Reusable injection device for distributing a preselected dose

• US 5,244,465 A
• Filed: 03/05/1992
• Issued: 09/14/1993
• Est. Priority Date: 10/19/1988
• Status: Expired due to Fees

• Current Assignee: BYK Gulden Lomberg Chemische Fabrik GMBH (Takeda Pharmaceutical Company Limited)
• Original Assignee: BYK Gulden Lomberg Chemische Fabrik GMBH (Takeda Pharmaceutical Company Limited)
• Inventors: Michel, Peter
• Primary Examiner(s): Rosenbaum, C. Fred
• Assistant Examiner(s): STRIGHT, RONALD K
• Application Number:
  US07/846,766
• Time in Patent Office: 558 Days
• Field of Search: 604/207-211, 604/187, 604/232-234, 604/220, 604/228, 604/218, 604/131, 604/134, 604/135
• US Class Current: 604/208
• CPC Class Codes: A61M 2005/2407 from the rear
• CPC Class Codes: A61M 2005/244 by flexible clip
• CPC Class Codes: A61M 2005/2488 via rotation, e.g. threads or bayonet
• CPC Class Codes: A61M 5/24 Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or carpules, e.g. automatic ampoules or carpules A61J1/06
• CPC Class Codes: A61M 5/31538 Permanent blocking, e.g. by medical personnel
• CPC Class Codes: A61M 5/3156 using volume steps only adjustable in discrete intervals, i.e. individually distinct intervals
• CPC Class Codes: A61M 5/31563 interacting with a displaceable stop member
• CPC Class Codes: A61M 5/3158 performed by axially moving actuator operated by user, e.g. an injection button
• CPC Class Codes: A61M 5/31591 Single dose, i.e. individually set dose administered only once from the same medicament reservoir, e.g. including single stroke limiting means

Abstract

A syringe-type injection device for dispensing a preset dose of a liquid drug includes two sleeve-like components releasably connected with each other so as to be aligned in axial direction. One of the sleeve-like components is a holder for a dispensing mechanism and the other of the sleeve-like components is adapted to accommodate an ampoule and a cannula. The dispensing mechanism includes an axially movable piston rod for actuating a plug of the ampoule. The piston rod has a radially projecting cam follower and the holder defines at least one axially extending slot having a predetermined length, wherein the cam follower is received by the at least one slot, such that only a single dose can be dispensed from an ampoule by an axial movement of the piston rod.

Claims

1. A syringe-type injection device including a dispensing mechanism for dispensing a preset dose of liquid drug, comprising:

first and second sleeve-like components releasably connected to each other so as to be aligned in an axial direction, wherein the first sleeve-like component is a holder for the dispensing mechanism and the second sleeve-like component is an ampoule sleeve having an ampoule and a cannula means for connecting the ampoule with the ampoule sleeve;

a plug in the ampoule;

an axially movable piston rod extending from said holder through the dispensing mechanism for actuating the plug of the ampoule, wherein said piston rod has a radially projecting cam follower;

at least one axially extending slot defined in said holder, wherein said slot has a predetermined length and wherein the cam follower is received by the at least one slot such that only a single dose can be dispensed from the ampoule by an axial movement of the piston rod;

the piston rod having a piston rod neck for acting on the plug of the ampoule; and

a cap for connecting the dispensing mechanism with the holder such that it cannot be disengaged.

2. The syringe device according to claim 1, further comprising:

a dose ring fixedly connected to the piston rod for joint displacement therewith and indicating the present dose of the liquid drug to be dispensed;

a returning spring supported in the holder by its dispensing mechanism for biasing the piston rod to a first position thereof in which no drug is dispensed; and

a dosing button cap mounted on an end of the piston rod remote from the ampoule sleeve for moving the piston rod, against the bias of the returning spring, to a second position in which the preset dose of the liquid drug is dispensed.

3. The syringe device according to claim 2, comprising cam and slot couplings connecting the dose ring to the piston rod, wherein the dose ring is provided on the periphery thereof with a scale.

4. The syringe device according to claim 3, wherein the holder has a window, the window being positioned such that the scale of the dose ring can be viewed therethrough.

5. The syringe device according to claim 1, wherein the holder has a plurality of axially extending slots of different lengths.

6. The syringe device according to claim 5, wherein the axially extending slots are spaced from each other uniformly in circumferential direction, and wherein the axially extending slots are arranged with increasing length around the periphery of the holder.

7. The syringe device according to claim 1, wherein the piston rod comprises an inner hollow cylinder bearing the piston rod neck and an outer hollow cylinder surrounding and formed integrally with the inner hollow cylinder, the outer hollow cylinder having an outer sleeve surface, the cam follower being mounted on the outer sleeve surface.

8. A syringe-type injection device including a dispensing mechanism for dispensing a preset dose of a liquid drug, comprising:

first and second sleeve-like components releasably connected to each other so as to be aligned in an axial direction, wherein the first sleeve-like component is a holder for the dispensing mechanism and the second sleeve-like component is an ampoule sleeve having an ampoule and a cannula means for connecting the ampoule with the ampoule sleeve the ampoule having a plug;

an axially movable piston rod extending from said holder through the dispensing mechanism for actuating the plug of the ampoule;

a radially projecting cam follower on the piston rod;

a plurality of axially extending slots defined on the holder, wherein said slots have different predetermined lengths and wherein the cam follower is received by a respective slot, such that only a respective single preset dose can be dispensed from the ampoule by an axial movement of the piston rod.

9. The syringe device according to claim 8, wherein the component accommodating the ampoule includes a housing, the housing being a single-piece component.

10. The syringe device according to claim 9, wherein the housing is of an optically opaque material.

11. The syringe device according to claim 10, wherein the opaque material is a polyamide.

12. The syringe device according to claim 8, wherein the ampoule is tightly connected to the ampoule sleeve such that it is difficult to disengage.

13. The syringe device according to claim 8, further comprising adjustable locking means for defining a position of the piston rod in which the cam follower is received in the respective slot.