Dose setting and correction structure and injection device

Abstract

The utility model relates to pen formula injection device technical field, concretely is a kind of dose setting and correction structure and injection device, dose setting and correction structure include: shell and dose setting ring, the double-direction ratchet wheel engagement tooth slot of being provided on the inner wall of shell one end, multiple curved arms are provided on dose setting ring, double-direction ratchet wheel tooth is provided on curved arm;Double-direction ratchet wheel tooth and double-direction ratchet wheel engagement tooth slot engage;When dose setting ring rotates one unit cell in time, double-direction ratchet wheel tooth is separated from current double-direction ratchet wheel engagement tooth slot, enters next double-direction ratchet wheel engagement tooth slot and is engaged, completes the setting of one unit cell dose;When dose setting ring rotates one unit cell in reverse, double-direction ratchet wheel tooth is separated from current double-direction ratchet wheel engagement tooth slot, retreats to last double-direction ratchet wheel engagement tooth slot and is engaged, completes the correction of one unit cell dose.The utility model can realize correction under dose setting error condition, improve injection accuracy, improve the use friendliness of injection device.

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