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Help Identifying International Time Recording Clock

jadersch

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Oct 21, 2020
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Hi all --

I recently acquired an interesting International Time Recording Co. wall clock, which looks to be from the mid-1920s. It's similar in design to the round ITR slave clocks from this era except that it's larger (case is about 19" in diameter, face is about 14.5") and it doesn't have the typical slave clock movement. Instead it's almost like a Self-Winding clock: there's a very small mainspring that's wound via a ratcheting mechanism driven by a solenoid. From experimentation, this mechanism doesn't automatically rewind the mainspring, it expects to be impulsed periodically to keep it wound.

The model plate has "11" on the left and "4" on the right side of the model number area. Serial number is 394135.

I can't find anything about this particular clock, and I've never seen another like it. There are definitely some parts missing from the inside of the clock (see the pictures -- on the right hand side there's a wood plate where something was mounted at one time), though the movement seems to be more or less all there. It doesn't appear it has enough hardware to have been a master clock, but it's not a slave clock either... Can anyone shed any light on this?

It's currently very filthy but I hope to be able to clean it and make it run in some manner, despite the missing parts. I'm missing the pendulum, so any leads there would be useful.

Thanks!
- Josh

20201022_060534282_iOS.jpg 20201022_060635803_iOS.jpg 20201022_060641353_iOS (2).jpg 20201022_060653893_iOS.jpg 20201022_060722066_iOS.jpg 20201022_060728008_iOS.jpg
 

Toughtool

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I am amazed at the odd things IBM manufactured. My guess is this is a master clock with a short pendulum, maybe a 170 beat per minute. It reminds me of the Western Union clock with a heavy lead pendulum weight. There is definitely a lot of things missing; most probably the relay logic and power supply components. I see four terminals, but there could have been more, but it may have been a master for a two wire plain impulse system. Two of the four shown look like 110 volt mains, a white and a black wire, and two more for A and C.

The contacts that are found on regulator movements could have been stripped to remove the load on the bearings and shafts. However the minimum contacts needed for a two wire non-correcting master clock system would be a minute impulse contact. No need for a rapid two second contact, a B line circuit, a stop relay circuit, etc. Anyone have a two wire plain impulse master?
 

ibm clock

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The 11-4 model number seems like it could be indicating a minute impulse master. Who really knows.
 

Toughtool

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I noticed this movement has the helical spring and will run for 51 to 53 minutes without power. I actually like this clock. I think my Trinkit pulser with the MOSFET will keep it wound. I guess it does not have the pendulum?
 

Toughtool

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Is it possible someone put the dial and movement in a metal case?
I don't think so. The case is unique, hinged at the top and clearly shows holes in the back plate where logic and power components were mounted. While the contact set and it's cam had been removed, along with several other master clock components, I am pretty sure this is a two wire impulse master. A two wire impulse master would have only one set of contacts, as shown in the image from the ITR Service instructions # 222, and simple logic. I just don't know about the pendulum length. The Model 11 master clock series listed in IBM's model list indicates 120 beats per minute but this list does not show a model 11-4, and that may be a higher beat per minute; therefore would have a shorter pendulum.

See Model 11, master clock series: https://www.ibm.com/ibm/history/documents/pdf/clocks.pdf
Image from Service instructions #222, page 14, at IBM's Clock Corner: https://www.ibm.com/ibm/history/exhibits/cc/pdf/cc_2407MCE1.pdf

Clipboard01.jpg
 

Toughtool

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I have drawn the equivalent schematic for a two-wire master clock system from the schematic in the ITR Service instructions No. 230, April 1, 1938, page 3. The only thing different is the original schematic's battery symbol is replaced with a 24 volt power adapter. A 1 amp power adapter will be more than enough to power the clock and several secondaries. I show three secondaries in parallel with the wind coils, connected to "C" and "A", the standard nomenclature. Also any self-correcting three wire secondary will work if the A and B secondary wires are connected together, to the "A" line. (Black and White)

All that is needed to get this clock running is a 24 volt power source, a pendulum, a minute impulse contact set and cam, and a Master Relay.

