The present disclosure relates to a medicament delivery device (1) comprising a body (11), an axially biased plunger rod (15) provided with a first external thread (15a), an activation member (5) arranged to activate the plunger rod (15), a tubular medicament scale member (21) receiving the activation member (5), which tubular medicament scale member (21) is rotatable relative to the body (11) and provided with a visual medicament dose scale (7), a stop nut (23) which receives the plunger rod (15) and which stop nut (25) is provided with an internal thread engaging with the first external thread (15a) of the plunger rod (15), and a gear train arrangement (37) arranged to, in a decoupled state decouple the stop nut (23) from the tubular medicament scale member (21), and in a coupled state couple the stop nut (23) to the tubular medicament scale member (21) for transferring rotational motion of the stop nut (23) to the tubular medicament scale member (21), in order to convey a measure of axial movement of the plunger rod (15) to the tubular medicament scale member (21), thereby providing an indication, on the visual medicament dose scale (7), of an amount of expelled medicament.本揭示內容有關藥物輸送裝置(1)，包含本體(11)；經軸向地偏向的柱塞桿(15)，設有第一外螺紋(15a)；啟動構件(5)，被配置來啟動該柱塞桿(15)；管狀藥物刻度尺構件(21)，承接該啟動構件(5)，該管狀藥物刻度尺構件(21)係可相對該本體(11)旋轉，並設有視覺之藥物劑量刻度尺(7)；止動螺帽(23)，其承接該柱塞桿(15)，且該止動螺帽(23)係設有與該柱塞桿(15)的第一外螺紋(15a)嚙合之內螺紋；及齒輪系配置(37)，被配置來在退耦狀態中將該止動螺帽(23)由該管狀藥物刻度尺構件(21)退耦，並於耦接狀態中將該止動螺帽(23)耦接至該管狀藥物刻度尺構件(21)，用於將該止動螺帽(23)的旋轉式動作傳送至該管狀藥物刻度尺構件(21)，以便將該柱塞桿(15)之軸向運動的測量運送至該管狀藥物刻度尺構件(21)，藉此在該視覺之藥物劑量刻度尺(7)上提供被排出藥物的數量之指示。
