INJECTOR APPARATUS

• US 20110092905A1
• Filed: 10/23/2009
• Published: 04/21/2011
• Est. Priority Date: 10/16/2009
• Status: Active Grant

• Current Assignee: Owen Mumford
• Original Assignee: Owen Mumford
• Inventors: COWE, Toby
• Granted Patent: US 8,608,708 B2
• Time in Patent Office: Days
• US Class Current: 604/135
• CPC Class Codes: A61M 2005/202 cocking means, e.g. to bias the main drive spring of an injector
• CPC Class Codes: A61M 2005/2407 from the rear
• CPC Class Codes: A61M 2005/2492 via snap connection
• CPC Class Codes: A61M 2005/3103 Leak prevention means for distal end of syringes, i.e. syringe end for mounting a needle
• CPC Class Codes: A61M 2205/581 by audible feedback
• CPC Class Codes: A61M 2205/583 by visual feedback
• CPC Class Codes: A61M 5/20 Automatic syringes, e.g. with automatically actuated piston rod, with automatic needle injection, filling automatically A61M5/142 , A61M5/46 take precedence; hypodermic projectiles F42B12/54
• CPC Class Codes: A61M 5/2033 Spring-loaded one-shot injectors with or without automatic needle insertion multishot dosing syringes A61M5/31525, needle insertion only A61M5/3287
• 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 5/3129 Syringe barrels A61M5/3205 and A61M5/50 take precedence
• CPC Class Codes: A61M 5/315 Pistons; Piston-rods; Guiding, blocking or restricting the movement of the rod or piston; Appliances on the rod for facilitating dosing ; Dosing mechanisms
• CPC Class Codes: A61M 5/31536 Blocking means to immobilize a selected dose, e.g. to administer equal doses
• CPC Class Codes: A61M 5/31548 Mechanically operated dose setting member
• CPC Class Codes: A61M 5/31551 including axial movement of dose setting member
• CPC Class Codes: A61M 5/31553 without axial movement of dose setting member
• CPC Class Codes: A61M 5/31556 Accuracy improving means
• CPC Class Codes: A61M 5/31558 using scaling up or down transmissions, e.g. gearbox
• CPC Class Codes: A61M 5/31561 using freely adjustable volume steps
• CPC Class Codes: A61M 5/31575 using scaling up or down transmissions, e.g. gearbox
• CPC Class Codes: A61M 5/31583 based on rotational translation, i.e. movement of piston rod is caused by relative rotation between the user activated actuator and the piston rod
• CPC Class Codes: A61M 5/31585 : performed by axially moving actuator, e.g. an injection button

Abstract

An injector apparatus comprises a housing (10¹, 10²) for a cartridge or syringe, a plunger (40) for cooperating in use with the cartridge or syringe to express successive doses, a dose setting arrangement (16, 20) to select a dose volume, and a drive mechanism (22, 24) releasable to advance said plunger in respective predetermined increments of magnitude to express said successive doses. The drive mechanism includes a drive spring (22) for imparting movement directly or indirectly to said plunger (40), and said dose setting arrangement comprises a dose setting element (16) moveable in a dose setting routine to define a magnitude of an increment of movement of said plunger for a given dose. The drive mechanism further includes a clutch arrangement (56) operable during said dose setting routine to inhibit forward movement of the plunger and/or to isolate said dose setting element from the force of said drive spring.

Claims

1. An injector apparatus for use with a cartridge (12) or syringe to deliver a plurality of doses therefrom, the injector apparatus comprising:

a housing (10¹, 10²) for the cartridge or syringe;

a plunger (40) for cooperating in use with the cartridge or syringe to express successive doses;

a dose setting arrangement (16, 20) to select a dose volume;

a drive mechanism (22, 24) releasable to advance said plunger in respective predetermined increments of magnitude to express said successive doses;

characterised in that said drive mechanism includes a drive spring (22) for imparting movement directly or indirectly to said plunger (40), and said dose setting arrangement comprises a dose setting element (16) moveable in a dose setting routine to define a magnitude of an increment of movement of said plunger for a given dose, said drive mechanism further including a clutch arrangement (56) operable during said dose setting routine to inhibit forward movement of the plunger and/or to isolate said dose setting element from the force of said drive spring.

2. An injector apparatus according to claim 1, wherein said dose setting element (16) is moveable angularly to define said increment of plunger movement.

