Injection devices

Patent metadata

Field	Value
Publication number	US-9814840-B2
Application number	US-201113878479-A
Country	US
Kind code	B2
Filing date	Sep 19, 2011
Priority date	Oct 14, 2010
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

An injection device includes an elongate housing ( 10 ), a syringe ( 12 ) disposed in the housing, and an internal piston ( 20 ) to express a dose from a needle ( 16 ) at its front end. The injection device further includes a shroud element ( 24 ) movable forwardly relative to the syringe to shroud the needle after use and a latch ( 74 ) movable between a latched state in which it restricts rearward movement of the shroud element, and a release state. The latch is moved to its latch state by a magnetic force ( 56 ).

First claim

The invention claimed is:

1. An injection device comprising: an elongate housing ( 10 ); a syringe ( 12 ) disposed in said housing and having an internal piston ( 20 ) to express a dose from a needle ( 16 ) located at a front end of the syringe; a shroud element ( 24 ) movable forwardly relative to the syringe to shroud the needle after use; a latch ( 74 ) movable between a latched state, in which the latch restricts rearward movement of the shroud element, and a release state; and a longitudinally movable plunger ( 48 ) for driving said piston, wherein one of the plunger ( 48 ) and the latch ( 74 ) comprises a magnetized portion, and the other of the plunger ( 48 ) and the latch ( 74 ) includes a ferro-magnetic portion, and wherein said latch ( 74 ) is urged to move into said latch state by a magnetic force ( 56 ), which arises from the magnetized portion and the ferro-magnetic portion, and acts between said latch ( 74 ) and said plunger ( 48 ).

2. The injection device according to claim 1 , wherein said plunger ( 42 ) incorporates the magnetized portion ( 56 ), and said latch ( 74 ) includes the ferro-magnetic portion.

3. The injection device according to claim 1 , wherein said latch ( 74 ) is anchored within the housing ( 10 ) at a rear end portion and extends forwardly to define a latch surface at a forward region.

4. The injection device according to claim 1 , wherein said shroud element ( 24 ) comprises a cylindrical portion mounted for telescopic movement with the housing.

5. The injection device according to claim 1 , wherein the shroud element ( 24 ) comprises a forward part of an integrally formed component including a spring portion ( 26 ) extending rearwardly from the shroud element and provided with a carrier portion ( 28 ) in which said syringe is received.

6. The injection device according to claim 1 , wherein at least a component of said magnetic force acting between the latch ( 74 ) and said plunger ( 48 ) is in a direction that urges the piston ( 20 ) towards the end of the stroke of the plunger.

7. The injection device according to claim 1 , wherein said latch ( 74 ) is anchored within the housing ( 10 ) at a rear end portion and extends forwardly to define a latch surface at a forward region.

8. The injection device according to claim 1 , wherein said shroud element ( 24 ) comprises a cylindrical portion mounted for telescopic movement with the housing.

9. The injection device according to claim 1 , wherein the shroud element ( 24 ) comprises a forward part of an integrally formed component including a spring portion ( 26 ) extending rearwardly from the shroud element and provided with a carrier portion ( 28 ) in which said syringe is received.

10. The injection device according to claim 1 , wherein at least a component of said magnetic force acting between the latch ( 74 ) and said plunger ( 48 ) is in a direction to assist forward urging of the piston ( 20 ) towards the end of the stroke of the plunger.

Assignees

• Cowe Toby
• Marshall Jeremy
• Owen Mumford Ltd

Inventors

• Cowe Toby
• Marshall Jeremy

Classifications

• A61M5/321 Primary

  Means for protection against accidental injuries by used needles · CPC title

• A61M2005/2073

  preventing premature release, e.g. by making use of a safety lock · CPC title

• A61M2005/206

  With automatic needle insertion · CPC title

• A61M2205/3515

  using magnetic means · CPC title

• A61M5/2033 Primary

  Spring-loaded one-shot injectors with or without automatic needle insertion (multishot dosing syringes A61M5/31525, needle insertion only A61M5/3287) · CPC title