Injection devices
First Claim
1. An injection device formed as two separate assemblies, the first assembly comprising a barrel having forward and rear ends, a syringe carrier for a syringe with a needle within the barrel axially movable between a rearward position, in which the needle of the syringe carried thereby is retracted within the forward end of the barrel, and a forward position, in which the needle projects from the forward end of the barrel, spring means urging the carrier towards the rearward position, and a connector, and the second assembly comprising a firing mechanism with a firing member which, when released, acts on the syringe to urge the syringe forwards to said forward position and then to eject a dose, wherein the firing mechanism is separable from the barrel and in that the connector has limited freedom of axial movement at the rear end of the barrel and is configured for attachment of the firing mechanism, the connector initially being held at a rearward position by the spring means acting through the syringe carrier, but moving to a forward position, taking the syringe carrier with it, as the barrel is held against the skin by the firing mechanism being pressed forwards, the syringe carrier then being in a position intermediate said forward and rearward positions of said syringe carrier from which said syringe carrier can be propelled to said forward position of said syringe carrier on actuation of the firing mechanism, and the connector reverting under the influence of the spring means to said rearward position after removal of the injection device from the skin.
1 Assignment
0 Petitions
Accused Products
Abstract
An injection device has a barrel (1) for housing and guiding a syringe (13) as it is urged forward to project its needle (14), while the dose is ejected, and as a return spring (22) retracts it. A firing mechanism (6) is connectable to the rear end of the barrel and is re-usable, whereas the barrel (1) with its spent syringe (13) is disposable. The connection (4) has limited freedom of axial movement so that, once made, forward pressure on the firing mechanism (6) moves the syringe (13) up to a ready position. A number of barrels (1) with syringes (13) can be housed in a common box (31) with a single firing mechanism (6), the forward end of each barrel (1) being screwed to a locator (32) on the base of the box. The engagement of the firing mechanism (16) with the rear end of each barrel (1) is also screw-threaded, but of opposite hand, so that screwing the firing mechanism (6) on and continuing to turn releases the complete device; and correspondingly the barrel (1) can be returned and located in the box (31) while the firing mechanism (6) is separated from it.
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Citations
9 Claims
- 1. An injection device formed as two separate assemblies, the first assembly comprising a barrel having forward and rear ends, a syringe carrier for a syringe with a needle within the barrel axially movable between a rearward position, in which the needle of the syringe carried thereby is retracted within the forward end of the barrel, and a forward position, in which the needle projects from the forward end of the barrel, spring means urging the carrier towards the rearward position, and a connector, and the second assembly comprising a firing mechanism with a firing member which, when released, acts on the syringe to urge the syringe forwards to said forward position and then to eject a dose, wherein the firing mechanism is separable from the barrel and in that the connector has limited freedom of axial movement at the rear end of the barrel and is configured for attachment of the firing mechanism, the connector initially being held at a rearward position by the spring means acting through the syringe carrier, but moving to a forward position, taking the syringe carrier with it, as the barrel is held against the skin by the firing mechanism being pressed forwards, the syringe carrier then being in a position intermediate said forward and rearward positions of said syringe carrier from which said syringe carrier can be propelled to said forward position of said syringe carrier on actuation of the firing mechanism, and the connector reverting under the influence of the spring means to said rearward position after removal of the injection device from the skin.
Specification