Two-wireMasterClock.jpg
 

Toughtool

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About all one can glean from looking at the model list on the IBM Clock Corner site is that is a secondary clock with a second hand. what its function beyond having a second hand is unknown.
There isn't a reason for a second hand to be on a one minute impulse secondary. They have a resolution of one minute, not one second. Only master clocks have a resolution of one second, and you can see that as the hand sweeps between one minute marker to the next. The impulse secondary jumps from one minute marker to the next, once a minute.

Also If this movement was a secondary, it would have the synchronization solenoid assembly and the ratchet mounted onto the escapement wheel so that this movement could be controlled by another master. (Image from IBM Clock Corner: https://www.ibm.com/ibm/history/exhibits/cc/pdf/cc_2407MCE1.pdf , page 17. This is Service Instructions No. 222.)
I think this clock may predate IBM's supervised master clock's sophistication (three wire system) and well before the secondaries with the (red) second hands which are controlled by a master but are actually synchronized 60 Hz AC motors (in the US).
 

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John Lippold

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Feb 2, 2011
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Hi Josh,

Your clock is a Master Clock. It was probably shipped from the factory in late 1929 or early 1930. There were two models, the model 11 (List 11) and the model 12 (List 12). The 120 beat escapement of the Master Clocks featured a large 30 tooth escape wheel and standard 60 beat verge. This arraignment avoids close adjustments and permits rugged construction. These Master Clocks contained all the control equipment for the system and all wiring was incorporated inside the case. The only connections necessary were the commercial power line, AC for the List 11, external DC for the List 12 and two or three wires to the secondary equipment. Three wires (3) being required for a supervised system and two (2) wires for a straight impulse system such as a door recorder. The Master Clock also included Duration Contacts for control of bells or buzzers. Sometimes these Master Clocks were used as a backup master to keep the clock system of a large enterprise functioning while the main facility Master Clock was being serviced or repaired. The case of my clock was originally factory painted flat black but is made of copper. I decided to remove the paint and enjoy the copper case. The pendulum bob is pot metal and tends to self-destruct over time. The clock runs great but is quite noisy with the clatter of the 6146 Unit Relay so I don't run it very often. I'm attaching some photos of a List 11-4 Master Clock in my collection so you can see what is inside the case. I believe these clocks to be quite rare as I have seen very few to them over the years I've been collecting International/IBM clocks.

John Lippold

m1-405066-(11-4)-06-30.jpg m1-405066-(11-4)-07-30.jpg m1-405066-(11-4)-08-30.jpg m1-405066-(11-4)-09-30.jpg m1-405066-(11-4)-10-30.jpg m1-405066-(11-4)-11-30.jpg m1-405066-(11-4)-12-30.jpg m1-405066-(11-4)-13-30.jpg m1-405066-(11-4)-14-30.jpg m1-405066-(11-4)-15-30.jpg m1-405066-(11-4)-16-30.jpg m1-405066-(11-4)-17-30.jpg m1-405066-(11-4)-18-30.jpg m1-405066-(11-4)-19-30.jpg m1-405066-(11-4)-20-30.jpg m1-405066-(11-4)-21-30.jpg
 

Toughtool

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John, Fantastic! Your clock is beautiful.Thanks for the photos and the history of this clock. That thing looks brand new.

So how long is the wood stick pendulum? I noticed Josh has the suspension spring so he probably won't have too much difficulty making a pendulum and bob for his clock. If Josh can find a minute impulse contact assembly and cam he can use this MOSFET driver circuit instead of the noisy relay, else use a pulser to keep the movement wound.
Joe

Two_wire MasterWMOSFET.jpg
 
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John Lippold

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Feb 2, 2011
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Hi Joe,

The pendulum stick length including top hanger is 10 1/4 inches.
The total length including the adjustment screw is 11 5/8 Inches.
The pendulum bob is 3 3/4 inches diameter.
The pendulum bob plus the adjustment nut weights 10 1/2 ounces.
You can take a look at my photos.

In looking back at Josh's photos I see the escapement on his clock (see note) is an earlier design than my clock uses. It is still a 120 beat clock but the escapement verge adjustments would be much more critical because of the fine teeth on the escapement wheel. Also ITR could not use their standard 30 tooth escapement wheel or 60 beat verge.

