The invention discloses a
torsion spring automatic
injector, comprising a pen body, the pen body is equipped with a
dose setting component and an injection component; the injection component comprises a release button, a
clutch cylinder, a small push rod, a
torsion spring and a push rod driving member, the
dose setting component comprises a knob, a
clutch tooth and a
jumping tooth, the upper end surface of the
clutch tooth is provided with an inner
ratchet ring, the knob is provided with an outer
ratchet ring, the
jumping tooth is movably installed in the knob, the lower end surface of the
jumping tooth is provided with an inner tooth block and an outer tooth block respectively meshing with the inner
ratchet ring and the outer ratchet ring, the knob is also provided with a plurality of rotating slots, the side of the jumping tooth is provided with a plurality of rotating blocks respectively inserted into the rotating slots, and the two ends of each rotating slot are respectively provided with a forward rotation rib block and a reverse rotation rib block for blocking the rotating block. The scheme has a simple structure, is easy to operate, is convenient to carry, and adopts axial jumping to adjust the
dose and make sounds.