Patent US2866723A successfully refreshed from Google Patents.
Patent USRE34515E successfully refreshed from Google Patents.
USRE34515E
Expired / Lapsed
US
⏱️ 0.0 years remaining
Steam sterilization indicator
Assignee: 3M Co
•
Filing: 1991-12-24
•
Granted: 1994-01-18
•
Expires: 2011-12-24
Abstract
Abstract An improved steam sterilization indicator is provided. The indicator includes a fusible material in tablet form, deposited in an embossment in one end of a thin aluminum backing. A wicking strip is attached to the backing with one end of the strip being in close proximity to the fusible tablet. A clear plastic material covers the tablet and the strip and is adhered to the backing. The melting point of the fusible tablet is depressed in the presence of saturated steam. Upon melt, the material in the tablet is absorbed by the wicking strip, producing a color front to provide an indication of the integration of time and temperature in the presence of steam. Various amounts of a binder are used in the tablet to provide a device which may be adjusted to reflect the thermal death curves of various types of microorganisms. The cover and the wick are bonded to the backing by an acyclic adhesive which also affects the rate of the indicator.
Inventors
- 👤 Theodore A. Foley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:51
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/22; G01N31/226; A; A61; A61L; A61L2/00; A61L2/26; A61L2/28
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
203 words
A steam sterilization indicator comprising: a tablet including a fusible material and a binder, said fusible material meltable at a predetermined temperature in the presence of substantially saturated steam, the melting point of said fusible material being substantially lower in the presence of saturated steam than when dry; a wicking strip having one end in close proximity to said tablet whereupon attainment of said predetermined temperature, said fusible material melts and moves along said strip at a rate proportional to the temperature of said saturated steam; a steam permeable membrane covering said tablet and said wicking strip, said binder holding said fusible material in tablet form prior to attainment of said predetermined temperature and further providing a mechanism for altering the rate movement of said fusible material along said wicking strip as a function of the amount of binder used for certain temperature ranges, such rate of movement being similar to spore death kinetics; a backing; and an acrylic adhesive, wherein said backing and said membrane enclose said tablet and said strip and said acrylic adhesive holds said membrane and said strip to said backing, said acrylic adhesive acting to further alter the rate of movement of said fusible material along said strip.
Claim 2
Dependent Claim
203 words
A steam sterilization indicator comprising: a tablet including a fusible material and a binder, said fusible material meltable at a predetermined temperature in the presence of substantially saturated steam, the melting point of said fusible material being substantially lower in the presence of saturated steam than when dry; a wicking strip having one end in close proximity to said tablet whereupon attainment of said predetermined temperature, said fusible material melts and moves along said strip at a rate proportional to the temperature of said saturated steam; a steam permeable membrane covering said tablet and said wicking strip, said binder holding said fusible material in tablet form prior to attainment of said predetermined temperature and further providing a mechanism for altering the rate movement of said fusible material along said wicking strip as a function of the amount of binder used for certain temperature ranges, such rate of movement being similar to spore death kinetics; a backing; and an acrylic adhesive, wherein said backing and said membrane enclose said tablet and said strip and said acrylic adhesive holds said membrane and said strip to said backing, said acrylic adhesive acting to further alter the rate of movement of said fusible material along said strip.
Claim 3
Dependent Claim
14 words
The indicator as set forth in claim 1 wherein said fusible material is salicylamide.
Claim 4
Dependent Claim
14 words
The indicator as set forth in claim 1 wherein said binder is .[.polyvinylpyrrolidine.]. .Iadd.polyvinylpyrrolidone.Iaddend..
Claim 5
Dependent Claim
24 words
The indicator as set forth in claim 1 further including a dye in said tablet for providing a moving color front on said strip.
Claim 6
Dependent Claim
28 words
An indicator as set forth in claim 4 wherein said dye is taken from the group consisting of Spirit Soluble Fast Black RE and Spirit Soluble Orange RR.
Claim 7
Dependent Claim
23 words
The device as set forth in claim 1 wherein said amount of binder is no greater than 3% by weight of said tablet.
Claim 8
Dependent Claim
28 words
The device as set forth in claim 1 wherein the amount of said binder is within the range of from 1% to 3% by weight of said tablet.
Claim 9
Dependent Claim
18 words
An indicator as set forth in claim 1 wherein at least a portion of said membrane is transparent.
Claim 10
Dependent Claim
115 words
A steam sterilization indicator comprising: a backing and a cover; said cover being permeable to steam; a fusible material being meltable at and above a said predetermined temperature; a wicking strip in substantial contact with said fusible material; said fusible material and said strip being located between said backing and said cover; said fusible material having its melting point substantially depressed in the presence of steam; said fusible material upon melting moving along said strip at a rate in proportion to the temperature of the saturated steam; an acrylic adhesive holding said cover to said backing and said strip to said backing for altering the rate of movement of said fusible material along said strip.
