Arc-preventing Fast-Breaking Surge Protection Device

Abstract

An arc-preventing fast-breaking surge protection device is disclosed. In one of implement, surge protection device includes an arc-preventing assembly consisted of an arc-preventing catapult and an elastic element, comprising a voltage sensitive assembly, a response switch assembly, a thermosensitive element, an inner shell and an outer cover. The voltage sensitive assembly is tightly coupled with the response switch assembly. When the instantaneous surge voltage in circuits causes the voltage sensitive assembly to continuously heat up due to the fault short-circuit current, the response switch assembly causes the arc-prevent assembly to be catapulted and separated by the thermal coupling response of the thermosensitive element, meanwhile the response switch assembly is conceal by the arc-preventing assembly, thus preventing the arc generated when the switch is s catapulted and separated from forming a short-circuit and an overload, thus effectively avoiding fire and explosion hazards and further preventing secondary damage of electronic devices.

Claims

1. An arc-preventing fast-breaking surge protection device, wherein the device comprises: an arc-preventing assembly comprising an arc-preventing catapult (4) and an elastic element (3); a voltage sensitive assembly comprising at least one voltage sensitive element (5); a response switch assembly comprising a thermosensitive element (30), a front electrode (51) and a tripping electrode (6), the tripping electrode (6) being consisted of a movable electrode slice (6a), an electrode welding end (6b) and a breaking section (6c), the breaking section (6c) being respectively electrically connected the movable electrode slice (6a) and the electrode welding end (6b); electrode pins comprising a flexible conductor (7), a first electrode pin (8) and a second electrode pin (9); and a housing comprising an inner shell (1) and an outer cover (2); wherein the response switch assembly is a normally closed switch in a normal operating state, the thermal element (30) is electrically connected in series and tightly thermally coupled with the voltage sensitive assembly; when the thermosensitive element (30) melts as the thermosensitive element reaches a preset melting temperature, the tripping electrode (6) is separated from the front electrode (51) due to an elastic stress of the elastic element (3), the tripping electrode (6) is rapidly catapulted and concealed in the arc-preventing catapult (4), meanwhile the arc-preventing catapult (4) is rapidly catapulted in a direction away from the front electrode (51) due to an elastic stress of the elastic member (3), thereby preventing arc generated during instantaneous catapulting of the tripping electrode (6) from forming an electrical breakdown and causing a short circuit and an overload; wherein when an instantaneous surge overvoltage, an overcurrent, a short circuit current or an overloading current through the breaking section (6c) exceeds a preset threshold value, the breaking section (6c) instantaneously melts and vaporizes so that the movable electrode slice (6a) separates from the electrode welding end (6b), while the arc-preventing catapult (4) and the movable electrode slice (6a) are rapidly catapulted in a direction away from the front electrode (51) due to the elastic stress of the elastic element (3), the movable electrode slice (6a) is concealed in the arc-preventing catapult (4), thus preventing arc generated during instantaneous melting and catapulting from forming an electrical breakdown and causing a short circuit and an overload.

2. The arc-preventing fast-breaking surge protection device according to claim 1, wherein a first cavity (1a) and a second cavity (1b) are formed when the inner shall (1) is engaged with the outer cover (2), the arc-preventing assembly and the response switch assembly is arranged in the first cavity (1a), the voltage sensitive element (5) is arranged in the second cavity (1b); wherein two metal electrode slice are respectively disposed on both sides of the voltage sensitive element (5), the front electrode (51) is disposed on one of the metal electrode slices, the front electrode (51) protrudes from the second cavity (1b) to the first cavity (1a), the other metal electrode slice is provided with a back electrode (52), the back electrode is in the second cavity (1b); wherein the elastic element (3) is consisted of a first elastic member (3a) and a second elastic member (3b), the first elastic member (3a) is disposed on the arc-preventing catapult (4), the second elastic member (3b) is disposed in the first cavity (1a); wherein the first cavity (1a) is provided with an inserting groove (14), and the second cavity (1b) is provided with a blocking groove (15); the first electrode pin (8) enters the first cavity (1a) through the inserting groove (14), and the second electrode pin (9) enters the second cavity (1b) through the blocking groove (15); two ends of the flexible conductor (7) are respectively electrically connected to the movable electrode slice (6a) and an inner end (8b) of the first electrode pin (8) by metal alloy soldering or spot welding, the back electrode (52) is electrically connected to an inner end (9b) of the second electrode pin (9) by metal alloy soldering; an outer end (8a) of the first electrode pin (8) and an outer end (9a) of the second electrode pin (9) extends out of the inner shell (1) to form external connection pins.

