Manufactured during the late 1800s by the Ohio Watch Tool Co. of Piqua, Ohio, the O.W.T was of unusual configuration for a watchmaker's lathe - though its basic design was of the traditional WW (Webster Whitcomb) pattern with a 50 mm centre height and a heavy, bevelled-edge bed cantilevered from a single supporting column beneath the headstock. However, what distinguished the lathe from any number of other similar contemporary models was a carriage driven by changewheels combined with a leadscrew that ran inside the bed - the drive being engaged by turning a serrated-edged wheel on the face of the apron that forced a clasp nut against the leadscrew. Given the great difficulty of building such a lathe from scratch without a considerable engineering background - and the necessary facilities - it might be that an existing lathe of the WW type was taken and modified (certainly, the headstock is pure WW from the era, though the tailstock is very different and not seen before on any other lathe of this type). While many watchmakers' lathes have been available with a feed to the top slide - usually through a keyed and universally-jointed shaft for screwcutting or just to give a powered drive - this is the only known example where the gearing was arranged in a manner more normally found on a small screwcutting lathe. Unfortunately, with the difficulty of arranging in the small space available a suitably high reduction ratio between headstock and leadscrew - and compounded by the use of coarse-pitch gear teeth - the slowest rate of carriage feed would have been relatively fast at around 0.01" per revolution of the spindle, the more usual rate for a small lathe being up to 10 times finer at between 0.001" and 0.006" per revolution. Screwcutting was, of course, possible - though without backgear to get the speed down it would have been very awkward to use under power, the technique used, if it had to be employed at all, being to turn the spindle by hand. Even so, the need to generate threaded components would have been very limited: by 1860 tiny screws were being manufactured using special machines on an industrial scale and American pocket watches mass produced with interchangeable parts - only obsolete designs or clocks might have required a horological repair man to custom-make components.
Surviving with a number of original accessories - a single swivelling slide rest (rather than the more usual compound type), a hand T-rest, what appears to be a full set of changewheels, fittings for the tailstock and the original countershaft unit the lathe dates from circa 1870 to 1885. Further evidence of course is provided by its style and the maker's patent applications for other watch related items. The number 15 is stamped on the end of the bed and also on the undersides of both headstock and tailstock: this might be either a serial, model type or assembly number, the latter used to ensure that the correct parts were mated together after cosmetic finishing. However, as the lathe would also have sold only in very limited numbers it could well be the 15th manufactured.
From an article in the Piqua Daily Call, for May 5th, 1938 it appears that the Ohio Watch Tool Co. was operated by three partners: Charles Olin and the brothers Augustin Thoma and Albin Thoma. Their business, located on the second floor of the A. Thoma & Sons Jewelery Shop at 122 North Main Street in Piqua, went out of business in 1886. However, as the Thoma family were well established in the area (as a genealogy search shows) their business interests continued and today they still trade from a fine 4-story building at 312 North Main Street not far from their original home
According to the paper, the brothers held patents for the lathe as well as for a "jeweling tool". This information confirms O.W.T as actual manufacturers - and not just dealers or distributors of bought-in watch-making tools with sufficient buying power to commission a batch of machines for sale under their own name - an example of this practice being the Paulson Company.
So far two horological patents have been found ascribed to the family, though neither is for the lathe: the first, Number 67,662, was by the father and sons together and granted on August 6th, 1867. It concerned:: Improvement in Instruments in Setting Jewels, with the patentees being Augustin Thoma (Snr.), Augustin F.Thoma and Albin Thoma. The purpose of the mechanism (in essence, just a pair of tweezers with a screw-operated spreading rod) was to raise the bezel surrounding and holding an old or broken jewel so that the latter could be removed and another put in its place. The second patent, Number 70,049 and closely connected to the first, was granted on October 22nd, 1867 to Augustin Thoma Snr. for a tool that: raises and closes the bezel or burr for securing the jewel in the plate at a single operation with great dispatch and accuracy.
In addition, Charles Olin is also recorded as filing two patents, the first being for a frictional centring-chuck (a form of collet chuck) on December 16th, 1879, granted under Number: 235283 on December 7th 1880. The aim of this device was to allow the operator to adjust the position of a part so that it lay exactly on the axis of the spindle to which it was attached. The second patent concerned a rather more prosaic device, a pendulum foot motor; applied for on March 5, 1884 it was granted under Number 305217, on September 16th, 1884. Foot motors, consisting of a flywheel assembly and some sort of foot-operated drive, were designed to run a small lathe by being mounted beneath the user's bench.
In addition, the American National Watch and Clock Museum (NAWCC) has a complete staking set on its original round wooden base ascribed to: The Ohio Watch Tool Co, Piqua, O and C.J. Olin's Patent - though the latter has yet to be located and may just have been an unsuccessful application, staking sets of all kinds being very common in the late 1800s.
Should any reader have an O.W.T. lathe the writer would be interested to hear from you..