Anyone heard of a North Plug or IBM wire relays ... Re: Jones plugs, or similar sorts of plugs

CSquared csquared3 at
Sat May 23 10:12:27 CDT 2009

----- Original Message ----- 
From: "Charles H Dickman" <chd_1 at>
To: "General Discussion: On-Topic and Off-Topic Posts" 
<cctalk at>
Sent: Friday, May 22, 2009 5:13 PM
Subject: Anyone heard of a North Plug or IBM wire relays ... Re: Jones 
plugs, or similar sorts of plugs

> William Donzelli wrote:
>>> There are two series of "Jones connectors", a large pin series and a 
>>> small-pin
>>> series. One may also hear them referred to as Cinch connectors or 
>>> Cinch-Jones
>>> connectors. The large-pin is the 2400 series and the small-pin the 300 
>>> series.
>> There is a third series, with very large (about 3/8 inch wide) pins.
>> --
>> Will
> In the early 60's a machine control my employer used on a can-end making 
> stamping presses (think pull-top beer cans) was built using IBM "wire" 
> relays. The IBM sourced chassis had an array of sockets for the relays 
> with a wirewrap (?) backplane. The chassis was connected to the machine 
> with a large multi-blade connector very similar to the Jones connectors 
> that have been talked about, although smaller in size, they were larger in 
> contact count. The connector was always described as the "North plug". 
> Our BOM system says it was sourced from North Electrical.
> The "wire" relays were quite simple. They consisted of multiple Form C 
> contacts. The moving contact was a wire tack welded to the armature. By my 
> time they had pretty much been replaced by a CD4000 based digital logic 
> system. Stories were told about the tack weld fatiguing and the wire 
> contact shorting things in arbitrary ways. Not a desirable feature for a 
> stamping press control.
> I have been curious about the relays since I found a cannibalized chassis 
> about 10 years ago, which I still have. I thought that the technology 
> might have been used on tabulating machines, but I never did any research. 
> I can take pictures of it to jog memories.
> Anybody (Mr. Donzelli) recall IBM equipment like this?
> -chuck

I'm not sure if these are the same relays or not that IBM used all over the 
place in everything from keypunches and verifiers (024/026/056) up to 1405 
disk drives and who knows what all else.  However, the ones I'm familiar 
with did not have the wires welded to anything.  There were 2 wires per 
contact, usually silver plated that could be slid out, cleaned, and/or 
replaced by simply slipping them back in through a metal "window" against 
which they rested and which provided the operating contact.  For certain 
critical applications (e.g. the 1405 where they actually were used IIRC to 
implement a very slow D/A converter) some of the wires and the posts they 
contacted were gold plated.  The ones I'm familiar with were pluggable as 
well with rectangular cross section pins.

Some pictures would be quite interesting.

Charlie Carothers
My email address is csquared3 at tx dot rr dot com

More information about the cctalk mailing list