3. The arc-preventing fast-breaking surge protection device according to claim 2, wherein the front electrode (51) is provided with a slotted hole (51a); the tripping electrode (6) is concealed in the arc-preventing catapult (4), the movable electrode slice (6a) of the tripping electrode (6) is misaligned by the first elastic member (3a); the movable electrode slice (4) thereon is misaligned by the second elastic member (3b).

4. The arc-preventing fast-breaking surge protection device according to claim 3, wherein a front end of the arc-preventing catapult (4) is provided with a through hole (4a) which is a port out of which the electrode welding end (6b) protrudes; when the arc-preventing catapult (4) contacts with the front electrode in the first cavity (1a), the through hole (4a) faces the position of the slotted hole (51a); the arc-preventing catapult (4) is provided with an exhaust vent (4b), when the tripping electrode (6) is disposed in the arc-preventing catapult (4) and the electrode welding end (6b) protrudes out of the through hole (4a), the breaking section (6c) faces the position of the exhaust vent (4b).

5. The arc-preventing fast-breaking surge protection device according to claim 4, wherein the electrode welding end (6b) protrudes out of the through hole (4a) and the slotted hole (51a), and is electrically connected to the front electrode (51) through the thermosensitive element (30) by soldering.

6. The arc-preventing fast-breaking surge protection device according to claim 5, wherein when the electrode welding end (6b) separates from the front electrode (51) due to thermal melting of the thermosensitive element (30) reaching the preset melting temperature, the tripping electrode (6) is catapulted back and concealed in the arc-preventing catapult (4) due to an elastic stress of the first elastic member (3a), while the arc-preventing catapult (4) is catapulted in a direction away from the front electrode (51) due to an elastic stress of the second elastic member (3b).

7. The arc-preventing fast-breaking surge protection device according to claim 5, wherein when the instantaneous surge overvoltage, the overcurrent, the short circuit current or the overloading current through the tripping electrode (6) exceeds the preset threshold value, the breaking section (6c) of the tripping electrode (6) instantaneously melts and vaporizes so that the movable electrode slice (6a) separates from the electrode welding end (6b), while the movable electrode slice (6a) is rapidly catapulted in a direction away from the electrode welding end (6b) due to an elastic stress of the first elastic member (3a), the arc-preventing catapult (4) is rapidly catapulted in a direction away from the front electrode (51) due to an elastic stress of the second elastic member (3b), the movable electrode slice (6a) is concealed in the arc-preventing catapult (4).

8. The arc-preventing fast-breaking surge protection device according to claim 6, wherein the arc-preventing fast-breaking surge protection device further comprises an indication module (10) for indicating a state of the arc-preventing fast-breaking surge protection device and a remote signaling alarm module (20) for indicating a state of the arc-preventing fast-breaking surge protection device; wherein the indication module (10) is an electrical indication module or a mechanical indication module; wherein the outer cover (2) is provided with an indication window (2a).

9. The arc-preventing fast-breaking surge protection device according to claim 1, wherein the thermosensitive element (30) is a fusible metal alloy solder or a conductive polymer; wherein the breaking section (6c) is a metal alloy material which is vaporized instantaneously after melting.

10. The arc-preventing fast-breaking surge protection device according to claim 1, wherein the voltage sensitive element (5) adopts a varistor sensitive element, a discharge tubular sensitive element, or a discharge gap sensitive element.

