A coupler for placing two fluid streams in communication

Abstract: The invention provides a coupler (11d) for placing two fluid streams and in particular two capillary fluid streams in communication as well as a method for making such a coupler. The coupler (11d) comprises two conduits (13a, 13b), a first housing body (21 a) holding one of said conduits (13a, 13b), a second housing body (21b) holding the other one of said conduits (13a, 13b), a clamping assembly (41) and a channel allowing the two fluid streams defined by the two conduits (13a, 13b) to be placed in communication.

Description: The present invention relates to a coupler for placing two fluid streams in communication, and, in particular, capillary scale fluid streams. Embodiments of the present invention provide a coupler for combining or interfacing two or more fluid streams in which one or more fluid streams entering or leaving the coupler has a flow rate of 1 nanoliter per minute to 200 microliters per minute. Analytical instruments often have several fluid streams, which fluid streams carry solutions to or from chromatography columns, pumps, valves, detector assemblies and the like. It is desirable to work with small volumes and to incorporate cleanly flushed geometries. Conventional fittings and coupling devices have large and often poorly swept internal volumes which may alter or compromise the results obtained when these devices are used. A conventional coupling used in chromatography is known from US -A-4 690 437. A coupler for combining and or interfacing two fluid streams, where each stream is defined by a conduit, characterized by small internal volume, is desired. The present invention relates to a coupler for placing two fluid streams in communication, and, in particular, capillary scale fluid streams. Embodiments of the present invention provide a coupler for combining two fluid streams in which one or more fluid streams has a flow rate of 1 nanoliters per minute to 200 microliters per minute, and preferably, 1-200 nanoliter per minute. The present invention is defined by the subject-matter of claim 1, specific embodiments are defined by dependent claims 2 to 7. A further embodiment of the present invention comprises a method for making a coupler for placing two fluid streams in communication according to claim 8. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 depicts a side partially sectional view of a coupler which is not part of the present invention. Figure 2 depicts a slightly elevated, partially sectional view of a housing body embodying features of a coupler which is not part of the present invention. Figure 3 depicts a slightly elevated view of a first housing planar surface embodying features of a coupler which is not part of the present invention. Figure 4 depicts a side, partially sectional view of a further embodiment of a coupler which is not part of the present invention. Figure 5 depicts a side, partially sectional view of a further embodiment of a coupler which is not part of the present invention. Figure 6 depicts a side, exploded view of a further embodiment of a coupler which is not part of the present invention. Figure 7 depicts a side view of Figure 6; and, Figure 8 depicts a side, partially sectional view of the present invention. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to coupler for placing two fluid streams in communication, and, in particular, capillary scale fluid streams. Embodiments of the present invention provide a coupler for combining or interfacing two and, preferably, three or more fluid streams in which one or more fluid streams has a flow rate of 1 to 200 nanoliters per minute and one or more fluid streams has a flow rate of approximately 1 to 200 microliters per minute. Embodiments of the present invention have particular applications in transporting micro-volumes of fluids. These embodiments are particularly useful in coupling disparate analytical apparatus to fluid streams originating with high performance liquid chromatography. For example, the couplers described herein can be used to place mass spectrometry apparatus in fluid communication with chromatography devices. Turning now to Figure 1, a coupler, generally designated by the numeral 11, has three conduits 13a, 13 b, and 13c for transporting fluid. Each of the conduits 13a, 13b, and 13c has at least one end 15a, 15b and 15c, as best seen in Figure 2, defining an opening in the conduit. Each of the conduits 13a, 13b, and 13c has an axis running parallel to the flow of fluid through the conduit. The coupler 11 further comprises a housing body 21 having a first housing planar surface 23. The housing body 21 is frusto-conical in shape tapering at the end opposite the planar surface 23. The housing body holds conduits 13a, 13b, and 13c in alignment wherein the axis of each conduit is substantially parallel to each other, and at least one end of each conduit 15a, 15b, and 15c is aligned about said first housing planar surface 23. Coupler 11 has a cap element 31 having a cap planar surface 33. The cap planar surface 33 is fixed to the first housing planar surface 23 in sealed engagement. At least one of the first housing planar surface 23 and the cap planar surface 33 has a channel 35 in fluid communication with the openings 15a, 15b, and 15c in the conduits 13a, 13b, and 13c, as best seen in Figure 