Archives October 17, 2002 admin
JLC (and Vacheron)
Forum: TimeZone – Advanced Forum
Date: Sat, 15 Nov 1997 03:18:43 GMT
From: Walt Odets <email@example.com>
The following post was first made in response to a question about winding efficiency of a mid 50’s Vacheron automatic.
Vacheron introduced the caliber 477/1 bumper automatic in 1950 (a JLC cal. 476) and in 1955 the cal. 498 and 499, both also based on a JLC, the 477. These are good movements but, mostly for the reasons Walt A. stated, they are not efficient automatic winders. They are also unidirectional wind. I have a JLC made in 1949 with the JLC cal. 481 and power reserve indication (the first power reserve ever used on an automatic wristwatch. The only difference between the 476/477 and the 481 is the reserve indication). This watch will progress from full wind to an unwound condition in about three weeks while on a Cyclomatic S winder. Obviously, the winder is slightly behind the movement’s power flow. In wearing the watch, it takes a full 16 hour day of ordinary activity to put 15-20 hours of wind on the barrel, which is cutting it pretty close. Interestingly, the 481 was JLC’s last use of its own shock resistance for the balance arbors (they went to KIF in the next automatic, the 493). The 481 is an 18,000 bph movement.
Vacheron did not introduce a bidirectional wind until the cal. P 1019 was introduced in 1957. This was a JLC calibre made especially for Vacheron and Audemars and based on the JLC 493. Larger than the 493, the Vacheron/Audemars movement measured 29.5 mm in diameter, 5.4 mm in height, had 21 jewels, and JLC shock resistance (compared to 21.3, 4.85,17, and KIF for the 493). These 493 derivitives were 360 degree, birdirectional wind movements using the now familiar JLC switching rocker for switching winding direction. The basic movement, however, is a “stacked” movement like those of the bumper automatics. Interestingly, the 493 dated back to 1951, but JLC used it only briefly. Apparently JLC felt that the bumper design provided a sturdier, flatter movement and one more amenable to complications. The 493 rotor ran on four large steel balls and this construction made it taller than later ball bearing designs.
JLC also introduced a bumper automatic with Bidirectional winding in 1953, the cal. 497. This movement (used in the JLC “Futurematic”) completely blocked the automatic winding mechanism (including rotor) at full wind and did not use a sliding stud on the mainspring. There was no provision for hand winding, and the crown for hand setting was on the back of the watch. The space left over because of this arrangement allowed a particularly large balance wheel and spring barrel (though with a power reserve of only 36 hours). Vacheron never used this either, for the lack of a winding crown was considered inappropriate to Vacheron’s conservative customers.
As it turned out, no one much like not being able to hand wind the watch (though it functioned well) and JLC went back to a conventional arrangement in the cal. 812, introduced in 1955. The 812 is a unidirectional bumper movement. Finally, in 1959, JLC introduced (and, itself, used) the cal. 881, which is the direct predecessor to the current 889/2. Between the 881 and 889, there was the caliber 888, which is used to this day by Vacheron (for example, in the triple date/moonphase, Ref. 47050 as Vacheron cal. 1126) and by Audemars, as the cal. 2125 in the Royal Oak and many of their other automatics. The 881, 888, and 889 are all 360 degree, bidirectional winders with switching rocker. Introduced in 1967, the 888 is, to this day, perhaps the most commonly used movement in very high grade watches. With 33 jewels (the 889/2 has 36), a diameter of 28.4 mm (the 889/2 is 26) and height of 3.25 mm (the 889/2 is identical), the 888 has defined an entire category of men’s automatic movements. Because many of their complications are designed around the 888, Vacheron and Audemars have not gone to the 889/2 used in current JLC watches like the Master Control