What is claimed is:
1. A vacuum cleaner comprising:
a vacuum tank which is previously evacuated to create a vacuum with an evacuating system, said vacuum tank, after evacuation, being independent of the evacuating system and kept at a pressure lower than atmospheric pressure;
a first valve connected to an opening of said vacuum tank, said first valve, when closed, keeping said vacuum tank airtight; and
a suction unit defining a passage of gas which, when said first valve is opened, is sucked into said vacuum tank because of a pressure difference between the inside and outside of said vacuum tank.
2. The vacuum cleaner according to claim 1,
wherein said suction unit is connected to said first valve, and
said first valve has an adjustable opening,
and wherein the suction force for sucking said gas into said suction unit is adjusted by adjusting said adjustable opening of said first valve.
3. The vacuum cleaner according to claim 2, wherein said first valve is a gate valve in which said adjustable opening is adjusted by adjusting the area in which its gate valve element covers said adjustable opening.
4. The vacuum cleaner according to claim 1, further comprising a second valve provided upstream of said first valve in the passage of said gas, said second valve having an adjustable opening,
wherein said suction unit is connected to said second valve, and
the suction force for sucking said gas into said suction unit is adjusted by adjusting said adjustable opening of said second valve.
5. The vacuum cleaner according to claim 4, wherein said second valve is a gate valve in which said adjustable opening is adjusted by adjusting the area in which its gate valve element covers said adjustable opening.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A semiconductor device having a fuse box, the fuse box comprising:
a common source region;
a plurality of fuses extending radially from the common source region, each fuse having a first end coupled to the common source region and a second end located at an opposing side of the first end; and
a fuse box wall provided proximate the second ends of the plurality of fuses.
2. The fuse box of claim 1, further comprising a common contact region provided in the common source region.
3. The fuse box of claim 2, wherein a area of the common source region is larger than that of the common contact region.
4. The fuse box of claim 1, wherein the fuse box wall having an enclosed shape, the fuse box wall enclosing the plurality of fuses.
5. The fuse box of claim 1, wherein the fuse box wall has eight sides.
6. The fuse box of claim 1, further comprising a plurality of conductive contacts connected to the second ends of the plurality of fuses, wherein at least one conductive contact is electrically connected to each second end, wherein the plurality of conductive contacts are circularly arranged.
7. The fuse box of claim 6, wherein two conductive contacts are electrically connected to each second end.
8. The fuse box of claim 7, wherein a area of the common source region is larger than that of the two conductive contacts.
9. The fuse box of claim 1, wherein each of two adjacent fuses in the plurality of fuses define substantially the same angle.
10. The fuse box of claim 1, wherein each of the plurality of fuses is separated from an adjacent fuse by substantially the same distance.
11. The fuse box of claim 1, further comprising a protection film formed within an area defined by the fuse box.
12. The fuse box of claim 11, wherein the protection film has substantially the same structure as the fuse box.
13. The fuse box of claim 11, wherein the protection film is circularly shaped.
14. The fuse box of claim 13, wherein the protection film has an octagonal shape.
15. The fuse box of claim 1, wherein a blowing region of the plurality of fuses is closer to the second end than the first end of the fuse.