3. Figure 3 depicts such channel 35 in the housing body 21. The channel 35 allows two or more fluid streams, each fluid stream defined by one of said conduits 13a, 13b, and 13c to be placed in communication. Conduits 13a, 13b, and 13c are, preferably, fused silica capillary tubes. Fused silica capillary tubes typically have an outside diameter of 375 microns. Such tubes typically are available with selected internal diameters of 5 to 250 microns. Common tube internal diameters for the present invention comprise internal diameter tubes of approximately 25 microns for 1-200 nanoliters per minute flow rates and approximately 50 microns for 1-200 microliters per minute flow rates. Preferably, the housing body 21 is an over-molded material such as a plastic. Preferred plastic materials are PEEK and/or PPS. The housing body 21, of over molded plastic can accommodate fused silica tubes of different internal diameters to create fluid streams of different flow rates. The cap element 31 may be made of the same material or, where electrical contact is desired with the solutions which comprise the fluid streams, a metal or electrically conductive material. A metal cap element allows the fluid to be grounded or an electrical potential imposed on such fluid. Preferably, the ends 15a, 15b and 15c of each conduit 13a, 13b, and 13c, aligned about said first housing planar surface 23, form a line and the channel 35 is a groove in said first housing planar surface 23. This groove can readily be made by laser etching. In the alternative, a gasket (not shown) is fitted between the first housing planar surface 23 and cap element 31. The gasket has a opening aligned with ends 15a, 15b and 15c of each conduit 13a, 13b and 13c to form a channel. Preferably, the gasket has alignment means such as interfitting cooperating pins and holes or indentations and projections to hold the gasket to the first housing planar surface 23 or cap planar surface 33. As illustrated in Figure 1, the coupler 11 further comprises a clamp assembly 41 holding the first housing planar surface 23 and the cap planar surface 33 in sealed engagement. Clamp assembly 41 has two screws 43 and a tab element 47. Screws 43 have threads 45 engaging at least one of the cap element 31, the housing body 21 or tab element 47. The housing body 21 has a flange 49 for receiving the tab element 47. Each screw extends through an opening (not shown) in the cap element 31 and an opening (not shown) in the tab element 47. Preferably, at least one of the openings of the tab element 47 and the cap element 31 has threads to receive cooperating threads 45 of the screw 43. The tab element 47 is a circular ring or C- shaped ring. Turning now to Figure 4, a further clamp assembly 41a is depicted. Clamp assembly 41a comprises a tab element 47a , and a cap retaining element 51. The housing body 21 has a housing flange 49 for receiving the tab element 47a on an abutment edge 53. Cap element 31 has a cap flange for engaging the cap retaining element 51 or some other engaging surface. As illustrated, cap element 31 has an indentation 57 for receiving a bearing 59. Similarly, cap retaining element 51 has an indentation 61. The bearing 59 allows at least on of the cap element 31 and tab element 47a to rotate with respect to the cap retaining element 51. The cap retaining element 51 has an opening for receiving the cap element 31, housing body 21 and tab element 47a. The cap retaining element 51 and tab element 47a having cooperating thread surfaces. The cap retaining element and tab element 47a are joined with the cooperating threads. Turning now to Figure 5, a further clamp assembly 41b is depicted. Clamp assembly 41b comprises a tab element 47b , and a cap retaining element 51b. The housing body 21 has a housing flange 49 for receiving the tab element 47b on an abutment edge 53b. Cap element 31 has a cap flange for engaging the cap retaining element 51b or some other engaging surface. As illustrated, cap element 31 has an indentation 57 for receiving a bearing 59. Similarly, cap retaining element 51b has an indentation 61. The bearing 59 allows at least one of the cap element 31 and tab element 47b to rotate with respect to the cap retaining element 51b. The tab element 47b has an opening for receiving the cap retaining element 51b, cap element 31, housing body 21. The cap retaining element 51b and tab element 47b having cooperating thread surfaces. The cap retaining element 51b and tab element 47b are joined with the cooperating threads. Turning now to Figure 6 and 7, a further clamp assembly 41c is depicted. Clamp assembly 41c is similar to that described with respect to Figure 5. Clamp assembly 41c comprises a tab element 47c , and a cap retaining element 51c. Tab element 41c is an open cylinder having an inner wall 71 defining an opening 69. Tab element 41c further comprises an abutment C-ring 65 and a retaining clip 67. Abutment ring 65 is received within an opening 69. Retaining clip 67 is flexible and is received in a indentation 70 in the inner wall 71 to allow removal of the retaining clip 67 if necessary. Retaining clip 67 holds abutment C-ring 65 in the tab element 41 c. The housing body 21 has a housing flange 49 for receiving the abutment C-ring 65. Cap element 31c has an engaging surface along the upper edge surface for receiving three ring bearings 75 