11. The arc-preventing fast-breaking surge protection device according to claim 7, wherein the arc-preventing fast-breaking surge protection device further comprises an indication module (10) for indicating a state of the arc-preventing fast-breaking surge protection device and a remote signaling alarm module (20) for indicating a state of the arc-preventing fast-breaking surge protection device; wherein the indication module (10) is an electrical indication module or a mechanical indication module; wherein the outer cover (2) is provided with an indication window (2a).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG. 1 is a disassembly diagram of an arc-preventing fast-breaking surge protection device according to Embodiment 1 of the present invention;

[0021] FIG. 2 is a back structure diagram of an inner shell according to Embodiment 1 of the present invention;

[0022] FIG. 3 is a cross-sectional view of a surge protection device in normal working state according to Embodiment 1 of the present invention;

[0023] FIG. 4 is a cross-sectional view of a surge protection device after a thermal trip and breakdown according to Embodiment 1 of the present invention;

[0024] FIG. 5 is a cross-sectional view of a surge protection device after current is cut off according to Embodiment 1 of the present invention;

[0025] FIG. 6 is a combined structure diagram of an arc-preventing catapult and a tripping electrode according to Embodiment 2 of the present invention;

[0026] FIG. 7 is a cross-sectional view of a surge protection device in normal working state according to Embodiment 2 of the present invention;

[0027] FIG. 8 is a cross-sectional view of a surge protection device after a thermal trip and breakdown according to Embodiment 2 the present invention;

[0028] FIG. 9 is a cross-sectional view of a surge protection device after current is cut off according to Embodiment 2 of the present invention;

[0029] FIG. 10 is a cross-sectional view of a surge protection device in normal working state according to Embodiment 3 of the present invention;

[0030] FIG. 11 is a cross-sectional view of a surge protection device after a thermal trip and breakdown according to Embodiment 3 the present invention;

[0031] FIG. 12 is a cross-sectional view of a surge protection device after current is cut off according to Embodiment 3 of the present invention;

[0032] FIG. 13 is a combined structure diagram of an arc-preventing catapult and a tripping electrode according to Embodiment 4 of the present invention;

[0033] FIG. 14 is a cross-sectional view of a surge protection device in normal working state according to Embodiment 4 of the present invention;

[0034] FIG. 15 is a cross-sectional view of a surge protection device after a thermal trip and breakdown according to Embodiment 4 the present invention;

[0035] FIG. 16 is a cross-sectional view of a surge protection device after current is cut off according to Embodiment 4 of the present invention;

[0036] FIG. 17 is a view showing a special structure of a tripping electrode according to the present invention.

[0037] Parts corresponding to reference numeral: 1inner shell; 1afirst cavity; 1bsecond cavity; 1cfirst end; 1dsecond end; 11electrode hole; 12recess; 13guide rail; 14inserting groove; 15blocking groove; 16remote signaling gap; 17stop block; 18electrode baffle; 2outer cover; 2aindication window; 3elastic element; 3afirst elastic member; 3bsecond elastic member; 4arcpreventing catapult; 4athrough hole; 4bexhaust vent; 41wing arm; 42spring groove; 43sliding groove; 5voltage sensitive element; 51front electrode; 51aslotted hole; 52back electrode; 6tripping electrode; 6amovable electrode slice; 6belectrode welding end; 6cbreaking section; 7flexible conductor; 8first electrode pin; 9second electrode pin; 8aouter end of the first electrode pin; 8binner end of the first electrode pin; 9aouter end of the second electrode pin; 9binner end of the second electrode pin; 10indication module; 20remote signaling alarm; 20aalarm pin; 30thermosensitive element.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

[0038] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. However, the scope of the present invention is not limited to the following preferred embodiments, and the technical solution for enhancing the arc-breaking and insulation effect by catapulting and concealing tripping electrode in accordance with the present disclosure is within the protection scope thereof; the surge protection device of the present invention does not limit the material types of the voltage sensitive element, the elastic element, the first elastic member, the second elastic member and the flexible conductor; in the following specific embodiments, as is taken as examples to describe in detail the structure of the surge protection device of the present invention, the elastic element 3 is compression springs 3, the first elastic member 3a is first compression springs 3a, the second elastic member 3b is second compression springs 3b, the voltage sensitive element 5 is a varistor 5, and the flexible conductor 7 is a flexible copper wire 7.

Embodiment 1

[0039] Referring now to FIG. 1 and FIG. 2, an arc-preventing fast-breaking surge protection device comprises an inner shell 1, an outer cover 2, two first compression springs 3a, two second compression springs 3b, an arc-preventing catapult 4, a varistor 5, a flexible copper wire 7, a first electrode pin 8, a second electrode pin 9, an indication module 10, a remote signaling alarm module 20 and a tripping electrode 6; the tripping electrode 6 is consist of a movable electrode slice 6a, a electrode welding end 6b and a breaking section 6c, and the movable electrode slice 6a is electrically connected with the electrode welding end 6b through the breaking section 6c. Both of the back silver electrode and the front silver electrode of the varistor 5 are provided with metal electrode slices by way of soldering, wherein one metal electrode slice is provided with a front electrode 51, a slotted hole 51a out of which the electrode welding end 6b protrudes is formed on the front electrode 51; a back electrode 52 is formed by an extending bending portion of the other metal electrode slice. The inner shell 1 has a frame structure. When the inner shell 1 and the outer cover 2 are engaged by a buckle, a first cavity 1a formed on the front surface of the inner shell 1, and a second cavity 1b is formed on the back surface of the inner shell 1. When the varistor 5 is placed in the second cavity 1a, the front electrode 51 protrudes into the first cavity 1a through the electrode hole 11 that penetrates the first cavity 1a and the second cavity 1b, as such, the slotted hole 51a is also located in the first cavity 1a; the back electrode 52 extends into the recess 12 on one side of the second cavity 1b. Two guide rails 13 perpendicular to the bottom of the inner shell 1 are disposed on both sides of the electrode hole 11 of the first cavity 1a, and the elongated slot openings of the two guide rails 13 are opposed to each other. An inserting groove 14 penetrating the bottom of the inner shell 1 is provided on the bottom of the side of the first cavity 1 farthest from the recess 12, a blocking groove 15 with L-shape structure and penetrating the bottom of the inner shell 1 is disposed on the side of the second cavity 1b closest to the recess 12, and the inner end of the blocking groove is communicated with the recess 12.

[0040] The arc-preventing catapult 4 with a box-like structure forms a cavity, and a spring groove 42 is provided on each side of the cavity. The front wall of the arc-preventing catapult 4 is provided with a through hole 42 out of which the electrode welding end 6b protrudes, and a wing arm 41 capable of being inserted into the guide rail 13 is provided on each side of the arc-preventing catapult 4. When the front electrode 51 protrudes out of the electrode hole 11, the arc-preventing catapult 4 slides along the guide rails 13 with the wing arm 41 of each side of the arc-preventing catapult 4 until touching the front electrode 51, as such, the positions of the through hole 4a and the slotted hole 51a face each other. The arc-preventing catapult 4 is further provided with an exhaust vent 4b. When the tripping electrode 6 is concealed in the cavity of the arc-preventing catapult 4 and the electrode welding end 6b protrudes out of the through hole 4a, the breaking section 6c faces the exhaust vent 4b.

[0041] In the present embodiment, the indication module 10 is a knockout pin which is disposed at the end of the arc-preventing catapult 4 and integral with the arc-preventing catapult 4. An indication window 2a is arranged in a corresponding position of the outer cover 2, out of which the indication module 10 may extends. The remote signaling alarm module 20 is an independent switch.

