PLUG UNIT AND CONNECTION SYSTEM FOR CONNECTING CAPILLARY TUBES, ESPECIALLY FOR HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

• US 20110298210A1
• Filed: 11/27/2009
• Published: 12/08/2011
• Est. Priority Date: 12/02/2008
• Status: Active Grant

• Current Assignee: Dionex Softron GmbH (Thermo Fisher Scientific Incorporated)
• Original Assignee: Dionex Softron GmbH (Thermo Fisher Scientific Incorporated)
• Inventors: Hochgraeber, Hermann, Satzinger, Adolf
• Granted Patent: US 9,134,283 B2
• Time in Patent Office: Days
• US Class Current: 285/357
• CPC Class Codes: F16L 19/00 Joints in which sealing surfaces are pressed together by means of a member, e.g. a swivel nut, screwed on or into one of the joint parts screw-threaded joints F16L15/00; F16L17/00 takes precedence; if using bolts or equivalent connecting means F16L23/00; electrically insulating F16L25/02; adjustable joints, joints allowing movement F16L27/00; specially adapted for pipes of brittle material F16L49/06
• CPC Class Codes: F16L 19/061 a pressure ring being arranged between the clamping ring and the threaded member or the connecting member
• CPC Class Codes: F16L 21/035 placed around the spigot end before connection F16L21/022, F16L21/025 take precedence
• CPC Class Codes: F16L 21/04 in which sealing rings are compressed by axially-movable members for joints using a threaded member F16L19/07; quick acting couplings F16L37/00; devices for covering leaks from inside a pipe F16L55/162
• CPC Class Codes: G01N 30/6026 Fluid seals
• CPC Class Codes: G01N 30/6039 in series
• CPC Class Codes: G01N 30/6091 Cartridges

Abstract

The invention relates to a plug unit 3 for connecting capillary tubes, especially for high-performance liquid chromatography, with a plug capillary tube 10 that projects through a hole of a plug housing 20, wherein the plug housing 20 is constructed so that it can be connected detachably to a bushing unit 5, wherein the front end of the plug capillary tube 10 projects into a capillary tube receptacle opening 53 of the bushing unit 5 when the plug unit 3 and bushing unit 5 are connected, and with its end face essentially aligned opposite a front end of a bushing capillary tube 57 or a bushing capillary tube opening 55 of the bushing unit 5 and the end face of which is butted against, and wherein the plug housing 20 applies a force, with its end face facing the end of the plug capillary tube 10, directly or indirectly on an annular sealing element 40 surrounding the plug capillary tube 10 in the region of the front end of the plug capillary tube 10 when the plug unit 3 and bushing unit 5 are connected such that the front end of the plug capillary tube 10 is sealed through elastic or elastic and plastic deformation of the sealing element 40 against the capillary tube receptacle opening 53 of the bushing unit 5. According to the invention, the end face of the annular sealing element 40 applies a force on a force-receiving region 11 of the front end of the plug capillary tube 10 projecting in the radial direction past the inner diameter of the annular sealing element 40 during assembly and when the plug unit 3 and bushing unit 5 are in the assembled state, wherein, during the assembly process, the plug capillary tube 10 moves, if necessary, with its end face against the end face of the bushing capillary tube 57 or bushing capillary tube opening 55 and is pressed against it in the assembled state.

Claims

1. Plug unit for connecting capillary tubes, especially for high-performance liquid chromatography,

(a) with a plug capillary tube (10),

(b) which projects through a hole in a plug housing (20),

(c) wherein the plug housing (20) is constructed so that it can be connected detachably to a bushing unit (5), wherein the front end of the plug capillary tube (20) projects into a capillary tube receptacle opening (53) of the bushing unit (5) when the plug unit (3) and bushing unit (5) are connected, and with its end face essentially aligned opposite a front end of a bushing capillary tube or a bushing capillary tube opening (55) of the bushing unit (5) and the end face (51) of which is butted against it, and

(d) wherein the plug housing (20) applies a force, with its end face facing the end of the plug capillary tube (10), directly or indirectly on an annular sealing element (40) surrounding the plug capillary tube (10) in the region of the front end of the plug capillary tube (10) when the plug unit (3) and bushing unit (5) are connected,

