Lucius1958 wrote:Actually, the "rollers" referred to were part of the "shock-proof" governor, used for a period on the Type B motor: a more complex mechanism than the standard governor, and which proved difficult to service.
There is a thread on the subject here:
View topic - Edison "shock proof" Gover ... Recordings
Bill
Thanks, Bill, for bringing up this old post.
That's my own post from back in November when I began to research the three spring “shock proof” governor that is on my C 250. I hadn't planned on getting too in depth on this topic, but I feel compelled to explain myself.
Since that November post, I’ve discovered a few things:
As it turns out, that version of governor (in my C 250) was not introduced until the 1920's; it was known as the “CENTRIFUGAL SPEED GOVERNOR” (Patent No. 1,583,783; filed November 14, 1923; awarded May 11, 1926).
I've determined that my C 250 mechanism had indeed been upgraded by a previous owner (probably in the mid 1920's) as it has this later type governor and a Dance Reproducer. These two features, and evidence that the mechanism was incredibly well maintained, suggests that the original owner truly cherished his C 250 and applied the available upgrades when they became available. This would have occurred many years after originally purchasing the machine, and of course, it's just as possible that a second (or third) owner may have done the improvement...I'll never know for certain.
I've also determined that the term Frow uses - "the shock proof governor" - refers to an engineered feature that protected the governor (on the Type B mechanism, specifically) from torsional damage to the weight springs from the “shock” of typically starting and stopping the Phonograph. I haven’t discovered the term “shock proof governor” used in any T. A. Edison Inc. period literature (or elsewhere) , and in my opinion, it seems to have been a term exclusively used by Frow in his Diamond Disc Phonographs [sic] book.
Additionally, in the article carried in the September 15, 1915 issue of
Talking Machine World (I referenced earlier in this post) the term used for the torsional distress caused to the governor weight springs by sudden starting and stopping was called
“tripping” (presumably by John Constable himself).
Taken from the above referenced article,
MECHANISM OF THE NEW "B" TYPE OF EDISON DIAMOND DISC PHONOGRAPH - Synopsis of an Address by John Constable of the Edison Laboratory at the Dealers Convention [August 1915]:
"...the reasons for the adoption of the two ball governor instead of the three ball were given, namely: more easily balanced, both for standing and running balance, insures quiet operation, and also the theoretical consideration which led to the discovery that the governor must be correctly proportioned to the main spring, which it has to govern. The adjustment of the governor was spoken of and particular attention called to the guide roller on the governor sleeve, it being particularly brought out that this roller should never be removed, especially on the two ball governor."
This statement illustrates that a three spring governor had been previously tried and abandoned, and indeed; a three spring governor is shown in Patent No. 1,290,138 - FRICTION SPEED GOVERNOR - filed December 2, 1913; awarded January 7, 1919.
I have not observed any of these earlier three weight governors
(shown in Patent No. 1,290,138) used on the Type B mechanisms that I've examined. Perhaps they were used on the Type A mechanism and abandoned with the development of the Type B mechanism?
On page 37 Frow includes a picture of a Type B mechanism with a three spring “shock proof” governor, and he continues to discuss the “shock proof” governor through page 38. Through my own observations, and diligent research, I now believe that he was referring to TWO completely different types of governor and may not have understood them very well.
The picture of the Type B mechanism, on page 37, is actually a later casting version (note the circular depression), and the three spring governor shown with it, suggests that this particular example may have been from the mid 1920‘s.
After sorting out what Frow was referring to, and doing a bit of my own research, it became obvious to me that there were at least TWO types of “shock proof” governors used on the Type B mechanism.
I shall refer to them as the "early type" and the "late type".
The “early type” shock proof governor I've observed had two weights, was relatively simple, and there were at least TWO VERSIONS of it. The only version of the “late type” shock proof governor I've observed had three weights and was much more complex than the “early type“:
1) The FIRST “early type” was provided with a machined slot in the governor sleeve, coupled with a machine screw and sleeve bushing (ROLLER) comprising the anti-torsion components. (See photo below)
2) The SECOND “early type” retained the machined slot in the governor sleeve, BUT, eliminated the sleeve bushing (ROLLER) and used only a precision shoulder screw comprising the anti-torsion components.
3) The “late type” governor (“CENTRIFUGAL SPEED GOVERNOR” - Patent No. 1,583,783) had three springs (three weights), and a system of two flanges with three pins and three sockets. The flange with the pins was anchored to the governor shaft on the end away from the friction (speed regulating) disc. The flange with the sockets was free to slide longitudinally along the governor shaft allowing the centrifugal weights to extend outward and control the speed of the mechanism. The pins of the one flange fit into the corresponding holes in the other flange, and prevented the springs from twisting, or "tripping". (See photo below)
Please remember that these are my own observations, and as more research is conducted, they may change.
Best,
Fran