US4757172A
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US
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Method and apparatus for the microwave joining of nonoxide ceramic items
Assignee: QUESTECH Inc A CORP OF
•
Filing: 1987-09-24
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Granted: 1988-07-12
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Expires: 2007-09-24
Abstract
Abstract A method for joining together two nonoxide ceramic items involves a preliminary step of either creating a vacuum or overpressurizing a cavity, followed by the steps of applying microwave radiation to the ceramic items, simultaneously applying compressive forces to the ceramic items in order to force such ceramic items together, and continually monitoring the joint being formed between the two ceramic items. An apparatus of four basic elements carries out the method. These elements are a vacuum/overpressurization system; a single mode microwave applicator; a compressive force applicator; and a nondestructive evaluator for monitoring the formation of the joint.
Inventors
- 👤 David E. Palaith
- 👤 E. Laurence Libelo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 04:13
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/64; H05B6/66; H05B6/68; C; C04; C04B; C04B35/00; C04B35/622; C04B35/64; C04B35/645; C04B37/00; C04B37/001; C04B37/02; C04B37/021; H05B6/80; C04B2235/00; C04B2235/65; C04B2235/656; C04B2235/6562; C04B2235/6567; C04B2235/658; C04B2235/6581; C04B2235/66; C04B2235/667; C04B2237/00; C04B2237/30; C04B2237/32; C04B2237/36; C04B2237/368; Y; Y02; Y02B; Y02B40/00
Claims Analysis
Total Claims: 66
Claim 1
Independent Claim
52 words
A method for joining together two items, comprising the steps of: a. creating a vacuum around the two items; b. radiating microwaves onto a joint being formed between the two items; c. applying compressive force simultaneously to the two items; and d. monitoring continuously the joint being formed between the two items.
Claim 2
Independent Claim
52 words
A method for joining together two items, comprising the steps of: a. creating a vacuum around the two items; b. radiating microwaves onto a joint being formed between the two items; c. applying compressive force simultaneously to the two items; and d. monitoring continuously the joint being formed between the two items.
Claim 3
Dependent Claim
27 words
The method according to claim 1, wherein: said microwave-radiation step includes the substep of applying direct single mode microwaves only to the joint between the two items.
Claim 4
Dependent Claim
41 words
The method according to claim 1, wherein: said force-applying step includes the substep of applying the compressive force across the two items, one end of each item being located at a position remote from the joint formed between the two items.
Claim 5
Dependent Claim
33 words
The method according to claim 1, wherein: said monitoring step includes the substep of nondestructively evaluating the joints being formed between the two items by measuring responses of said joint to acoustic stimulation.
Claim 6
Dependent Claim
34 words
The method according to claim 1, wherein: said monitoring step includes the substep of nondestructively evaluating the joint being formed between the two items by detecting and measuring spontaneous acoustic emission from the joint.
Claim 7
Dependent Claim
32 words
The method according to claim 1, wherein: said monitoring step includes the substep of nondestructively evaluating the joint being formed between the two items by measuring stimulated acoustic emissions from the joint.
Claim 8
Dependent Claim
16 words
The method according to claim 1, wherein: said two items are both made of nonoxide ceramic.
Claim 9
Dependent Claim
28 words
The method according to claim 1, wherein: one of said two items is made of nonoxide ceramic and the other of said two items is made of metal.
Claim 10
Independent Claim
57 words
An apparatus for joining together two items comprising: a. means for creating a vacuum around the two items; b. means for radiating microwaves onto a joint being formed between the two items; c. means for applying compressive force simultaneously to the two items; and d. means for monitoring continuously the joint being formed between the two items.
Claim 11
Independent Claim
57 words
An apparatus for joining together two items comprising: a. means for creating a vacuum around the two items; b. means for radiating microwaves onto a joint being formed between the two items; c. means for applying compressive force simultaneously to the two items; and d. means for monitoring continuously the joint being formed between the two items.
Claim 12
Dependent Claim
25 words
The apparatus according to claim 9, wherein: said radiating means applies direct single mode microwaves only to the joint being formed between the two items.
Claim 13
Dependent Claim
26 words
The apparatus according to claim 9, wherein: said radiating means applies direct microwaves of variable frequency only to the joint being formed between the two items.
Claim 14
Dependent Claim
37 words
The apparatus according to claim 9, wherein: said force-applying means applies compressive force across the two items, one end of each item being located at a position remote from the joint being formed between the two items.
Claim 15
Dependent Claim
68 words
The apparatus according to claim 9, further comprising: a chamber means for containing the two items between which a joint is being formed in an internal cavity having a resonant frequency, said chamber means having an iris means in a front wall thereof for allowing entry of microwaves and also having a slidable rear wall means for allowing a change in the resonant frequency of the internal cavity.
Claim 16
Dependent Claim
15 words
The apparatus according to claim 13, wherein: said iris means has a fixed opening therethrough.
