American 3 pin mains plug and socket
 

The third grounding pin seems to be always round and with no taper in any
sense. The socket I have here has a ground-pin recess that is a conflation
of a semicircle and half a square in cross section . Equally solid, ie no
springing action. Or is there a taper down the length of the ground pin
recess that I cannot gauge . I expected a round pin with a tapered flat and
a slot along the length of the pin to give some sprung gripping/ latitude
for dimensional inconsistency.

While at it, are the holes in each flat pin , for anti-tugging latch pins ?

American 3 pin mains plug and socket
 

On 8/5/2011 10:06 AM, N_Cook wrote:
While at it, are the holes in each flat pin , for anti-tugging latch pins ?

That's to make it easier to connect solid wire from the outlet box
directly to the plugs when you're too cheap to buy a new receptacle.

Jeff


--
"Everything from Crackers to Coffins"

American 3 pin mains plug and socket
 

Jeffrey Angus wrote in
:

On 8/5/2011 10:06 AM, N_Cook wrote:
While at it, are the holes in each flat pin , for anti-tugging latch
pins ?

That's to make it easier to connect solid wire from the outlet box
directly to the plugs when you're too cheap to buy a new receptacle.

Jeff



IIRC,a new receptacle costs less than $1 at Wal-Mart.

BTW,I've seen a lot of US power plugs with ground pins that are folded
sheet brass that has the half-round/half-square,or U-shape cross-
section,with a bevel at the end. Maybe cheaper to make than a solid round
pin?

the holes in the flat blades are probably a leftover originally intended
for some sort of detent (ball detent?)to help retain the plug.

--
Jim Yanik
jyanik
at
localnet
dot com

American 3 pin mains plug and socket
 

Jim Yanik wrote in message
4...
Jeffrey Angus wrote in
:

On 8/5/2011 10:06 AM, N_Cook wrote:
While at it, are the holes in each flat pin , for anti-tugging latch
pins ?

That's to make it easier to connect solid wire from the outlet box
directly to the plugs when you're too cheap to buy a new receptacle.

Jeff



IIRC,a new receptacle costs less than $1 at Wal-Mart.

BTW,I've seen a lot of US power plugs with ground pins that are folded
sheet brass that has the half-round/half-square,or U-shape cross-
section,with a bevel at the end. Maybe cheaper to make than a solid round
pin?

the holes in the flat blades are probably a leftover originally intended
for some sort of detent (ball detent?)to help retain the plug.

--
Jim Yanik
jyanik
at
localnet
dot com


I should have said I am in the UK
Now you say that I've seen a plug with a U channel ground pin ,somewhere
along the way. I could see that arrangement maybe giving some sort of
sprung/ tolerating fit. But how does a cylindrical brass pin make good
contact with an unsprung receptacle pin ?

American 3 pin mains plug and socket
 

N_Cook wrote:
Jim Yanik wrote in message
4...
Jeffrey Angus wrote in
:

On 8/5/2011 10:06 AM, N_Cook wrote:
While at it, are the holes in each flat pin , for anti-tugging latch
pins ?
That's to make it easier to connect solid wire from the outlet box
directly to the plugs when you're too cheap to buy a new receptacle.

Jeff


IIRC,a new receptacle costs less than $1 at Wal-Mart.

BTW,I've seen a lot of US power plugs with ground pins that are folded
sheet brass that has the half-round/half-square,or U-shape cross-
section,with a bevel at the end. Maybe cheaper to make than a solid round
pin?

the holes in the flat blades are probably a leftover originally intended
for some sort of detent (ball detent?)to help retain the plug.

--
Jim Yanik
jyanik
at
localnet
dot com


I should have said I am in the UK
Now you say that I've seen a plug with a U channel ground pin ,somewhere
along the way. I could see that arrangement maybe giving some sort of
sprung/ tolerating fit. But how does a cylindrical brass pin make good
contact with an unsprung receptacle pin ?



The internal split wiper pairs of the AC socket are under some tension,
to make a good electrical contact, this holds for the ground pin as well.

As for the holes in the flat pins, I can't find a reference easily but
believe that they are for dimples in earlier sockets that are no longer
present. It could also be that dimples exist in ceiling outlets
only...you can do some hunting and report back!

