One of the coolest watches made by Seiko in the ’60s is the 4006 Bell Matic automatic alarm complication. It was released as the 4006-7000 in Japan in 1966 with a 27 jewel movement. It was not the first alarm movement, that honor goes to Eterna shortly after 1900, but it was a clever, robust movement that featured the first centrally pivoted full winding rotor. 

The dial features a day/date window and iridescent machine turned finishes reminiscent of the times. The crystal is plastic which was a common feature of many watches in the ’60s including Rolex.

One of the most distinctive features is the knob on the right side of the case to activate the alarm which gives off a metallic chiming buzzing sound. The main knob sets the time, the alarm time and winds the alarm spring with is not automatically wound.

So how does this thing work? Pulling the crown out to the first stop and rotating it backwards sets the bezel in motion counterclockwise. As the bezel rotates, the cut-out below the red bar regressively reveals 1-hour sections on the lower chapter ring. The arrow at the center of the red bar indicates the currently selected alarm time. So for example, if the arrow is pointing to the first 10-minute hash mark on the alarm scale just left of 12 o’clock, the alarm is now set for 11:50.

The non-hacking, non-manual-winding movement’s mainspring is wound only by the motion of the rotor, while a separate spring powering the alarm is manually wound with the crown set to its fully-inward position. About twelve turns is all it takes to fully wind the alarm spring. Now that we’ve set our alarm time and wound the spring, the final step is to pull out the arming button at 2 o’clock. The alarm is now set and armed and will ring at the pre-selected time. It rings for about 10 seconds, or can be manually shut off by pushing the arming button back in.

Adjust day/date on the Bellmatic

Pull the crown out to position two and you’re now in time-setting mode. Spinning the hands clockwise also advances the non-quickset day every 24 hours. Something a bit odd is the way you set the date: the alarm arming button at 2 o’clock serves a second purpose. Pushing it in actually advances the date one day at a time. The date also advances with the day every 24 hours while advancing the main hands through 12:00am. Once you’ve played around with it for a bit, the entire system actually becomes quite intuitive.