In the late 1920s, three classes at the University of Sioux Falls in South Dakota pooled their contributions and bought a state-of-the-art IBM clock system for the school.  The clock is in perfect condition and hangs in the lobby of the administration building. Below is correspondence from Ernie Jenson, member of NAWCC Chapters 133 and 190, to the University of Sioux Falls concerning their IBM Master Clock which they sent to Ernie for service.

General  Information –I did not find any problem with the clock except the arm at B arrow needed adjusting .  A arrow points to the pivot of the arm that advances the wind spring one tooth of the wind wheel.  When you close the solenoid with 12 V DC or by hand and then let the solenoid open, the ratchet arm should move forward a little more than one tooth and then relax to exactly one tooth.

B arrow points to the pivot point of the arm that determines how far the ratchet arm will relax to grab the next tooth.   If you loosen the screw and move that arm down as far as touching the coil, that is too far.  It should be adjusted so that the ratchet grasps a little more than one tooth and then relaxes to exactly one tooth.

Every minute when the second hand points straight up, the solenoid should close and advance the wind wheel one tooth.  When this clock was first installed it closed a relay that sends this same pulse to maybe 50 secondary clocks throughout the school. Place the second hand to point straight up when the contact closes for the proper appearance.  There is a second contact on the back side of the black switch plate.  This closes 5 seconds after the wind and time pulse to ring the buzzers to start or dismiss a class.  The big programmer in the center of the clock case would determine which minute of the day to allow the pulse through to the buzzer.  This clock is still in excellent condition and still ready to run any number of secondary clocks and buzzers or bells providing additional power and a relay was provided to do the job for many clocks.  It is nearly 100 years old and shows very little wear!

Problem Solving– If the clock stops, then the first step is to see if the wind spring is wound. The wind spring is good for a number of hours before it is completely unwound.  This permits the clock to keep running for most power interruptions.  To diagnosis the cause of the problem, it is possible to reach behind the face and squeeze the solenoid together to get one minute’s power each squeeze.  If you are familiar with the location of the ratchet activated wind wheel, then with the pointer finger reach in the right side of the clock between the plates and advance the wind wheel by pulling downward and listening to the clicking of the ratchet. If unwound, it can be advanced one rotation; if wound it will not advance and no clicking will be heard. The wind spring is on the lowest arbor in the clock works and centered between the plates.  It is the wheel in the center of the picture midway between the plates and the arrows.  One should hear the solenoid close on the minute when the second hands points straight up at 60.  If there is not a solenoid closing then there is an electrical problem.  The contact is dirty or the power supply is failing to deliver a half amp at 12 VDC.  Maybe the contact arm is sticky and not dropping on the cam properly.  There is a stop pin on the wind wheel and a stop pin on the going wheel.  When completely wound these two pins should contact each other.  If partially unwound the two pins should slowly move towards each other as one tooth of the wind wheel is more than one tooth on the running wheel.  When the clock is completely wound, sometimes the solenoid will close but the ratchet can’t grasp the next tooth because the pins on the two wheels hit each other first preventing the ratchet reaching the next tooth. 

Installing the clock– It will be necessary to set the clock in beat again after adjustments have been made and the pendulum may need to be adjusted a tiny bit as the clock may run a little slower or faster than before.  The distance from the crutch is now a little closer than before to get the most energy to the pendulum.  The pendulum is now swinging a little further than before.  The little nut on the crutch will need to be adjusted a tiny bit to get it perfectly in beat (equal time between the ticks).  Position the minute hand so it is exactly on the minute when the solenoid clicks for appearance.

Note: Some Master Clocks have a button at the bottom of the case, the wind button.  Each push of the button winds the clock enough for one minute. The proper way to start the clock when there is a long power failure and the clock is completely unwound, is to push the wind button a few times so the spring has enough power to keep the clock running when one pushes the pendulum gently to start the clock. Otherwise it may not start ticking until it has been started a few times and the second hand has passed 60 and the solenoid has closed delivering the wind pulse.  

Since I could not test the clock with the original power supply, I used a 12 VDC power supply.  I used it for the 2 weeks that I tested the clock.  It ran perfectly with the use of this power supply.  If you suspect yours, use the one enclosed.