John :-#)#

John :-#)#
--
(Please post followups or tech enquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

American 3 pin mains plug and socket
 

On Fri, 5 Aug 2011 17:45:14 +0100, "N_Cook" wrote:

Jim Yanik wrote in message
. 44...
Jeffrey Angus wrote in
:

On 8/5/2011 10:06 AM, N_Cook wrote:
While at it, are the holes in each flat pin , for anti-tugging latch
pins ?



I should have said I am in the UK
Now you say that I've seen a plug with a U channel ground pin ,somewhere
along the way. I could see that arrangement maybe giving some sort of
sprung/ tolerating fit. But how does a cylindrical brass pin make good
contact with an unsprung receptacle pin ?


All the outlets I've checked have some type of spring material on all
the contacts. Some are better made than others (a receptacle with a
brand I recognize versus a $1 nameless duplex receptacle at WalMart).
I spent a bit more for the 20 amp receptacle that sees use with a
table saw and a small wirefeed welder. The saw can hit 20 amps at
startup and the welder can run near 20 amps continuously, but I rarely
have the arc going for more than a 30 seconds at a time - I'm not
building bridges, just welding small things such as a hanger for a
garden hose or repairing a metal stand for a bird feeder.

John

American 3 pin mains plug and socket
 

On Fri, 05 Aug 2011 10:00:16 -0700, John Robertson wrote:

As for the holes in the flat pins, I can't find a reference easily but
believe that they are for dimples in earlier sockets that are no longer
present. It could also be that dimples exist in ceiling outlets
only...you can do some hunting and report back!

I have seen, in the past, 'security' locks (both metal and plastic) that
engage both the mains pins through these holes and prevent insertion
into an outlet.

Probably NOT what the holes are for, but such a lock could be A Good
Idea on some appliances or equipment in an environment with children.

Jonesy
--
Marvin L Jones | jonz | W3DHJ | linux
38.24N 104.55W | @ config.com | Jonesy | OS/2
* Killfiling google & XXXXbanter.com: jonz.net/ng.htm

American 3 pin mains plug and socket
 

"N_Cook" wrote in :

Jim Yanik wrote in message
4...
Jeffrey Angus wrote in
:

On 8/5/2011 10:06 AM, N_Cook wrote:
While at it, are the holes in each flat pin , for anti-tugging
latch pins ?

That's to make it easier to connect solid wire from the outlet box
directly to the plugs when you're too cheap to buy a new
receptacle.

Jeff



IIRC,a new receptacle costs less than $1 at Wal-Mart.

BTW,I've seen a lot of US power plugs with ground pins that are
folded sheet brass that has the half-round/half-square,or U-shape
cross- section,with a bevel at the end. Maybe cheaper to make than a
solid round pin?

the holes in the flat blades are probably a leftover originally
intended for some sort of detent (ball detent?)to help retain the
plug.

--
Jim Yanik
jyanik
at
localnet
dot com


I should have said I am in the UK

I think you did.

Now you say that I've seen a plug with a U channel ground pin
,somewhere along the way. I could see that arrangement maybe giving
some sort of sprung/ tolerating fit. But how does a cylindrical brass
pin make good contact with an unsprung receptacle pin ?



AFAIK,the receptacle female contacts are one-piece,formed from sheet
stock,and the blade or ground pin goes in between the sides,spreading them
apart slightly.
the female contacts have some springiness built in. They are like a very
deep U shape.

BTW,I checked a "hospital-grade" plug,and it's ground pin is U-shaped flat
stock,as I described earlier. Pretty heavy gauge stock,around 1/16" thick.

--
Jim Yanik
jyanik
at
localnet
dot com

American 3 pin mains plug and socket
 

On Fri, 5 Aug 2011 16:06:10 +0100, "N_Cook" wrote:

While at it, are the holes in each flat pin , for anti-tugging latch pins ?
Close - spring loaded pins with a ball-shaped end, designed to hold
the blade in the outlet. As better alloys were developed the
construction became much simpler, but the detents remained.

PlainBill

American 3 pin mains plug and socket
 

I came across an old bakellite 3 pin USA receptacle yesterday. The third pin
socket in that was 2 definite sprung flat contacts, touching across a
diameter of the pin