A system for preventing delivery of less than a predetermined minimum dose of a medicament by providing a dose setting mechanism (104) having a clutch ring (130 200) rotationally fixed relative to the housing (120) when a dose less than the minimum allowable dose is selected. The dose setting mechanism also includes a drug delivery device housing (120) and a dose dial component (122 202) positioned in the housing and rotatable during a dose setting step. A drive sleeve (124 206) is positioned within the dose dial component, a spindle (126) is positioned within the drive sleeve, and a clutch (128 212) is positioned between the dose dial component and the drive sleeve. When the dose dial component is rotated to select a dose less than a minimum dose, a clutch ring (130 200) prevents the drive sleeve from rotating to thereby prevent the selected dose from being administered.一種藉由提供一劑量設定機構(104)用以避免小於一預先決定的最小劑量之藥物之輸送之系統,劑量設定機構(104)具有一離合器環(130;200),其在選擇一小於最小可允許劑量之劑量時,與殼體(120)相對的被旋轉地固定。劑量設定機構亦包含一藥品輸送裝置殼體(120)以及一劑量標度元件(122;202),其安置在殼體中且在一劑量設定步驟期間可旋轉。一驅動套筒(124;206)安置在劑量標度元件之內,一主軸(126)安置在驅動套筒之內,且一離合器(128;212)安置在劑量標度元件與驅動套筒之間。當劑量標度元件被旋轉以選擇一小於一最小劑量之劑量時,一離合器環(130;200)避免驅動套筒旋轉,藉以避免選擇劑量被供給。104...劑量設定機構/劑量標度機構112...標度把手113...劑量按鈕120...殼體122...數字套筒/劑量標度元件/劑量標度套筒124...驅動套筒126...主軸128...離合器130...離合器環132...金屬彈簧134a、b...主軸撓性臂/主軸臂/主軸驅動臂136...近端方向138...驅動套筒內螺紋/驅動螺紋156...外螺紋160...遠端方向
