When handwheel 1 is rotated about fixed axis A-A, screw 2 traverses slide 3, whose lower end is a nut, along fixed guide d. As soon as slide 3 runs up against stop 4, or the mechanism is overloaded, cam surface a of handwheel 1, designed as an inclined plane, begins to turn with respect to mating cam surface b of screw 2. This shifts shaft 6 to the left, compressing spring 5 and screw 2 remains stationary.
$3074$SmC,ML$