American Long Case clock by Globe Clock Co

The detailed information and the pictures of this clock were provided by Ian Pomfret and are copyright by him
Case:

Mahogany, sadly rather a good example of "Attic Burn". Probably due to being stored in an attic at high summer temperatures, the shellacked finish has bubbled on most of the external surfaces
original drawn (wavy) glass throughout.

Manufacturer information (from the backplate):- The Globe Clock Co, USA, pat'd Oct 18.25 (sic). On the dial, below the handstack is engraved the word - ELECTRIC.

I would be grateful for any further information on this manufacturer.

The time train is powered by the three weights acting together in parallel. One end of each weight cord is secured to the seat board, the other to the wooden cross piece which has a pulley which connects to the endless chain. The escapement is a Graham deadbeat type, operating an uncompensated steel bar pendulum.

Synchronous electric motor - custom made, spring loaded conical bearing at the front (Dial side), conical bearing seating in a custom uncaged ball bearing at the rear.
The motor is always on - no 110 v switching.! Winding is based on the Huygens endless chain principle. The power to chime and strike is controlled by two synchronized racks and snails. The Huygens endless chain is wound at this time.

Chiming and Striking is achieved from the same motor / drive train by disengaging a segment of the wheel teeth driving the chiming barrel, the strike (hammer) lever then engages allowing the correct strike count to be achieved.

Of particular interest are the following :-

a.. Huygens endless chain gives the advantage of backup operation during power outage (approx 5 hours) and maintaining power during rewind, although the chime and strike no longer operate they remain synchronized.

b.. The use of an uncaged ball bearing at the back of the Synchronous motor.

c.. The always on synchronous motor is allowed to stop gently by the use of a spring loaded clutch rather than the more conventional Fly

d.. Over-winding and hence stalling of the strike /chime mechanism is prevented by a second clutch (1) which normally drives the Huygens endless chain to power the time train. I have not done the calculations, but observation indicates that the time train overwinds over a twelve hour period - giving the clock the ability to recover from a power outage.

e.. The disengaging segment (2) of the drive wheel to the chiming barrel. A very elegant solution to having only one motor and drive train for both chiming, striking and winding of the time train, however, this part is physically very light and seems to be the source of endless reliability problems. This was solved un-intrusively by means of a wire guide (3) attached underneath one of the main post screws which "helps" gravity drop the lever out of engagement.

References in d and e above are to the annotated picture w0826d

This clock is unusual and of interest as an early example of the use of electricity to wind clocks. Note that the patent date given on the backplate is 1925, at this time electrical supplies were not held accurately to frequency and could not be relied on for timekeeping. In this case the synchronous motor is used to drive the chime / strike train directly and rewind the weights powering the time train, which has a normal deadbeat escapement and pendulum. Another point of interest is that the three visible weights are linked by a wooden cross piece and pulley and only power the time train, while maintaining the appearance of a normal weight driven clock.