Medication delivery pen having improved dose delivery features
First Claim
1. An injection device for injecting selected dosages of fluid, comprising:
- an elongate housing;
means for mounting a fluid containing cartridge of the type including an internal piston to said housing;
manually operable piston moving means including a piston rod axially movably mounted within said housing for displacing fluid from a cartridge by moving said piston is said cartridge;
dose setting means for selecting the amount of fluid to be delivered by said device including a manually rotatable unit counter ring, a tens counter ring positioned in adjoining relation to said units counter ring, and transmission means for connecting said units counter ring and said tens counter ring, said transmission means including means for causing said tens counter ring to rotate a selected number of degrees upon rotation of said units counter ring through a selected angular displacement; and
means responsive to said dose setting means for controlling the axial movement of said piston rod such that the distance said piston rod can be moved is dependent upon the rotational position of said units and tens counter rings.
1 Assignment
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Accused Products
Abstract
An injection device is provided for injecting fluids such as insulin within body tissue. The device includes a housing, a piston rod movably mounted within the housing, and a dose setting mechanism for controlling the movement of the piston rod with respect to a fluid containing cartridge removably positioned within the housing. The dose setting mechanism includes a units counter ring and a tens counter ring. A transmission key is provided for selectively coupling the units and tens counter rings so that they rotate together only during selected portions of the dose setting procedure. The piston rod includes a plunger and a lead screw slidably positioned within the plunger. The plunger and lead screw are coupled by a pair of half nuts. The half nuts may be uncoupled from the lead screw in order to allow it to slide freely with respect to the plunger. A new cartridge may accordingly be installed quickly and easily as the lead screw is easily displaced by a new cartridge.
346 Citations
13 Claims
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1. An injection device for injecting selected dosages of fluid, comprising:
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an elongate housing; means for mounting a fluid containing cartridge of the type including an internal piston to said housing; manually operable piston moving means including a piston rod axially movably mounted within said housing for displacing fluid from a cartridge by moving said piston is said cartridge; dose setting means for selecting the amount of fluid to be delivered by said device including a manually rotatable unit counter ring, a tens counter ring positioned in adjoining relation to said units counter ring, and transmission means for connecting said units counter ring and said tens counter ring, said transmission means including means for causing said tens counter ring to rotate a selected number of degrees upon rotation of said units counter ring through a selected angular displacement; and means responsive to said dose setting means for controlling the axial movement of said piston rod such that the distance said piston rod can be moved is dependent upon the rotational position of said units and tens counter rings. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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Specification