| 摘要 |
An endoscopic instrument with a deflectable distal end (16, figure 1) is connected via at least one control wire 32, 34 to a proximal actuation wheel (18, figure 1). A belt drive arranged between the control wire and the actuation element forms a safety coupling which limits a force exerted by the actuation element onto the control wire. Preferably the belt drive is a toothed belt 36 coupling two sprockets 24, 28; the actuation element (18, figure 1) being coupled to the first sprocket and a wheel 30 to which the control wires are mounted being connected to the second sprocket. Excess force applied through the actuation element causes the belt to deform and disengage from the sprocket teeth. Guides 38, 40 mounted at each end of the belt drive prevent the belt slipping laterally and may have a U—shape section accommodating escape of the belt in the radial direction. |
