KR920008895Y1 - Syringe assembly - Google Patents

Abstract

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Description

Syringe assembly

1 is a perspective view of a syringe assembly of the present invention.

2 is a side view of the syringe assembly of FIG.

3 is a side view of the syringe barrel of FIG. 1 as seen from the distal end of the syringe barrel.

4 is a cross-sectional view of the syringe assembly taken along line 4-4 of FIG.

5 is a partially enlarged view taken from the piston region of the syringe assembly of FIG.

6 is a partially enlarged view taken from the piston region of the syringe assembly of FIG.

7 is a side view of a syringe of the present invention comprising a distal flange portion, a needle shield and a plunger shield on the barrel.

8 is a side view of the syringe assembly of FIG. 7 as viewed from the distal end.

9 is a cross-sectional view of the assembly taken along line 8-9 of the eighth.

* Explanation of symbols for main parts of the drawings

20: syringe assembly 21: barrel

22: co-extrusion body portion 27: chamber

31: (plastic material) inner part 32: solid plastic material

33 hub portion 34 cannula

40: plunger 45: piston

47: flange

The present invention relates to a syringe assembly, in particular a syringe assembly having a barrel having a portion made of co-extruded plastic material.

Generally, hypodermic syringes are made of thermoplastic material or glass and have a tip that is adapted to engage a sharp needle cannula or to engage a hypodermic needle assembly and an open end adapted to receive an elastic stopper and a plunger rod assembly. It consists of a cylindrical barrel. One of the purposes of the closure is to provide a relatively airtight seal between the closure itself and the syringe barrel, so that the up and down movement of the closure causes the liquid drug, blood or other fluids to be drawn into or ejected from the syringe through the tip. The stopper is moved along the syringe barrel by applying an axial force to a rigid plunger rod that is coupled to the stopper and long enough to reach out of the barrel. The stopper should have sufficient flexibility to seal the inner diameter of the barrel while moving it up and down the barrel without requiring excessive force.

Known prior art closures are manufactured to have an outer diameter larger than the inserted syringe inner diameter to ensure a tight seal between the rigid syringe barrel and the elastic stopper. The syringe-stopper assembly is designed to be pressurized enough to provide a suitable pressure to seal the surface between the syringe barrel and the stopper when the stopper is inserted into the syringe barrel.

In prior art devices, the elastic stopper must be chemically stable such that an undesirable amount of various chemical components of the stopper are not introduced into the liquid contained in the syringe. Because subcutaneous syringes are often used to inject drugs into the human body or to extract blood for later analysis, it is not desirable to introduce foreign substances in which the stopper may affect pharmaceutical or blood analysis. Hypodermic syringe caps are usually made of materials such as natural rubber or butyl rubber. Although rubber stoppers have desirable physical properties, they have a number of disadvantages. For example, rubber stoppers contain ancillary chemical components such as fillers and cure accelerators that can seep into the surface and come into contact with the liquid in the syringe to affect blood test results or drug efficacy. In addition, rubber stoppers are expensive to manufacture because of the long molding process time required for the curing step performed while in the mold.

In view of the above deficiencies in rubber stoppers, it is desirable to provide a syringe assembly having a stopper or piston made of plastic material. Usually, thermoplastic materials are less expensive to manufacture because of the short molding process time which improves the productivity of the molding machine. The impact of fillers and hardeners on the liquid contents of the syringe can be ruled out because these additives are not essential for the manufacture of plastic stoppers or pistons. In addition, when the thermoplastic syringe cap is used with a plastic barrel, the complexity of the pharmaceutical compatibility test can be reduced, thereby forming a material stopper having chemical properties similar to that of the barrel.

US Pat. No. 4,500,310 to Christine discloses an improved plunger rod design that allows the use of an elastic thermoplastic stopper. Christine overcomes many of the cost and possible functional problems associated with rubber stoppers but requires additional elastomeric stoppers coupled to the plunger rod as in prior art syringes.

