide varistor with a first conductive element disposed in-between for electrical connection, the first surface of the second metal-oxide varistor partially overlapped with the first surface of the third metal-oxide varistor with a second conductive element disposed in-between for electrical connection;
an insulating body including a first part and a second part assembled for the metal-oxide varistors to be disposed therein, the first part having a first open section and a third open section and the second part having a second open section and a fourth open section for externally electrical connection of the metal-oxide varistors;
an insulating band surrounding a periphery of the second metal-oxide varistor and having a thickness greater than a thickness of the second metal-oxide varistor to fill in spaces between the stair-like metal-oxide varistors and the insulating body, protecting the metal-oxide varistors from external impacts and defining four isolated insulating areas around the metal-oxide varistors;
a spring element having a fixed section and a springy free end;
a pushing element having a lower section abutting correspondingly on a bimetal plate and an upper surface compressing the spring element under a bottom of the second part of the insulating body for the spring element to be resiliently displaceable;
a strap disposed under the pushing element and having a first end passing through the first open section and welded to a connecting area of the first surface of the third metal-oxide varistor by low-temperature solder paste, and a second end passing through the second open section and welded to a connecting area of the first surface of the second metal-oxide varistor, so as to fix a position of the pushing element under the second part of the insulating body;
a fourth contact piece having an elastic section at a top thereof, the elastic section including a free end passing through the third open section of the first part of the insulating body and being welded on the first surface of the first metal-oxide varistor by low-temperature solder paste;
whereby when an overvoltage occurs, temperature of the second and third metal-oxide varistors rises up instantly to a degree that is higher than a melting point of the low-temperature solder pastes, loosening the strap, releasing the free end of the spring element to displace the pushing element and thereby breaking a electrical circuit thereof;
or when an overvoltage occurs, temperature of the first metal-oxide varistor rises up instantly to a degree that is higher than a melting point of the low-temperature solder pastes, releasing the elastic section and thereby breaking a electrical circuit thereof.
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Accused Products
Abstract
An anti-surge structure built in switches includes three metal-oxide varistors disposed in an insulating body in stair-like arrangement. The metal-oxide varistors further has an insulating band surrounding a middle metal-oxide varistor and defining four isolated insulating areas within the insulating body, so as to avoid high voltage flashover and to protect the structure from external impacts. With the stair-like arrangement, each metal-oxide varistor has a connecting area for both ends of a metal strap to be welded thereon by low-temperature solder paste. When the low-temperature solder paste are melted by heat, a compressed spring element thereof is ejected to displace a pushing element thereof and to further detach two connecting points of the structure, so as to break a circuit connected by the structure.
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Citations
10 Claims
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1. An anti-surge structure built in switches, comprising:
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a housing; a first metal-oxide varistor, a second metal-oxide varistor, a third metal-oxide varistor, each having a first surface at a side thereof and a second surface at an opposite side thereof, said metal-oxide varistors partially overlapped in stair-like arrangement, the first surface of the first metal-oxide varistor and the second surface of the third metal-oxide varistor being left completely exposed, the second surface of the first metal-oxide varistor partially overlapped with the second surface of the second metal-oxide varistor with a first conductive element disposed in-between for electrical connection, the first surface of the second metal-oxide varistor partially overlapped with the first surface of the third metal-oxide varistor with a second conductive element disposed in-between for electrical connection; an insulating body including a first part and a second part assembled for the metal-oxide varistors to be disposed therein, the first part having a first open section and a third open section and the second part having a second open section and a fourth open section for externally electrical connection of the metal-oxide varistors; an insulating band surrounding a periphery of the second metal-oxide varistor and having a thickness greater than a thickness of the second metal-oxide varistor to fill in spaces between the stair-like metal-oxide varistors and the insulating body, protecting the metal-oxide varistors from external impacts and defining four isolated insulating areas around the metal-oxide varistors; a spring element having a fixed section and a springy free end; a pushing element having a lower section abutting correspondingly on a bimetal plate and an upper surface compressing the spring element under a bottom of the second part of the insulating body for the spring element to be resiliently displaceable; a strap disposed under the pushing element and having a first end passing through the first open section and welded to a connecting area of the first surface of the third metal-oxide varistor by low-temperature solder paste, and a second end passing through the second open section and welded to a connecting area of the first surface of the second metal-oxide varistor, so as to fix a position of the pushing element under the second part of the insulating body; a fourth contact piece having an elastic section at a top thereof, the elastic section including a free end passing through the third open section of the first part of the insulating body and being welded on the first surface of the first metal-oxide varistor by low-temperature solder paste; whereby when an overvoltage occurs, temperature of the second and third metal-oxide varistors rises up instantly to a degree that is higher than a melting point of the low-temperature solder pastes, loosening the strap, releasing the free end of the spring element to displace the pushing element and thereby breaking a electrical circuit thereof;
or when an overvoltage occurs, temperature of the first metal-oxide varistor rises up instantly to a degree that is higher than a melting point of the low-temperature solder pastes, releasing the elastic section and thereby breaking a electrical circuit thereof. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification