Claims
- 1. A time delay fuse comprising a casing means housing a plate-like fusible element and a heat conduction member made of ceramics, said heat conduction member formed from one piece and having first, second, third, and fourth planes opposing the sides of said casing means respectively, fifth, sixth, and seventh planes opposing an upper plate of said casing means that is perpendicular to the sides of said casing means, eighth and ninth planes, between which is located said seventh plane, opposing said first and second planes respectively so as to form a recess together with said seventh plane, and a tenth plane opposing said fifth, sixth and seventh planes, said heat conduction member further having a groove in which said heat conduction member is in contact with said fusible element, said groove extending from said third plane toward said fourth plane with regard to depth and having width corresponding substantially to the thickness of said fusible element, said fusible element including a first convex arc portion directed toward said upper plate, said first convex arc portion having a fusible portion in the middle thereof, first side portions elongating toward said tenth plane from the ends of said first convex arc portion where one end of said first side portions is continuously connected to said first convex arc portion, second convex arc portions directed toward said tenth plane and formed outside said first side portions and extending from opposing ends of said first side portions, second side portions elongating toward said fifth and sixth planes from one end of said second convex arc portions where each end of said second side portions is continuously connected to said second convex arc portions, third convex arc portions directed toward said fifth and sixth planes and formed outside said second side portions and extending from each end of said second side portions, third side portions elongating toward said tenth plane from one end of said third convex arc portions where one end of said third side portions is continuously connected to third convex arc portions, and terminal portions provided on the other end of said third side portions, said first to third convex arc portions and said first to third side portions of said fusible element being arranged symmetric to a line connecting a top point of said first convex arc portion with a middle point of a straight line, which connects one end of said first convex arc portion with the other end of said first convex arc portion, said first and second side portions and second and third convex arc portions of said fusible element being secured to said heat conduction member in said groove by means of ceramic adhesive so as to provide contact of said heat conduction member with said fusible element, said first convex arc portion being disposed within said recess so that said heat conduction member is kept apart from said first convex arc portion, said heat conduction member being spaced and thermally isolated from said casing means, whereby in an overcurrent condition of short duration said heat conduction member will absorb the heat generated in said fusible element, but in a sustained overcurrent condition, the temperature of said heat conduction member will rise to an extent allowing said fusible element to fuse.
- 2. The time delay fuse of claim 1 wherein said terminal portions are supported by said casing means.
- 3. The time delay fuse of claim 2 wherein said heat conduction member is provided with a heat insulating space therearound.
- 4. The time delay fuse of claim 2 wherein said terminal portions are enclosed by said casing means.
- 5. The time delay fuse of claim 2 wherein said terminal portions project from the inside to the outside of said casing means.
- 6. A time delay fuse comprising a casing means housing a plate-like fusible element and a heat conduction member made of ceramics, said heat conduction member formed from one piece and having first, second, third, and fourth planes opposing the sides of said casing means respectively, fifth, sixth, and seventh planes opposing an upper plate of said casing means that is perpendicular to the sides of said casing means, eighth and ninth planes, between which there is said seventh plane, opposing said first and second planes respectively so as to form a space together with said seventh plane, and a tenth plane opposing said fifth, sixth, and seventh planes, said heat conduction member further having a groove in which said heat conduction member is in contact with said fusible element, said groove extending from said third plane toward said fourth plane with regard to depth and having width corresponding substantially to the thickness of said fusible element, said fusible element including a first convex arc portion directed toward said upper plate, said first convex arc portion having a fusible portion in the middle thereof, first side portions elongating toward said tenth plane from the ends of said first convex arc portion where one end of said first side portions is continuously connected to said first convex arc portion, second convex arc portions directed toward said tenth plane and formed outside said first side portions and extending from other ends of said first side portions, second side portions elongating toward said fifth and sixth planes from one end of said second convex arc portions where one end of said second side portions is continuously connected to said second convex arc portions, third convex arc portions directed toward said fifth and sixth planes and forward outside of said second side portions and extending from the other ends of said second side portions, third side portions elongating toward said tenth plane from one end of said third convex arc portions where one end of said third side portions is continuously connected to third convex arc portions, and terminal portions provided on the other ends of said third side portions, said first to third convex arc portions and said first to third side portions of said fusible element being arranged symmetric to a line connecting a top point of said first convex arc portion with a middle point of a straight line, which connects one end of said first convex arc portion with the other end of said first convex arc portion, said first and second side portions and second and third convex arc portions of said fusible element being secured to said heat conduction member in the groove by means of ceramic adhesive so as to provide contact of said heat conduction member with said fusible element, said first convex arc portion being disposed within said space so that said heat conduction member is kept apart from said first convex arc portion, said heat conduction member being spaced and thermally isolated from said casing means, whereby in an overcurrent condition of short duration said heat conduction member will absorb the heat generated in said fusible element, but in a sustained overcurrent condition, the temperature of said heat conduction member will rise to an extent allowing said fusible element to fuse.
