Patent Application
20120223517
Traditional plastic connectors for three or more pieces of tubing has been to mold a separate plastic or metal fitting having three or more barbed extensions, each extension having a hollow bore therethrough and connecting to the bores of each of the other extensions, a plurality of tubing, each tubing having a hollow bore and each tubing mounted over the barb of each barbed extension and a device to mechanically hold the tubing to each extension such as a cable tie or a tubing locking device such as a Barblock®device. These devices have several issues. The security of the tubing connection to the barbed fitting is not always sufficient and the tubing can be dislodged during installation or use. Additionally, the seal by the mechanical device may not enclose the entire circumference which can lead to leakage.
Alternatively, one has used adhesives to bond the inner surface of the tubing to the extension and to keep the tubing over the barb. However adhesives are not generally acceptable as they can spread and either block off the tubing or provide extractable materials to the fluid that passes through the tubing.
More recently a new design and method has been used to make such a device by first molding the first and second extensions with their associated tubing by using a Y shaped removable core pin placed within the bore of the first and second tubings. The third portion of the Y shaped core pin has a removable mold insert over it. The assembly is placed in a specially designed mold to mold the first two extensions. The mold insert and the Y shaped core pin are removed with a pair of pliers. A third piece of tubing has a straight third portion core pin inserted into the bore such that a portion of the pin extends from each end of the third tubing piece. The semi finished connector with the third core pin is placed back into the mold and the third extension is molded over the third tubing and to the first and second extension. The connector is then removed from the specially designed mold and the core pin is removed to provide an integral connector having the bores of all three tubings in fluid communication with each other. See U.S. Pat. No. 6,290,265.
One limitation of this method is that at least the third tubing must be relatively short (i.e. if the tubing segments are extremely long, one can't easily put a core pin into the tubing bore nor remove it after molding). Another is that it requires the use of like materials so that they bond to each other during the molding. Moreover, the process is slow as it requires two steps to mold the device and the use of special molds and mold inserts.
The present invention provides a device and process for making it that overcomes the limitations of the prior art devices and methods.
The present invention is a device for fluid movement and method of making the same. The device has a core element comprised of a preformed barbed fitting having two or more barbed extensions, preferably three or more extensions. Each extension has a central bore connected to the central bores of the other extensions so as to provide fluid communications between them. A tube having a central bore is fitted over the barb of each extension. A molded housing is formed over the fitting and tubes to form the device.
It is an object of the present invention to provide a tubular fitting for fluid comprising a barbed fitting having two or more barbed extensions, each extension having a hollow bore therethrough and connecting to the bores of each of the other extensions, a plurality of tubing, each tubing having a hollow bore and each tubing mounted over the barb of each barbed extension and an overmolded housing entrapping the barbed fitting and a portion of each tubing at least beyond the end of the barbed extensions.
It is another object of the present invention to provide a barbed fitting made of a plastic, such as thermoplastic or thermoset, or a metal.
It is a further object of the present invention to provide an overmolding formed of a plastic, such as a thermoplastic or a thermoset.
It is another object of the present invention to provide a method of making an integrated connector with two or more tubings extending from the connector comprising the steps of forming a barbed fitting having two or more barbed extensions, each extension having a hollow bore therethrough and connecting to the bores of each of the other extensions, sliding a tubing having a hollow bore over each barbed extension and overmolding a housing entrapping the barbed fitting and a portion of each tubing at least beyond the end of the barbed extensions.
If desired, one can use an adhesive or heat bond (not shown) to further secure the tube over an extension. Alternatively, one can use a tie wrap or a locking mechanism such as a Barblock® device available from Saint Gobain to further secure the tube(s) 6 to the extension 4 barb(s) (not shown). In most cases however, these features are unnecessary as the overmolded cover 8 as explained in relation to
A method of making the present invention is to first make a barbed fitting with the desired number of extensions arranged in the desired manner. The extensions may be of the same size (length and diameter) or different size if desired. Likewise they may be equally spaced apart from each other or spaced at different angles as the need or desire requires. For example, it is one preferred embodiment that the extensions be equally spaced apart, with an equal angle between and that they all be of the same length and diameter. Alternatively, one or more extensions can be a length different from the rest or the extensions are not equally spaced apart (for example in a manifold design one could have one extension on one side and two or more on the opposite side) or at least one has a different angle between it and at least one of its neighboring extensions as the other extensions.
