What is claimed is:
1. A method of embossing expanded graphite sheet material comprising embossing said material in an embossing atmosphere at a reduced pressure less than atmospheric pressure and maintaining a reduced pressure at least during the embossing step.
2. The method of claim 1 wherein said embossing atmosphere is an inert gas.
3. The method of claim 2 wherein said inert gas is selected from the group consisting of nitrogen, helium and argon.
4. The method of claim 1 wherein said inert gas is substantially pure nitrogen.
5. The method of claim 1 further comprising continuing to evacuate gases from said embossing atmosphere during said embossing step.
6. The method of claim 1 wherein said material comprises a plurality of sheet materials comprising at least one expanded graphite sheet, and the method further comprising laminating said plurality of sheet materials during said embossing step.
7. The method of claim 6 wherein said plurality of sheet materials comprises at least one sheet of metal foil.
8. The method of claim 1 wherein said reduced pressure is less than or equal to about 400 torr.
9. The method of claim 1 wherein said reduced pressure is less than or equal to about 350 torr.
10. The method of claim 1 wherein said reduced pressure is less than or equal to about 170 torr.
11. The method of claim 1 wherein said reduced pressure is less than or equal to about 50 torr.
12. The method of claim 1, further comprising puncturing at least one surface of said material prior to embossing said material.
13. A method of embossing expanded graphite sheet material comprising removing at least a portion of the gas from within said material by exposing said material to a pressure less than atmospheric pressure, and then embossing said material.
14. The method of claim 13 wherein said material comprises a plurality of sheet materials comprising at least one expanded graphite sheet, and the method further comprising laminating said plurality of sheet materials during said embossing step.
15. The method of claim 14 wherein said plurality of sheet materials comprises at least one sheet of metal foil.
16. The method of claim 13 wherein said reduced pressure is less than or equal to about 400 torr.
17. The method of claim 13 wherein said reduced pressure is less than or equal to about 350 torr.
18. The method of claim 13 wherein said reduced pressure is less than or equal to about 170 torr.
19. The method of claim 13 wherein said reduced pressure is less than or equal to about 50 torr.
20. The method of claim 13, further comprising puncturing at least one surface of said material prior to exposing said material to said pressure less than atmospheric pressure.
21. An apparatus for embossing expanded graphite sheet material at a pressure less than atmospheric pressure comprising:
(a) at least one embossing device;
(b) at least one compression mechanism adapted to urge said embossing device against said material;
(c) an embossing chamber comprising said at least one embossing device and adapted to receive said material, and to be substantially gas-tight at least when said embossing device is urged against said material by said compression mechanism; and
(d) an evacuation mechanism for reducing the pressure within said embossing chamber.
22. The apparatus of claim 21 wherein said at least one embossing device is a die.
23. The apparatus of claim 21 wherein said at least one pressing device is a press platen.
24. The apparatus of claim 21 further comprising an inert gas source fluidly connectable to said embossing chamber.
25. The apparatus of claim 24 wherein said inert gas is selected from the group consisting of nitrogen, helium and argon.
26. The apparatus of claim 24 wherein said inert gas is substantially pure nitrogen.
27. The apparatus of claim 21 wherein said evacuation mechanism is capable of reducing said pressure within said embossing chamber to about 400 torr or less.
28. The apparatus of claim 21 wherein said evacuation mechanism is capable of reducing said pressure within said embossing chamber to about 350 torr or less.
29. The apparatus of claim 21 wherein said evacuation mechanism is capable of reducing said pressure within said embossing chamber to about 170 torr or less.
30. The apparatus of claim 21 wherein said evacuation mechanism is capable of reducing said pressure within said embossing chamber to about 50 torr or less.
31. The apparatus of claim 21 further comprising at least one sealing member associated with said embossing chamber for maintaining a gas-tight seal therein.
32. The apparatus of claim 31 wherein said sealing member comprises at least one device selected from the group consisting of O-rings, bellows, compressible seals and inflatable bladders.
33. The apparatus of claim 31 wherein said sealing member comprises at least one O-ring.
34. The apparatus of claim 31 wherein said sealing member comprises at least one compressible seal.
35. The apparatus of claim 31 wherein said sealing member comprises at least one inflatable bladder.
36. The apparatus of claim 21 wherein said at least one embossing device is a roller die.
37. The apparatus of claim 21 wherein said at least one pressing device is a roller.
38. An apparatus for embossing expanded graphite sheet material, said apparatus comprising:
(a) a chamber adapted to receive said material and to maintain a reduced pressure less than atmospheric pressure at least when said material is in said chamber;
(b) an evacuation mechanism for reducing the pressure within said embossing chamber; and
(c) at least one roller die associated with said chamber for receiving said material from said chamber.
