Multiple chamber medication dispensing apparatus
First Claim
1. A medication dispensing apparatus comprising:
- a fluid container defining a medication-filled reservoir including an injection chamber and a storage chamber in fluid flow communication, said fluid container including an outlet;
a first plunger including a piston sealing an end of said injection chamber, said first plunger movable relative to said fluid container while maintaining the seal to alter the volume of said injection chamber;
a second plunger including a piston sealing an end of said storage chamber, said second plunger movable relative to said fluid container while maintaining the seal to alter the volume of said storage chamber;
said sealed end of said injection chamber having a cross-sectional area that is smaller than a cross-sectional area of said sealed end of said storage chamber;
a drive assembly drivingly connected to said first plunger and said second plunger, said drive assembly operable during dose setting to shift said first and second plungers relative to said fluid container different distances so as to reduce the volume of said storage chamber while simultaneously increasing the volume of said injection chamber a similar amount; and
an actuator movable to shift said first plunger relative to said fluid container to reduce the volume of said injection chamber to force medicine in said reservoir through said outlet.
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Accused Products
Abstract
A medication dispensing apparatus that can be actuated with a small force to deliver a precise dose. The apparatus includes a fluid container having an injection chamber and a storage chamber in fluid flow communication. A first plunger is movable to alter the volume of the injection chamber, and a second plunger is movable to alter the volume of the storage chamber. The injection chamber has a cross-sectional area that is smaller than a cross-section area of the storage chamber. During dose setting, a drive assembly drivingly connected to the plungers shifts the plungers different distances so as to reduce the volume of the storage chamber while simultaneously increasing the volume of the injection chamber a similar amount. After dose setting, an actuator is movable with a small force to shift the first plunger to reduce the volume of the injection chamber to force medicine through an outlet of the fluid container.
69 Citations
12 Claims
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1. A medication dispensing apparatus comprising:
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a fluid container defining a medication-filled reservoir including an injection chamber and a storage chamber in fluid flow communication, said fluid container including an outlet;
a first plunger including a piston sealing an end of said injection chamber, said first plunger movable relative to said fluid container while maintaining the seal to alter the volume of said injection chamber;
a second plunger including a piston sealing an end of said storage chamber, said second plunger movable relative to said fluid container while maintaining the seal to alter the volume of said storage chamber;
said sealed end of said injection chamber having a cross-sectional area that is smaller than a cross-sectional area of said sealed end of said storage chamber;
a drive assembly drivingly connected to said first plunger and said second plunger, said drive assembly operable during dose setting to shift said first and second plungers relative to said fluid container different distances so as to reduce the volume of said storage chamber while simultaneously increasing the volume of said injection chamber a similar amount; and
an actuator movable to shift said first plunger relative to said fluid container to reduce the volume of said injection chamber to force medicine in said reservoir through said outlet. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. The medication dispensing apparatus of claim I wherein said piston of said second plunger is designed to accommodate hydraulic pressure variance in said reservoir.
Specification