Pen shaped medication injection devices
First Claim
Patent Images
1. A delivery device that comprises:
- a fluid cartridge holder comprising a cartridge containing fluid,a housing,a piston drive mechanism situated within the housing and comprising a hollow piston rod and a drive-shaft,which hollow piston rod has an internal thread on at least a portion of its inner surface and a non-circular outer section,and which drive-shaft has an external thread which mates with the internal thread of the hollow piston rod forming a thread connection and being axially restrained in the proximal direction relative to the housing,a piston drive mechanism for rotating the drive-shaft such that upon activation of the driving mechanism the piston rod is forced to move axially in the distal direction causing ejection of the fluid from the cartridge, the delivery device further characterized in that the internal threads on the hollow piston rod and the external threads on the drive shaft are not exposed when the cartridge holder is removed.
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Abstract
The present invention provides a delivery device comprising a fluid cartridge holder, housing and a piston drive mechanism that comprises a hollow piston rod and a drive-shaft. The hollow piston rod has an internal thread that mates with the external thread of the drive-shaft, forming a thread connection and being axially restrained in the proximal direction relative to the housing. The drive mechanism is in turn connected to the housing via a one way ratchet such that the piston rod is prevented from moving in the proximal direction.
59 Citations
45 Claims
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1. A delivery device that comprises:
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a fluid cartridge holder comprising a cartridge containing fluid, a housing, a piston drive mechanism situated within the housing and comprising a hollow piston rod and a drive-shaft, which hollow piston rod has an internal thread on at least a portion of its inner surface and a non-circular outer section, and which drive-shaft has an external thread which mates with the internal thread of the hollow piston rod forming a thread connection and being axially restrained in the proximal direction relative to the housing, a piston drive mechanism for rotating the drive-shaft such that upon activation of the driving mechanism the piston rod is forced to move axially in the distal direction causing ejection of the fluid from the cartridge, the delivery device further characterized in that the internal threads on the hollow piston rod and the external threads on the drive shaft are not exposed when the cartridge holder is removed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45)
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Specification