Figure 11-25.-Types of clutches.
means of stopping or starting the driven part. There are
that seen in bicycles. It engages the rear sprocket with
two general classes of clutches: positive clutches and
the rear wheel when the pedals are pushed forward and
lets the rear wheel revolve freely when the pedals are
Positive clutches have teeth that interlock. The
simplest is the jaw or claw type (fig. 11-25, A), usable
The object of a friction clutch is to connect a rotating
only at low speeds. The teeth of the spiral claw or ratchet
member to one that is stationary, to bring it up to speed,
type (fig. 11-25, B) interlock only one waythey
and to transmit power with a minimum of slippage.
cannot be reversed. An example of this type of clutch is
Figure 11-25, C, shows a cone clutch commonly used