MULTI-DOSE INJECTOR

• US 3,859,996 A
• Filed: 07/18/1973
• Issued: 01/14/1975
• Est. Priority Date: 07/18/1973
• Status: Expired due to Term

• Current Assignee: Mizzy A. Robert, Vito L. Pierannunzi
• Original Assignee: Mizzy A. Robert, Vito L. Pierannunzi
• Inventors: Mizzy, A. Robert, Pierannunzi, Vito L.
• Primary Examiner(s): Gaudet, Richard A.
• Assistant Examiner(s): Recla, Henry J.
• Application Number:
  US05/380,357
• Time in Patent Office: 545 Days
• Field of Search: 128/173H,173R,173.1,214.2,218A,239 141/346,351,352,67 227/8
• US Class Current: 604/70
• CPC Class Codes: A61M 2005/2013 triggering of discharging means by contact of injector with patient body
• 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

Abstract

An improved multi-dose injector comprising a body portion, an ejector nozzle mounted at one end of said body portion, including a discharge orifice, an exit passage in said body portion leading to said orifice, powerized means for ejecting measured doses of liquid under pressure through the exit passage and out of the orifice against the epidermis of the recipient, the apparatus being characterized by a pressure sensitive trigger mechanism whereby triggering of the dose releasing apparatus is effected only after a predetermined pressure of the trigger mechanism against the subject is sensed. The trigger apparatus assures optimal and predictable administration of a medicament by initiating an operative cycle only when the injector is pressed against the subject with a selected force, while preventing accidental or inadvertent firing. In addition, the novel trigger mechanism reduces the likelihood of slippage or movement of the apparatus relative to the subject during administration of a dosage.

Claims

1. An injector apparatus comprising, in combination, a body portion, an ejector nozzle mounted at one end of said body portion including a discharge orifice, an exit passage in said body portion leading to said orifice, a liquid reservoir, intermittently actuatable powerized discharge means for expelling liquid from said reservoir into said exit passage for ejection of a given amount of liquid out said orifice, trigger means for actuating said discharge means, said trigger means including a slide member mounted on said one end of said body portion adjacent said orifice for reciprocal movement in the direction of said discharge orifice, said slide member including a trip portion projecting forwardly beyond said orifice to touch the surface to be injected, resilient means biased between said slide member and said body portion for urging said slide member to a forward position, said slide member being shiftable rearwardly from said forward position against the biasing pressure of said resilient means by abutment of the trip portion against the surface to be injected, and sensing means for actuating said discharge means in response to a predetermined rearward movement of said slide member.

2. Apparatus in accordance with claim 1 in which means are provided for regulating the quantity of liquid expelled from said reservoir.

3. Apparatus in accordance with claim 1 in which means are provided to reset the powerized discharge means for actuation by said trigger means for the next discharge cycle.

4. Apparatus in accordance with claim 3 in which means are provided to prevent actuation of said discharge means by actuation of said trigger means until after a previous discharge cycle has been completed.

5. Apparatus in accordance with claim 3 in which means are provided to maintain the discharge means actuated for a complete cycle even if said trigger means are released during such cycle.

6. Apparatus in accordance with claim 3 in which means are provided to maintain the discharge means actuated for a complete cycle even if said trigger means are released during such cycle and means are provided to prevent actuation of said discharge means by actuation of said trigger means until after a previous discharge cycle has been completed.

7. Apparatus in accordance with claim 1 wherein said sensing means includes an air conduit, means for inducing a predetermined air pressure level in said conduit, means for sensing the pressure level in said conduit and activating said discharge means responsive to pressures sensed in said conduit which vary from said level and means on said slide means for varying said pressure in said conduit responsive to predetermined rearward movement of said slide means.

8. The apparatus of claim 7 wherein said means for sensing the pressure in said conduit is remote from said body portion.

9. The apparatus of claim 7 wherein said means for varying said pressure level includes an open end portion on said conduit, and said slide means includes a valve element positioned to engage and seal said open end portion responsive to predetermined rearward movement of said slide.

10. The apparatus of claim 7 wherein said means for inducing said pressure level and said sensing means are remote from said body portion.

11. The apparatus of claim 7 wherein said means for inducing said pressure value comprises a source of air under pressure, and said conduit includes vent aperture means in said body portion, said slide member including a valve element positioned to seal said aperture means responsive to predetermined rearward movement of said slide member, thus to increase the pressure in said conduit.

12. Apparatus in accordance with claim 7 wherein said conduit includes a vent aperture adjacent said slide portion normally discharged to the atmosphere, and said means for varying the pressure in said conduit comprises a closure element positioned to cut off discharge of gas through said vent aperture.

13. The apparatus of claim 12 and including a manual trigger assembly having a trigger, normally open valve means operatively connected to said trigger, said valve means being vented to the atmosphere in the open position thereof and being shut responsive to actuation of said trigger, and a take-off tube connecting said valve means and said conduit and forming a second vent path to the atmosphere in the open position of said valve, whereby the pressure level in said conduit will vary from said level only when said vent aperture is sealed and said valve means is closed.

14. The apparatus of claim 13 and including means on said trigger assembly for holding said valve means in said closed position.

15. The apparatus of claim 13 and including a control member interposed between said slide and said body portion, said control member being shiftable between first and second positions, respectively locking said slide in said rearward position, and permitting said movement of said slide relative to said body portion.

16. In a multi-dose injector apparatus including a body portion, an ejector nozzle mounted at one end of said body portion including a discharge orifice, an exit passage in said body portion leading to said orifice, and powerized means for ejecting measured doses of liquid under pressure through said exit passage and out of the orifice, and means to energize said powerized means, the improvement which comprises a trigger assembly for energizing said powerized means comprising a slide member reciprocately mounted on said body portion and disposed adjacent and projecting forwardly beyond said orifice, said slide being mounted for reciprocation between extended and retracted positions in a path parallel to the axis of said orifice, resilient means biased between said body and said slide and normally urging said slide to said projected position, sensing means for energizing said powerized means responsive to movement of said slide from said extended to said retracted position, the forwardly projecting portion on said slide being adapted to touch the surface to be injected and to shift said slide to said retracted position responsive to pressure against such surface.

17. Apparatus in accordance with claim 16 and including means for varying the pressure necessary to shift said slide.