Because of the stress created by the tight fit that is substantially sufficient to seal tightly between the stopper and the barrel, the piston of the syringe moves along the barrel and requires an excessive amount of force to inject the drug. It is believed that the manufacture of syringes is not desired. In addition, a close fit between the barrel and the stopper over a period of time using a thermoplastic material can result in pressure hardening on the piston and / or barrel. In other words. The stress at the interference fit between the stopper and the syringe can cause cold flow to the thermoplastic piston and / or barrel, which can reduce the diameter of the stopper or enlarge the diameter of the barrel so that the stopper can no longer effectively seal the contents of the syringe. Can't. Costly control of dimensional errors of lubricants and elements can reduce these problems.

Although prior art syringes using rubber stoppers have performed excellent functions in the medical field over the years, there are issues of component price and suitability associated with the stoppers. Although Christine offered a significant improvement by allowing the use of thermoplastic elastomeric stoppers, it is still possible to manufacture simple, simple, reliable and easily manufactured syringes with plungers and pistons made of low cost rigid materials such as thermoplastics. The need still exists.

A viable syringe assembly of the present invention includes a barrel having a cylindrical co-extruded body portion having a longitudinal axis, the body portion defining a sidewall defining a chamber containing fluid spaced apart from the axis. The body portion includes a tip having an open distal end and a fluid communication path with the chamber. The body portion includes a plastic inner portion and a rigid plastic portion surrounding the inner portion. The rigid portion is harder than the inner portion. A plunger is provided comprising an elongated shaft portion having a rigid piston portion at the distal end, the distal end and the distal end. The piston portion has an outer diameter larger than the inner diameter of the inner portion and a hardness greater than the inner portion. The piston part is liquid-tight engaged and slidably mounted inside the barrel, where the liquid-tight engagement is caused by the piston pressing the inner part. The piston can move fluid from the chamber through the passageway upon movement toward the tip of the barrel and can easily suck fluid into the chamber through the passageway when moving from the tip of the barrel. The distal end of the plunger projects out of the distal end of the barrel so that the piston can be easily moved relative to the barrel.

In another embodiment of the present invention, the syringe assembly has a coextruded body portion with a longitudinal axis. The body portion moves away from the axis to form a side wall that defines the chamber containing the fluid. The body portion includes an open end portion, a tip portion, a plastic inner portion and a rigid material portion surrounding the inner portion. The rigid part is harder than the inner part. The hub attached to the tip includes a passage in fluid communication with the chamber. An elongated cannula having a distal end, a tip, and a lumen through them is attached to the hub so that the lumen is in communication with the passageway. The side wall is provided with a volumetric indication. A plunger is provided comprising an elongated shaft portion having a distal end, a tip and a rigid piston portion at the distal end. The piston portion has an outer diameter larger than the inner diameter of the inner portion and the hardness is greater than the inner portion. The piston part is slidably mounted in the barrel by liquid tight engagement. The liquid tight engagement is caused by pressurizing the inner portion, whereby the piston can move fluid from the chamber through the passageway when moving the rapeseed from the chamber toward the passageway as it moves toward the tip. The piston can easily suck fluid into the chamber through the passage as it moves from the tip. The distal end of the plunger projects out of the distal end of the barrel so that the piston portion can be easily moved relative to the barrel.

According to another aspect of the present invention, the syringe barrel comprises a cylindrical co-extruded main body having a long axis, wherein the body portion defines a side wall defining a chamber containing fluid spaced apart from the shaft, the body portion having an open end portion. And an open tip, a plastic inner portion and a rigid plastic portion surrounding the inner portion. The rigid part is harder than the inner part. The hub member is attached to the tip of the body portion. The hub member includes a passage in fluid communication with the chamber.

While the subject innovation is satisfied with various other forms of embodiments, it is to be understood that the present description is contemplated as illustrating the principles of the subject innovation and that the subject innovation is not intended to be limited to the illustrated embodiments. Is shown in the drawings and described in detail.

The scope of the present invention is measured by the appended claims of utility model registration and equivalents thereof.

1-6, a viable syringe assembly 20 of the present invention has a coaxial extruded body portion 22 having a major axis 23 and preferably transparent and having a coextruded body portion 22 preferably transparent. One barrel 21 is included. The body portion defines a side wall 25 that is spaced apart from the shaft 23 and defines the chamber 27 containing the liquid. The coextruded body portion 22 includes an open distal end 28 and a tip 29. The body portion includes a plastic inner portion 31 and a rigid plastic portion 32 surrounding the inner portion 31. The rigid portion 32 is harder and less elastic than the inner portion 31.