39. The apparatus of claim 38 wherein said chamber comprises at least one resilient member extending from an interior surface of said chamber and adapted to contact said material.
40. The apparatus of claim 38 wherein said chamber comprises an upper portion and a lower portion, said upper portion comprising a plurality of resilient sealing members extending downwardly therefrom, and said lower portion comprising a plurality of resilient sealing members extending upwardly therefrom, both sets of said sealing members adapted to contact said material.
41. The apparatus of claim 40, further comprising at least one feed roller for directing said material to said chamber.
42. The apparatus of claim 41 wherein said at least one feed roller is a pin roller.
43. The apparatus of claim 38 wherein said chamber comprises at least two rollers adapted to contact a major surface of said material, such that a substantially gas-tight seal is formed therebetween.
44. The apparatus of claim 43 wherein at least one of said rollers and said at least one roller die are the same.
45. The apparatus of claim 43 wherein said at least two rollers comprise at least two pair of opposed rollers, each of said pairs of opposed rollers adapted to contact opposing major surfaces of said material.
46. The apparatus of claim 43, further comprising at least one sealing member associated with said chamber for maintaining a gas-tight seal therein.
47. The apparatus of claim 46 wherein said at least one sealing member comprises a sealing member disposed at each end of at least one of said rollers.
48. The apparatus of claim 46 wherein said at least one sealing member comprises a resilient member adapted to contact the cylindrical surface of at least one of said rollers, such that a substantially gas-tight seal is formed therebetween.
49. The apparatus of claim 46, further comprising a resilient member adapted to contact the cylindrical surface of at least one of said rollers, such that a substantially gas-tight seal is formed therebetween.
50. The apparatus of claim 45 wherein at least one of said rollers is driven.
51. The apparatus of claim 45, further comprising at least one feed roller for directing said material to said chamber.
52. The apparatus of claim 51 wherein said at least one feed roller is a pin roller.
53. An apparatus for embossing expanded graphite sheet material at a pressure less than atmospheric comprising:
(a) means for embossing said material;
(b) an embossing chamber comprising said embossing means, and adapted to receive said material and to be substantially gas-tight at least during embossing; and
(c) means for reducing the pressure in said embossing chamber to less than atmospheric pressure.
54. The apparatus of claim 53 wherein said means for reducing the pressure in said embossing chamber reduces said pressure to about 400 torr or less.
55. The apparatus of claim 53 wherein said means for reducing the pressure in said embossing chamber reduces said pressure to about 350 torr or less.
56. The apparatus of claim 53 wherein said means for reducing the pressure in said embossing chamber reduces said pressure to about 170 torr or less.
57. The apparatus of claim 53 wherein said means for reducing the pressure in said embossing chamber reduces said pressure to about 50 torr or less.
58. The apparatus of claim 53 further comprising means for providing an inert atmosphere within said embossing chamber.
59. The apparatus of claim 53 further comprising sealing means for maintaining a substantially gas-tight seal within said embossing chamber at least during the embossing of said material.
60. An apparatus for embossing expanded graphite sheet material, said apparatus comprising:
(a) a chamber adapted to receive said material and to maintain a reduced pressure less than atmospheric pressure at least when said material is in said chamber;
(b) means for reducing the pressure in said chamber to less than atmospheric pressure; and
(c) means for embossing said material.
61. The apparatus of claim 60 wherein said means for reducing the pressure in said chamber reduces said pressure to about 400 torr or less.
62. The apparatus of claim 60 wherein said means for reducing the pressure in said chamber reduces said pressure to about 350 torr or less.
63. The apparatus of claim 60 wherein said means for reducing the pressure in said chamber reduces said pressure to about 170 torr or less.
64. The apparatus of claim 60 wherein said means for reducing the pressure in said chamber reduces said pressure to about 50 torr or less.
