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Northern Electric Telephone Case Compression Molding

Started by Ktownphoneco, September 05, 2016, 07:02:19 PM

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Ktownphoneco

I ran across this picture recently, and although it most likely came out of a magazine at some point, it does show the machine used by Northern Electric to cast the Bakelite Uniphone cases.
The caption under the picture reads .. " Before injection molding machines, parts were often made on compression machines, such as this 350 tone Duo Press used by Northern Electric to mold phone parts.
I cleaned up the photograph as best I could, but it's still not in the best of shape, but looking closely at the picture, the cases of both a model 1, and model 2 Uniphone telephone can be seen sitting on the lower jaw of the open press.   The machine looks more like a "hippo", than a press.     I'm initially posting the picture at it's original size  of 4" x 6", but if it's too small, I'll scan it at a larger size and modify this post.

Jeff Lamb
 

unbeldi

The resolution isn't high enough to be sure just what those items are sitting, on the jaw.

I would suspect that those might be the dies for the housings not housings themselves.
Being called "Duo Press", does that imply two identical housings are pressed or one each of the two kinds you mentioned?  It would be harder to understand why they would have different kinds in one press, but perhaps the press could be used with the two different dies.

Ktownphoneco

Karl  ..  The part I typed in quotations is the only thing that was written about the machine.   My eyes see what appears to be a model 1 and a model 2 case sitting there, and it also appears as if the actual die is attached to the upper jaw with the cradle posts pointing down.    It's quite possible that the model 1 and model 2 cases were just placed on the lower jaw for the purposes of taking the picture.
I know nothing about the press, other than what was written in the very short synopsis under the photo.
It would make financial sense that if Northern decided to buy the machine(s), that it / they, be capable of making cases for both the model 1 and and the model 2 by merely changing dies.   I would also imagine that the press was designed to make more than simply one case at a time.    However, here's a enlargement scan of the original image, but it still doesn't produce a silk purse out of the proverbial sow's ear.   I've searched around the web trying to find a better picture, but so far no luck.    At this point, it is what it is.

Jeff
 

unbeldi

Thanks, Jeff.
Somehow, it still seems to me that the press has one die pointing downwards, as you stated, and another pointing upward, pressing two housings out of one batch of resin. Perhaps this is the meaning of Duo ? I can see that such an arrangement might utilize space more efficiently.

TelePlay

Isn't that another one, a second machine, to the left in the closed position and from the back opposite corner showing the control levers?

Ktownphoneco

It's possible John, but I can't see those same 2 control levers on the machine that was photographed.    I wish the reproduced photo was of a better quality. 

Jeff
   

unbeldi

I would assume that they had many of these presses in one hall.  Phenyl resin take perhaps 3 minutes to finish the reaction to Bakelite, so with a single press they could only make perhaps over 200 housings per eight-hour day if the press produces two at a time.

TelePlay

Quote from: Ktownphoneco on September 06, 2016, 08:22:47 PM
I wish the reproduced photo was of a better quality.     

Yes, that is unfortunate.

I was looking at the dome of the unmovable part on each and they looked the same. I am just guessing but having the machines rotated 180 degrees on the floor would put the control handles of each machine between the two machines allowing one person to operate both machines.