For the purposes of the description of the present invention, the term "tip" refers to the end of the syringe assembly closest to the needle cannula or the portion of the syringe assembly to which the needle cannula can be attached, whereas the term "end" By end of the syringe assembly is the furthest from the portion of the syringe assembly having the needle cannula.

The hub portion 33 is attached to the tip portion 29 of the body portion. The hub includes a passage (not shown) in fluid communication with the chamber 27. An elongated cannula 38 having a distal end 35, a tip 37, and a lumen (not shown) through them is attached to the hub 33 so that the lumen is in fluid communication with the passageway.

The plunger 40 includes a long shaft portion 41, a distal end 43, a tip 44 and a rigid piston portion 45 at the tip 44. The piston portion 45 has an outer diameter larger than the inner diameter of the inner portion of the co-extruded body portion. The piston portion is also larger and less elastic than the inner portion. The piston portion is slidably mounted and slideable inside the coextruded body portion of the barrel. Liquid tight engagement is caused by the piston 45 pressing the inner portion 31 of the co-extrusion body. This deflection is shown in FIGS. 4 and 5. The structure of the present invention, in which the piston is harder and less elastic than the inner part of the barrel, is the main difference between the present invention and the prior art. Conventional disposable syringes have relied on rubber or thermoplastic elastomer stoppers that are less rigid and elastic than the barrels around to achieve a liquid tight seal between the stopper and the barrel. In the present invention this relationship is reversed so that a harder and more resilient member is the piston part and most deformation occurs in the barrel rather than the piston.

The rigid piston portion 45 can move fluid through the passage from the chamber 27 as it moves toward the tip 29 of the body portion. The rigid piston portion 45 can also easily hop fluid into the chamber through the passageway as it moves from the tip 29 of the body portion. The distal end 43 of the plunger 40 protrudes out of the open distal end 28 of the main body, so that the piston can be easily moved with respect to the co-extruded main body of the barrel. The distal end 43 of the plunger is provided with a disc flange 47. The disc flange 47 is a structure that is convenient to apply a force to the plunger against the barrel.

In this embodiment, the hub 33 is imposed on the tip of the co-extruded main body by an interference fit, and the diameter of the cylindrical end portion 38 of the hub 33 is larger than the inner diameter of the tip of the co-extruded main body. This engagement type introduces two advantages to the present syringe assembly. Firstly, attaching the hub to the body without using the adhesive eliminates the additional cost of the adhesive and any possible problems with the adhesive attached in the chamber. Secondly, the inner diameter of the body portion immediately adjacent to the rear wall 39 of the hub is expanded due to the interference fit between the hub and the body portion, so that the syringe 45 can be assembled to the direct load so that the piston 45 is supported by the rear wall 39. In this position, slightly smaller stresses are generated by the interaction of the pistons deflecting the inner part 31 of the coextruded body part. This smaller stress area minimizes any chance of creep or relaxation of plastic elements that can reduce the liquidtight sealing effect between the piston and the body portion.

In this preferred embodiment, the piston has a diameter of 0.196 inches (5.0 mm) and the coextruded body portion has an inner diameter of about 0.185 inches (4.7 mm). The inner portion of the plastic material is about 0.015 inches (0.38 mm) thick and the rigid portion surrounding the inner portion is about 0.02 inches (0.51 mm) thick.

It is within the scope of the present invention to include physically shaping the coextruded body portion into a narrow opening that receives the passageway without using a separate hub, or preferably providing a separate hub as described above. Those skilled in the art have a variety of methods for joining the cylindrical body portion to the hub, including using mechanical means, adhesion, ultrasonic welding, heat sealing, or other suitable means, such as being used in preferred embodiments of the present invention. It will be apparent that the fit is merely illustrative of one of these various possibilities.

It is also within the art that the piston portion includes a plunger integrally formed with an elongated body portion forming a unitary structure as shown in the preferred embodiments 1-6. It is also within the scope of the present invention to include a plunger with a separately molded piece of portion that is attached to the elongated shaft portion using mechanical joining, gripping, ultrasonic welding, heat sealing or other known techniques.

The construction of these two elements may be desirable when choosing a more expensive material for the piston part, such as pletetra polouroethylene, which exhibits a natural smoothness, ie lubricity not found in other plastics.

