Nozzle assembly with lost motion connection for medical injector assembly

• US 5,891,085 A
• Filed: 01/09/1997
• Issued: 04/06/1999
• Est. Priority Date: 01/09/1995
• Status: Expired due to Fees

• Current Assignee: Antares Pharma Incorporated
• Original Assignee: Medi-Ject Corporation
• Inventors: Lilley, Stephen John, Theobald, David Reginald, Taylor, Hugh Francis, Carlson, Craig J., Rosen, David I., Johnson, Thomas R.
• Primary Examiner(s): Coggins, Wynn Wood
• Assistant Examiner(s): Sadula, Jennifer R.
• Application Number:
  US08/780,917
• Time in Patent Office: 817 Days
• Field of Search: 604/68-73, 604/133-5, 604/140, 604/141, 604/143, 604/146, 604/147, 604/206, 604/207
• US Class Current: 604/68
• CPC Class Codes: A61J 1/201 having one piercing end
• CPC Class Codes: A61J 1/2044 having slits
• CPC Class Codes: A61J 1/2051 having tap means, e.g. tap means activated by sliding
• CPC Class Codes: A61J 1/2055 having gripping means
• CPC Class Codes: A61J 1/2096 Combination of a vial and a syringe for transferring or mixing their contents
• CPC Class Codes: A61M 5/2053 Media being expelled from injector by pressurised fluid or vacuum for infusion A61M5/145, A61M5/155
• CPC Class Codes: A61M 5/30 Syringes for injection by jet action, without needle, e.g. for use with replaceable ampoules or carpules
• CPC Class Codes: F41B 11/64 having a piston effecting a compressor stroke during the firing of each shot
• CPC Class Codes: F41B 11/642 the piston being spring operated
• CPC Class Codes: F41B 11/646 Arrangements for putting the spring under tension
• CPC Class Codes: F41B 11/81 for ejecting powder, e.g. pepper

Abstract

A needleless injection system and method for injecting a medical product including a needleless injection device having a nozzle assembly defining an ampule chamber for holding medication, an energy device for pushing medication out of the nozzle assembly, and an energy device actuating mechanism is disclosed. These components are operatively contained in a housing configured for hand held operation. The energy device is a self-contained gas spring operatively connected to a plunger operating within the ampule chamber. The gas spring is preferably stepped which can be used in many different applications, an air gun being one. The injection device can be provided with a coupling device for coupling a medication supply vial to the nozzle assembly. The nozzle assembly is removably situated in the housing with the plunger removable therewith.

Claims

1. A nozzle assembly for a needleless injection device having an energy source for propelling medication through said nozzle assembly comprising:

a generally hollow body defining a chamber having an end terminal wall with an orifice for passage of medication therethrough and an open end opposite said terminal wall, said body having means for removably connecting to an injection device;

a pressure wall member movably positioned within said chamber, said pressure wall member having means for sealing said chamber from said open end, wherein said pressure wall member is movable toward and away from said terminal wall to introduce and expel medication into and out of said chamber through said orifice; and

a lost motion connecting mechanism for removably connecting said pressure wall member to an energy source and for providing a predetermined free travel distance between the pressure wall member and an energy source, said lost motion connecting mechanism including a resilient snap fit member which extends from said pressure wall member in a direction opposite said terminal wall,

said snap fit member including a plurality of prongs, each prong extending from the pressure wall member and having a tab extending radially inwardly, said prongs forming a connection between said pressure wall member and an energy source, wherein said prongs are confined within said chamber and are dimensioned to slide inside said chamber with an inner wall of said chamber confining said prongs from moving laterally outwardly to maintain locking engagement between said pressure wall member and an energy source during use.

2. The nozzle assembly of claim 1, wherein said snap fit member defines a gap between the tabs of each prong and the pressure wall member so that when an energy source is associated with the prongs, the energy source is capable of traveling through the predetermined free travel distance across the gap to meet the pressure wall member.

