MECHANISM OF REDUCING ESTABLISHED DOSE FOR COCKED PREFILLED SYRINGE Russian patent published in 2014 - IPC A61M5/315 A61M5/20 

FIELD: medicine.

SUBSTANCE: invention refers to medical equipment, namely to a mechanism of reducing an established dose for an injection device comprising a torsion spring to provide a drug dose injection from the injection device. The mechanism for reducing the established dose in the injection device comprises the torsion spring curled when the dose is established by rotating a dose establishing element in relation to a body in the first direction and uncoiled when the above element rotates in the second direction opposite to the first one. The mechanism additionally comprises a fixing member, and at least one ratchet coupled to the dose establishing element. The fixing member is coupled with the body and provided with a number of inverted teeth. At least one ratchet is coupled with one or more teeth of the fixing member and profiled to prevent the rotation of the dose establishing element in the second direction while the above ratchet is coupled with one or more teeth of the fixing member. The mechanism additionally comprise a re-establishing element which rotates in the second direction to activate the ratchet so that to release the fixing element and thereby to make the dose establishing element rotate in the second direction. At least partially inside the dose establishing element, the re-establishing element in the form of a tube fixed in the axial direction in relation to the dose establishing element is provided. At least one ratchet has at least one portion projecting therefrom in the radial direction, and its external radius measured from the central axis of the injection device exceeds the external radius of the rest of the ratchet. The re-establishing tube is provided with the projecting re-establishing element distal in relation to the re-establishing tube having an effect on at least one portion of the ratchet to detach the above ratchet from one or more teeth of the fixing member.

EFFECT: invention provides high strength and less damageable.

3 cl, 5 dwg