Actually, "Bendix drive" is a little more specific.
Modern starters employ a "starter solenoid," a short-stroke linear
motor that forces the starter pinion into the ring gear; when the
solenoid piston (? don't know correct term) bottoms out, some
contacts connect the motor to 12V, and the starter motor cranks the
engine.
Not all starters use a solenoid to force the starter pinion into the
ring gear. The "Bendix drive" omitted the solenoid. Instead, the key
drives a relay somewhere that turns the motor on *before* the starter
pinion has engaged the ring gear.
The pinion keys to the motor shaft with a tooth riding in a spiral cut
on the motor shaft. When the motor begins to spin, the inertia of the
pinion itself causes it to ride the twisting spiral into the ring
gear. A light spring and the rapidly-decelerating motor help it to
ride back home when you release the key. If you don't let go of the
key quickly enough, the faster-turning ring gear will spin the pinion
back home.
As you can imagine, the Bendix drive isn't as reliable as the "modern"
solenoid method, and that's why it isn't used anymore (that I know
of). I seem to recall that US-spec MGs used a Bendix drive starter,
at least until they abandoned the US in the 80s.
By-the-way, the solenoid-style starters employ an "overrunning clutch"
between the starter motor and the pinion; it allows the engine to turn
faster than the motor without damaging anything if you don't let go of
the ignition key quick enough. If you hold the key at START after the
engine is running, you're heating up that overrunning clutch. Those
clutches usually outlast the starter (not always). This "overrunning
clutch" is occasionally referred to as a "Bendix drive," although I
think that's inaccurate.
Bendix is still a large ongoing concern. They make brakes and friction
linings used in many US vehicles; they may still be making starters too
(?). I don't know if they have a website (www.bendix.com isn't active),
but a quick search for 'bendix corp' using Altavista found lots of stuff,
including www.bendix.com.au, and some washing machines :-) .
Sorry for the windy post; I just realized I've offered *nothing* to the
original post :-(.
Good Luck,
stuart hastings