a, 75 b, and 75c. The ring bearings 75 a, 75 b, and 75c allow at least one of the cap element 31c and tab element 47c to rotate with respect to the cap retaining element 51c. The tab element 47c has an opening 69 for receiving the cap retaining element 51c, cap element 31c, and housing body 21. The cap retaining element 51c and tab element 47c having cooperating thread surfaces (not shown) or some other retaining system: The cap retaining element 51c and tab element 47c are joined with the cooperating threads or such other retaining system. Preferably, the housing body 21 and the cap element 31c have alignment elements illustrated as interfitting pins and holes 81 and 83 as best seen in Figure 6. An embodiment of the present invention comprises a coupler 11d for placing two or more fluid streams in communication, as best seen in Figure 8. Coupler 11d comprises a first housing body 21a and a second housing body 21b. Each housing body 21a and 21b has a conduit 13a and 13b, respectively, for transporting fluid. Each of the two conduits 13a and 13b has at least one end (not shown) defining an opening in the conduit. Each of the conduits 13a and 13b has an axis running parallel to the flow of fluid through the conduit. First housing body 21a having a first housing planar surface 23a. First housing body 21a holds conduit 13a in alignment wherein the axis of the conduit is substantially perpendicular to, and the opening is aligned about the first housing planar surface 23a. Second housing body 21b has a second housing planar surface23b. The second housing body 21b holds conduit 13b in alignment wherein the axis of each conduit is substantially perpendicular to, and the one end of conduit 13b is aligned with the second housing planar surface 23b. The second housing planar surface 23b is fixed to said first housing planar surface 23a in sealed engagement with conduit 13a of the first housing body 21a and conduit 13b of the second housing body in fluid communication. The first and second housing bodies allow two or more fluid streams, each fluid stream defined by one of said conduits, to be placed in communication. Preferably, or in the alternative, each housing body 21a or 21b or one of the housing bodies 21a or 21b, has a gasket (not shown). The gasket has a opening aligned with conduit 13a and 13b to allow the fluid streams to be placed in communication. A clamp assembly 41 d holds first housing body 21 a and second housing body 21b with first housing planar surface 23a and second housing planar surface 23b in sealed engagement. Clamp assembly 41d has a cylindrical clamp housing 91 with an interior wall 93. First housing body 21a and second housing body 21b are held in the clamp housing 91 by tab elements 47d and abutment C- rings 65. Tab elements 47d and clamp housing 91 have cooperating threads which hold tab elements 47d in place. A further embodiment of the present invention comprises a method for making a coupler 11 for placing two or more fluid streams in communication. The method comprises the steps of providing two or more conduits 13a and 13b for transporting fluid. Each of the two or more conduits has at least one end defining opening in the conduits. Each of the conduits has an axis running parallel to the flow of fluid through the conduit. The method further comprises the step of providing a housing body 21 having a first housing planar surface. The first housing body 21 holds at least one conduit 13 in alignment wherein the axis of the conduit is substantially perpendicular to the planar surface 23. And, at least one end of each conduit 13 is aligned about the first housing planar surface 23. The method further comprises providing a cap element 31 having a cap planar surface 33 where the first housing body 21 has two or more conduits. The cap element 31 is fixed to said first housing planar surface 21 in sealed engagement. The method comprises the step of providing a second housing body 21b having a second housing planar surface 23b. The second housing body 23b holds one conduit 13 in alignment wherein the axis of the conduit is substantially perpendicular to the planar surface 23b. And, at least one end of each conduit is aligned about the second housing planar surface 23b. Where one of the first housing body 21a or the second housing body 21b has two or more conduits, at least one of the first housing planar surface, second housing planar surface and said cap planar surface has a channel in fluid communication with the openings in the two or more conduits. The channel allows two or more fluid streams, each fluid stream defined by one of said conduits, to be placed in communication. Preferably, the housing body 21 is comprised of an over-molded material which material is potted about said conduits. A preferred over molded material is plastic. A preferred plastic is PEEK and PPS. The method has particular application where the conduits are fused silica capillary tubes. After the housing body is formed, the excess fused silica capillary tubes are trimmed flat with the planar surfaces. A groove forming a channel may be mechanically carved into the planar surface or laser etched. Thus, the present invention has been described with respect to preferred embodiments with the understanding that the invention is subject to modification and alteration limited only by the following claims.