In the present preferred embodiment, the plastic material inner portion 31 of the co-extruded body portion is preferably formed of elastic transparent polyurethane having a hardness of 85 ^A in Shore hardness. Hardness 70 ^A- 90 ^A is preferable. It is within the scope of the present invention to include a material of substantially any hardness in the plastic inner portion as long as the effective hardness of the piston portion is greater than the hardness of the plastic inner portion. In addition, in the syringe assembly, the inner portion should be flexible and sufficiently elastic to be sufficient for the liquid sealing action between the inner portion of the body portion and the piston.

In this preferred embodiment, the piston portion is integrally formed with the elongated shaft portion to form a single plunger 40 of polystyrene material. In this embodiment, the rigid plastic part surrounding the plastic material inner part in the co-extruded body part is preferably formed of transparent and firm polyvinyl chloride.

Preferred coextrusion body parts comprise two materials, a softer inner part and a rigid outer part made of cylindrical elements using a coextrusion process. Such processes are described in US Pat. Nos. 4,250,072 and 4,282,876 to Flynn and US Pat. No. 4,627,844 to Schmidt.

Prior art syringe stoppers and / or barrels use lubricants to lower the force required to move the rubber stopper along the barrel rate, especially after long time storage of prior art syringes prior to use. In the present invention, careful selection of the materials used for the inner portion of the body portion and the pistons may exclude or reduce the amount of lubricant required for acceptable syringe assembly performance.

An advantage and difference of the present invention over the prior art is the use of coextruded tubes to form part of the syringe barrel. Coextruded tubes can be produced more quickly and at lower capital costs than injection molded barrel parts. The dual layer of the co-extruded body allows the use of a more flexible and more elastic inner part than the piston, eliminating the need for a separate rubber or thermoplastic elastomer stopper, while the rigid part surrounding the inner part provides a low rigidity in this syringe structure. Thereby providing satisfactory structural integrity of the entire assembly. It is within the scope of the present invention to include two or more layers of material in Schmidt's published three-layer rheology co-extruded body part. The only condition is that the rigid part surrounding the inner part has a higher hardness or stiffness.

A preferred embodiment of the syringe assembly of the present invention includes an indication on the barrel. This indication may be the dose measurement indication 49 and / or instructions for use, other trademark or manufacturer information.

A further teaching in the prior art is to improve the readability of the volumetric indication by providing a higher quality volumetric indication on the syringe barrel. In addition, corona discharge treatment of various molded plastic product surfaces, such as syringe barrels, improves the suitability of the surface for printing inks to provide higher quality markings. Such a method is described in US Pat. No. 4.724,508.

7-9 illustrate the structure of an alternative embodiment syringe assembly. Thus, substantially similar elements that function substantially similarly are numbered the same as the elements of the embodiments of FIGS. 1-6 except for using the subscript “a” to identify those elements in FIGS. 7-9. Number. In this variant, the syringe assembly 50 comprises a barrel 21a with a coextruded body portion 22 having a plastic material inner portion 31a and a rigid plastic material portion 32a that encloses the inner portion thereof. Bar, the rigid portion has a higher hardness than the inner portion. The hub portion 33a attached to the front end of the co-extruded main body portion 22a includes a through passage in fluid communication with the chamber 27a. An elongated cannula having a distal end 35a, a distal end 37a and lumens through them is attached to the hub. Cannula 34a also includes a sharp tip 51. The cannula 34a is attached to the hub 33a such that the lumen is in fluid communication with the passageway, which in turn is in fluid communication with the chamber 27a. The tip of the cannula extends forward from the hub. The needle shield is detachably coupled to the hub 33a so that the tip of the cannula 34a is embedded in the needle shield. The needle shield can be used to protect the disinfection of the cannula before use and to prevent damage to the sharp tip 51 of the cannula. In this embodiment, the needle shield is frictionally engaged with the hub by an interference fit, wherein a portion of the needle shield has an inner diameter smaller than the corresponding portion of the hub to which it is to be joined. Needle shields are well known in the art and feature features such as holes covered by a disinfectant filter to aid disinfection and, in use, allow the disinfectant gas to pass freely into the syringe but allow microorganisms to enter the path. It may contain various structures such as maze passages to prevent them. The needle shield shown in this embodiment is merely one example of the structure of various possible needle shields, all of which are within the scope of the present invention.

