Strowger (Automatic Electric Co.) later model dial desk set.

1909

model
second generation Strowger dial
manufacturer
Automatic Electric Company
condition
Mint, original condition.

About

There are a few Strowger dial telephones circulating out there, but this particular Stronger dial is a very special and historically significant phone. The Strowger dial was the first automatic dial telephone but the early versions of the dial had two flaws. Calling impulses were irregular because the person dialing could not dial the number at exactly the same speed and there were also premature releases of the switches because the dial could go backward. The telephone shown here is the only known example of the Strowger dial after patented improvements began in 1908. This particular Strowger dial telephone has been provided with the common dial and also a supplemental or controlling dial, forcing the dial in a forward direction, but not backward. With this arrangement both dials will rotate forward and when a subscriber releases them, only the inner (or common) dial will then rotate back to the normal position. This prevents any forcing or accelerating of the backward rotation of the calling dial, inasmuch as the outside or supplementary dial is always positively locked against back rotation. An arrangement of this character insures the proper transmission of the electrical impulses for operating the switches at the exchange or central station.  The scan is from the U.S. patent office.  The patent for this improvement was filed in 1908 and granted in 1915.  Other scans are from original Strowger photos, catalogs and magazines.

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