Patent ID: 11911599
Assignee: BECTON, DICKINSON AND COMPANY
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 5:
6. A method for delivering a dose of medication from an injection pen comprising:
a housing including a retract nut having flat sides,
a lead screw axially moveable in the housing and engaged to the flat sides of the retract nut,
a dose set member for dose setting and dose correcting, the dose set member including teeth and an internal shoulder, and the dose set member being connected to the housing,
a setback member including tabs, an enlarged head portion and teeth, the enlarged head portion being operatively connected to the internal shoulder of the dose set member during the dose setting and the dose correcting,
a clicker operatively connected to the dose set member and the setback member,
a rotatable driver including grooves that are operatively connected to the tabs of the setback member, the rotatable driver being operatively connected to the lead screw, and
a push button,, the method comprising:
rotating the dose set member to set or correct the dose, where the driver is prevented from rotating, the teeth of the setback member slide over the teeth of the dose set member, arms of the clicker pass over at least one of the teeth of the dose set member and the teeth of the setback member, and the setback member is rotatably locked by engagement of the tabs of the setback member with the grooves of the rotatable driver, and
depressing the push button until the dose set member fully rotates back into the housing, wherein the retract nut is rotationally fixed to the housing to prevent the lead screw from rotating, and the teeth of the setback member engage the teeth of the dose set member, which causes the driver to rotate and axially move the lead screw via engagement of the tabs in the setback member and the grooves in the driver to push a stopper and dispense the dose of medication.