Telescopingly Coupled Syringe And Vial

Abstract

An inverted type syringe in which a double-ended needle is molded into a solid post with a socket at its upper end complementary to a stopper piston closing a cylindrical vial. In use, as the stopper is inserted into the socket it is punctured by the needle so that a continued pressure on the vial causes ejection of the contents. In a preferred form, a cylindrical plastic holder telescopically receives the vial and a hub on the holder is cemented or sealed to the post.

Parent Case Text

This is a continuation-in-part of Application Ser. No. 749,448, filed Aug. 1, 1968, and now abandoned.

Description

This invention is intended to simplify the molding of inverted type syringes so the cost can be made low enough for one-time use.

In the drawing,

FIG. 1 is a sectional view of the syringe with the parts shown slightly separated;

FIG. 2 is a section through the body of the syringe; and

FIG. 3 is a top plan view of a portion of a tree of molded plastic syringe bodies prior to the completion of their manufacture.

The syringe consists generally of a body 1 carrying the needle, a holder 2 enclosing the body, a needle protector 3 and a vial 4 filled to the desired dosage and closed by a stopper or piston 5 slidably received in the bore of the vial. In use, the vial is telescoped into the holder or over the body of the syringe and the stopper serves as a piston to expel the contents through the needle. At the completion of the injection, the parts are thrown away so it is desirable that each of the parts be as inexpensive as possible.

The body of the syringe is molded of plastic and comprises a solid center post or hub 6 with a socket 7 at its upper end of larger outside diameter than the hub. A double-ended needle 8 is molded into the hub and has its pointed upper end 9 near or above the upper end of the socket 7 and has its pointed lower end 10 projecting out the lower end of the hub so as to be accessible for injection. The hub 6 has a length substantially equal to the length of the vial so that at the end of the injection operation the vial can be completely telescoped over the hub.

In order to hold the needle securely in place an intermediate section of the needle is provided with a bend 11 which anchors the needle within the hub. This is conveniently done by the mold of U.S. Pat. No. 3,330,004 which centralizes the upper and lower ends of the needle while bending the intermediate section.

The lower end of the hub or post 6 has a reduced section 12 telescoped within a hub 13 extending through the bottom wall 14 of the holder 2. The holder 2 is a separately molded piece which is cemented or otherwise sealed or bonded to the reduced section 12 of the hub 6. The needle protector 3 is also separately molded and has its upper end 15 in frictional engagement with the projecting lower end 16 of the hub 13. In FIG. 1 the needle protector 3 is shown fully telescoped over the lower end 16 of the hub 13 but the body 1 is shown slightly elevated so that a tapered section 17 on the hub 6 is spaced above a tapered section 18 on the hub 13. When in the fully assembled position, the body 1 will be lowered into the holder 2 and the tapered sections 17 and 18 will be in engagement as shown in FIG. 2.

The socket 7 has internal threads 19 complementary to external threads 20 on a reduced projection 21 of the stopper 5. As the lower or open end of the vial 4 is telescoped into the holder 2, the pointed needle end 9 enters a longitudinal bore 22 in the plug 5 and the threads 20 on the plug make initial engagement with the threads 19 in the socket. Rotation of the vial relative to the holder causes complete engagement of the threads 19 and 20 and forces the pointed end 9 of the needle through a web 23 separating the bore 22 from a bore 24 leading to the upper end of the stopper 5. This establishes communication between the liquid contents of the vial and the needle. As the vial is pressed downward relative to the holder the stopper acts as a piston forcing the liquid contents out through the bores 24, 22, and the needle 8. The stopper has external ribs 25 which maintain a seal between the stopper and the inner side walls of the vial while permitting the necessary sliding movement. The holder 2 has a projecting flange 26 by which the holder may be gripped during injection.

The body 1 of the syringe is molded in a multi-cavity mold in which plastic is injected through a plurality of interconnected runners 27 which feed the plastic into a plurality of locations around the upper edge of each of the sockets 7. At the end of the molding cycle there is ejected from the mold a tree consisting of a plurality of bodies 1 connected to each other through a tree of runners 27. The tree of molded parts can easily be handled as a unit. All of the molded parts will depend from the tree and will be in accurate relation to each other. In order to complete the assembly of syringes, a plurality of needle protectors 3 and holders 2 are assembled into a fixture in which the holders and needle protectors are held on the same spacing as the bodies 1 in the tree 27. The reduced sections 12 at the lower ends of the needle hubs 6 are coated with a suitable adhesive or solvent and the tree is then lowered so that each of the bodies 1 enters its holder. The solvent provides an adhesive coating. As the reduced sections 12 are telescoped within the hubs 13 of the holders, the parts are adhesively joined in assembled relation. At the end of the assembly each body is joined or bonded to its holder and each needle is protected by its needle protector. In lieu of the adhesive or solvent, ultrasonic sealing may be used to bond the parts. In this process, ultrasonic vibrations cause local fusion of the plastic surfaces in contact with each other. After the joint has set up, the tree is broken to separate the individual syringes. After appropriate sterilization, each individual syringe is ready for use in conjunction with an appropriate vial as described above.

The body, holder and needle protector are made in simple molds. The tree 27 holds the molded bodies 1 in positive spacing or alignment so as to permit easy assembly. The plastic to plastic joint between the hubs 12, 13 does not require epoxy cements necessary for bonding metal to plastic. The solvent or cement for the joint is kept away from the needle. Supersonic sealing fuses the contacting surfaces without requiring solvent or adhesive. A major portion of the length of the needle is molded into the plastic providing an extended gripping surface which prevents dislodging of the needle. When the projection 21 is screwed into the socket 7, the plunger may be pulled outward to aspirate blood from a vein into the needle to determine that a vein has been punctured.

Claims

What is claimed as new is:

1. A syringe comprising a cylindrical vial having a closed end and an open end sealed by a resilient stopper in slidable sealing engagement with the bore of the vial, a needle having both ends pointed, a plastic body having a solid needle hub molded around and in gripping contact with a major portion of the length of the needle, said needle hub having an integral socket at its upper end, the open end of the socket facing the open end of the vial, the socket being of larger outside diameter than the hub and of smaller outside diameter than the bore of the vial and the combined length of the needle hub and socket being greater than the length of the vial to permit telescoping of substantially the full length of the vial over the socket and the upper portion of the needle hub, the lower pointed end of the needle projecting from the lower end of said needle hub so as to be accessible to an injection site and the upper pointed end of the needle projecting into said socket so as to be presented to the stopper, a projection on the stopper fitting into the socket, interengaging means on the projection and socket as the projection is inserted into the socket for establishing a push or pull thrust transmitting connection between the stopper and the needle hub and for causing the upper end of the needle to penetrate the stopper and communicate with the interior of the vial as the vial is moved axially relative to the hub so the contents of the vial may be injected by pressure on the closed end of the vial, and holding means connected to the lower end of the needle hub for holding the syringe while exerting pressure on the closed end of the vial.

2. The syringe of claim 1 in which the molding means is a separate cylindrical plastic holder with a bore receiving the vial and comprises a hub in telescoping relation with and being united to the lower end of the needle hub.

3. The syringe of claim 2 in which the bore in the cylindrical holder is closed around its hub.

4. The syringe of claim 2 in which the needle hub has a reduced section at its lower end telescoping into and bonded to the hub of the holder.

5. The syringe of claim 4 in which the plastic body as molded is united with and depends from a tree of runners leading to the socket, said tree serving as a support by which the plastic body may be positioned for movement into telescoping relation with the holder.

6. The syringe of claim 4 having a needle protector telescoped over the needle onto the hub of the holder.