Patent Application
20080143107
The present invention relates generally to fittings for connecting tubing to a secondary structure, and in particular to fittings that releasably retain the tubing to the secondary structure without permanently deforming the tubing.
Fittings for connecting tubing are known. One popular model of a tube fitting is the Ultrapure Flare Style by Flaretek® for use with several plumbing applications where purified water or chemicals are being distributed. This particular tube fitting is used in conjunction with a flaring tool and heat resulting in a semi-permanent to permanent deformation of the tubing through the creation of a sharp edge and flared end on the tubing. Watertight connection seal is made and maintained by creating a pinch point at this sharp edge between the fitting body and a tube nut.
U.S. Pat. No. 6,412,832 describes a self-flaring plastic fitting in which a flare tool and heat are not necessary. However, the particular fitting includes a tapered end and a fitting nut having at least one annular groove engaging portion such that as when the fitting nut is tightened the tube will self-flare. This annular groove engaging portion is commonly known within the art as a ‘barb.’
Accordingly, there is a need to be able to connect tubing to a secondary structure with permanently deforming the tubing thereby allowing the tubing to be connected and disconnected multiple times.
According to one aspect of the present invention, a connector for coupling tubing includes a structure for receiving the tubing and a mechanism for releasably retaining the tubing over the tubing receiving structure. The structure for receiving the tubing includes an exterior surface with portions of the exterior surface of the structure defining a tapered section and at least one ring. Portions of the mechanism for releasably retaining the tubing over the tubing receiving structure define a longitudinal bore through which the tubing can be inserted. The retaining mechanism includes an interior surface with portions of the interior surface defining a tapered section.
When the tubing is positioned over the tapered section and the at least one ring of the tubing receiving structure and the tubing receiving structure is engaged with the retaining mechanism fluids seals are created or present. A first fluid seal is present between the tapered section of the tubing receiving structure, the tubing, and the tapered section of the retaining mechanism. A second fluid seal is present between the tubing and the at least one ring of the tubing receiving structure.
According to another aspect of the present invention, a connector for coupling tubing to another structure includes a structure for receiving the tubing and a mechanism for releasably retaining the tubing over the tubing receiving structure. The structure for receiving the tubing includes an exterior surface with portions of the exterior surface of the structure defining a tapered section, a threaded section, and at least one ring located between the threaded section and the tapered section. Portions of the mechanism for releasably retaining the tubing over the tubing receiving structure define a longitudinal bore through which the tubing can be inserted. The mechanism includes an interior surface with portions of the interior surface defining a tapered section and a threaded section.
When the tubing is positioned over the tapered section and the at least one ring of the tubing receiving structure and the threaded section of the tubing receiving structure is engaged with the threaded section of the retaining mechanism fluid seal are created or present. A first fluid seal is present between the tapered section of the tubing receiving structure, the tubing, and the tapered section of the retaining mechanism. A second fluid seal is present between the tubing and the at least one ring of the tubing receiving structure.
In the detailed description of the preferred embodiments of the invention presented below, reference is made to the accompanying drawings, in which:
The present description will be directed in particular to elements forming part of, or cooperating more directly with, apparatus in accordance with the present invention. It is to be understood that elements not specifically shown or described may take various forms well known to those skilled in the art.
The present invention includes a connector, often referred to as a fitting for coupling or connecting tubing to a secondary structure and releasably retaining the tubing to the secondary structure. The connector includes a structure for receiving the tubing and a mechanism for releasably retaining the tubing over the tubing receiving structure.
The structure for receiving the tubing includes an exterior surface with portions of the exterior surface of the structure defining a tapered section and at least one ring. The mechanism for releasably retaining the tubing over the tubing receiving structure is releasably engagable with the tubing receiving structure. Portions of the mechanism define a longitudinal bore through which the tubing can be inserted. The mechanism includes an interior surface with portions of the interior surface defining a tapered section.
When the tubing is positioned over the tapered section and the at least one ring of the tubing receiving structure and the tubing receiving structure is engaged with the retaining mechanism, at least two fluid seals are created or present. A first fluid seal is present between the tapered section of the tubing receiving structure, the tubing, and the tapered section of the retaining mechanism. A second fluid seal is present between the tubing and the at least one ring of the tubing receiving structure.