The barbed fitting may be made of metal such as stainless steel or aluminum, a thermoplastic or a thermoset plastic such as epoxy. Preferably it is formed of metal or thermoplastic. More preferably it's formed of a thermoplastic such as polyethylene, polypropylene, polysulfone, polyethersulfone, polyarylsulfone, polyvinylidene fluoride, PTFE, polyether ether ketone and the like. Thermosets can be epoxy, silicone and ethylene-propylene diene monomers.
The tubes can be any generally used in the pharmaceutical or medical industry and include but are not limited to thermoplastic tubes such as those made of polyethylene or polypropylene; thermoset tubes such as silicone tubes or other specialty materials such as C-Flex® tubes and the like.
The cover material/overmolding/overmolded housing can be formed of a thermoplastic such as polyethylene, polypropylene, polysulfone, polyethersulfone, polyarylsulfone, polyvinylidene fluoride, PTFE, polyether ether ketone and the like or a thermoset plastic such as silicone, epoxy, polyurethane and ethylene-propylene diene monomers.
The silicone for the fitting and/or cover or overmolded housing may be room temperature, or moist curable or platinum or other metal based catalyst curable as is well known in the art.
It is preferred that the materials of the tubing and cover be compatible to form the most appropriate connection possible between each of the elements. All three elements including the fitting may be compatible with each other. In a further embodiment, all the components (fitting, tubing and cover) are formed of the same material and more preferably all are formed from a thermoplastic such as polyethylene or polypropylene or thermoset such as a silicone or polyurethane or epoxy.
Tubes are fit over each of the extensions such that the barb on each extension secures the tube in place. As mentioned above, one can add additional retention features such as welds, adhesives or mechanical devices to further secure the tubes in place. Optionally, one can use a tube stop 3 in lieu of or additionally to the optional retention features if desired. The bore of the fitting and each extension thereof is alignment with and fluid communication with the bore or lumen of each tube.
The tube/fitting subassembly is then molded with a cover 8. This can be accomplished in a mold if desired as explained in relation to
In one preferred embodiment, the device is all formed of thermoplastic with a thermoplastic fitting 2, tubes 6 and cover 8. In this embodiment, the thermoplastic of each component may be the same or it may differ so long as they are compatible with each other. For example, one may use a thermoplastic with a higher melting point for at least the fitting 2 than the other components so that the fitting 2 doesn't collapse or distort when exposed to the molten thermoplastic of the cover during formation. Likewise one may select both the fitting and tubes be made of a thermoplastic with a higher melting point than that of the cover material to prevent collapse and/distortion.
In another embodiment, one can select a material for the tubing that at least softens when in the presence of the molten cover material so that one obtains a heat bond as well as a mechanical bond between at least the tube and the cover and preferably between the fitting, tube and cover.
In another preferred embodiment one can use a metal fitting with thermoplastic tubes and cover material.
In an additional preferred embodiment, one can use a metal, thermoset or plastic fitting with silicone tubes and cover material.
In a further embodiment, one can use a thermoset fitting such as an epoxy or urethane fitting with a thermoplastic or silicone tubes and a thermoset cover material.
As one can appreciate the combinations are extensive allowing one to select the best components for the desired application.
This application claims the benefit of U.S. Provisional Patent Application No.: 61/448,933, filed on Mar. 3, 2011, the entire contents of which are incorporated by reference therein. The present invention relates an integral connector and tube fitting. More particularly it relates to a disposable, integral connector and tube fitting for two or more tubings.
| Number | Date | Country | |
|---|---|---|---|
| 61448933 | Mar 2011 | US |
