US4070285A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chromatography tube
Assignee: Waters Investments Ltd
•
Filing: 1975-12-24
•
Granted: 1978-01-24
•
Expires: 1995-12-24
Abstract
Abstract A column for use in liquid chromatographic processes wherein the column is formed with an external reinforcing sleeve that has been found to contribute dimensional stability which results in surprising and important advantages in improving chromatographic performance. Another aspect of the invention comprises the preparation of the internal wall of the column which has an advantageous finish of 32 micro inches or better.
Inventors
- 👤 Louis Abrahams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:42
CPC Classifications
B; B01; B01D; B01D15/00; B01D15/08; B01D15/10; B01D15/22; G; G01; G01N; G01N30/00; G01N30/02; G01N30/60; G01N30/6052; G01N30/6073; G01N30/6004
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
125 words
In a chromatographic column of the type comprising an elongate chamber filled with a porous mass of chromatographic packing material, the improvement wherein said chamber is formed of a cylinder having a mechanical strength such that the diameter of said cylinder will be increased by less than about 0.01% when subjected to an internal pressure of 5000 psi, wherein said column comprises a relatively thin tubular sleeve of a chemically-resistant material within an exterior reinforcing tube formed of a material having relatively greater resistance to strain and wherein said exterior reinforcing tube is formed of a metal having a yield strength (0.2% offset) of over 100,000 psi and wherein said tubular sleeve is formed of stainless steel which has been expanded to the elastic limit.
Claim 2
Dependent Claim
125 words
In a chromatographic column of the type comprising an elongate chamber filled with a porous mass of chromatographic packing material, the improvement wherein said chamber is formed of a cylinder having a mechanical strength such that the diameter of said cylinder will be increased by less than about 0.01% when subjected to an internal pressure of 5000 psi, wherein said column comprises a relatively thin tubular sleeve of a chemically-resistant material within an exterior reinforcing tube formed of a material having relatively greater resistance to strain and wherein said exterior reinforcing tube is formed of a metal having a yield strength (0.2% offset) of over 100,000 psi and wherein said tubular sleeve is formed of stainless steel which has been expanded to the elastic limit.
Claim 3
Dependent Claim
21 words
A column as defined in claim 1 wherein said tubular sleeve has a finish of less than about 32 microinches rms.
Claim 4
Dependent Claim
21 words
A column as defined in claim 1 wherein said tubular sleeve has a finish of up to about 16 microinches rms.
Claim 5
Dependent Claim
15 words
In a column as defined in claim 1 wherein said yield strength is about 150,000.
Claim 6
Dependent Claim
18 words
In a column as defined in claim 1 wherein said chamber has a maximum diameter of 0.625 inches.
Claim 7
Dependent Claim
32 words
In a column as defined in claim 4 wherein said tubular sleeve has a finish of less than about 16 microinches rms and said chamber has a maximum diameter of 0.625 inches.
Claim 8
Dependent Claim
130 words
In the process of filling a chamber of a chromatographic column by the deposition of a filter cake of chromatographic packing therein by the passage of a slurry of packing in a liquid carrier into one end of said chamber, at a pressure of about 2,000 psig or higher, and the removal of said liquid carrier from the other end of said chamber the improvement wherein the volume of the chamber is maintained within a tolerance of 0.01% during the addition of said slurry; and wherein said tolerance is achieved by utilizing a column formed of a metal having a yield strength (0.2 offset) of over 90,000 psi and lining the interior of said column with a stainless steel tubing expanded beyond the elastic limit of said stainless steel tubing.
Claim 9
Dependent Claim
130 words
In the process of filling a chamber of a chromatographic column by the deposition of a filter cake of chromatographic packing therein by the passage of a slurry of packing in a liquid carrier into one end of said chamber, at a pressure of about 2,000 psig or higher, and the removal of said liquid carrier from the other end of said chamber the improvement wherein the volume of the chamber is maintained within a tolerance of 0.01% during the addition of said slurry; and wherein said tolerance is achieved by utilizing a column formed of a metal having a yield strength (0.2 offset) of over 90,000 psi and lining the interior of said column with a stainless steel tubing expanded beyond the elastic limit of said stainless steel tubing.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-01-23 | 1981-07-25 | 1982-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-23 | 1985-07-25 | 1986-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-23 | 1989-07-25 | 1990-01-24 | $7700.00 | Window Closed / Lapsed |