- 7. The time delay fuse of claim 6 wherein said terminal portions are supported by said casing means.
- 8. The time delay fuse of claim 7 wherein said heat conduction member is provided with a heat insulating space therearound.
- 9. The time delay fuse of claim 7 wherein said terminal portions are enclosed within said casing means.
- 10. The time delay fuse of claim 7 wherein said terminal portions project from the inside to the outside of said casing means.
- 11. A time delay fuse comprising a casing means housing a plate-like fusible element and a heat conduction member made of ceramics, said heat conduction member formed from one piece and having first, second, third, and fourth planes opposing the sides of said casing means respectively, fifth, sixth, and seventh planes opposing an upper plate of said casing means that is perpendicular to the sides of said casing means, eighth and ninth planes, between which there is said seventh plane, opposing said first and second planes respectively so as to form a recess together with said seventh plane, and a tenth plane opposing said fifth, sixth, and seventh planes, said heat conduction member further having a groove in which said heat conduction member is in contact with said fusible element, said groove extending from said third plane toward said fourth plane with regard to depth and having width corresponding substantially to the thickness of said fusible element, said fusible element including a first convex arc portion directed toward said upper plate, said first convex arc portion having a fusible portion in the middle thereof, first side portions elongating toward said tenth plane from ends of said first convex arc portion where one end of said first side portions is continuously connected to said first convex arc portion, second convex arc portions directed toward said tenth plane and formed outside of said first side portions and extending from the other end of said first side portions, second side portions elongating toward said fifth and sixth planes from one end of said second convex arc portions where one end of said second side portions is continuously connected with said second convex arc portions, third convex arc portions directed toward said fifth and sixth planes and formed outside of said second side portions and extending from the other ends of said second side portions, third side portions elongating toward said tenth plane from one end of said third convex arc portions where one end of said third side portions is continuously connected with third convex arc portions, and terminal portions provided on the other end of said third side portions, said first to third convex arc portions and said first to third side portions of said fusible element being arranged symmetric to a line connecting a top point of said first convex arc portion with a middle point of a straight line, which connects one end of said first convex arc portion with the other end of said first convex arc portion, said first and second side portions and second and third convex arc portions of said fusible element being embedded in said heat conduction member in said groove by means of ceramic adhesive so as to provide contact of said heat conduction member with said fusible element, said first convex arc portion being disposed within said recess so that said heat conduction member is kept apart from said first convex arc portion, said heat conduction member being spaced and thermally isolated from said casing means, whereby in an overcurrent condition of short duration said heat conduction member will absorb the heat generated in said fusible element, but in a sustained overcurrent condition, the temperature of said heat conduction member will rise to an extent allowing said fusible element to fuse.
- 12. The time delay fuse of claim 11 wherein said terminal portions are supported by said casing means.
- 13. The time delay fuse of claim 12 wherein said heat conduction member is provided with a heat insulating space therearound.
- 14. The time delay fuse of claim 12 wherein said terminal portions are enclosed within said casing means.
- 15. The time delay fuse of claim 12 wherein said terminal portions project from the inside to the outside of said casing means.
Priority Claims (2)
Number |
Date |
Country |
Kind |
55-58756 |
Apr 1980 |
JPX |
|
55-58757 |
Apr 1980 |
JPX |
|
Parent Case Info
This application is a continuation application of U.S. application Ser. No. 254,658, filed Apr. 16, 1980, now abandoned.
US Referenced Citations (8)
Foreign Referenced Citations (4)
Number |
Date |
Country |
138719 |
Apr 1902 |
DE2 |
2714797 |
Feb 1979 |
DEX |
727057 |
Jun 1932 |
FRX |
1043620 |
Nov 1953 |
FRX |
Continuations (1)
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Number |
Date |
Country |
Parent |
254658 |
Apr 1980 |
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