Antique Trumbull electric 710 knife switch

[JohnDeere]

I got the old knife switch today, I wanted to know what this switch may have been used for back in the day. It seems to have date stamp of 2-1923. It seems kinda dangerous with all the exposed conductors. Also, what might it be worth?

 

[Firebrick43]

Well your not supposed to lick them.

 

[Drill Sergeant Arc]

Is that the trap you buy to kill robot mice?

 

[nadogail]

Is that a Double Pole Double Throw?

 

[beemerphile]

...It seems kinda dangerous with all the exposed conductors.

I worked in the control room of a glass furnace many many years ago and one wall was full of knife switches much larger than this. The control room was about 4 ft. wide and 20 ft. long. You had to turn sideways to pass the other operator. When a new operator showed up he got the warning about the live front switches that consisted of "Hey Leon, show him your back!" Leon would raise his shirt and turn around to reveal a skin burn tattoo in the shape of the knife switch. No-one ever died from it and not many people besides Leon ever tested one. Later the switches were replaced with draw out metal switchgear for safety reasons. A maintenance man was injured pretty badly when he vaporized a screwdriver trying to bypass the door interlock.

 

[dave*99]

I used them for science fair projects in the 60's They were sold at the hardware store.

 

[wyliesdiesels]

Is that a Double Pole Double Throw?

Yes like a 4-way switch

 

[dave*99]

Yes like a 4-way switch

Kinda.
A 4 way has 4 terminals and internal cross connections.
This knife switch has 6 terminals. And an off position. So it’s a double pole double throw center off switch.
You can add those cross connections to this knife switch and have it function as a 4 way.

 

[S-K Tool Fanatic!]

A maintenance man was injured pretty badly when he vaporized a screwdriver trying to bypass the door interlock.

A moment of silence for the screwdriver.

 

[htmdude57]

what might it be worth?

Depending on what you paid for it- either more than that, or less than that.

 

[kbuhagiar]

You'll probably generate more interest amongst the tool-challenged masses if you call it a Frankenstein switch.

 

[txvwnut]

Well your not supposed to lick them.

Now you nell me!

 

[fartymarty]

Well your not supposed to lick them.

Now you nell me!

I saw what you did there.
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I thought those were only used in prison movies to energize the electric chair.

 

[JohnDeere]

I got it for free.

Depending on what you paid for it- either more than that, or less than that.

 

[Zeke]

I don't see room nor lugs on the top contacts. Maybe just a parking spot?

 

[dave*99]

I don't see room nor lugs on the top contacts. Maybe just a parking spot?

I see 3 heavily oxidized screws and 1 shiny copper spot where a screw fell out.
I believe there are 2 screws under the handle. That's how the one I owned was built.

There are 6 lugs - there are tapped holes in the rivets.

 

[dave*99]

I found a better photo:

 

[Bert_]

I love this old electrical gear. I have my share of this stuff stashed away but I've never seen a double throw version in person.

I pulled out what I could find to share.

 

[Drill Sergeant Arc]

A moment of silence for the screwdriver.

I heard he had it coming. . .