Part I. Foundations – Early Case Design Innovations
Origin Stories (mid-1800s)
According to one knowledgeable source, the earliest documented water resistant case dates to the 1851 Great Exhibition in London. W. Pettit & Co. of London reportedly exhibited a watch in a water-filled glass globe surrounded by goldfish. The UK Intellectual Property Office reportedly has been unable to find evidence of a patent corresponding to this watch case. But a pre-1880 pocket watch signed W Pettit Commercial Road East suggests Pettit may have been a Swiss watch importer – in which case Trappett may have originated the case design. Unfortunately, nothing more is known about this early water resistant case.
Dennison Threaded & Packed Case (1872)
Aaron Dennison was a watch industry pioneer, founding Waltham Watch Co., initiating mechanized watch parts mass production in the US and significantly influencing Swiss and UK watchmaking. Dennison learned the manual watchmaking trade while apprenticing to a watchmaker in Brunswick, Maine. After moving to Boston in 1833 and studying the Springfield Armoury’s mass-production methods Dennison formed a watch manufacturing company in 1849 employing mechanized assembly techniques to produce the first inexpensive factory-made watches, ultimately reorganized as the Waltham Watch Company. He later established a case factory in England, assisting with establishment of the International Watch Co. (IWC). Dennison was well-regarded for their relationships with top manufactures including Jaeger-LeCoultre, Longines, Omega, Rolex, Tudor and Zenith among many others.
Given his reputation, it’s not surprising some attribute invention of the screw-down crown to Dennison – but little concrete evidence has been found to corroborate the claim. “Traveler” or “explorer” watches employed screw-down crown caps as early as the 1870s; but a threaded crown that itself seals the stem housing had to wait for Fitch’s 1881 patent. That’s not to say Dennison wasn’t an important case design innovator – on the contrary, his 1872 UK patent No. 356 employed a threaded bezel and threaded case-back. The design also specified the winding arbor and hand-setting push-piece could be sealed with a gland (sometimes referred to as packing or a packing ring) to enhance dust and water-resistance.
Fitch Front-Loading Case (1879)
In April 1879 Ezra Fitch obtained US patent No. 214642 for a design without a case back opening, eliminating one case joint requiring a seal. Fitch’s 1879 design incorporated a threaded bezel (similar to Dennison), and removable cap enclosing the crown (like earlier explorer models) as “proof against the entrance of dust or moisture.” Because it lacked a rear opening Fitch specified a hinged movement carrier ring. This “swing ring” design held the movement in place while facilitating movement installation and removal.
To seal the gap where the winding stem enters the case, Fitch employed a removable stem cap threaded to the end of the pendant (the tube housing the winding stem where it enters the case). While the screw-down cap was borrowed from earlier designs, Fitch also specified a packing ring (basically, a gasket) could be installed at the pendant shoulder to further inhibit dust and water intrusion.
Waltham Screw-Down Crown (1881)
In 1881 Fitch obtained US patent No. 237377, a refinement to his previous removable crown cap design, this time using the watch crown rather than a cap to seal the case. Fitch’s innovation appears to represent the earliest recorded screw-down crown. On Fitch’s design, the crown is internally threaded, screwing into external pendant threads. The base of the crown thereby could be screwed down to press against the pendant shoulder, sealing the case.
Fitch employed a left-hand thread for the crown and pendant to allow tightening the crown fully after winding. Screwing down the crown after full winding would be impossible with a right-hand thread, leaving the case open to dust and moisture. But this also presented an inconvenience – if the watch is fully wound and the crown is screwed down with a left-hand thread, it can’t be unscrewed to reset the hands, because the fully-wound mainspring prevents turning the crown forward.
In 1883 Fitch became president of the American Watch Company of Waltham, which manufactured his patented “dust proof” watches with screw down crowns during the 1880s. But the early Fitch design suffered another flaw – the external pendant threads had a tendency to accumulate grime and wear rapidly. This was particularly troublesome for manual-wound watches prevalent during the era.But Waltham rectified this issue quickly. Just a few months after Fitch registered his patent another Waltham inventor, Almon Twing, was granted a screw-down crown patent in June 1881. Twing’s design incorporated a clutch in the winding-stem assembly, allowing the crown to be unscrewed even when the mainspring is fully wound. Taken together, the Fitch and Twing designs commercialized by Waltham included the key features adopted much later by the Rolex Oyster – i.e., threaded bezel and case-back, and screw-down crown with a clutch.
Droz l’Imperméable (1883)
Also long before the Rolex Oyster, the Fitch designs were further refined by Alcide Droz & Fils, issued UK and US patents in 1883 and 1884. The Droz case was dubbed “l’Imperméable” for its dust and water-resistance. It featured a threaded bezel and no case-back opening, after Fitch’s 1879 design, and a screw-down crown similar to Fitch’s 1881 design. However, Droz introduced an important innovation by locating the threads on the stem and on the pendant interior, hence better protected from accumulation of grime.
Early Borgel Case (1891)
Born in Geneva in 1856, at age 24 François Borgel commenced his esteemed career as a watch case fitter, ultimately becoming one of the top Swiss watch case manufactures. Borgel’s hallmark was recorded in 1887, comprised of the founder’s initials over the iconic Geneva key.
Capped and screw-down crowns were important early innovations, but for everyday use these features sometimes present unnecessary inconvenience. Seeking a more pragmatic approach, in 1891 Borgel patented (brevet 4001) a water resistant case providing greater dust and water resistance than standard cases of the era without the inconvenience of a screw-down or caped crown, incorporating features of the earlier Dennison and Fitch designs.
Borgel employed a modular case without rear opening (after Fitch and Droz), with threaded bezel (after Dennison and Fitch). In place of a capped or screw-down crown, Borgel employed a variation on Dennison’s design, relying on a spring to hold the crown and hand-set pusher in place flush to the case. While Borgel’s design relied on a metal-to-metal seal, packing materials of the era (e.g., oiled leather) were notoriously unreliable and required frequent replacement. Thus, while less dust and water resistant in certain respects, overall some consider Borgel’s design a respectable compromise providing significant dust and water resistance in a lower-maintenance package with greater convenience relative to other contemporary cases.
Foundation for Transitional and Modern Case Designs
While some claim the Rolex Oyster as the first “waterproof” wristwatch, in fact it was preceded by many water resistant case designs employing similar features. Rolex’s Oyster employed a better-sealed crown than Borgel’s threaded case, but the early Oyster case was less convenient than the earlier Borgel design for everyday wear. Rolex’s acclaimed screw-down crown was borrowed from preceding Waltham and Droz designs, and the Oyster case was hand-threaded like many significantly earlier designs. It wasn’t until 1931 that Rolex introduced a tool allowing the threaded case to be more tightly fitted; but even then did not claim the Oyster was suitable for diving, leaving introduction of the true dive watch to Omega and other later competitors. Stay tuned for Parts II and III introducing classic transitional and modern case designs incorporating and improving upon features of these early, foundational designs!
(c) Copyright 2021, P. Scott Burton & Mitka Engebretsen, all rights reserved.
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