[0042] As shown in FIG. 3, the remote signaling alarm module 20 is disposed in the outer cover 2, of which an alarm pin 20a extends out of the outer cover 2. The two second compression springs 3b are respectively arranged in the two guide rails 13, and the arc-preventing catapult 4 is inserted into the guide rails 41 through the side wing arms 41 until touching the front electrode 51, and the two second compression springs 3b are in compressed state. The two first compression springs 3a are respectively arranged in the two spring grooves 42, and the tripping electrode 6 inserted into the arc-preventing catapult 4 until the electrode welding end 6b protrudes out of the through hole 4a and the slotted hole 51a, and the movable electrode slice 6a compresses the two first compression spring 3a to be in compressed state. As such, the elastic stress of the first compression springs 3a is greater than the elastic stress of the second compression springs 3b. The electrode welding end 6b is electrically connected to the front electrode 51 through a thermosensitive element 30 by way of soldering; the first electrode pin 8 and the second electrode pin 9 are respectively fixed to the inner shell 1 through the inserting groove 14 and the blocking groove 15, and an outer end 8a of the first electrode pin 8 and an outer end 9a of the second electrode pin 9 extends outside the inner shell 1 to form external connection pins, and two ends of the flexible copper wire 7 are respectively electrically connected to the movable electrode slice 6a and an inner end 8b of the first electrode pin by metal alloy soldering or spot welding; the back electrode 52 is electrically connected to an inner end 9b of the first electrode pin 9 by metal alloy soldering, so that these electric conductors are connected in series with the varistor 5 to form a normally closed switch. When the surge protection device is employed in the power system, the two external connection pins are respectively connected to the phase line and the neutral line or the ground line. As such, the indication module 10 is located in the indication window 2a, and the switch of the remote signaling alarm module 20 is free from the compression of the external stress under the normal working state of the surge protection device.

[0043] According to an embodiment of the present invention, when temperature of the varistor 5 is increased due to a short circuit current, an overloading current through circuits or a leakage current because of the aging thereof, the generated heat is transmitted to the front electrode 51, thus enabling the thermo sensitive element 30 to melt when reaching a preset temperature threshold. As shown in FIG. 4, the electrode welding end 6b is rapidly catapulted in the arc-preventing catapult 4 due to elastic stresses of the two first compression springs 3a on the movable electrode slice 6a; simultaneously the arc-preventing catapult 4 is rapidly catapulted in a direction away from the front electrode 51 due to elastic stresses of the two second compression springs 3b. Finally, the indication module 10 extends out of the indication window 2a, and the switch of the remote signaling alarm module 20 is compressed to be stationary by ends of the movable electrode slice 6a and the arc-preventing catapult 4, thereby causing its switch state to change. As Such, a mechanical indication for invalidation is realized, meanwhile a remote signal for indicating fault of the surge protection device is sent out. A sufficiently large dielectric strength is formed between the electrode welding end 6b and the front electrode 51, and the tripping electrode 6 and the front electrode 51 are completely isolated from each other.

[0044] According to another embodiment of the present invention, when an instantaneous surge overvoltage, an overcurrent, a short circuit current or an overload current through the tripping electrode 6 exceeds a preset threshold value, the breaking section 6c of the tripping electrode instantaneously melts and vaporizes so that movable electrode slice 6a separates from the electrode welding end 6b. Referring to FIG. 5, the movable electrode slice 6a and the arc-preventing catapult 4 are simultaneously catapulted in a direction away from the front electrode 51 due to the elastic stresses of the first compression springs 3a and the second first compression springs 3b. At last, the indication module 10 extends out of the indication window 2a, and the switch of the remote signaling alarm module 20 is compressed to be stationary by ends of the movable electrode slice 6a and the arc-preventing catapult 4, thereby causing its switch state to change. As Such, a mechanical indication for invalidation is realized, meanwhile a remote signal for indicating failure of the surge protection device is sent out. In this way, the electrode welding end 6b separates from the movable electrode slice 6a. A sufficiently large dielectric strength is formed between the electrode welding end 6b and the movable electrode slice 6a, and the movable electrode slice 6a and the front electrode 51 are completely isolated from each other.

Embodiment 2

[0045] Another embodiment of an arc-preventing fast-breaking surge protection device of the present invention is as follows. This embodiment has similar structure and usage as most of the components of Embodiment 1, the main differences of them lie in the catapulting mode of the arc-preventing assembly, the structure of the tripping electrode 6 and the remote signaling alarm module 20 missing in the surge protection device.

