Patent ID: 9022991
Filing Date: 2015-05-05
Classification: A61M

Abstract:
1. An injection syringe apparatus in which when a dose is set an injection button elevates from an end of the syringe apparatus a distance proportional to the set dose, the injection syringe apparatus comprising: a. a non-rotatable, longitudinally displaceable, guided threaded piston rod having a distal end for pressing medicine out of a cartridge; b. a tubular element that is rotatable and axially displaceable, wherein the injection button is fixed to the tubular element at a proximal end of the tubular element so that the injection button rotates and translates with the tubular element; c. a housing element; d. a nut element threadedly engaging the thread on the piston rod thereby forming a first threaded arrangement, wherein the nut element screws up the piston rod away from a defined position in the housing element and can be pressed back to the defined position carrying the piston rod with it when a set dose is injected, wherein the axial distance the nut element is moved is less than the axial distance the injection button is moved; wherein the nut element comprises a connecting element comprised of connection bars or a tubular connection element for rotating the nut element when setting the dose; e. a dose setting drum that rotates during the setting of a dose, the dose setting drum being threadedly engaged with the housing element via a second threaded arrangement so that when the threaded dose setting drum is rotated it is axially displaced relative to the housing element, wherein the second threaded arrangement is different than the first threaded arrangement so that the injection button has a larger stroke than the piston rod; f. a helical scale disposed on an exterior surface of the dose setting drum; and g. a coupling that couples and decouples rotational motion of the dose setting drum with the tubular element and the injection button, the coupling comprised of a pair of releaseably engageable elements, wherein when a dose is set by rotating the dose setting drum, the tubular element and dose setting drum rotate together but when a user injects a dose by pressing on the injection button, the dose setting drum is rotationally decoupled from the tubular element so that the dose setting drum rotates back to a zero position while the tubular element, the nut element, the piston rod, and the injection button move axial without rotating.