Patent US4918941A successfully refreshed from Google Patents.
US4918941A
Expired / Lapsed
US
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Cryogenic ultramicrotome seal
Assignee: The University of Texas System
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Filing: 1989-05-16
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Granted: 1990-04-24
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Expires: 2009-05-16
Abstract
Abstract A cryogenic seal, and a cryogenic ultramicrotome using the seal are presented. The seal allows a microtome arm to pass through an aperture in the wall of a cryogenic microtome chamber providing thermal insulation while allowing manipulation of the microtome arm within the chamber. The seal includes a thermally conductive seal container having a number of thermally insulating baffle inserts therein. The baffle inserts are placed within the seal container to form a plurality of baffle chambers, and each baffle insert includes an aperture which is larger in circumference than the external circumference of the microtome arm. Within each baffle chamber is a baffle membrane, each membrane having an aperture through which the microtome arm passes in sliding contact. The baffle inserts and baffle membranes together form a thermally insulating labyrinth seal between the interior and the exterior of the cryogenic chamber, and allow the microtome arm to be easily and accurately manipulated from the exterior of the chamber.
Inventors
- 👤 Herbert K. Hagler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:55
CPC Classifications
F; F16; F16J; F16J15/00; F16J15/44; F16J15/447; F16J15/4472; F16J15/4474; F16J15/16; G; G01; G01N; G01N1/00; G01N1/02; G01N1/04; G01N1/06; G01N1/28; G01N1/42; Y; Y10; Y10T; Y10T83/00; Y10T83/283; Y10T83/293
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
151 words
A thermal seal for use in a cryogenic ultramicrotome having a cryogenic chamber and a microtome arm extending through an aperture in said cryogenic chamber from a reactively high temperature exterior of said chamber to a relatively low temperature interior of said chamber, said seal comprising: a seal container attached to said cryogenic chamber; a plurality of thermally insulating baffle inserts within said container together forming a plurality of baffle chambers, each baffle insert having an aperture therein substantially aligned with said aperture of said cryogenic chamber and being larger than an exterior dimension of a cross-section of said microtome arm; and a plurality of thermally insulating baffle membranes, each membrane being located and moveable within a respective one of said baffle chambers, each membrane having an aperture substantially aligned with said aperture of said cryogenic chamber and being dimensioned for slidable engagement with said exterior dimension of said microtome arm.
Claim 2
Dependent Claim
151 words
A thermal seal for use in a cryogenic ultramicrotome having a cryogenic chamber and a microtome arm extending through an aperture in said cryogenic chamber from a reactively high temperature exterior of said chamber to a relatively low temperature interior of said chamber, said seal comprising: a seal container attached to said cryogenic chamber; a plurality of thermally insulating baffle inserts within said container together forming a plurality of baffle chambers, each baffle insert having an aperture therein substantially aligned with said aperture of said cryogenic chamber and being larger than an exterior dimension of a cross-section of said microtome arm; and a plurality of thermally insulating baffle membranes, each membrane being located and moveable within a respective one of said baffle chambers, each membrane having an aperture substantially aligned with said aperture of said cryogenic chamber and being dimensioned for slidable engagement with said exterior dimension of said microtome arm.
Claim 3
Dependent Claim
14 words
A seal as recited in claim 1, wherein said seal container is thermally conductive.
Claim 4
Dependent Claim
18 words
A seal as recited in claim 2, further comprising, mean for heating a surface of said seal container.
Claim 5
Dependent Claim
13 words
A seal as recited in claim 2, wherein said seal container is aluminum.
Claim 6
Dependent Claim
13 words
A seal as recited in claim 2, wherein said seal container is copper.
Claim 7
Dependent Claim
13 words
A seal as recited in claim 2, wherein said seal container is brass.
Claim 8
Dependent Claim
13 words
A seal as recited in claim 1, wherein said baffle inserts are polystyrene.
Claim 9
Dependent Claim
13 words
A seal as recited in claim 1, wherein said baffle membranes are anti-static.
Claim 10
Dependent Claim
13 words
A seal as recited in claim 1, wherein said baffle membranes are mylar.
Claim 11
Dependent Claim
17 words
A seal as recited in claim 1, wherein said baffle membranes are mylar having an anti-static coating.
Claim 12
Dependent Claim
39 words
A seal as recited in claim 1, further comprising a thermally insulating baffle wall plug attached to said seal chamber, said plug having an external dimension suitable for press fitting said plug into said aperture of said cryogenic chamber.
Claim 13
Dependent Claim
155 words
A cryogenic ultramicrotome comprising: a thermally insulating cryogenic chamber for maintaining an interior of said chamber at a low temperature relative to an exterior of said chamber, said chamber having at least one aperture between said interior and exterior; a thermally insulating microtome arm extending through said chamber aperture and being moveable relative to said chamber; and a cryogenic seal attached to said chamber and surrounding said arm, said seal comprising: a seal container attached to said cryogenic chamber and surrounding said arm; a plurality of thermally insulating baffle inserts located within and substantially fixed relative to said seal container to form a plurality of baffle chambers between adjacent baffle inserts, each of said inserts having an aperture through which said arm passes without contact; and a plurality of baffle membranes located within said seal container between adjacent baffle inserts, each of said membranes having an aperture through which said arm passes in sliding contact.
Claim 14
Dependent Claim
155 words
A cryogenic ultramicrotome comprising: a thermally insulating cryogenic chamber for maintaining an interior of said chamber at a low temperature relative to an exterior of said chamber, said chamber having at least one aperture between said interior and exterior; a thermally insulating microtome arm extending through said chamber aperture and being moveable relative to said chamber; and a cryogenic seal attached to said chamber and surrounding said arm, said seal comprising: a seal container attached to said cryogenic chamber and surrounding said arm; a plurality of thermally insulating baffle inserts located within and substantially fixed relative to said seal container to form a plurality of baffle chambers between adjacent baffle inserts, each of said inserts having an aperture through which said arm passes without contact; and a plurality of baffle membranes located within said seal container between adjacent baffle inserts, each of said membranes having an aperture through which said arm passes in sliding contact.
Claim 15
Dependent Claim
15 words
A cryogenic ultramicrotome as recited in claim 12, wherein said seal container is thermally conductive.
Claim 16
Dependent Claim
21 words
A cryogenic ultramicrotome as recited in claim 13, further comprising a defrosting heater attached to an exterior of said seal container.
Claim 17
Dependent Claim
31 words
A cryogenic ultramicrotome as recited in claim 12, further comprising a wall plug fitted within said at least one aperture of said cryogenic chamber, and being attached to said cryogenic seal.
References Cited (Backward Citations)
US3204424A
Cited
US3218896A
Cited
US3236133A
Cited
US3351396A
Cited
US3495490A
Cited
US3447594A
Cited
US3701536A
Cited
US3828571A
Cited
US4290610A
Cited
US4278263A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-23 | 1993-10-23 | 1994-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-23 | 1997-10-23 | 1998-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-23 | 2001-10-23 | 2002-04-24 | $7700.00 | Window Closed / Lapsed |