图1所示之虎钳,从结构上看与一般虎钳不同,它的螺母可以减少力矩,也就是使力臂达到极小值(图2)。这样,便可降低螺母与虎钳传动丝杆间的磨损,同时还可消除动钳口的窜动(图3上)。一般虎钳螺母承受的是偏心力,力矩较大(图3下),由于力矩大所以易磨损,影响其使用精度。这种新型虎钳的所有运动部件都是密封的,防止了因污物或切屑侵入而造成的 The vise shown in Figure 1 is structurally different from a normal vise. Its nut reduces the torque, which means that the lever arm reaches a minimum value (Figure 2). In this way, the wear between the nut and the vise drive screw can be reduced and the movement of the movable jaw (Figure 3) eliminated. General vise nuts bear eccentric force, torque larger (Figure 3), due to large torque so easy to wear, affecting the accuracy of its use. All moving parts of this new type of vise are sealed to prevent intrusion of dirt or chips