Abstract:
A connector and tubing assembly including a multi-lumen molded connector having at least three flexible tubes also molded into the connector. The connector may be “Y” shaped and include three flexible tubes. A process of making the connector and tubing assembly involves forming a first part of the connector with two tubes molded therein and then removing an internal mold member prior to molding the final connector portion and third tube in place.

Description:
This application is a continuation of application Ser. No. 09/951,366 (now abandoned), filed on Sep. 13, 2001 which is a divisional of application Ser. No. 08/909,450 filed Aug. 11, 1997 (now U.S. Pat. No. 6,290,265), the disclosures of which are fully incorporated herein by reference. 

   FIELD OF THE INVENTION 
   The present invention generally relates to tubing and connector assemblies and, specifically, to those assemblies utilizing multi-lumen connectors. 
   BACKGROUND OF THE INVENTION 
   Tubing assemblies including flexible tubing and multi-lumen connectors have been used in many applications, including those that require a high degree of assurance that contamination will not enter the system by way of the connector. Applications of such systems include closed systems in the medical field in which the flexible tubing may be clipped into a peristaltic pump used for medical purposes. Past tubing and connector assemblies have required various means for securing the connectors to the flexible tubing, including mechanical connectors or adhesive. These systems are therefore susceptible to contaminants entering the system at the point of connection. 
   Connectors have been molded directly to two tubes, however, to Applicant&#39;s knowledge, there has never been an acceptable method of directly molding a multi-lumen connector to three or more flexible tubes. In general, this is due to the problems associated with maintaining fluid passages within the connector and between the multiple tubes during and after the molding process. 
   Therefore, it would be desirable to provide a tubing and connector assembly as well as a method of molding such an assembly in a cost-efficient manner to produce an integral tubing and connector assembly that maintains a high degree of system integrity. 
   SUMMARY OF THE INVENTION 
   The present invention therefore generally provides an integral connector and tubing assembly including a one-piece, multi-lumen connector having at least three connector portions and at least three tubes. Each of the tubes is molded into one connector portion, and a fluid path extends within each connector portion and communicates between each of the three tubes. The connector may be “Y” shaped with three connector portions respectively receiving three flexible tubes. The connector assembly may also have additional connector portions and a like number of additional flexible tubes. The connector is preferably molded from liquid silicone while the tubes are preferably flexible and formed from a thermoset silicone. 
   A method of molding a connector and tubing assembly of the present invention generally includes molding first and second portions of a connector around respective ends of first and second tubes while maintaining fluid passages through the first and second portions and in communication with internal fluid bores of the first and second tubes and then molding a third portion of the connector around an end of a third tube and connected with the first and second portions while maintaining a fluid passage between the end of the third tube and the fluid passages in the first and second portions. Preferably, first and second rod members are placed in the respective ends of the first and second tubes prior to molding the first and second portions and a third rod member is placed in the end of the third tube prior to molding the third portion. Prior to molding the third portion, the first and second rod members are removed from the first and second portions of the connector. The first and second rod members may be part of a “Y” shaped member and each molding step may be performed in a single mold. 
   A more specific and preferred method of making the connector and tubing assembly according to this invention includes the steps of: connecting the internal fluid bores of respective ends of first and second tubes to first and second rod members; placing the rod members and the ends of the first and second tubes into a first mold cavity; filling the first mold cavity with curable material to form first and second connector portions around the ends of the first and second tubes and the first and second rod members such that the first and second rod members form fluid passages through the connector; withdrawing the first and second rod members; inserting a third rod member into the internal fluid bore in an end of a third tube; placing the end of the third tube into a second mold cavity and in engagement with at least one of the fluid passages; filling the second mold cavity with additional curable material to form a third connector portion; and removing the third rod member. 
   Preferably, the first and second mold cavities communicate with one another in the same mold. The mold may be an injection mold. For allowing the use of a single mold, a mold insert may be placed within the second mold cavity prior to filling the first mold cavity with the curable material. This prevents the curable material from filling the second mold cavity during this initial molding step. The mold insert is generally solid but preferably includes a central hole. The first and second rod members may be part of a “Y” shaped member. In this case, the second step further includes placing a third leg of the “Y” shaped member within the central hole of the insert and placing the insert within the second mold cavity. The mold insert may have a protrusion surrounding the hole and this protrusion may then form a recess in communication with the passages in the initially formed connector portions. This recess can be used to locate or receive the third tube prior to the second molding step, i.e., prior to filling the second mold cavity with additional curable material. 
