10 1/2”’ | Hand Wind | Swiss Lever | Sweeping Seconds |

Remarks:

• According to Barrie Smiths’ book “Smiths Watches, Pierhead Publications Ltd., 2009”, the movement belongs to the so-called Streamline series
• Balance bridge instead of balance cock
• Click riveted
• Dial screws clamp the dial feet directly with their heads

• Listing ID: 4074
• Manufacturer / Brand: Smiths
• Caliber: 637
• Size in French Lignes: 10 1/2'''
• Size range mm largest diameter: 22 - 31 mm
• Shape: Round
• Winding: Manual (Crown)
• Hands Setting: Crown
• Seconds Hand: Sweeping seconds (central seconds)
• Escapement: Lever (Swiss, English, Glashütte)
• Date, Day, Month...: None
• Jewels: 17
• Setting Lever Screw/Pin Position: Left
• Balance Position: Bottom (120 - 240°)
• Shock Protection: KIF Trior
• Beats per hour: 18,000
• Balance Type: Nickel
• Power Reserve: Unknown
• Production Period: Unknown, probably around 1970. The Streamline movements existed from 1966.
• Identification: Barrel bridge marked CAL. 637.
• External Link: https://uhrforum.de/threads/identifizierte-uhrwerke-die-weder-bei-ranfft-lorenz-noch-im-watch-wiki-zu-finden-sind.86322/page-16#post-2736257
• Country: United Kingdom
• Contributor ©: Uhrforum.de member Badener (Andreas Kelz)