1952 Gruen Bumper Auto-Wind

I’ve had automatic watches before, but this Gruen Precision is my first bumper automatic. Automatic watches uses the movement of the wearer’s arm to cause a semi-circular rotor to pivot back-and-forth and wind the watch “automatically.” Most autos rotate a full 360° but bumpers (or hammers) only move 180° — hitting a small bumper at each end of its path of travel.

I’m not sure when they stopped making bumpers, but I’m thinking not long after this watch was made. The original Gruen Company shut down in 1958. Another interesting bit about this watch is the inscription on the back, which reads:

Presented to N.B. Somers
By Office Staff
Canada Wire & Cable Co.
June 13-52