Cartridge interface assembly

摘要

A cartridge interface assembly (80) characterized by a driving plunger (82) including an outer shaft (84), and a driver (86) including an inner shaft (88) movable telescopically with respect to the outer shaft (84), wherein rotation of the driver (86) causes the driving plunger (82) to advance in a direction away from the driver (86), and wherein the cartridge interface assembly (80) is inserted in a cartridge (22) in which a plunger (24) is slidingly disposed, and rotation of the driver (86) causes the driving plunger (82) to advance distally in the cartridge (22) until abutting against the plunger (24).

主权项

1. A combination cartridge and cartridge interface assembly comprising:
a rotationally immobile cartridge (22) having an inner cylindrical surface, a first stopper (24) slidingly inserted in the cartridge (22), a distal end and a substance therein for administration to a subject; and a cartridge interface assembly (80) comprising:
a driving plunger (82) comprising a first shaft (84), the driving plunger (82) having an abutting surface and one or more outer surfaces in contact with the inner cylindrical surface of the cartridge (22);a driver (86) comprising a gear wheel and a second shaft (88) rotatably fixed to the gear wheel, said second shaft (88) mating with said first shaft (84), so that said shafts are movable telescopically with respect to one another, wherein rotation of said driver (86) causes said driving plunger (82) to linearly advance in a direction away from said driver (86), the arrangement being such that on insertion of the cartridge interface assembly (80) in the rotationally immobile cartridge (22), the one or more outer surfaces of the driving plunger (82) and the inner cylindrical surface of the cartridge (22) have a frictional relationship such that it is easier for the driving plunger (82) to move linearly than rotate within the cartridge, wherein the frictional relationship is the only force impeding rotation of the driving plunger (82) with respect to the cartridge (22) such that rotation of said driver (86) causes said driving plunger (82) to linearly advance only towards the distal end until the abutting surface of the driving plunger (82) abuts against the stopper (24) whereupon the driving plunger (82) urges the stopper (24) towards the distal end for metering substance from the cartridge; anda locking assembly that permits said driver (86) to rotate in a first rotational direction and blocks rotation of said driver (86) in a second rotational direction opposite to the first rotational direction.