초록 ▼

A syringe for injection of doses of a medicine from an exchangeable cartridge has a housing comprising a cartridge holder and a dosing mechanism by which a dose is set and injected by successively advancing a piston rod to press a piston into the cartridge. The dosing mechanism comprises a threaded

A syringe for injection of doses of a medicine from an exchangeable cartridge has a housing comprising a cartridge holder and a dosing mechanism by which a dose is set and injected by successively advancing a piston rod to press a piston into the cartridge. The dosing mechanism comprises a threaded spindle and a nut member cooperating with the spindle. A dose is set by relative rotation of the spindle and nut member whereby the nut member is moved along the spindle. The position of the nut member on the spindle defines how far the piston rod is advanced. The spindle and the nut are locked against relative rotation when the dosing mechanism is not operated to set a dose. Access to the cartridge holder is obtained by opening a lid connected to the housing and coupled to the dosing mechanism in such a way that the locking of the nut element in its position on the spindle is released when the lid is opened, and the opening movement of the lid is transmitted to a piston rod retraction mechanism.

대표청구항 ▼

[ I claim:] [1.] A syringe for dosed injection of a medicine from a replaceable cartridge, said syringe comprising:a housing comprising a cartridge holder for receiving a replaceable cartridge of the type having a piston which can be forced into the cartridge to press out a dose of medicine;a lid co

[ I claim:] [1.] A syringe for dosed injection of a medicine from a replaceable cartridge, said syringe comprising:a housing comprising a cartridge holder for receiving a replaceable cartridge of the type having a piston which can be forced into the cartridge to press out a dose of medicine;a lid coupled to the housing for movement between closed and open positions, wherein the lid, when in the latter position, provides access to the cartridge holder for changing cartridges; anda dosing mechanism including a piston rod moveable within the housing for administering doses of medicine from a cartridge; a threaded spindle; a nut member selectively engageable with the spindle so that relative rotation of the spindle and the nut member moves the nut member along the spindle; and a coupling mechanism for moving the piston rod during an injection a distance dependent upon the relative position of the nut member on the spindle; and wherein the lid is coupled to the dosing mechanism so that, when the lid is closed, relative movement between the spindle and nut occurs only when the nut member and spindle are rotated relative to one another and, when the lid is opened, the nut member can be moved relative to the spindle without relative rotation between the spindle and nut member.