Rotary cam syringe

Abstract

A syringe apparatus includes a housing having upper and lower end portions and a hollow interior. A rotary cam position inside the hollow interior has a projecting portion for operating a cartridge when the apparatus is used. The housing has a rotary bearing for supporting the cam. A syringe cartridge (single chamber or dual chamber) removably fits the housing interior, the cartridge including a barrel with at least one chamber for containing medicine to be dispensed and a dispensing orifice. The cartridge includes a piston having an upper plunger that engages the cam. The piston slides within the barrel chamber forcing contained medicine through the dispensing orifice (e.g., needle) during use. The upper plunger end of the piston engages the rotary cam during dispensing. The cam is movable between first and second positions, the second position being a dispensing position that positions the projecting portion of the cam at the piston. A spring urges the cam to rotate from the first to the second position. A trigger is provided for engaging and holding the cam in the first position. The trigger can be activated to release the trigger and cam from engagement when in the first position so that the spring can move the cam from the first to the second position when the trigger is operated by a user. The needle automatically retracts after dispensing is complete.

Dependencies are inferred from the claim text.