Auto-Stop Gauge

[audiophile102]

Having finally getting the auto-stop on my Sonora Elite to work every record, I have one question I hope someone here can answer.  What do the calibration numbers on the metal dial indicate?  Has it something to do with RPM?  I have used it successfully mostly by guessing where the record will end.  If Sonora had a formula, I would like to know what it was.

[phonogfp]

It's appears to be a scale, based on a rather arbitrary total of "500."  One ellipse represents distance from the beginning of the record, and the other represents distance to the end.  I admit that the delineations of tens in blocks, and fives in dots, is lost on me!

 

George P.

[audiophile102]

I placed a small piece of painters tape on the side of the turn table, moved the auto-stop to the 100 mark on the outside ring and released the brake.  I counted the revolutions of the turn table until the auto-stop was engaged.  The turn table came to a stop at exactly 100 revolutions of the turn table.  Pretty cool.  In order to figure out where to set the auto-stop for each record I start it at 250.  When the record stops, I count how many revolutions continue until the auto-stop finally engages.  Subtract the answer from 250 and I have the perfect setting for one record.  I record the number for future plays.  As you might have surmised, I have a lot of free time to experiment for fun.  I ignore the inside ring of numbers, because I don't understand why they are there at all.  If you have a clue as to the use of the inside ring of numbers, please enlighten me.

[shoshani]

12 hours ago, audiophile102 said:

I placed a small piece of painters tape on the side of the turn table, moved the auto-stop to the 100 mark on the outside ring and released the brake.  I counted the revolutions of the turn table until the auto-stop was engaged.  The turn table came to a stop at exactly 100 revolutions of the turn table.  Pretty cool.  In order to figure out where to set the auto-stop for each record I start it at 250.  When the record stops, I count how many revolutions continue until the auto-stop finally engages.  Subtract the answer from 250 and I have the perfect setting for one record.  I record the number for future plays.  As you might have surmised, I have a lot of free time to experiment for fun.  I ignore the inside ring of numbers, because I don't understand why they are there at all.  If you have a clue as to the use of the inside ring of numbers, please enlighten me.

It appears to be the same set of numbers as the outer ring, but in inverse sequence. Perhaps it was there as a guide to help determine a mean average setting, or something. (Conjecture on my part, though. If a manual could somehow be unearthed, it could potentially yield its secrets...)

[Roaring20s]

You could create something like this.

 

James.

[RodPickett]

This has been an interesting discussion and it appears audiophile102 has determined the nomenclature.  It would be nice to find some original instructions to determine how the operation was described to an owner.

 

Didn’t some records begin at the center, and play outward?  That could be the reason for the second grid.

[audiophile102]

Thanks to everyone for providing clues to the gauge numbering system.  The auto-stop gearing mechanism has no reverse switch, so I don't think it was designed to use with center start records.  If it did, the inner gauge ring numbers would make more sense.  As it is I'm still left scratching my head.  Somewhere, someone has a Sonora manual that explains everything.  Please if you can find such a manual, post a picture to this thread.  

[phonogfp]

Here are a couple of pages from the manual that came with a 1924 Sonora "William and Mary."  I don't think these instructions will be any help in deciphering the meaning of the dial posted above.  However, it's the only documentation I can offer...

 

Apparently, the OP's auto-stop is an earlier design which was replaced with this one.

 

Have you checked R.J. Wakeman's book on Sonora on the APS website?

 

George P.

 

 

 

[audiophile102]

Thanks George.  When the Sonora book was published, I downloaded it and printed several pages.  There was nothing specific about the auto-stop on my Elite.  It's a Rube Goldberg design and I'm not surprised that it was replaced in subsequent years.  As complicated as it is, I just had to get it working again and try to understand it's function.  The parts that make up the auto-stop are small and I'm frankly amazed that I was able to get it to function.  It works really well when the lever is set to the correct number.

 

[RodPickett]

Instructions_Other_Sonora-Minuet

 

is posted in the APS Member library and is essentially the same as George's De Luxe instructions.

 

No mention of an autostop feature.

[audiophile102]

There is a patent date on the gauge with an October 1913 date so I did a Google search for the patent and couldn't find it.  I did find this image of an ad from one of the trade magazines, but I'm not sure which issue it came from.  Do you know how to search for a patent for this Auto-stop?

[BenL]

On 4/29/2023 at 11:02 AM, audiophile102 said:

Do you know how to search for a patent for this Auto-stop?

 

Is this the right one? 

(https://patents.google.com/patent/US1148477A/en?assignee=sonora+phonograph&before=priority:19150101&after=priority:19100101) 

[audiophile102]

34 minutes ago, BenL said:

 

Is this the right one? 

(https://patents.google.com/patent/US1148477A/en?assignee=sonora+phonograph&before=priority:19150101&after=priority:19100101) 

This is it!  I searched all over the web and gave up.  Thank you, Ben.  You can clearly see all the Rube Goldberg elements in the patent.  Sonora must have purchased the rights which they no doubt came to regret due to the complex nature of the auto-stop.  I'm still going through my record collection assigning the correct number for each one.  Oh, it works great but I'm sure Sonora was correct to drop it when a better and simpler system was invented.  I think it only appeared on their machines for one year?