The invention relates to pruning shears (100) comprising cutting head (200) with a spring-biased blade (201) pivotally connected to a jaw (202) arranged to sever a workpiece received in a bight (203) formed by the jaw (202). A drive mechanism (300) is connected to the cutting head (200) and an elongate housing (400) is connected to the drive mechanism (300). The drive mechanism (300) comprises a rotation prevention means for preventing rotation of a second pulley in relation to the drive mechanism (300) when a drawing torque is applied to the second pulley, wherein the drawing torque is greater than a threshold torque, resulting in a second pulley being stationary in relation to the drive mechanism (300) and the first pulley rotating in relation to the drive mechanism (300).本發明涉及一種修枝剪，包括：剪切頭部，所述剪切頭部具有彈簧偏壓的刀片，所述彈簧偏壓的刀片可樞轉地連接到刀片夾，所述刀片夾佈置成切斷接收在由所述刀片夾形成的灣部中的工件。驅動機構連接到剪切頭部並且細長殼體連接到所述驅動機構。驅動機構包括抗旋轉機構，用於在將牽引轉矩施加到第二滑輪時防止第二滑輪相對於驅動機構旋轉，其中，所述牽引轉矩大於閾值轉矩，從而導致所述第二滑輪相對於所述驅動機構靜止而所述第一滑輪相對於所述驅動機構旋轉。