   Various objects and advantages of the invention will become more readily apparent to those of ordinary skill upon review of the following detailed description of one preferred embodiment taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a connector and tubing assembly constructed in accordance with the preferred embodiment of this invention; 
       FIG. 2  is a perspective view, partially exploded, of the initial steps of a molding process used to form the product of  FIG. 1 ; 
       FIG. 3  is a perspective view of the molding process at a later stage; 
       FIG. 4  is a perspective view of an intermediate product formed by the molding process; 
       FIG. 5  is a sectional view taken generally along line  5 — 5  of  FIG. 4  and also showing the removal of an internal “Y” shaped mold member as well as an additional tube containing a rod used later in the molding process; and, 
       FIG. 6  is the intermediate product shown in perspective within the mold cavity with the third tube in place just prior to the final molding step. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1  illustrates a connector and tubing assembly  10  after a connector  11  has been molded with portions  12 ,  14 ,  16  holding flexible tubes  18 ,  20 ,  22  together for fluid communication therebetween. This structure therefore forms an integral fluid conveyance system which is not easily compromised at the junctions between connector  11  and tubes  18 ,  20 ,  22 . 
     FIGS. 2–6  illustrate the preferred manner of making the connector and tubing assembly  10 . First, a mold half  30  is provided having an internal mold cavity  31  in the shape of the desired connector  11 . Cavity  31  is preferably formed by three smaller cavities  32 ,  34 ,  36  each having respective ports  38 ,  40 ,  42 . Curable mold material, such as conventional liquid silicone, may be injected through ports  38 ,  40 ,  42  into cavity  31  after a second mold half is brought into facing engagement, as will be described below. Recesses  44 ,  46 ,  48  are respectively provided for holding tubes  18 ,  20 ,  22  such that respective connecting ends  18   a ,  20   a ,  22   a  extend within cavity portions  32 ,  34 ,  36 . An inner mold member  50  is provided and may be formed from low density polyethylene (LDPE). Mold member  50  may be generally “Y” shaped and serves to help form a fluid passageway between the internal fluid bores  18   b ,  20   b ,  22   b  of tubes  18 ,  20 ,  22  after molding is complete. 
   Referring to  FIG. 2 , first and second tubes  18 ,  20  are inserted onto respective first and second rod members  52 ,  54  of mold member  50  and a third rod member or leg  56  receives a mold insert  58  which may be formed of metal, such as stainless steel, and generally takes the shape of cavity portion  36 . Mold insert  58  includes a central protrusion on an end facing cavity portions  32 ,  34  and includes a central hole  62  for receiving rod member  56  of inner mold member  50 . 
   The items described with respect to  FIG. 2  are attached together and placed within mold half  30  as shown in  FIG. 3  and a second mold half  64  is brought into facing engagement with mold half  30 . It will be understood that mold half  64  has cavities and recesses (not shown) which are the mirror image of cavity portions  32 ,  34 ,  36  and recesses  44 ,  46 ,  48  of mold half  30 . The mold is then shot, i.e., curable mold material is injected into cavities  32 ,  34  of mold  30  through ports  38 ,  40 , and after curing thereof, an intermediate product as shown in  FIG. 4  will result. In this step, cavities  32 ,  34  act as one cavity for producing connector portions  12 ,  14  which, in turn, form a single integral connector portion. Metal mold insert  58  is removed from rod member  56  and then the “Y” shaped inner mold member  50  is withdrawn from connector portions  12 ,  14  and tubes  18 ,  20  by pulling on rod member  56 . Mold member  50  is flexible and may be withdrawn with reasonable manual force being applied by a pair of pliers. 
   After mold member  50  is withdrawn, as shown in  FIG. 5 , the third tube  22  is prepared for the final molding step. That is, a straight plastic rod  66 , also preferably formed of LDPE, is inserted into tube end  22   a  with a small portion  66   a  extending outwardly from end  22   a . This assembly is placed into mold half  30  as shown in  FIG. 6  with rod end  66   a  extending into a passage  67  formed within connector portions  12 ,  14  by rod member  56  and with tube end  22   a  held within a recess  68  formed by protrusion  60  ( FIG. 2 ) on mold insert  58 . It will therefore be appreciated that rod end  66   a  will maintain fluid passage  67  open during the second molding step. Mold half  64  is again brought into facing engagement with mold half  30  and the final cavity  36  is injected with curable mold material, again taking the form of conventional liquid silicone. After this portion of connector  11  has cured, rod  66  may be blown out of tube  22  by injecting pressurized air into tube  18  after tube  20  has been plugged, or into tube  20  after tube  18  has been plugged. 
   Although a preferred embodiment of the present invention has been shown and described, along with a preferred method of making the product of this invention, the details provided herein are not intended to limit the scope of protection. For example, certain modifications such as the incorporation of additional connector portions and tubes are possible as well as the use of any number of shapes for the connector. The connector portions do not have to have readily distinguishable shapes as specifically preferred herein, but may be formed as part of one shape. It will also be appreciated that multiple connectors of this invention may be used in a single system. Those of ordinary skill will readily recognize many further modifications within the spirit and scope of the inventive concepts. Therefore, Applicants intend to be bound only by the legal scope of the appended claims.