The retaining mechanism of the connector includes structure, for example, threads, a clamp, a retaining ring, a pin, etc. so that the retaining mechanism is releasably engagable with the tubing receiving structure. The tubing receiving structure includes the appropriate complementary structure so that the retaining mechanism is releasably engagable with the tubing receiving structure.
Example embodiments of the present invention will now be described with reference to
Referring to
Tubing receiving structure 24 includes an exterior surface 28 with portions of exterior surface 28 defining a tapered section 4, a threaded section 8, and at least one ring 6, 7 located between threaded section 8 and tapered section 4. Tubing receiving structure 24 can include a longitudinal bore 36 through which fluid can pass. Longitudinal bore 36 can include a tapered section 42 (shown in
Portions of retaining mechanism 26 define a longitudinal bore 2 through which tubing can be inserted. Mechanism 26 includes an interior surface 30 with portions of interior surface 30 defining a tapered section 12 and a threaded section 14.
Referring to
Fluid seals 32 and 34 are maintained by the engagement of threaded section 8 of tubing receiving structure 24 with threaded section 14 of retaining mechanism 26. Tubing 16 is also releasably retained by the engagement of threaded section 8 of tubing receiving structure 24 with threaded section 14 of retaining mechanism 26.
Referring to
Referring to
The presence of tapered section 4 helps to eliminate the need for tube flaring devices often used in conjunction with prior art fittings. This is advantageous because flaring devices can permanently deform tubing 16 reducing its useful life. In the present invention, tubing 16 is left virtually unaffected when first fluid seal 32 is created.
The presence of taper section 12 of retaining mechanism 26 helps to gradually urge tubing 16 over tapered section 4 of tubing receiving structure 24 without permanently deforming tubing 16 and helps to increase the area over which first fluid seal 32 is formed. This is advantageous when compared to prior art fittings, especially prior art fittings that use tube flaring devices, because prior art fittings use the tube flaring device to create a pinch point type of fluid seal at the point of tube flare. Instead, first fluid seal 32 of the present invention is distributed substantially along the entire portion of tapered sections 4 and/or tapered section 12
Referring back to
Additional second fluid seals 34 can be provided on connector 22 if desired. In
Connector 22 can be fabricated from various materials depending on the specific application contemplated. For example, tubing receiving structure 24 and/or retaining mechanism 26 can be made from a plastic material or a metal material, for example, a high purity metal such as stainless steel, titanium, etc., using a molding process.
All or portions of connector 22 can be polished. For example, portions of the exterior surface 28 of tubing receiving structure 24 and/or portions of the interior surface 30 of retaining mechanism 26 contactable with tubing 16 can be polished. When tubing receiving structure 24 and/or retaining mechanism 26 is made from a plastic material, vapor polishing of regions contactable with tubing 16 help to remove flash or part line discontinuity from mold halves thereby reducing the likelihood of tearing and/or permanently deforming tubing 16. When tubing receiving structure 24 and/or retaining mechanism 26 is made from a metal material, electropolishing techniques can be used. As such, the present invention provided for a cleaner environment for fluid connection as compared to prior art fittings. By reducing the likelihood of the presence of barbs and/or extreme tube flaring, the likelihood of small pieces of tubing breaking off and contaminating fluid are also reduced.
Tubing 16 can be made from various types of material, for example, PE, PP, PFA, PTFE, FEP, LLDPE, etc. The present inventions is advantaged over prior art fittings in that connector 22 can be used with thin wall tubing, for example, tubing having a wall thickness ranging between 0.010 and 0.050 inches. Thin wall tubing typically could not be used with many prior art fittings because many prior art fittings required the use of a flaring device to create the fluid seal. Tapered section 12 and/or tapered section 4 help in the creation of first fluid seal 32 even when thin wall tubing is used with connector 22.
First fluid seal 32 and second fluid seal 34 of connector 22 as described herein have been demonstrated to satisfactorily perform, with connector 22 being only hand tightened, at room temperature and elevated temperature and at pressures ranging from 100 to 300 PSI. This makes connector 22 suitable for use in typical inkjet environments as well as other applications. When used in an inkjet environment, connector 22 can be used, for example, to connect a fluid storage tank(s) to a printhead(s); a fluid supply and/or return line(s) to fluid storage tanks and/or printheads; etc. Connector 22 also does not require special tools for connection and/or disconnection.
Other ways of releasably engaging tubing receiving structure 24 with retaining mechanism 26 are permitted and can be used with the present invention. Referring to
Referring to
The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the scope of the invention.
