INJECTION DEVICES

• US 20100324485A1
• Filed: 02/03/2009
• Published: 12/23/2010
• Est. Priority Date: 02/08/2008
• Status: Active Grant

• Current Assignee: Owen Mumford
• Original Assignee: Owen Mumford
• Inventors: Cowe, Toby
• Granted Patent: US 8,647,303 B2
• Time in Patent Office: Days
• US Class Current: 604/134
• CPC Class Codes: A61M 2005/202 cocking means, e.g. to bias the main drive spring of an injector
• CPC Class Codes: A61M 2005/206 With automatic needle insertion
• CPC Class Codes: A61M 2005/2407 from the rear
• CPC Class Codes: A61M 2005/2492 via snap connection
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• 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 5/326 Fully automatic sleeve extension, i.e. in which triggering of the sleeve does not require a deliberate action by the user
• CPC Class Codes: A61M 5/46 having means for controlling depth of insertion
• CPC Class Codes: A61M 5/482 Varying injection pressure, e.g. by varying speed of injection

Abstract

An autoinjector device comprises a drive housing 10 and a syringe housing 12 which can be disconnected to allow insertion of a syringe. A drive mechanism in the drive housing is cocked by means of a cord 8 connected between the drive housing and the syringe housing. The drive mechanism comprises a drive gear 22 rotatably mounted in the drive housing and acting as a rotary crank connected by a connecting rod 26 to a plunger 28. In use the drive gear 22 is driven by a torsion spring 35 so that the drive mechanism extends the syringe from the syringe housing and expels a dose and then retracts the syringe back into the housing. A firing button 14 releases the drive gear to be driven by the torsion spring but is also engageable as a brake on the rim of the drive gear.

Claims

1. An autoinjector comprising:

a body portion (12) for receiving in use a syringe or cartridge (60) having a bung slideably mounted therein for expelling a dose;

a drive mechanism (35, 22, 26, 28) including energy storage means (35) and adapted to be released from a cocked position to a fired position on actuation of a trigger (14), said mechanism when released being operable to drive the bung to expel a dose,

characterised by a cocking arrangement (8, 30, 40) comprising an elongate flexible element (8) for being pulled to cock said drive mechanism.

2. An autoinjector according to claim 1, wherein said cocking arrangement includes a mechanical advantage configuration (38, 8) whereby the stroke of movement of said elongate flexible element (8) is substantially greater than the stroke of linear movement of said drive mechanism.

3. An autoinjector according to claim 1, wherein said cocking arrangement includes retraction means (39) for retracting said elongate flexible element (8) after said drive mechanism has been cocked.

4. An autoinjector according to claim 1, wherein said drive mechanism comprises a rotary crank element (22) connected to a slideable drive plunger (28) by a connecting rod (26) in a crank-slider relationship, and said energy storage means (35) acts on said rotary crank element (22).

5. An autoinjector according to claim 4 including a lost motion connection (64, 66) between at least two out of the rotary crank element (22), the connecting rod (26) and the drive plunger (28).

6. An autoinjector according to claim 4, wherein said energy storage means (35) comprises a torsion spring connected at one end to said rotary element and relatively fixed at its other end.

7. An autoinjector according to claim 6, wherein said cocking arrangement comprises a rotary element, or pulley (38) around which is wrapped said elongate flexible cocking element (8) and a clutch arrangement (32, 36) for transmitting rotation to said rotary crank element in the cocking sense only, and means (39) for rewinding said clocking element or pulley after cocking to retract said elongate flexible element.

8. An autoinjector according to claim 1, wherein said trigger (14) is operable to apply or modulate a braking force on said drive mechanism to allow control of the speed of movement thereof from said cocked position, and thereby the speed of movement of at least one of the syringe or cartridge and bung.

9. An autoinjector according to claim 1, wherein said body portion comprises a forward portion (12) for receiving said syringe or cartridge, and a rearward portion (10) removably connected to said forward portion and housing said drive mechanism.

10. An autoinjector according to claim 9, wherein said elongate flexible element (8) extends from said rearward portion (10) to a connection on said forward portion (12).

11. An autoinjector according to claim 10, wherein the connection on said forward portion allows sliding movement of said elongate flexible element (8) for a preset distance against a slight bias, whereby on initial separation of said forward and rearward portions, said elongate flexible cocking element (8) moves longitudinally relative to said forward portion.

12. An autoinjector according to claim 1 including a penetration depth adjustment element (20) disposed in a forward end of the body portion (12) and for being placed against the injection site in use, said adjustment element being connected to a depth adjustment mechanism for advancing and/or retracting said adjustment element incrementally relative to said body portion upon manual actuation of a separate depth adjustment actuator (18).

13. An autoinjector according to claim 12, wherein said adjustment element (20) is threadedly mounted on said body portion (12), and said depth adjustment mechanism comprises at least one push button (18) cooperating with said adjustment element incrementally to rotate said adjustment element upon each actuation of said button.

14. An autoinjector according to claim 13, including push buttons (18) disposed on opposite sides of said body portion, each cooperating with said depth adjustment element (20).

15. An autoinjector according to claim 13, wherein the or each push button (18) and said adjustment element (20) cooperate by means of a ratchet and pawl.

16. An autoinjector according to claim 12, wherein said depth adjustment mechanism is operable on said depth adjustment element reaching a preset longitudinal position (20), to return said depth adjustment element to a start position.

20. An autoinjector according to claim 2, wherein said cocking arrangement includes retraction means (39) for retracting said elongate flexible element (8) after said drive mechanism has been cocked.

17. An autoinjector comprising:

a body portion (10,12) for receiving in use a syringe or cartridge (60) having a bung slideably mounted therein for expelling a dose;

a drive mechanism including energy storage means (35) and adapted to be released from a cocked position to a fired position on actuation of a trigger (14), said mechanism when released being operable to drive the bung to expel a dose,

characterised in that said drive mechanism includes a rotary crank element (22) connected to a slideable drive plunger (28) by a connecting rod (26) in a crank-slider relationship, and said energy storage means (35) acts on said rotary crank element.

18. An autoinjector comprising:

a body portion (10, 12) for receiving in use a syringe or cartridge (60) having a bung slideably mounted therein for expelling a dose;

a drive mechanism including energy storage means (35) and adapted to be released from a cocked position to a fired position on actuation of a trigger (14), said mechanism when released being operable to drive the bung to expel a dose,

characterised in that said drive mechanism includes user operable means (14) for applying or modulating a braking force to control the speed of operation of said mechanism.

19. A penetration depth adjustment arrangement for an injection device, said arrangement comprising:

—

a housing (10, 12) having a forward end region through which the injection is effected;

a depth adjustment element (20) disposed in said forward end region and for being placed against the injection site in use, and

a depth adjustment mechanism for advancing and/or retracting said adjustment element incrementally relative to said housing upon manual actuation of a separate depth adjustment actuator (18).