[TR] My worst car ever

[Michael Marr]

> Having worked for a Saab dealership in the 60's when the Ford V4 engines
> were being used, I can attest to how neat they were.  But the real
> interesting innovation was the free-wheeling device that they used.  It 
> was
> a simple roller/ramp affair that allows the roller bearings to roll freely
> in one direction but have to climb a ramp in the other direction.  That
> caused them to lock down when the ramp became too tight for free travel.

These devices are variously known as sprag clutches, overrun clutches, or 
conveyor backstops.  They are very versatile - for example, they are often 
used on the top drum of an inclined conveyor to stop it running backwards 
when the motor is off, and my company uses them on several of our double 
ended electric generators that are driven by a gas turbine at one end and a 
steam turbine at the other end.  The gas turbine always drives but the steam 
turbine only drives when there is a call for steam from its exhaust port - 
the rest of the time it idles.  The sprag clutch enables the gas turbine to 
devote all its work to turning the generator and not the idling steam 
turbine.

Mike