3. The nozzle assembly of claim 2, wherein the gap is at least about 3.5 mm.

4. The nozzle assembly of claim 1, wherein said nozzle assembly is composed of a medical grade material.

5. The nozzle assembly of claim 4, wherein said nozzle assembly is composed of a material selected from the group consisting of gamma stabilized high impact polycarbonate, polypropylene, glass, and glass composite.

6. Nozzle assembly for a needleless injection device having an energy source for propelling medication through said nozzle assembly comprising:

a generally hollow body defining a chamber having an end terminal wall with an orifice for passage of medication therethrough and an open end opposite said terminal wall, said body having means for removably connecting to an injection device;

a plunger movably positioned within said chamber, said plunger having means for sealing said chamber from said open end, wherein said plunger is movable toward and away from said terminal wall to introduce and expel medication into and out of said chamber through said orifice; and

a lost motion connecting means for removably connecting said plunger to an energy source, wherein said plunger is connected to an energy source by pushing said plunger toward an energy source and disconnected by pulling said plunger away from an energy source, wherein the force required to disconnect said plunger from an energy source is substantially greater than the force required to move said plunger away from said terminal wall during introduction of medication into said chamber, wherein said lost motion connecting means comprises a resilient snap fit member for association with an enlarged head of an energy source, said resilient snap fit member extending from said plunger in the direction opposite said terminal wall, wherein said snap fit member includes a plurality of prongs made of resilient material, which upon being attached to an enlarged head expand and return to their original configuration once said enlarged end is fully connected, with each prong extending from said plunger and, each of said prongs having a tab extending radially inwardly and confining an enlarged end connected to said plunger, wherein said entire prongs are confined within said ampule chamber, said prongs being dimensioned to slide inside said ampule chamber and an inner wall of said ampule chamber confining said prongs from moving laterally outwardly to maintain an enlarged end locked to said plunger during use.

7. The nozzle assembly of claim 6, wherein said snap fit member defines a gap defined between the tabs of each prong and the plunger so that when an enlarged end is positioned between the prongs, the enlarged end is capable of traveling a predetermined distance across the gap to meet the plunger.

8. The nozzle assembly of claim 6, wherein said nozzle assembly is composed of a medical grade material.

9. The nozzle assembly of claim 8, wherein said nozzle assembly is composed of a material selected from the group consisting of gamma stabilized high impact polycarbonate, polypropylene, glass, and glass composite.

10. A nozzle assembly for a needleless injection device having an energy source for propelling medication through said nozzle assembly comprising:

a generally hollow body defining a chamber having an end terminal wall with an orifice for passage of medication therethrough and an open end opposite said terminal wall, said body having means for removably connecting to an injection device;

a plunger movably positioned within said chamber, said plunger having means for sealing said chamber from said open end, wherein said plunger is movable toward and away from said terminal wall to introduce and expel medication into and out of said chamber through said orifice; and

a lost motion connecting mechanism for removably connecting said plunger to an energy source and for providing a predetermined free travel distance between the plunger and an energy source, said lost motion connecting mechanism including a resilient snap fit member which extends from said plunger in a direction opposite said terminal wall,

said snap fit member including a plurality of prongs, each prong extending from the plunger and having a tab extending radially inwardly, said prongs forming a connection between said plunger and an energy source, wherein said prongs are confined within said chamber and are dimensioned to slide inside said chamber with an inner wall of said chamber confining said prongs from moving laterally outwardly to maintain locking engagement between said plunger and an energy source during use.

11. The nozzle assembly of claim 10, wherein said snap fit member defines a gap between the tabs of each prong and the plunger so that when an energy source is associated with the prongs, the energy source is capable of traveling through the predetermined free travel distance across the gap to meet the plunger.

12. The nozzle assembly of claim 11, wherein the gap is at least about 3.5 mm.

13. The nozzle assembly of claim 10, wherein said nozzle assembly is composed of a medical grade material.

14. The nozzle assembly of claim 13, wherein said nozzle assembly is composed of a material selected from the group consisting of gamma stabilized high impact polycarbonate, polypropylene, glass, and glass composite.