[0046] As shown in FIG. 6, the arc-preventing catapult 4 has a cavity structure with an open top, and a T-shaped sliding groove 43 is formed on each side wall of the arc-preventing catapult 4, and the extending portion of each side of the movable electrode slice 6a of the tripping electrode 6 passes through the sliding groove 43 and extends out of the arc-preventing catapult 4, and a front wall of the arc-preventing catapult 4 is provided with a through hole 4a out of which the electrode welding end 6b extends. When the extending portion of each side of the movable electrode slice 6a slides to a front end of the sliding groove 43, the electrode welding end 6b protrudes out of the arc-preventing catapult 4 through the through hole 4a, and the indication module 10 is a knockout pin which is disposed at the end of the arc-preventing catapult 4 and integral with the arc-preventing catapult 4.

[0047] The structure shown in FIG. 6 is replaced with the corresponding structure in FIG. 3. As shown in FIG. 7, two compression springs 3 are respectively placed in the two guide rails 13, and the extending portion of each side of the movable electrode slice 6a is inserted into the guide rail 13 and drives the arc-preventing catapult 4 until toughing the front electrode 51. In this way, the electrode welding end 6b protrudes out of the through hole 4a and the slotted hole 51a, and the movable electrode slice 6a presses the two compression springs 3 to be in compressed state. The electrode welding end 6b is electrically connected to the front electrode 51 through a thermosensitive element 30 by way of soldering. When the surge protection device is employed in the power system, the two external connection pins are respectively connected to the phase line and the neutral line or the ground line. As such, the indication module 10 is compressed in the indication window 2a under the normal working state of the surge protection device.

[0048] According to illustrative example of the present invention, when temperature of the varistor 5 is increased due to a short circuit current, an overloading current through circuits or a leakage current because of the aging of the varistor 5, the generated heat is transmitted to the front electrode 51, thus enabling the thermosensitive element 30 to melt when reaching a preset temperature threshold. As shown in FIG. 8, the electrode welding end 6b is rapidly catapulted in the through hole 4a due to elastic stresses of the compression springs 3 on the movable electrode slice 6a; the extending portion of each side of the movable electrode slice slides to end of the sliding groove 43 and drives the arc-preventing catapult 4 to continuously catapult in a direction away from the front electrode 51. At last, the indication module 10 extends out of the indication window 2a and is blocked to be stationary. As Such, a mechanical indication for invalidation is realized. A sufficiently large dielectric strength is formed between the electrode welding end 6b and the through hole 4a, the through hole 4a and the front electrode 51, and the tripping electrode 6 and the front electrode 6b are completely isolated from each other.

[0049] According to another embodiment of the present invention, when an instantaneous surge overvoltage, an overcurrent, or short circuit current or overload current through the tripping electrode 6 exceeds a preset threshold value, the breaking section 6c of the tripping electrode 6 instantaneously melts and vaporizes so that movable electrode slice 6a separates from the electrode welding end 6b. Referring to FIG. 9, the movable electrode slice 6a is catapulted in a direction away from the front electrode 51 due to the elastic stresses of the compression springs, and then the extending portion of each side of the movable electrode slice 6a slides to end of the sliding groove 43 and drives the arc-preventing catapult 4 to continuously catapult in a direction away from the front electrode 51. At last, the indication module 10 extends out of the indication window 1a and is blocked to be stationary. As Such, a mechanical indication for invalidation is realized. A sufficiently large dielectric strength is formed between the electrode welding end 6b and the through hole 4a, the through hole 4a and the movable electrode slice 6a, and the movable electrode slice 6a and the front electrode are completely isolated from each other.

Embodiment 3

[0050] Another embodiment of an arc-preventing fast-breaking surge protection device of the present invention is as follows. This embodiment has similar structure and usage as most of the components of Embodiment 2, the main differences of them lie in the catapulting mode of the arc-preventing assembly and the indication module 10 and the indication window 1a missing in the surge protection device.

