Rack and pinion drive for by-pass cartridge
Inventors
Reynolds, David L. • MacDonald, Daniel • McCarthy, Roger
Assignees
Universiteit Gent • Vlaams Instituut voor Biotechnologie VIB • Duoject Medical Systems Inc
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Publication Number
US-8123084-B2
Publication Date
2012-02-28
Expiration Date
Abstract
A device for mixing a substance comprised of two constituents contained in a cartridge (12) and having a cartridge holder (32) thereabout, the device comprising a plunger rod (46) for pushing a closure member (20) to permit the transfer of a diluent in a second chamber (28) through a by-pass channel (24) to mix with a constituent in a first chamber (26), the plunger rod (48) being driven by means of a rack (48) and a pinion gear (50) arrangement to prevent overly rapid movement of the plunger rod (46).
Core Innovation
A device for mixing a substance comprised of two constituents includes a cartridge and a cartridge holder. The cartridge has a first closure member at a fluid communication end and a second closure member at an actuation end, with a piston within the cartridge intermediate the first and second closure members. The cartridge further includes a by-pass channel for enabling fluid to by-pass the piston when the piston is in a by-pass position.
Mixing is actuated by a plunger rod engageable with the second closure member for moving the second closure member within the cartridge. The plunger rod has a rack gear formed thereon, and the rack gear has a length to permit the plunger rod to advance the second closure member only to proximate the by-pass channel. A housing includes a pinion gear engageable with the rack gear, and a handle connected to the pinion gear drives the rack gear.
The cartridge is described as having a cap with a piercing member and a passageway covered by a gas permeable hydrophobic membrane to evacuate air while retaining liquid. The partial content also describes an alternate embodiment with a shorter housing or cover that allows manual pushing of the plunger after mixing once the rack-driven travel is complete.
Claims Coverage
The independent claim covers a mixing device with a cartridge having two closure members and an intermediate piston with a by-pass channel, actuated by a rack gear and pinion gear driven by a handle, with the rack length configured to limit plunger advancement to proximate the by-pass channel. Dependent refinements further specify venting structure for gas and liquid retention, content organization using a first chamber with a dry constituent and a second chamber with a diluent, and manual pushing mode when rack teeth do not engage the pinion.
By-pass cartridge with two closure members and intermediate piston
A cartridge having a first closure member at the fluid communication end, a second closure member at the actuation end, a piston within the cartridge intermediate the first and second closure members, and a by-pass channel for enabling fluid to by-pass the piston when the piston is in a by-pass position.
Rack-limited plunger rod advancement to proximate the by-pass channel
A plunger rod engageable with the second closure member for moving the second closure member within the cartridge, the plunger rod having a rack gear formed thereon, the rack gear having a length to permit the plunger rod to advance the second closure member only to proximate the by-pass channel.
Handle-driven pinion engaging rack gear within a housing
A housing including a pinion gear mounted within the housing, the pinion gear being engageable with the rack gear, and a handle connected to the pinion gear.
Cartridge cap with piercing member and gas permeable hydrophobic membrane
A cap for attachment at the cartridge end that includes a piercing member and a fluid passageway covered by a gas permeable hydrophobic membrane to evacuate air while retaining liquid.
First and second chambers with dry constituent and diluent
A cartridge arrangement in which a first chamber contains a dry pharmaceutical component and a second chamber contains liquid diluent, separated by the piston and closure members.
Screw-threaded engagement between cap and cartridge holder
A cap that is screw-threadedly engaged with the cartridge holder.
Rack gear tooth portion enables manual pushing when disengaged
A rack gear whose teeth cover only a portion of a plunger rod length so that when the rack gear is disengaged from a pinion gear, the plunger rod can be pushed manually.
Across the independent claim and identified dependent refinements, the core inventive coverage is the use of a piston with a by-pass channel in a cartridge to enable bypass mixing, with a rack-limited plunger actuation mechanism using a handle-driven pinion engaging the rack, supplemented by venting via a piercing-member cap and gas permeable hydrophobic membrane, plus chamber organization and specific mechanical engagement and manual pushing behavior.
Stated Advantages
Not explicitly described in patent.
Documented Applications
A pharmaceutical bypass cartridge mixing/delivery device attachable to a pen injector.
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