-Ernie Jenson FNAWCC

An interesting Self Winding Clock Company movement with a Gravity Escapement

The Self Winding Clock company was formed in 1886 and marketed an innovative electro-mechanical clock mechanism. The movement incorporated a small electric motor that rewound the mainspring each hour. The vast majority of SWCC clocks have Style “F” movements. They were produced in 60,80,120 and 140 beat versions. These movements appeared in 1898 and are wound hourly by a vibrating armature. The earliest SWCC movements were wound each hour with a rotary motor that was patented in 1884 by Chester Pond, one of the company founders.

In addition to the conventional Style “A”, “C”, and “F” movements the SWCC made a few much larger movements which they designated the Style “E” movement. This movement operated hands for dials up to 50 inches. All styles of SWCC movements have Graham dead beat escapements. The pictured Style “E” movement is a rare exception for it has a Gerry Gravity Escapement.

The Gerry Gravity escapement was patented by James Gerry in 1883. Gerry worked for the E. Howard clock company and later became the Supervisor of the SWCC. The Gerry Gravity escapement is unique for it employs 4 gravity arms rather two gravity arms to operate the escapement. The operating movement can be seen on Youtube by clicking on this link.

This presentation was presented at the Exhibit on Railroad Time at the Greater Los Angeles Regional of the National Association of Watch and Clock Collectors held at the Pasadena Convention Center on January  30-31, 2015.

The gauge may be used to measure the strength of a cell in a battery used for electric clock systems during the period the first electric clocks were introduced in the United States. Without dismantling the pocket watch size meter with the snap-back removed, two small series connected electromagnets can be seen. The  pole pieces are arranged to form a flux gap.  A curved armature pivoted on the the axis of a toothed segment is attracted to the flux gap when the electromagnets are energized. A spiral hair-spring opposes the rotation of the toothed segment carrying the armature .  The toothed segment engages a  pinion mounted on the axis of the pointer. Experiment with a single flashlight cell causes the needle pointer to rotate clockwise about forty-five degrees pointing to the middle of the scale. I believe the gauge likely has a full scale reading of less than three volts based on the logic of the electrical potential of the  LeClanche (zinc-carbon) cells or the lead-acid cells commonly making up telephone and clock system batteries of the pre-900 industrial period.    Note the serial number, 2634 on the face and compare with number 22 in the advertisement.   This would suggest that Warner’s Electric Gauge was a widely used service  tool in primary battery systems. The gauge was listed on eBay. I bid and lost. Several days later, while visiting Dave O’Dell, I noticed the gauge on his workbench.  The identity of winning auction bidder J3442’s  was revealed.  Thanks Dave.

In 2007, Chapter 133 took on a project to restore and install two Self Winding clocks in the restored Union Pacific station at Kelso, California which had been repurposed in 2005 as the Visitors Center for the Mojave National Preserve. We made contact with the Linda Slater, who was the ranger in charge of preservation and found out that Union Pacific had donated a clock for use in the depot but it was in need of repairs and replacement of parts needed for the synchronization function. This clock would fit nicely in the restored visitor’s lobby but we also felt a clock should be present in the ticket office too. We put together a plan, got the go ahead from the National Preserve, and began to move forward. Alan Bloore, Don Stocker, Tom Faragher, and I made a trip to the Preserve HQ in May of 2007 to view the donated clock and after lunch at the Mad Greek in Baker drove to the Visitor Center to view the proposed clock locations. We agreed that the ticket office needed a clock too and Alan Bloore had one that he agreed to donate to the project. Tom Faragher fabricated the missing parts and the two clocks were rewired and tested by Alan. Finally, the clocks were working and we made a trip to Kelso on November 7, 2007 for the installation. Linda Slater met us and helped with the logistics. A write up was made in the Preserve newsletter giving us credit for our help. The clocks are still keeping good time almost seven years later. On May 30 of this year I visited Kelso and did a tuneup to adjust the rate and improve the beat which was off a bit with the office clock. The personnel at Kelso find the clocks both useful and interesting and make the battery changes and tweak the rate as needed.