As far as the MOSFET driver circuit is concerned, yes he could do that. He would still hear the wind solenoid winding the main spring every minute. If it were my clock I would try to completely restore it back to original. It could be done but would take some time finding the correct parts. The contact stack and rapid impulse parts on my clock are the same ones his clock should have. The same parts were used on pendulum master clocks at that time.

Note: The escapement used in Josh's clock was used in earlier 120 beat wood case master clocks.

Thank you for your kind comments,

John

m1-405066-(11-4)-22-30.jpg m1-405066-(11-4)-23-30.jpg
 

Toughtool

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John, Thanks for providing your pendulum measurements. It will help Josh and anyone else who finds this model clock and needs a pendulum.

So you think this is a supervised three wire master instead of a plain impulse two wire master? What do you look for to determine that? Also I agree restoring the clock would be best but the MOSFET driver is an alternative. Joe
 

John Lippold

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Feb 2, 2011
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John, Thanks for providing your pendulum measurements. It will help Josh and anyone else who finds this model clock and needs a pendulum.

So you think this is a supervised three wire master instead of a plain impulse two wire master? What do you look for to determine that? Also I agree restoring the clock would be best but the MOSFET driver is an alternative. Joe
Joe,

You can tell if the Master Clock supports three wire correction by looking at the clocks contacts and connections. If the Master Clock has connections A, B and C, for secondary clock connection, a Two Second Contact for rapid advance of secondary clocks, an Advance/35 Second Contact and a Stop/50 Minute Contact then it supports three wire correction. I looked back at Josh's clock and I can see marks on the fiber asbestos board where the A B C connections were located. I can also see indications on the movement where the Stop/50 Minute Contact had been mounted. This would indicate Josh's clock also supported three wire correction. You know ITR applied for the patent for this correction system in 1924 and it was approved in 1928. The ITR Marketing representatives were actively selling the concept and clock systems even before the patent was approved. This correction system was a very good design and used up until and even after the IBM Time Equipment Division was sold to Simplex on December 1, 1958.

John
 

Toughtool

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OK, I see the marks for the C terminal. I didn't know where it would be until your photos. I saw the two wires for A and B (Black and white) but missed the fact that the green wire was missing. So I agree this is a three wire self correcting master. I am assuming the stop contact is the lower left, and the two seconds contact would be to the right of the escapement wheel, right near the exposed 110 volt exposed fuse. Nice call. Joe

Clipboard01.jpg
 

John Lippold

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Feb 2, 2011
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Joe,

If you look at my 4th photo in the upper right hand corner, the top two connections (ring terminals with red bands) are AC input connections to the transformer primary. "A" terminal (red wire), "B" terminal (yellow wire) and "C" terminal (blue wire) are the connections to the secondary clock. Yes, the lower contact is the stop contact and yes, the two second contact is near the left hand Fusetron fuse and escape wheel.

My Master Clock with S/N 405066 would likely have been shipped from the factory in July 1930.

The earliest Master Clock I've seen with three wire correction was shipped from the factory around January 1926. There are probably earlier examples.

John
 

John Lippold

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Feb 2, 2011
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International Model "A" Master Clock

Hello, I'm wondering if anyone has one of these International Model "A" Master Clocks, a parts manual or any other documentation about these master clocks. I'm trying to find out what the configuration of the optional Duration Contacts were and where they were mounted on the movement. Thank you,

John

m1-216009-(A)-07-21.jpg m1-216009-(A)-08-21.jpg m1-216009-(A)-09-21.jpg m1-216009-(A)-10-21.jpg m1-216009-(A)-11-21.jpg m1-216009-(A)-12-21.jpg m1-216009-(A)-13-21.jpg M1-216009-(A)-14-21.jpg M1-216009-(A)-15-21.jpg
 

Toughtool

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John,
I think you should start a new thread as this is a completely different master clock than the master this thread discusses.
This is a very nice looking clock! I hope someone knows a little about this model. Joe
 

Toughtool

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OK John, it's easy. From the first page of this forum (Electric Horology) you will see a window. The example shown (below) has my happy face. Select a prefix, then place your title. Then you will get to the window to post your text. Hope this helps. Joe

Clipboard01.jpg
 

Toughtool

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The second option is to click on the report button on the lower left and request the moderator to move it to a new thread. Reports go to the moderator for some action. A report is not limited to reporting a rule violation.
 
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