In article <
nyyfbegfubjuvyypb...@srv1.howhill.co.uk>,
I think we have exactly the same one!
It's got a very clever automatic spindle lock built into the tail
end of the gearbox (which I didn't actually appreciate until I had
the gearbox in pieces one day). If the motor is driving the bit
(in either direction), it rotates freely. If the bit it trying to
drive the gearbox (as happens if you try using it as a manual
screwdriver), it instantly locks the bit solid. It has a set of
rollers in something which looks a bit like a minature wankel
engine, relying on the rollers jamming or not, to engage or
disengage the locking of the bit to the case. It was a bugger
to reassemble. I initially gave up, being unable to see what
that part did. Then I found I couldn't use it as a manual
screwdriver as it tended to cause the motor to spin instead.
Took it all apart again, and with much difficulty, managed to
get all the rods back in place, and it was working again.
I'm sure that locking mechanism must have a name, and probably
a patent too.
Charger is just an AC wall wart, with a half-wave rectifying
diode in the holder which makes contact with the charging
contacts. Amazingly, I have actually got long life and lots
of use out of each set of batteries.