(e) the front end of the plug capillary tube (10) is sealed by an elastic and/or plastic deformation of the sealing element (40) against the capillary tube receptacle opening (53) of the bushing unit (5),

characterized in that

(f) the end face of the annular sealing element (40) applies a force on a force-receiving region (11) of the front end of the plug capillary tube (10) projecting in the radial direction beyond the inner diameter of the annular sealing element (40) during assembly and when the plug unit (3) and bushing unit (5) are in the assembly state wherein, during the assembly process, the plug capillary tube (10) moves, if necessary, with its end face against the end face (51) of the bushing capillary tube (57) or bushing capillary tube opening (55), and is pressed against it in the assembled state.

2. Plug unit according to claim 1, characterized in that the force-receiving region (11) of the plug capillary tube (10) is constructed rotationally symmetric to the longitudinal axis and advantageously has an outer diameter increasing continuously or in steps toward the end face of the plug capillary tube (10).

3. Plug unit according to claim 1, characterized in that the force-receiving region of the plug capillary tube (10) comprises arms extending outward in the radial direction.

4. Plug unit according to one of the preceding claims, characterized in that the inner diameter of the sealing element (40) essentially corresponds to the outer diameter of the plug capillary tube (10) when mounted on the plug capillary tube (10).

5. Plug unit according to claim 4, characterized in that the sealing element (40) is constructed elastically so that it surrounds the plug capillary tube with biasing tension when mounted on the front region of the plug capillary tube (10).

6. Plug unit according to claim 4 or 5, characterized in that the sealing element (40) is constructed as a slotted ring element and can be slid onto the plug capillary tube (10) or slipped onto it laterally.

7. Plug unit according to one of the preceding claims, characterized in that the outer diameter of the sealing element (40) is greater than the outer diameter of the force-receiving region (11) of the plug capillary tube (10).

8. Plug unit according to claim 6, characterized in that the sealing element (40) is constructed so that, in the non-pressurized state, it can hold the force-receiving region (11) of the plug capillary tube (10) in a positive-fit manner with its front region.

9. Plug unit according to one of the preceding claims, characterized in that a pressure piece (30) that has an axial hole in which the plug capillary tube (10) is held is provided between the plug housing (20) and the sealing element (40) in the axial direction, wherein the pressure piece (30) transmits the axial force of the plug housing (20) with its front end face to the sealing element (40).

10. Plug unit according to one of the preceding claims, characterized in that the plug housing (20) has an axial threaded region (22) that interacts with a mating thread (52) of the bushing unit (5) for forming a connection.

11. Plug unit according to one of the preceding claims, characterized in that the plug capillary tube (10) has an outer jacket layer (12) and the force-receiving region (11) of the front end of the plug capillary tube (10) is formed from the outer jacket layer (12) that is advantageously formed from a plastically deformable material.

12. Connection system for connecting capillary tubes, especially for high-performance liquid chromatography,

(a) with a bushing unit (5) and a plug unit (3) that can be connected detachably to this bushing unit,

(b) wherein the plug housing (20) is constructed so that when the plug unit (3) and bushing unit (5) are connected, the front end of the plug capillary tube (10) projects into a capillary tube receptacle opening (53) of the bushing unit (5) and with its end face essentially aligned opposite a front end of a bushing capillary tube or a bushing capillary tube opening (55) of the bushing unit (5), and whose end face is loaded bluntly, and

(c) wherein the plug housing (20) applies a force, with its end face facing the end of the plug capillary tube (10), directly or indirectly on an annular sealing element (40) surrounding the plug capillary tube (10) in the region of the front end of the plug capillary tube (10) when the plug unit (3) and bushing unit (5) are connected,

(d) the front end of the plug capillary tube (10) is sealed by an elastic and/or plastic deformation of the sealing element (40) against the capillary tube receptacle opening (53) of the bushing unit (5),

characterized in that

(e) the plug unit (3) is a plug unit according to one of the preceding claims.