[54] FILM CONFINED TO A FRAME HAVING RELATIVE ANISOTROPIC EXPANSION CHARACTERISTICS
[75] Inventors: William W. Merrill, White Bear Lake;
John C. Harvey, Woodbury, both of
Minn.; Reney R. Langlois, River Falls,
Wis.; Michael W. Mills, St. Paul,
Minn.; Rosalind E. Peebles, Chicago,
111.; Fred J. Roska, Woodbury, Minn.
[73] Assignee: 3M Innovative Properties Company, St. Paul, Minn.
[21] Appl. No.: 09/164,841 [22] Filed: Oct. 1, 1998
[51] Int. CI.7 A47G 1/06; G02B 5/30
[52] U.S. CI 359/500; 359/494; 359/896;
40/701; 40/710
[58] Field of Search 349/9, 58, FOR 125;
40/701, 710; 359/500, 892, 820, 896, 483, 492, 494, 501, 900; 362/19; 353/20
[56] References Cited
U.S. PATENT DOCUMENTS
2,917,855 12/1959 Schneider 40/701
3,068,162 12/1962 Roche .
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3,585,255 6/1971 Sevenich 260/873
3,649,100 3/1972 Kirst 40/701
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4,138,620 2/1979 Dickson 313/1
4.329.396 5/1982 Kropp 428/354
4.443.397 4/1984 Hahn et al 264/171
4,780,643 10/1988 Ellis et al 313/503
4,952,023 8/1990 Bradshaw et al 362/29
5,162,827 11/1992 Marshall 40/710
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5,260,827 11/1993 Dziekan 359/500
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(List continued on next page.)
FOREIGN PATENT DOCUMENTS
724101 12/1965 Canada 154/122
573905 12/1993 European Pat. Off G02B 27/28
406095110 4/1994 Japan .
WO 94/29765 12/1994 WIPO B29C 59/04
WO 95/27919 4/1995 WIPO G02B 27/28
(List continued on next page.)
OTHER PUBLICATIONS
W. Nowacki, "New Trends of Investigation in Thermoelas-
ticity",Thermoelasticity, pp 585-589, 1962.
S. G. Lekhnitskii, "The Simplest Cases of Elastic Equilib-
rium", Theory of Elasticity of an Anisotropic Body, Mir
Publishers, English Translation, pp 79-89, 1981.
H. S. Carslaw and J. C. Jaeger, "Conduction of Heat in an
Anisotropic Solid", Conduction of Heat in Solids, Oxford
University Press, Second Edition, pp 38-49, 1959.
T. C. T. Ting, "Thermo-Anisotropic Elasticity", Anisotropic
Elasticity: Theory and Applications, Oxford University
Press, pp. 506-511, 1996.
Primary Examiner—Cassandra Spyrou
Assistant Examiner—-John Juba, Jr.
Attorney, Agent, or Firm—Robert J. Pechman
[57] ABSTRACT
An assembly comprising a film bounded by a frame, the film having a first thermal expansion coefficient along a first direction parallel to the film and a second thermal expansion coefficient along a second direction parallel to the film, wherein thermal expansion of the film compared to that of the frame is greater along the first direction than along the second direction, and wherein the film has a shape at an ambient reference temperature different from that of the frame, the shape of the film being selected to reduce clearance while allowing sufficient room between the film and the frame for thermal expansion in the first direction for temperatures up to a predetermined elevated reference temperature.
11 Claims, 6 Drawing Sheets
Microfiche Appendix Included
(2 Microfiche, 140 Pages)