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.-44. (canceled)
45. A transformer comprising
a bobbin having a structure and an opening;
a three legged magnetic core having a middle leg passing through the bobbin opening;
a first winding provided in a first concentric path around the middle leg of the magnetic core;
a second winding provided in a second concentric path around the middle leg of the magnetic core, wherein the first and second concentric paths are isolated from each other by the structure of the bobbin, wherein the first concentric path comprises two longitudinal passages enclosed by the structure of the bobbin, wherein the first winding exits the bobbin through a first opening to the longitudinal passages at a first end and where a second opening is provided at a second end opposing the first opening, wherein the second opening allows feeding of the first winding about the first concentric path.
46. The transformer according to claim 45, wherein the second winding comprises a single turn.
47. The transformer according to claim 45, wherein the second winding is formed using Litz wire.
48. The transformer according to claim 45, further comprising a spacer provided to maintain the second winding in a predefined position in one of the passages.
49. The transformer according to claim 45, wherein the three legged magnetic core further comprises:
a top section;
a bottom section;
with two further legs in addition to the middle leg;
wherein there is a gap defined between each leg and the top section and a gap defined between each leg and the bottom section.
50. The transformer according to claim 50, wherein each defined gap has a gap length of between 10 \u03bcm and 200 \u03bcm.
51. The transformer according to claim 50, further comprising a spacer provided in each gap to define the gap length.
52. The transformer according to claim 51, further comprising adhesive provided in the gaps.
53. The transformer according to claim 45, further comprising one or more PTH connections moulded with the bobbin for connecting to an underlying circuit board.
54. The transformer according to claim 45, further comprising one or more SMT connections moulded with the bobbin for connecting to an underlying circuit board.
55. An apparatus comprising:
a bobbin for a transformer, the bobbin having a structure and defining an opening for receiving the leg of a magnetic core, the bobbin being arranged to receive a first winding in a first concentric path around the opening, the bobbin being further arranged to receive a second winding in a second concentric path around the opening, wherein the first and second concentric paths are isolated from each other by the structure of the bobbin, wherein the first concentric path includes:
a first enclosed longitudinal passage provided along a first side of the opening and having a first opening at a first end of the first enclosed longitudinal passage and a second opening at an opposite end of the first enclosed longitudinal passage, wherein the first enclosed longitudinal passage has a longitudinal axis, and
a second enclosed longitudinal passage provided along a second side of the opening which is opposite the first side and having a third opening at a first end of the second enclosed longitudinal passage and a fourth opening at the opposite end of the second enclosed longitudinal passage to allow feeding of a first winding about the first concentric path through the first opening, second opening, third opening and fourth opening, wherein the second enclosed longitudinal passage has a longitudinal axis.
56. The apparatus according to claim 55, wherein the first opening and second openings are co-axial with the longitudinal axis of the first enclosed longitudinal passage.
57. The apparatus according to claim 55, wherein the third opening and fourth openings are co-axial with the longitudinal axis of the second enclosed longitudinal passage.
58. The apparatus according to claim 55, wherein the bobbin includes an inner wall transverse to and between the second opening and third openings, wherein the inner wall is provided in a recess defined in the bobbin.
59. The apparatus according to claim 55, wherein the bobbin is a single piece construction.
60. The apparatus according to claim 55, wherein the bobbin is a split bobbin construction with the first concentric path provided by a first part and a second concentric path provided by a second part.
61. The apparatus according to claim 55, wherein the bobbin further includes one or more PTH connections for connecting to an underlying circuit board.
62. The apparatus according to claim 55, wherein the bobbin further includes one or more SMT connections for connecting to an underlying circuit board.
63. The apparatus of claim 55, further comprising:
the magnetic core;
the first winding in the first concentric path around the opening; and
the second winding in the second concentric path around the opening.
64. An apparatus comprising:
a magnetic core that includes a plurality of legs including a first leg, a second leg, and a third leg, a top section, and a bottom section, wherein the top section, the bottom section and each one of the plurality of legs includes a laminar piece of magnetic material, wherein there is a gap defined between each leg of the plurality of legs and the bottom section, and wherein there is a gap having a gap length defined between each leg of the plurality of legs and the top section; and
a spacer included in each defined gap to define the gap length.
65. The apparatus of claim 64, further comprising:
a bobbin having a structure and an opening;
a first winding provided in a first concentric path around the second leg of the magnetic core; and
a second winding provided in a second concentric path around the second leg of the magnetic core, wherein the first and second concentric paths are isolated from each other by the structure of the bobbin, and wherein each defined gap has a gap length of between 10 \u03bcm and 200 \u03bcm.