Claim 17
Dependent Claim
15 words
The apparatus according to claim 13, wherein: said iris means has an adjustable opening therethrough.
Claim 18
Dependent Claim
56 words
The apparatus according to claim 9, further comprising: a chamber means for containing the two items between which a joint is being formed in an internal cavity having a predetermined resonant frequency, said chamber means having an iris means in a front wall thereof for allowing entry of microwaves and also having a fixed rear wall.
Claim 19
Dependent Claim
15 words
The apparatus according to claim 16, wherein: said iris means has a fixed opening therethrough.
Claim 20
Dependent Claim
15 words
The apparatus according to claim 16, wherein: said iris means has an adjustable opening therethrough.
Claim 21
Dependent Claim
16 words
The apparatus according to claim 9, wherein: said two items are both made of nonoxide ceramic.
Claim 22
Dependent Claim
29 words
The apparatus according to claim 9, wherein: one of said two items is made of nonoxide ceramic and the other of said two items is made of a metal.
Claim 23
Dependent Claim
24 words
The apparatus according to claim 9, wherein: said monitoring means includes a nondestructive evaluating means for measuring responses of said joint to acoustic stimulation.
Claim 24
Dependent Claim
25 words
The apparatus according to claim 9, wherein: said monitoring means includes a nondestructive evaluating means for detecting and measuring spontaneous acoustic emissions from the joint.
Claim 25
Dependent Claim
25 words
The apparatus according to claim 9, wherein: said monitoring means includes a nondestructive evaluating means for detecting and measuring stimulated acoustic emissions from the joint.
Claim 26
Dependent Claim
39 words
The apparatus according to claim 21, wherein: said nondestructive evaluating means includes (i) a transducer means for converting electric pulses to acoustic pulses; and (ii) an acoustic magnifying lens means for maximizing acoustic signals to and from the joint.
Claim 27
Dependent Claim
22 words
The apparatus according to claim 24, wherein: said monitoring means includes a pulser means for transmitting electric pulses to the transducer means.
Claim 28
Dependent Claim
23 words
The apparatus according to claim 24, wherein: said monitoring means includes means for receiving electric pulses from the transducer means for further transmission.
Claim 29
Dependent Claim
25 words
The apparatus according to claim 25, wherein: said monitoring means includes an oscilliscope means for displaying the electric pulses transmitted further from the receiving means.
Claim 30
Dependent Claim
32 words
The apparatus according to claim 24, wherein: said monitoring means includes a pyrometer means, connected to the nondestructive evaluating means, for measuring temperatures at the joint being formed between the two items.
Claim 31
Dependent Claim
24 words
The apparatus according to claim 28, wherein: said monitoring means includes a recorder means, connected to the pyrometer means, for displaying a temperature/power/time porfile.
Claim 32
Dependent Claim
45 words
The apparatus according to claim 29, wherein: said monitoring means includes means connected between the radiating means and the recorder means, for inputting a measurement of a difference between forward power from the radiating means and reflected power from the joint into the recorder means.
Claim 33
Independent Claim
52 words
A method for joining together two items, comprising the steps of: a. overpressurizing a cavity around the two items; b. radiating microwaves onto a joint being formed between the two items; c. applying compressive force simultaneously to the two items; and d. monitoring continuously the joint being formed between the two items.
Claim 34
Independent Claim
52 words
A method for joining together two items, comprising the steps of: a. overpressurizing a cavity around the two items; b. radiating microwaves onto a joint being formed between the two items; c. applying compressive force simultaneously to the two items; and d. monitoring continuously the joint being formed between the two items.
Claim 35
Dependent Claim
22 words
The method according to claim 31, wherein: said overpressurizing step includes the substep of feeding an inert gas around the two items.
Claim 36
Dependent Claim
29 words
The method according to claim 31, wherein: said microwave-radiating step includes the substep of applying direct single mode microwaves only to the joint being formed between the two items.
Claim 37
Dependent Claim
42 words
The method according to claim 31, wherein: said force-applying step includes the substep of applying the compressive force across the two items, one end of each item being located at a position remote from the joint being formed between the two items.
Claim 38
Dependent Claim
33 words
The method according to claim 31, wherein: said monitoring step includes the substep of nondestructively evaluating the joint being formed between the two items by measuring responses of said joint to acoustic stimulation.
Claim 39
Dependent Claim
34 words
The method according to claim 31, wherein: said monitoring step includes the substep of nondestructively evaluating the joint being formed between the two items by detecting and measuring spontaneous acoustic emissions from the joint.
Claim 40
Dependent Claim
32 words
The method according to claim 31, wherein: said monitoring step includes the substep of nondestructively evaluating the joint being formed between the two items by measuring stimulated acoustic emissions from the joint.
Claim 41
Dependent Claim
16 words
The method according to claim 31, wherein: said two items are both made of nonoxide ceramic.
Claim 42
Dependent Claim
28 words
The method according to claim 31, wherein: one of said two items is made of nonoxide ceramic and the other of said two items is made of metal.
