Patent ID: 6582405
Filing Date: 2003-06-24
Classification: A61M

Abstract:
An electrically-driven dental injector comprising a housing having a nose portion, a support member secured to said nose portion and having a forwardly protruding socket for receiving a barrel adapted to contain a cartridge therein, means for coupling said barrel with said socket, a plunger rod sidably mounted in a bore in said support member and movable between its initial position and it's forwardly advanced position to push a plunger rubber in the cartridge, said plunger rod having a rack, a pinion meshed with said rack to advance said plunger rod, an electrical motor with reduction gear mounted within said housing, a planetary reduction gear located between said motor and said pinion and housed in a casing, a latch mechanism for coupling a ring gear of said planetary reduction gear with said casing or uncoupling said ring gear from said casing to transmit drive rotation of the motor to said pinion or interrupt the transmission of the rotation between said motor and said pinion, and an operating rod extending through said support member and operatively cooperating with said latch mechanism, whereby when said plunger rod is manually pushed from it's advanced position toward its initial position, said latch mechanism is released and at the same time, said operating rod protrudes beyond the inner bottom surface of the socket, and when said barrel is coupled to said socket, it pushes back said operating rod barrel with an end face of the barrel to engage said latch mechanism.