Injector apparatus

• US 8,608,708 B2
• Filed: 10/23/2009
• Issued: 12/17/2013
• Est. Priority Date: 10/16/2009
• Status: Active Grant

• Current Assignee: Owen Mumford
• Original Assignee: Owen Mumford
• Inventors: Cowe, Toby
• Primary Examiner(s): Lucchesi, Nicholas
• Assistant Examiner(s): Zhang, Jenna
• Application Number:
  US12/604,782
• Publication Number:
  US 20110092905A1
• Time in Patent Office: 1,516 Days
• Field of Search: 604/135, 604/71
• US Class Current: 604/208
• 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 includes 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 the plunger in respective predetermined increments of magnitude to express the successive doses. The drive mechanism includes a drive spring (22) for imparting movement directly or indirectly to the plunger (40), and the dose setting arrangement includes a dose setting element (16) moveable in a dose setting routine to define a magnitude of an increment of movement of the plunger for a given dose. The drive mechanism further includes a clutch arrangement (56) operable during the dose setting routine to inhibit forward movement of the plunger and/or to isolate the dose setting element from the force of the 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 and in which advance of said plunger (40) is controlled by a control member (24) that moves angularly in response to an axial advance of said plunger;

said dose setting arrangement including 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 axially moveable relative to said housing (10¹, 10²) from a rest position to a dose setting position wherein said first dose setting element (16) is movable in rotation for setting the dose volume, said second dose setting element (20) being constrained to rotate with said control member (24),

whereby on release of said drive mechanism by returning said first dose setting element (16) from the dose setting position to the rest position, said control member (24) and said second dose setting element (20) rotate until the second dose setting element (20) returns to said first limit position with respect to said first dose setting element (16) and prevents further rotation of the control member (24).

2. An injector apparatus according to claim 1, wherein said first dose setting element (16) includes a plurality of fingers (62) which engage in respective recesses (64) associated with said housing when said first dose setting element is in the rest position and prevents rotation of said first dose setting element relative to the housing, the plurality of fingers being shifted clear of the respective recesses when said first dose setting element is moved to the dose setting position, thereby allowing rotation of the first dose setting element.

3. An injector apparatus according to claim 1, wherein a clutch element (56) is connected to move axially with said first dose setting element so that, as said first dose setting member is moved between the rest position and the dose setting position, the clutch element moves between a disengaged position and an engaged position in which the clutch element engages and holds the control member (24) against rotation.

4. An injector apparatus according to claim 1, wherein said second dose setting element (20) moves axially relative to the control member as said first control member is moved in rotation to set a dose.

5. An injector apparatus according to claim 1, wherein said second dose setting element includes a helical scale and said first dose setting element includes at least one of a mark or window enabling the scale to be read.

6. An injector apparatus according to claim 5, wherein the helical scale comprises a plurality of complete turns.