Vertical Clutch and Automatic Winding
Three automatic chronograph watches were released in 1969. Without a doubt, the one with the most lasting impact was the Seiko Caliber 6139. The combination of the compact automatic winding mechanism with a vertical clutch for more precise stopwatch measurement and a column wheel, which became widespread among high-end chronograph watches, is still favored by many watchmakers today.
No talk of 1969 would be complete without mentioning the Caliber 6139. This revolutionary movement had a fascinating background and a lasting influence.
An automatic chronograph was the dream of many watchmakers starting in the 1940s. Albert Piguet, the renowned watch designer for Lemania, had his doubts, however. “If you try to build an automatic chronograph, the case will end up being twice as thick,” he explained. The only way to raise the winding efficiency would be to make a large automatic winding mechanism. Building in a 12-hour counter and stop lever for the chronograph would also require a lot of space. Shrinking the automatic winding and chronograph mechanisms was essential to creating an automatic chronograph, but it was not until 1969 that this became possible.
Toshihiko Ohki, who had successfully created the hand-winding Crown Chronograph in 1964 at Suwa Seikosha (now Seiko Epson), was put in charge of developing the new chronograph. The automatic winding 61 Series he had designed on its base was adopted in the 61 5 Sports, which became a big hit. Buoyed by this success, Ohki at last set about designing an automatic chronograph.
At the time, Suwa Seikosha was making use of the Magic Lever, winding the mainspring with pawls as its automatic winding mechanism. The Magic Lever had the advantages of high winding efficiency, few parts and compactness, making it ideal for the automatic chronograph. However, it would need to be combined with a small chronograph mechanism.
Nearly all mechanical chronographs branch the motive power to the chronograph mechanism by engaging a clutch at the fourth wheel, which rotates once per minute. Normally the fourth wheel is opposite the winding stem, and a horizontally sliding clutch is necessary for engaging with the centrally placed seconds chronograph wheel. In the case of the 61 Series automatic winding mechanism, however, which places the fourth wheel at the center, the horizontal clutch employed in conventional chronographs cannot be used. Ohki therefore chose to place the clutch that moves the chronograph directly on the fourth wheel. While his aim was uncertain, the vertical clutch, moving longitudinally, was clearly more compact than a horizontal clutch.
As Ohki recalled, “It was really a desperate situation. The problem was that there was no spring that would not bend in the direction of rotation (of the fourth wheel) and that would slacken on disengagement. So I came up with the idea of a special disk spring (for the vertical clutch).” In 1969, Suwa Seikosha completed Caliber 6139, an automatic chronograph movement with the Magic Lever and a vertical clutch. On May 21 of that year came the official release of the 61 5 Sports Speed-Timer. Judging by the release date, this was without doubt the world’s first mass-production automatic chronograph.
The Caliber 6139 movement became a landmark in the world of watches. In the mid-1980s, the 6139’s disk spring vertical clutch was adopted, with modifications, in the Caliber 1185 slim automatic chronograph of Swiss maker Frédéric Piguet. As this design was imitated by a succession of other firms, the Seiko vertical clutch became the global standard for automatic chronographs.
Continuing this tradition today are two automatic chronographs announced in 2019. Both the Seiko Automatic Chronograph 50th Anniversary Limited Edition and the Seiko Chronograph 55th Anniversary Limited Edition incorporate the automatic chronograph Caliber 8R48 movement made by Seiko Instruments. This movement mounts a chronograph module with vertical clutch on the dial side of the automatic winding 6R Series with Magic Lever.
The reason Seiko adopted a vertical clutch in the first place was to reduce torque loss when starting and stopping the chronograph and prevent second hand jumping during chronograph operation, providing superior accuracy. It was this innovative thinking and technological wizardry that led to development of the world’s first mass-production automatic chronograph. Not to be forgotten is the additional advantage of the vertical clutch in that it enabled the chronograph mechanism to be made smaller than with a horizontal clutch.
Caliber 6139, combining a compact automatic winding mechanism and a vertical clutch, is the origin of today’s automatic chronographs. Without this movement, the history of the automatic chronograph would be completely different.
Timeline of Seiko Chronograph-Related Development
(D) means made by Daini Seikosha (current SII), and (E) by Suwa Seikosha (current Seiko Epson)
1941: Japan’s first pocket watch chronograph was developed and, adopted by the Japanese military as a type 1 luminous stopwatch (D)
1962: Aiming to become official timekeeper for the Tokyo Olympics, Seiko developed a new split-second stopwatch for athletic competitions (D) which won the approval of the Technical Committee of the IAAF in Belgrade, Yugoslavia (today’s Republic of Serbia)
1964: Served as the official timer for the Tokyo Olympics. The Seiko Crown Chronograph (Caliber 5719), incorporating a chronograph mechanism in the crown, went on sale in time for the Olympics (E). Following the Olympics, the Crown Chronograph Calendar (Caliber 5717), adding a date display to Caliber 5719, was released (E).
1968: The 61 5 Sports, aimed at the youth market, was a big hit (E)
1969: The 61 5 Sports Speed-Timer (Caliber 6139), with vertical clutch and column wheel, was developed as the world’s first mass-production automatic chronograph (E)
1970: The 61 Chronograph (Caliber 6138) appeared, adding a 12-hour counter to Caliber 6139, which previously had only a 30-minute counter (E). The 70 5 Sports Chronograph Week Data (Caliber 7017) was introduced as the world’s slimmest (at the time) automatic chronograph (D).
1971: The 70 5 Sports Speed-Timer (Caliber 7018) added a 30-minute counter to Caliber 7017 (D)
1972: Served as the official timer for the Sapporo Winter Olympics. The 70 5 Sports Speed-Timer (Caliber 7016) added 30-minute and 12-hour counters to Caliber 7017 (D).
1998: The Credor Power Reserve Chronograph (Caliber 6S74) was introduced as a hand-winding chronograph with power reserve display (SII)
1999: A limited-edition run of 25 watches of the Credor Chronograph skeleton model (Caliber 6S99) went on sale, celebrating 25 years of the Credor brand (SII). A second commemorative model, the Credor Pacifique Power Reserve Chronograph, saw a limited-edition release, it was based on Caliber 6S74 but used the automatic winding Caliber 6S77 (SII). The Credor Phoenix Chronograph was introduced with Caliber 6S78, eliminating the power reserve display of Caliber 6S77 (SII).
2000: The Credor Pacifique Power Reserve Chronograph 2000 (Caliber 6S77), equipped with a carbon fiber dial, was sold as a limited-edition release (SII)
2007: The first Grand Seiko chronograph appeared, incorporating the Spring Drive Caliber 9R8 Series and equipped with a chronograph mechanism combining a column wheel and vertical clutch (E)
2009: The automatic winding Caliber 8R28 incorporated a chronograph mechanism with a column wheel and vertical clutch on the dial side of Caliber 6R Series (SII)