ratchet wheel

When the tympanum vibrates under the influence of the voice, the stylus acts as a pawl and turns a ratchet-wheel.

SB is the primitive radius of the club tooth wheel, but both primitive and real radius of the ratchet wheel.

On the pendulum he had a little ratchet wheel, R, having thirty teeth.

On the side of the clock case was a contact maker, which closed the circuit by the pin on the ratchet wheel, R, once every minute.

An' this ratchet-wheel isn't on the pawl prop'ly—not like what this book says it ought to be.