The open end 28a of the co-extruded body portion 22a includes a flange element 61a connected to the flange housing 59 and provided to facilitate the manipulation, positioning and operation of the syringe assembly during filling and drug administration. do. The flange element 61 also provides stability to the syringe by preventing it from rolling when the syringe is placed on a table or work surface. The flange housing 59 also has a housing boss 62 having a circular outer diameter that detachably frictionally engages the plunger shield 64 that seals the open end of the cylindrical body portion in a manner very similar to the needle shield shielding the syringe needle end. ). Also, various structures are available for the plunger shield, all of which are within the scope of the present invention, the structure being determined in part by the functional conditions and the sterilization method used, as well as whether additional protective packaging is provided in the syringe assembly. do.

Variations of FIGS. 7-9 provide self-contained syringes that, when properly constructed and dictated, serve as their own disinfection packaging. Thus, the syringe is reduced to the minimum possible packaging. Self-contained packaging is presumed to be desirable for many users, such as diabetics, who carry syringes to provide insulin dosages during the working day, depending on the insulin regimen or supplemental dosage as needed.

The syringe assembly of the present invention and the syringe barrel of the present invention assembled to the syringe assembly can be used to inject drugs such as insulin using well known clinically safe techniques for aspirating a drug into a syringe and injecting the drug into a patient. .

The coextruded body part of the syringe barrel of the present invention can be made of various kinds of materials. Polyurethane, polytetrafluoroethylene and thermoplastic elastomers are preferred for the inner part of the plastic material, and polyvinyl chloride, polycarbonate and Polyethylene is preferred for the hard part. Low pressure solidification materials are preferred for the inner part. In embodiments of the present invention that are primarily sold to users who are diabetic, a material suitable for insulin for the inner portion is preferred. Although various materials are suitable for use in the body portion of the syringe barrel of the present invention, the coextrusion process may limit the various composites of the inner portion and the rigid portion material to be compatible with each other in the coextrusion process. Transparent materials are preferred over opaque materials and translucent materials. It is within the scope of the present invention to include a two-layer barrel that is not made for co-extrusion but results in an equivalent body in which the inner portion is in a harder rigid portion.

In the case of making pistons separately, a variety of rigid materials are suitable for plungers and pistons, where injection molded polymers such as polystyrene, polyethylene, polypropylene, polytetrafluoroethylene and polyvinyl chloride are desired and polystyrene is preferred. Lubricants, such as known pharmaceutical grade silicone lubricants, may be applied to the piston and / or the inner portion to reduce the force required to move the piston along the body portion.

In addition, various types of rigid materials are suitable for needle shields, flange housings and plunger shields, with injection moldable polymers such as polystyrene, polypropylene and polyethylene being preferred. The cannula is preferably made of medical grade stainless steel and is attached to the hub using a variety of known means including mechanical connectors and adhesives such as thermoset and UV curable adhesives. Various types of commercially available inks can be used to mark on the barrel. Inks or coatings usable in the present invention should be of medical grade quality. Therefore, all elements used in the syringe assembly must be chosen to withstand the sterilization process used.

Therefore, it can be seen that the present invention provides a simple, simple and easily manufactured syringe assembly having a plunger and a piston made of an inexpensive and rigid material such as thermoplastic.

Claims (1)

A cylindrical coaxially extruded body portion having a longitudinal axis and an elongated shaft portion, the body portion forming a sidewall defining a chamber containing a fluid spaced apart from the axis and having an open end with a through passage in fluid communication with the chamber. And a rigid plastic portion, including a tip portion, which encloses the inner portion of the plastic portion and the inner portion thereof and has a higher hardness than the inner portion. The shaft portion. A mixing end, a distal end and an outer diameter larger than the inner diameter of the inner portion and comprising a rigid piston portion at the tip portion, the piston portion being harder than the inner portion and slidably liquid tightly engaged inside the barrel; Liquid-tight engagement is caused by the piston pressing the inner portion and the piston portion. When moving toward the tip, fluid can be moved from the chamber through the passage, and when moving from the tip, fluid can be easily drawn from the tip through the passage, and the distal end of the plunger Surgical syringe assembly for protruding outward from the tip of the to easily move the piston portion relative to the barrel.