Claim 43
Independent Claim
57 words
An apparatus for joining together two items, comprising: a. means for overpressurizing a cavity around the two items; b. means for radiating microwaves onto a joint being formed between the two items; c. means for applying compressive force simultaneously to the two items; and d. means for monitoring continuously the joint being formed between the two items.
Claim 44
Independent Claim
57 words
An apparatus for joining together two items, comprising: a. means for overpressurizing a cavity around the two items; b. means for radiating microwaves onto a joint being formed between the two items; c. means for applying compressive force simultaneously to the two items; and d. means for monitoring continuously the joint being formed between the two items.
Claim 45
Dependent Claim
21 words
The apparatus according to claim 40, wherein: said overpressurizing means includes means for feeding an inert gas around the two items.
Claim 46
Dependent Claim
25 words
The apparatus according to claim 40, wherein: said radiating means applies direct single mode microwaves only to the joint being formed between the two items.
Claim 47
Dependent Claim
26 words
The apparatus according to claim 40, wherein: said radiating means applies direct micowaves of variable frequency only to the joint being formed between the two items.
Claim 48
Dependent Claim
36 words
The apparatus according to claim 40, wherein: said force-applying means applies compressive force across the two items, one end of each being located at a position remote from the joint being formed between the two items.
Claim 49
Dependent Claim
68 words
The apparatus according to claim 40, further comprising: a chamber means for containing the two items between which a joint is being formed in an internal cavity having a resonant frequency, said chamber means having an iris means in a front wall thereof for allowing entry of microwaves and also having a slidable rear wall means for allowing a change in the resonant frequency of the internal cavity.
Claim 50
Dependent Claim
15 words
The apparatus according to claim 45, wherein: said iris means has a fixed opening therethrough.
Claim 51
Dependent Claim
15 words
The apparatus according to claim 45, wherein: said iris means has an adjustable opening therethrough.
Claim 52
Dependent Claim
56 words
The apparatus according to claim 40, further comprising: a chamber means for containing the two items between which a joint is being formed in an internal cavity having a predetermined resonant frequency, said chamber means having an iris means in a front wall thereof for allowing entry of microwaves and also having a fixed rear wall.
Claim 53
Dependent Claim
15 words
The apparatus according to claim 48, wherein: said iris means has a fixed opening therethrough.
Claim 54
Dependent Claim
15 words
The apparatus according to claim 48, wherein: said iris means has an adjustable opening therethrough.
Claim 55
Dependent Claim
16 words
The apparatus according to claim 40, wherein: said two items are both made of nonoxide ceramic.
Claim 56
Dependent Claim
28 words
The apparatus according to claim 40, wherein: one of said two items is made of nonoxide ceramic and the other of said two items is made of metal.
Claim 57
Dependent Claim
24 words
The apparatus according to claim 40, wherein: said monitoring means includes a nondestructive evaluating means for measuring responses of said joint to acoustic stimulation.
Claim 58
Dependent Claim
25 words
The apparatus according to claim 40, wherein: said monitoring means includes a nondestructive evaluating means for detecting and measuring spontaneous acoustic emissions from the joint.
Claim 59
Dependent Claim
25 words
The apparatus according to claim 40, wherein: said monitoring means includes a nondestructive evalutaing means for detecting and measuring stimulated acoustic emissions from the joint.
Claim 60
Dependent Claim
38 words
The apparatus according to claim 53, wherein: said nondestructive evaluating means includes (i) a transducer for converting electric pulses to acoustic pulses; and (ii) an acoustic magnifying lens means for maximizing acoustic signals to and from the joint.
Claim 61
Dependent Claim
22 words
The apparatus according to claim 56, wherein: said monitoring means includes a pulser means for transmitting electric pulses to the transducer means.
Claim 62
Dependent Claim
23 words
The apparatus according to claim 56, wherein: said monitoring means includes means for receiving electric pulses from the transducer means for further transmission.
Claim 63
Dependent Claim
25 words
The apparatus according to claim 57, wherein: said monitoring means includes an oscilliscope means for displaying the electric pulses transmitted further from the receiving means.
Claim 64
Dependent Claim
32 words
The apparatus according to claim 56, wherein: said monitoring means includes a pyrometer means connected to the nondestructive evaluating means, for measuring temperatures at the joint being formed between the two items.
Claim 65
Dependent Claim
24 words
The apparatus according to claim 60, wherein: said monitoring means includes a recorder means, connected to the pyrometer means, for displaying a temperature/power/time profile.
Claim 66
Dependent Claim
45 words
The apparatus according to claim 61, wherein: said monitoring means includes means, connected between the radiating means and the recorder means, for inputting a measurement of a difference between forward power from the radiating means and reflected power from the joint into the recorder means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1991-07-12 | 1992-01-11 | 1992-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-12 | 1996-01-11 | 1996-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-12 | 2000-01-11 | 2000-07-12 | $7700.00 | Window Closed / Lapsed |