[0051] As shown in FIG. 10, the remote signaling alarm module 20 is disposed in the outer cover 2, of which an alarm pin 20a extends out of the outer cover 2. The arc-preventing catapult 4 is a baffle, which is vertically fixed under the electrode hole 11. The baffle is provided with a through hole 4a out of which the electrode welding end 6b protrudes, and a spring groove 42 is provided on each side of the through hole 4a. Two compression springs 3 are respectively arranged in the two spring grooves 42. The extending portion of each side of the movable electrode slice 6a is inserted into the guide rail 13 until the electrode welding end 6b protrudes out of the through hole 4a and the slotted hole 51a; the movable electrode piece 6a presses the two compression springs 3 to be in compressed state. The electrode welding end 6b is electrically connected to the front electrode 51 through a thermosensitive element 30 by way of soldering. When the surge protection device is employed in the power system, the two external connection pins are respectively connected to the phase line and the neutral line or the ground line. As such, the switch of the remote signaling alarm module 20 is free from the compression of the external stress under the normal working state of the surge protection device.

[0052] According to an embodiment of the present invention, when temperature of the varistor 5 is increased due to a short circuit current, an overloading current through circuits or a leakage current because of the aging of the varistor 5, the generated heat is transmitted to the front electrode 51, thus enabling the thermosensitive element 30 to melt when reaching a preset temperature threshold. As shown in FIG. 11, the electrode welding end 6b is rapidly catapulted in the through hole 4a by the movable electrode slice 6a due to an elastic stress of the compression springs 3 and catapulted continuously in a direction away from the front electrode 51. At last, the switch of the remote signaling alarm module 20 is compressed to be stationary by end of the movable electrode slice 6a, thereby causing its switch state to change, and then a remote signal for indicating fault of the surge protection device is sent out. A sufficiently large dielectric strength is formed between the electrode welding end 6b and the through hole 4a, and the tripping electrode 6 and the front electrode 51 are completely isolated from each other.

[0053] According to another embodiment of the present invention, when an instantaneous surge overvoltage, an overcurrent, a short circuit current or overload current through the tripping electrode 6 exceeds a preset threshold value, the breaking section 6c of the tripping electrode 6 instantaneously melts and vaporizes so that the movable electrode slice 6a separates from the electrode welding end 6b. Referring to FIG. 12, the movable electrode slice 6a is catapulted in a direction away from the front electrode 51 due to the elastic stresses of the compression springs 3, At last, the switch of the remote signaling alarm module 20 is compressed and blocked to be stationary by end of the movable electrode slice 6a, thereby causing its switch state to change, then a remote signal for indication fault of the surge protection device is sent out. A sufficiently large dielectric strength is formed between the electrode welding end 6b and the movable electrode slice 6a, and the movable electrode slice 6a and the front electrode 51 are completely isolated from each other

Embodiment 4

[0054] Another embodiment of an arc-preventing fast-breaking surge protection device of the present invention is as follows. This embodiment has similar structure and usage as most of the components of Embodiment 1, the main differences of them lie in the structure of the tripping and the indicating modes for working state of the surge protection device.

[0055] As shown in FIG. 13, the arc-preventing catapult 4 with a box-like structure forms a cavity, and a spring groove 42 is provided on each side of the cavity. The front wall of the arc-preventing catapult 4 is provided with a through hole 4a out of which electrode welding end protrudes 6b. The arc-preventing catapult 4 is further provided with an exhaust vent 4b. The indication module 10 with baffle structure is disposed on one side of the arc-preventing catapult 4, and the other side of the arc-preventing catapult 4 extends a wing arm 41 that can be provided with a spring. The remote signaling alarm module 20 is a bump disposed at the end of the wing arm 41. A remote signaling gap 16 is formed at the bottom of the first cavity 1a f the inner shell 1, and two stop blocks 17 and an electrode baffle 18 that can be provided with a spring are disposed on the first cavity 1a.

[0056] As shown in FIG. 14, two ends of a second compression spring 3b are respectively fixed on the electrode baffle 18 and the wing arm 41, and the arc-preventing catapult 4 is orientated by the stop blocks 17 until touching the front electrode. The second compression spring 3b is in compressed state. The two first compression springs 3a are respectively placed in the two spring grooves 4a, and the tripping electrode 6 is inserted into the arc-preventing catapult 4 until the electrode welding end 6b protrudes out of the through hole 4a and the slotted hole Ma. The movable electrode slices 6a compress the two first compression springs 3a to be in compressed state. As such, the elastic stress of the first compression spring 3a is greater than the elastic stress of the second compression spring 3b. The electrode welding end 6b is electrically connected to the front electrode 51 through the thermosensitive element 30 by way of soldering. When the surge protection device is employed in the power system, the two external connection pins are respectively connected to the phase line and the neutral line or the ground line. As such, the remote signaling alarm module 20 blocks the remote signaling gap 16, and the indication module 10 is at the first end 1c of outer wall of inner shell 1. The indication window 2a faces the second end 1d of outer wall of inner shell 1 under the normal working state of the surge protection device.