Claims: A coupler (11d) for placing two fluid streams in communication, comprising: a. two conduits (13a, 13b) for transporting fluid, each of said conduits having at least one end defining an opening in said conduit; b. a first housing body (21a) having a first housing planar surface (23a), said first housing body holding one of said conduits (13a, 13b) substantially perpendicular to said first housing planar surface such that said conduit's end defining said opening is flush with said first housing planar surface; c. a second housing body (21b) having a second housing planar surface (23b), said second housing body holding the other one of said conduits (13a, 13b) substantially perpendicular to said second housing planar surface such that said conduit's end defining said opening is flush with said second housing planar surface; d. a channel provided either in said first housing planar surface (23a) or in said second housing planar surface (23b) with said channel being in fluid communication with said openings in said conduits and allowing two fluid streams, each fluid stream defined by one of said conduits, to be placed in communication; and e. a clamping assembly (41) holding said first housing planar surface (23a) and said second housing planar surface (23b) in sealed engagement. The coupler of claim 1 wherein said conduits (13a, 13b) are fused silica capillary tubes. The coupler of claim 1 wherein at least one of said first housing body (21 a) and said second housing body (21b) is an over-molded material. The coupler of claim 3 wherein said over-molded material is plastic. The coupler of claim 4 wherein said plastic is PEEK or PPS. The coupler of claim 1 wherein said channel is a groove in said first housing planar surface (21a). The coupler of claim 1 wherein at least one of said first housing body (21a) and said second housing body (21b) has a gasket, said gasket having an opening aligned with said conduits. A method for making a coupler (11d) for placing two fluid streams in communication, comprising the following steps: a. providing two conduits (13a, 13b) for transporting fluid, each of said conduits having at least one end defining an opening in said conduits; b. providing a first housing body (21a) having a first housing planar surface (23a), said first housing body holding one of said conduits (13a, 13b) substantially perpendicular to said first housing planar surface such that said conduit's end defining said opening is flush with said first housing planar surface; c. providing a second housing body (21b) having a second housing planar surface (23b), said second housing body holding the other one of said conduits (13a, 13b) substantially perpendicular to said second housing planar surface such that said conduit's end defining said opening is flush with said second housing planar surface; d. providing a channel provided either in said first housing planar surface (23a) or in said second housing planar surface (23b) with said channel being in fluid communication with said openings in said conduits and allowing two fluid streams, each fluid stream defined by one of said conduits, to be placed in communication; and e. providing a clamping assembly (41) holding said first housing planar surface (23a) and said second housing planar surface (23b) in sealed engagement. The method of claim 8 wherein said conduits (13a, 13b) are fused silica capillary tubes. The method of claim 8 wherein at least one of said first housing body (21a) and said second housing body (21b) is an over-molded material which material is potted about said conduits (13a, 13b). The method of claim 10 wherein said over-molded material is plastic. The method of claim 11 wherein said plastic is PEEK and PPS. The method of claim 8 wherein at least one of said first housing body (21a) and said second housing body (21b) has a gasket, said gasket having an opening aligned with said conduits.

Inventors: ANTOCCI JOSEPH D, DELLAROVERE DENNIS, DOURDEVILLE THEODORE A, ANTOCCI, JOSEPH D., DELLAROVERE, DENNIS, DOURDEVILLE, THEODORE A.
Applicants: WATERS INVESTMENTS LTD, WATERS INVESTMENTS LIMITED
Application year: 2000
Main classification: F16L19
IPC codes: G01N30, F16L19, F16L49