"michael adams" wrote in message
...

"charles" wrote in message
...
In article ,
Tim Streater wrote:
In article , Sam E
wrote:

On 08/29/2017 02:11 PM, Rod Speed wrote:

[snip]

The bigger problem is that if you arent careful when wiring the
socket in, you can end up with the active on the outer metal which
is often touchable when changing a bulb and with a bulb failure,
not everyone turns the light off before changing the bulb because
it isnt obvious that its still turned on to the technoklutzes.

Why are you touching the metal part of the socket when changing bulbs?

You're not seeking to do that deliberately, but it may happen -
especially if the bulb is hard to get out due to having been screwed in
too tight.

whereas bayonet bulbs never jam in their sockets?

How would that happen ?

Corrosion between the bulb base and the socket.

The bulb is secured in the slot by the spring in the socket.

Yes.

For the bulb to jam presumably the spring would need to jam or break in
the open position.

That’s just one way.

Which would be malfunction in the apparatus

Same with corrosion.

and totally divorced from possible human error.

On the other hand one of the supposed benefits of screw fit bulbs is that
when fully screwed home they are more secure than a bayonet fit bulb.

Nothing supposed about it, they are.

However among possible disadvantages -

"It is possible to over-tighten the screw and jam the bulb"

Never had that happen, essentially because the
central contact deforms if you do over tighten it.

This is a fault which is solely the result of possible human error.

Basically screwing and unscrewing threaded bulbs requires a degree of
judgement and finesse which isn't required when using bayonet bulbs.

In practice it doesn’t.

And can't necessarily be taken for granted, But then Thomas Edison was not
only an American but was a genius, right ?

And produced a much better arrangement whose main downside
is that is possible to wire the socket so the outer is active.