I recently overhauled this Sessions black mantel clock from around 1903 – 1910. It was a routine overhaul including polishing the pivots and installing bushings. A previous repairer had installed two screw-in bushings (a no-no!). I replaced these with KWM size 4 American bushings. The mainwheels were made with Gilbert-style clicks, which are more robust then the standard Sessions clicks.
The original mainsprings seemed too strong. The time spring was 0.0182 inch thick, and the strike spring was 0.0178 inch thick. I replaced both with thinner mainsprings, Merritt’s Antiques P-1956, 0.0165 inch thick, to reduce future wear to the mainwheel teeth. The escapement takes an excellent motion.
I recently overhauled this clock. The repairs included:
Polished all of the train wheel pivots (some were rough when the clock left the factory);
Installed 10 bushings (including rear time mainwheel bushing). One bushing had been installed by a previous repairer. It was crooked in the movement plate. To correct this, I installed a bushing with a hole too small for the pivot, then used a cutting broach to open the hole while uprighting it. Then the hole was polished with a smoothing broach;
Replaced the click on the strike mainwheel, as it was very worn, and had been filed down. I installed a steel clickspring, and a steel rivet;
Filed wear from the click on the time mainwheel, replaced the wimpy brass clickspring with a steel one, and replaced the brass rivet with a steel one;
Installed the correct size suspension rod, and installed an original Sessions mantel clock pendulum bob;
The strike mainspring was a replacement that was too thick (0.018 inches). I replaced it with a spring 3/4 inch wide, 0.0165 inches thick, and 96 inches long, Merritt’s Antiques part no. P-1956;
The time mainspring had been ground narrower by a previous repairer. It was rough with sharp edges. I installed the same type of mainspring as above, Merritt’s Antiques part no. P-1956;
The new mainsprings mentioned above (in the last two items) provide plenty of power to operate the clock. The movies below show the operation of the escapement, the clock striking, and the movement with pendulum. This clock strikes bim-bam on two chime rods.
Here is a slide show of some of the repair steps:
The label on the rear door says the following:
No. 277 P
Eight-day Turn Back
Striking the hours on Two-Tone Chime
Half-Hours in Harmony
The Sessions Clock Company
Forestville, Conn., U.S.A.
NOTICE
The Pendulum Ball and Key are fastened to bottom of clock.
DIRECTIONS FOR STRIKING
In order to make Clock strike the hour desired, turn the long hand up to twelve and allow the clock to strike. Then turn back to nine and forward again to twelve. Continue in this way until the Clock strikes correctly.
TO REGULATE
Should it be desired to have the clock run faster, place the small end of the key on the arbor at twleve and turn TOP of key to the left toward F. To run slower turn TOP of key to the right toward S.
There is a date code of 9-38 (September 1938) stamped on the label.