[0057] According to an embodiment of the present invention, when temperature of the varistor 5 is increased due to the short circuit and overloading current through circuits and the leakage current because of the aging thereof, the generated heat is transmitted to the front electrode 51, thus enabling the thermosensitive element 30 to melt when reaching a preset temperature threshold. As shown in FIG. 15, the electrode welding end 6b is rapidly catapulted in the arc-preventing catapult 4 due to elastic stresses of the first compression springs 3a on the movable electrode slice 6a; meanwhile the arc-preventing catapult 4 is rapidly catapulted in a direction away from the front electrode 51 due to an elastic stress of the second compression spring 3b. As a result, the remote signaling alarm module 20 is misaligned with the remote signaling gap 16, and the indication module 10 is moved to the second end 1d and blocked to be stationary, thus realizing a mechanical indication for invalidation, a sufficiently large dielectric strength is formed between the through hole 4a and the electrode welding end 6b and between the front electrode 51 and the through hole 4a, and the tripping electrode 6 and the front electrode 51 are completely isolated from each other.

[0058] According to another embodiment of the present invention, when an instantaneous surge overvoltage, an overcurrent, a short circuit current or an overload current through the tripping electrode 6 exceeds a preset threshold value, the breaking section 6c of the tripping electrode 6 instantaneously melts and vaporizes so that movable electrode slice 6a separates from the electrode welding end 6b. Referring to FIG. 16, the movable electrode slice 6a and the arc-preventing catapult 4 are simultaneously catapulted in a direction away from the front electrode 51 due to the elastic stresses of the first compression springs 3a and the second first compression spring 3b. At last, the remote signaling alarm module 20 is misaligned with the remote signaling gap 16, and the indication module 10 is moved to the second end 1d and blocked to be stationary, thus realizing a mechanical indication for invalidation, a sufficiently large dielectric strength is formed between the through hole 4a and the electrode welding end 6b and between the movable electrode slice 6a and the through hole 4a, and the movable electrode slice 6a and the front electrode 51 are completely isolated from each other.

[0059] Preferably, the outer surface of the indication module 10 can be coated with a bold color, such as red color. When the indication module 10 is moved from the first end 1c to the second end 1d, color change can be observed from the indication window 2a, thereby indicating protection failure of the varisto 5; meanwhile, if a user utilizes the remote signaling alarm module 20 to trigger a switch passing through the remote signaling gap 16 on the assembling platform. When the remote signal alarm module 20 that originally blocked the remote signal gap 16 and compressed a button of the switch is misaligned with the remote signaling gap 16, the button of the switch isn't compressed any longer, and the switch state of the switch changes immediately, thereby sending out a remote signal for indicating validation of the surge protection device.

Embodiment 5

[0060] As shown in FIG. 17, it is an alternative example to the tripping electrode. The movable electrode slice 6a, the electrode welding end 6b, and the breaking section 6c are different portions of the same alloy. To limit the cross-sectional area of the breaking section 6c to ensure that it can be cut off at the breaking section 6c when an instantaneous surge overvoltage, an overcurrent, a short circuit current or overloading current through the tripping electrode 6 exceeds its threshold value, the breaking section is designed as indentation shape, and a notch is formed on a copper piece near the breaking section 6c to limit the length of the breaking section 6c.

[0061] The features or combinations of features described in the above embodiments may be present separately or may be combined with features or combinations of features in other embodiments. According to instantaneous catapult to separate and conceal the tripping electrode and adopting the metal material to realize breaking function of the short circuit overload current in the present disclosure, those skilled in the art can made various modifications or changes to the above embodiments, which are all within the scope of protection of the present invention.