Single-piece ferrule with undercut tapering part

Patent metadata

Field	Value
Publication number	US-9751085-B2
Application number	US-201214412654-A
Country	US
Kind code	B2
Filing date	Jul 5, 2012
Priority date	Jul 5, 2012
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

A single-piece ferrule for a fitting for coupling a capillary to another component of a fluidic device, wherein the ferrule comprises a ferrule body, wherein the ferrule body has a lumen configured for receiving at least a part of the capillary, wherein the ferrule body has a tapering front part configured for forming a sealed connection with a housing of the fitting, wherein a back side of the tapering front part has an annular undercut.

First claim

The invention claimed is:

1. A single-piece ferrule for a fitting for coupling a capillary to another component of a fluidic device, the ferrule comprising:
a single-piece ferrule body of unitary construction;
wherein the ferrule body comprises a cone end, a compression end, and a lumen extending from the cone end to the compression end and configured for receiving at least a part of the capillary;
wherein the ferrule body comprises a tapering front part at the cone end configured for forming a sealed connection with a housing of the fitting, the tapering front part comprising a front face, a back face, and a lateral surface tapering from the back face toward the front face;
wherein a back side of the tapering front part has an annular undercut formed as a circumferential recess extending into the back face along an extension direction of the lumen and tapering inwardly in a direction extending from the compression end to the cone end; and
wherein the ferrule body has a tapering middle part adjacent to the annular undercut of the tapering front part.

2. The ferrule according to claim 1 , wherein the annular undercut has a triangular shape in a cross-section along a plane containing the extension direction of the lumen.

3. The ferrule according to claim 1 , wherein the annular undercut is configured to be radially reduced in volume upon compressing the ferrule for forming the sealed connection with the housing.

4. The ferrule according to claim 1 , wherein the tapering front part tapers steeper than the tapering middle part.

5. The ferrule according to claim 1 , wherein the tapering front part comprises:
a conical section located between a rounded tip and a beaked section, the beaked section passing into the annular undercut.

6. The ferrule according to claim 5 , wherein a neck angle (a) is formed as an intersection angle between a surface of the tapering middle part and a surface of a tapering portion within the annular undercut adjacent to the beaked section, and the neck angle (α) is selected from the group consisting of: an acute angle; an angle in a range between 5° and 45°; an angle in a range between 15° and 35°; and an angle in a range between 20° and 30°.

7. The ferrule according to claim 1 , wherein the ferrule body has a back part with a rear surface configured for being compressed by a housing of the fitting to thereby transmit a forward force to the tapering front part for sealing the tapering front part to the housing and to the capillary.

8. The ferrule according to claim 7 , wherein the back part has a configuration selected from the group consisting of:
the back part has a larger radial extension than the tapering front part;
the back part is cylindrical;
the back part has at least one annular groove extending from an outer circumferential surface of the back part towards the and spaced with regard to the lumen of the ferrule body;
the back part has plurality of annular grooves;
the back part has at least one V-shaped or U-shaped annular groove;
the back part has at least one annular groove configured to be axially reduced in volume upon compressing the ferrule; and
a combination of two or more of the foregoing.

9. The ferrule according to claim 1 , wherein the ferrule body comprises a back part, and further comprising a tapering transition portion connecting the tapering middle part to the back part.

10. The ferrule according claim 9 , wherein the tapering transition portion tapers steeper than the tapering middle part.

11. The ferrule according to claim 1 , wherein the lumen has a first cylindrical lumen section having a first diameter (D), a second cylindrical lumen section having a second diameter (d) differing from the first diameter (D), and a tapering lumen section connecting the first cylindrical lumen section to the second cylindrical lumen section.

12. The ferrule according to claim 11 , wherein the first cylindrical lumen section has a configuration selected from the group consisting of:
the first cylindrical lumen section is configured for receiving part of the capillary and the second cylindrical lumen section is configured for sealingly receiving another part of the capillary;
the first diameter (D) is larger than the second diameter (d); and
both of the foregoing.

13. A fitting for coupling a capillary to another component of a fluidic device, the fitting comprising:
a housing; and
the ferrule according to claim 1 ;
wherein the tapering front part of the ferrule is configured for forming the sealed connection with the housing.

14. The fitting according to claim 13 , comprising the capillary, wherein the capillary has a configuration selected from the group consisting of:
the capillary comprises glass or fused silica;
the capillary comprises a lumen having a diameter (L) of one of (a) less than 1.0 mm (0.039 inch) and (b) less than 0.2 mm (0.008 inch);
both of the foregoing.

15. The fitting according to claim 13 , wherein the housing comprises a male piece and a female piece, wherein the ferrule is to be compressed between the male piece and the female piece when being assembled.

16. The fitting according to claim 15 , wherein the male piece and the female piece have cooperating threads to be connected to one another by screwing upon assembling the male piece and the female piece.

17. A fluidic device for processing a fluidic sample, the fluidic device comprising:
a capillary for conducting the fluidic sample;
another component to be coupled to a first end of the capillary;
a processing element coupled to a second end of the capillary and being configured for interacting with the fluidic sample for processing the fluidic sample; and
the fitting according to claim 13 for coupling the capillary to the other component.

18. A method of designing the single-piece ferrule according to claim 1 , the method comprising:
configuring the lumen of the ferrule body for receiving said at least the part of the capillary;
configuring the tapering front part of the ferrule body for forming the sealed connection with the housing of the fitting; and
configuring the annular undercut of the back side of the tapering front part to thereby adjust frictional contact characteristics between the ferrule and the housing.

19. A method of coupling a capillary to another component of a fluidic device utilizing the fitting according to claim 13 , the method comprising:
receiving said at least the part of the capillary in the lumen of the ferrule body of the single-piece ferrule of the fitting; and
forming the sealed connection between the tapering front part of the single-piece ferrule and the housing of the fitting, wherein the back side of the tapering front part has the annular undercut.

Assignees

• Pa Ponna Peter
• Agilent Technologies Inc

Inventors

• Pa Ponna Peter

Classifications

• Y10T29/49

  Method of mechanical manufacture · CPC title

• B01L3/5635 Primary

  connecting two containers face to face, e.g. comprising a filter · CPC title

• G01N30/6026

  Fluid seals · CPC title

• G01N30/6039

  in series · CPC title

• B01L2300/0838

  Capillaries · CPC title