3. An injector apparatus according to claim 2, wherein said clutch arrangement includes a clutch element (56) moveable between disengaged and engaged positions.

4. An injector apparatus according to claim 3 wherein said clutch element (56) is adapted to move axially with said dose setting element (16), whereby axial movement of said dose setting element from a first, rest, position to a second, dose-setting, position causes said clutch element (56) to engage to inhibit forward movement of the plunger.

5. An injector apparatus according to claim 4, wherein said dose-setting element (16) and said housing (10¹, 10²) include complementary abutments (62,64) that engage to prevent relative rotation of said dose setting element relative to said housing when said dose setting element is in its rest position, but disengage to allow relative rotation therebetween when said dose setting element is in its setting position.

6. An injector apparatus according to claim 5, wherein upon moving said dose setting element (16) from said rest position to said setting position, said clutch element (56) engages before engagement of the abutments (62, 64) on said dose setting element and said housing.

7. An injector apparatus according to claim 4, wherein the thrust of the drive spring (22) is reacted by said dose setting element (16) when said dose setting element is in its rest position.

8. An injector apparatus according to claim 4, wherein returning said dose setting element (16) to said first position after having set a predetermined dose disengages the clutch element (56) to release the drive mechanism (22,24) to cause said plunger (40) to advance by a predetermined increment corresponding to said predetermined set dose.

9. An injector apparatus according to claim 1, wherein said plunger (40) is threadedly engaged with an associated control element (24), whereby linear movement of said plunger is accompanied by rotation of one of the plunger and the control element, and the magnitude of the increment of movement is controlled by limiting said rotation.

10. An injector apparatus according to claim 9, wherein a stop surface (54) associated with said dose setting element (16), is adjustable on movement of said dose setting element to define an angular increment of movement for the relative rotation between the plunger (40) and the control element (24) upon release of said drive mechanism.

11. An injector apparatus according to claim 10, wherein an intermediate shuttle member (20) is threadedly engaged with said dose setting element (16) and is constrained to rotate with the rotatable one of the plunger (40) and the control element (24), with the extent of relative angular movement of the shuttle member (20) and the dose setting element being set by the relative position of the stop surface associated with the dose setting element.

12. An injector apparatus according to claim 1, wherein said drive spring (22) is a torsion spring.

13. An injector apparatus according to claim 1, wherein said drive spring (22) is a compression spring.

14. An injector apparatus for use with a cartridge (12) or syringe to deliver a plurality of doses therefrom, the injector apparatus comprising:

a housing (10¹, 10²) for the cartridge or syringe;

a plunger (40) for cooperating in use with the cartridge or syringe to express successive doses;

a dose setting arrangement (16, 20) to select a dose volume;

a drive mechanism (22, 24) releasable to advance said plunger in respective predetermined increments of magnitude to express said successive doses;

characterised in that said drive mechanism includes a rotary stored energy element (22) with a preload sufficient to deliver at least a plurality of said successive doses.

15. An injector apparatus according to claim 14, wherein said rotary stored energy element (22) has a preload selected to deliver substantially the entire usable contents of to empty the syringe or cartridge over a succession of doses.

16. An injector apparatus according to claim 14, which includes means for re-energising said rotary stored energy element.

17. An injector apparatus for use with a cartridge (12) or syringe to deliver a plurality of doses therefrom, the injector apparatus comprising:

a housing (10¹, 10²) for the cartridge or syringe;

a plunger (40) for cooperating in use with the cartridge or syringe to express successive doses;

a dose setting arrangement (16, 20) to select a dose volume;

a drive mechanism (22, 24) releasable to advance said plunger in respective predetermined increments of magnitude to express said successive doses and in which advance of said plunger 40 is controlled by a control member (24) that moves angularly in response to advance of said plunger;

characterised in that said dose setting arrangement includes first and second complementary dose setting elements (16,20) threadedly engaged for relative threaded movement away from a first limit position, with said first dose setting element (16) being moveable relative to said housing (10¹, 10²) in a setting routine from a rest position to a variable angular position that sets the dose volume, and said second dose setting element (20) being constrained to rotate with said control element (24),

whereby on release of said drive mechanism said control member (24) and said second member (20) rotate until the second member returns to said first limit position with respect to the first member and prevents further rotation of the control member (24).