Claim 11
Dependent Claim
115 words
A steam sterilization indicator comprising: a backing and a cover; said cover being permeable to steam; a fusible material being meltable at and above a said predetermined temperature; a wicking strip in substantial contact with said fusible material; said fusible material and said strip being located between said backing and said cover; said fusible material having its melting point substantially depressed in the presence of steam; said fusible material upon melting moving along said strip at a rate in proportion to the temperature of the saturated steam; an acrylic adhesive holding said cover to said backing and said strip to said backing for altering the rate of movement of said fusible material along said strip.
Claim 12
Dependent Claim
13 words
An indicator set forth in claim 9 wherein said fusible material is salicylamide.
Claim 13
Independent Claim
15 words
A device as set forth in claim .[.10.]. .Iadd.12 .Iaddend.wherein said binder is .[.polyvinylpyrrolidine.]. .Iadd.polyvinylpyrrolidone.Iaddend..
Claim 14
Dependent Claim
32 words
An indicator as set forth in claim 9 further including a binder added to said fusible material for further slowing down the rate of movement of said fusible material along said strip.
Claim 15
Dependent Claim
149 words
A steam sterilization indicator comprising: a metallic backing having an embossment near one end thereof; a tablet including both an amount of salicylamide which is fusible at a predetermined temperature and having the quality of having its melting point depressed in the presence of a substantial amount of moisture and an amount of polyvinylpyrrolidone, said tablet received in said embossment; a wicking strip adhered to said metallic backing, said wicking strip having a portion thereof received in said embossment and in contact with said tablet; a steam permeable cover having a transparent portion and received over said backing and adhered thereto by acrylic adhesive for further controlling the rate of movement of salicylamide along said strip; and a dye associated with said tablet for indicating the movement of said salicylamide along said wicking strip, said polyvinylpyrrolidone also controlling the rate of movement of molten salicylamide along said wicking strip.
Claim 16
Dependent Claim
149 words
A steam sterilization indicator comprising: a metallic backing having an embossment near one end thereof; a tablet including both an amount of salicylamide which is fusible at a predetermined temperature and having the quality of having its melting point depressed in the presence of a substantial amount of moisture and an amount of polyvinylpyrrolidone, said tablet received in said embossment; a wicking strip adhered to said metallic backing, said wicking strip having a portion thereof received in said embossment and in contact with said tablet; a steam permeable cover having a transparent portion and received over said backing and adhered thereto by acrylic adhesive for further controlling the rate of movement of salicylamide along said strip; and a dye associated with said tablet for indicating the movement of said salicylamide along said wicking strip, said polyvinylpyrrolidone also controlling the rate of movement of molten salicylamide along said wicking strip.
References Cited (Backward Citations)
US1703880A
Cited
US197902A
Cited
CA917548A
Cited
US3018611A
Cited
US161118A
Cited
US1917048A
Cited
CA823264A
Cited
CA498481A
Cited
US1000673A
Cited
US1238123A
Cited
US1191572A
Cited
US1441307A
Cited
US1426569A
Cited
US1558153A
Cited
US1535536A
Cited
US1676536A
Cited
US1788104A
Cited
US1843234A
Cited
US1894015A
Cited
US2118144A
Cited
US1951650A
Cited
US2046863A
Cited
US2049867A
Cited
US2195395A
Cited
US2277278A
Cited
US2278749A
Cited
US2222067A
Cited
US2308087A
Cited
US2269038A
Cited
US2337534A
Cited
US2335999A
Cited
GB551783A
Cited
US2490933A
Cited
US2379459A
Cited
US2606654A
Cited
GB602753A
Cited
US2552477A
Cited
US2460215A
Cited
US2567445A
Cited
GB647379A
Cited
US2579738A
Cited
US2560537A
Cited
US2614430A
Cited
US2677278A
Cited
US2716065A
Cited
US2799167A
Cited
US2928791A
Cited
US2798855A
Cited
US2798856A
Cited
US2708896A
Cited
US2889799A
Cited
US2847067A
Cited
US2918893A
Cited
US2826073A
Cited
US2971852A
Cited
US2850393A
Cited
US2854384A
Cited
US2951764A
Cited
US2932971A
Cited
US3065083A
Cited
US2915405A
Cited
US3046786A
Cited
US3055759A
Cited
US3059474A
Cited
GB889573A
Cited
US3047405A
Cited
US3067015A
Cited
US3002385A
Cited
US2998306A
Cited
US3114349A
Cited
GB910520A
Cited
US3098751A
Cited
US3465590A
Cited
US3118774A
Cited
US3078182A
Cited
US3471422A
Cited
US3093242A
Cited
US3082624A
Cited
US3620677A
Cited
GB1026950A
Cited
US3399284A
Cited
CH425276A
Cited
US3243303A
Cited
US3205158A
Cited
US3242733A
Cited
US3288718A
Cited
US3324723A
Cited
GB1027417A
Cited
US3352794A
Cited
US3460964A
Cited
US3386807A
Cited
US3360338A
Cited
US3311084A
Cited
US3360337A
Cited
FR1461252A
Cited
GB1132334A
Cited
US3360339A
Cited
US3344670A
Cited
AU141266A
Cited
US3440144A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-01-17 | 1997-07-19 | 1998-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-01-17 | 2001-07-19 | 2002-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-01-17 | 2005-07-19 | 2006-01-18 | $7700.00 | Window Closed / Lapsed |