Method of fabricating connector

• US 5,578,157 A
• Filed: 09/28/1994
• Issued: 11/26/1996
• Est. Priority Date: 12/23/1991
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Company (HP Inc.)
• Original Assignee: Microsensor Technology, Inc.
• Inventors: Higdon, William R.
• Primary Examiner(s): Maki, Steven D.
• Application Number:
  US08/314,479
• Time in Patent Office: 790 Days
• Field of Search: 422/89, 422/103, 96/106, 285/21, 285/284, 285/332, 285/915, 285/21 R, 156/294, 156/158, 156/304.2, 156/304.6, 156/278, 156/280, 156/305, 210/198.2, 264/262
• US Class Current: 156/278
• CPC Class Codes: F16L 29/00 Joints with fluid cut-off means quick-acting joints with cut-off means F16L37/28
• CPC Class Codes: G01N 2030/8881 Modular construction, specially adapted therefor
• CPC Class Codes: G01N 30/30 of temperature
• CPC Class Codes: G01N 30/6034 joining multiple columns
• CPC Class Codes: G01N 30/6039 in series
• CPC Class Codes: G01N 30/6078 Capillaries
• CPC Class Codes: G01N 30/6091 Cartridges
• CPC Class Codes: G01N 30/88 Integrated analysis systems specially adapted therefor, not covered by a single one of the groups G01N30/04 - G01N30/86

Abstract

A detachable column cartridge for a gas chromatograph is disclosed. The cartridge column contains analytical and reference columns, a heater and a thermocouple, and connects via detachable connectors to a base unit containing an injector, a detector and other components normally found in gas chromatographs. The cartridge arrangement permits a substitute column to be connected to the base unit easily, in the field, when different gases are to be separated and analyzed. Also included are specific connectors for detachably connecting the columns with capillary tubes in the base unit of the gas chromatograph.

Claims

1. A method of fabricating a connector, said method comprising the steps of:

providing a fitting having a bore, said bore including a tapered section which terminates at an aperture formed in a flat exterior surface of said fitting, said bore and said aperture sharing a common central axis and said flat exterior surface being perpendicular to said central axis, said tapered section including a first portion tapered at an angle β and

a second portion tapered at an angle θ

wherein said first portion is between said aperture and said second portion, wherein, in a cross section of said first portion which includes said common central axis, opposing sides of the first portion define said angle β

, wherein, in a cross section of said second portion which includes said common central axis, opposing sides of said second portion define said angle θ and

wherein said angle β

is greater than said angle θ

;

providing a capillary tube having an exterior coating;

inserting said capillary tube into said tapered section of said bore until an end of said capillary tube abuts an interior wall of said tapered section;

heating said fitting and said capillary tube, thereby causing said exterior coating to melt; and

allowing said fitting and capillary tube to cool, thereby causing said exterior coating to solidify and bonding said capillary tube to said fitting.

2. The method of claim 1 wherein the diameter of said aperture is substantially equal to the inside diameter of said capillary tube.

3. The method of claim 1 comprising the additional step of introducing an adhesive into said bore around said capillary tube.

4. The method of claim 1 comprising the additional step of depositing a metal film on said flat exterior surface.

5. The method of claim 4 wherein said metal film comprises a metal selected from the group consisting of gold, aluminum and nickel.