Ratchet wheel 1 is rotated by a drive mechanism (not shown). When button 2 is pressed, pin a is withdrawn so that it no longer brakes wheel 1, and crank lever 3 enters a slot in the stem of button 2, holding pin a in the withdrawn position. Ratchet wheel 1 begins to rotate at increasing speed. After a short acceleration to a speed not exceeding the normal value for the device, elastic strip 5 is released by turning lever 4. As it comes into contact with the teeth of wheel 1, strip 5 begins to oscillate. As it deviates downward, it strikes a tooth, braking the wheel and receiving an activating impulse. During one full oscillation (down and up) of strip 5, wheel 1 turns through an angle corresponding to one tooth. The period and amplitude of oscillation of strip 5 is regulated by damper 6 with a felt tip which is held against the strip by spring 7. The damper varies the active length of strip 5. Vise 8 can be turned about fixed axis A to change the setting angle of strip 5.
$2748$RG,G$