History of "GEM box"?

[mdshunk]

Here are some pictures of the box Marc is talking about, ...

Exactly. The one's I noticed were the GEM-D model, with beveled corners, loom knockouts in the top and bottom, as well as the sides. Your GEM-X model, pictured, seems to have square corners and has loom knockouts in the back as well.

 

[stickboy1375]

Exactly. The one's I noticed were the GEM-D model, with beveled corners, loom knockouts in the top and bottom, as well as the sides. Your GEM-X model, pictured, seems to have square corners and has loom knockouts in the back as well.

Yeah, I've seen both versions. usually they have clamps installed also... :wink: except this job.

 

[mdshunk]

Yeah, I've seen both versions. usually they have clamps installed also... :wink: except this job.

Some of my old catalogs show you had to, or rather could, purchase the box and clamps separately.

 

[electricman2]

I don't think they forgot the clamps. The threw them away because they needed room in darn thing. You ever try to replace a switch in one of these. The EC in those days sure had the craft of stuffing wires in a box.

Wonder what they would have done if they had to put a GFCI receptacle in it?

 

[480sparky]

Wonder what they would have done if they had to put a GFCI receptacle in it?

Or a 1000w dimmer?:-?

 

[LarryFine]

Wonder what they would have done if they had to put a GFCI receptacle in it?

Or a 1000w dimmer?:-?

More than 50 years ago???

 

[POWER_PIG]

Gangable Electrical Metal = G.E.M

 

[480sparky]

More than 50 years ago???

Today. Ever try to cram one in when there's 4 or 5 old NMs soldered & taped?

 

[LarryFine]

Today. Ever try to cram one in when there's 4 or 5 old NMs soldered & taped?

Um, no. I've needed to, but figured on replacing the box from the get-go.

 

[mdshunk]

Gangable Electrical Metal = G.E.M

where'd you find that?

 

[LarryFine]

where'd you find that?

Why, you jealous? :grin:

 

[mdshunk]

Why, you jealous? :grin:

Yeah, very! I tried and tried, and I've got resources and skills beyond measure . I came up blank.

 

[chris kennedy]

I've got resources and skills beyond measure .

And tools and testers.:wink:

 

[mdshunk]

I think I found the patent on the things, but I can't find who the assignor was or who the inventor might have worked for (or maybe he was a company owner). They most closely match the 1917 patent of John C. Boyton.

 

[al hildenbrand]

I'm doing a job now where whoever installed these boxes forgot to install the clamps.

A lot of the loom simply wasn't secured at the Gem box.If the concealed K&T was roughed in on porcelain knobs, and the distance into the Gem box is so short that the knob prevents the loom from pushing back out of the box. I see a lot of fished loom that isn't clamped. There were quicker materials than the Gem clamps, such as these wire clips:

Wonder what they would have done if they had to put a GFCI receptacle in it?

The old switches and receptacles, with their porcelain bodies, were every bit as bulky as a modern big bodied device (GFI or Dimmer). The installation technique was different.

One secured the conductors under the terminal screws after mounting the device to the box.

I pulled the switch out with the wires on in this photo above, for the photo only. If the box was still in the wall, the conductors would have to be removed from the terminal screws before the device could be pulled out as there wouldn't be any slack.

Also, most splices of conductor to conductor were done outside of the Gem boxes, occuring at the roughed in, or fished in, conductor runs.

 

[GUNNING]

Could GEM stand for General Electric Manufacturing? Kinda like BX stands for Brooklyn Manufactured by General Electric?

 

[mdshunk]

Could GEM stand for General Electric Manufacturing? Kinda like BX stands for Brooklyn Manufactured by General Electric?

That had crossed my mind, but I was unable to find any reference on the net or in old catalogs to "General Electric Manufacturing". Matter of fact, most of the stuff in GE catalogs in the 20's and 30's as far as electrical hardware was made by other people and just sold in the GE catalog. I even have an old Western Union telegram manual with abbreviations for almost every electrical company and electrical item, and nothing about GEM in it. I had thought that maybe GEM was a Western Union telegram abbreviation for something like some of the other slang is.

 

[K8MHZ]

Could GEM stand for General Electric Manufacturing? Kinda like BX stands for Brooklyn Manufactured by General Electric?

I was told by a very informed source that 'BX' stood for 'B Experimental'.

To support this I found the following on this forum: http://forum.allaboutcircuits.com/showthread.php?t=260

Per Jim Dollins, VP of Product Development for AFC Cable Systems, the term "BX" stands for "Product "B" - Experimental."

Apparently, back when the product was first developed, the first manufacturer of this product had only one product at the time: "Product "A"". So when they developed this product they didn't know what to call it. Somebody suggested "Product "B" with the suffix "X" added as the product was at that time experimental.