Patent Union Chronometer

Over the past few years I have been privileged to be given the opportunity to work on several of these exceptionally rare timepieces by collectors of rare and complex pocket watches most of which are never seen. On this occasion I have been informed that I am to offer this item for sale a short period before disappearing into his collection once again. The watch arrived in non working condition needing a full service and escapement operation restoring after poor setup.

“The Patent Union Chronometer does have the merit that the escapement cannot unlock twice if the balance amplitude should increase beyond a turn in one direction. This is achieved without the balance being abruptly or violently brought to rest. Very few have survived in their original cases.

Out of  700 auction catalogues, only 8 examples of the P.U.C. have appeared, most of which were not signed at all (except perhaps with ‘Chronometer’ or ‘Patent Chronometer’), two were signed ‘Arnold and Lewis’ and one ‘Thomas Yates’ also note that this is a helical hairspring the most desirable and scarce variant  of these chronometers.

Technical details:

Patent Union Chronometer escapement, with a duplex ‚escape wheel locked by a pointed lever pallet system, acting on its short radial pointed teeth. The pallet system allows the ‘escape wheel to advance as in a Robin escapement, with alternating short and long  drops. During the larger drops, impulse is transmitted to a pallet set in a roller on the balance staff, by the short upstanding triangular teeth on the band (rim) of the ‘escape wheel. Contact between the pallet system and the balance staff is made by a pointed ‘fork’ working with the duplex roller on the staff. The locking surfaces of the pallets have negative draw, so the fork is held in contact with the tubular shaped ruby roller, on one side or the other, except during impulse. There is a complex  sliding pallet bridge arrangement , to optimise the critical depth between the pallets and the ‘escape wheel & depthing of the pallet fork release/engagement. As you can see a also a helical hairspring.

The patent (final form) was taken by Charles GrantG. Kelvey and William Holland of Rock Ferry, Birkenhead on Sept 4th, 1863 (No. 2184) .

Anthony G. Randall, The Time Museum Catalogue of Chronometers, Rockford, Ill. 1991, 271-272.

Case:

Many of the Patent Union Chronometers signed ‘Simmons’ with original cases do have a case punched CG in an oval (Caroline Green, 15 President Street East, Goswell Road, Clerkenwell, registered 3rd June 1861).

• Wolf Brüggemann in his DGC article lists No. 3152 (case made by Green), signed Yates, Preston (cf. DGC Mitteilungen No. 103 [2005] 9)
• The Time Museum Catalogue of Chronometers has watch No. 2963 (case made by Green, numbered 2962), signed Patent Union Chronometer (cf. Anthony G. Randall, The Time Museum Catalogue of Chronometers, Rockford, Ill. 1991, 272)

She must have been in business until the mid 1870s since she has registered another punch mark (but no more than that) in 1873. I conclude from this fact, that Mrs Green (must have been one of the few women in this male dominated craft) ran a small to medium sized business during the years 1861 until the mid 1870s. It is quite unlikely therefore, that many of her cases are on the market for an easy exchange. The number on this case (for movement #2964) is a five-digit number, incused very small, with corrections. This may well be a  the internal control number given by the case maker . I believe the case to be all original, with no evidence or traces for filled holes which would be the most likely if it were a re-cased watch. furthermore, there are no other screw marks on the case which has the movement matching exactly and secured by a single peg screw. The case bears the hallmarks for 1861/62

Note some of photographs are before cleaning