10 3/4”’ | Hand Wind | Pin Lever | No Seconds | Alarm

Remarks:

• Rocking bar winding
• Click on the dial side
• Alarm realized by an electric buzzer that is triggered by closing an electric circuit between the dial and the movement
• Motifications during production:
  • 1966: three-armed spring on regulator
  • 1975: movable instead of fixed hairspring stud-holder, and other small modifications
  • 1976: rocking bar made of plastic
• Movement family:
  • Ruhla UMF 24-24: 0 jewels, dot display (transparent discs instead of hands)
  • Ruhla UMF 24-26: 0 jewels, child’s watch with moving eyes
  • Ruhla UMF 24-30: 0 jewels, no seconds
  • Ruhla UMF 24-31: 0 jewels, small seconds
  • Ruhla UMF 24-32: 0 jewels, indirect sweeping seconds
  • Ruhla UMF 24-33: 0 jewels, indirect sweeping seconds, date
  • Ruhla UMF 24-34: 0 jewels, digital display, bigger base plate
  • Ruhla UMF 24-35: 0 jewels, indirect sweeping seconds with stop mechanism
  • Ruhla UMF 24-36: 0 jewels, digital display
  • Ruhla UMF 24-39: 0 jewels, traveling miniature alarm clock (Midimatic, Sumatic)
  • Ruhla UMF 24-41: 2 jewels, small seconds
  • Ruhla UMF 24-42: 2 jewels, indirect sweeping seconds

• Listing ID: 10974
• Manufacturer / Brand: Ruhla UMF
• Caliber: 24-39
• Size in French Lignes: 10 3/4''' (10 1/2''' according to the manufacturer)
• Size range mm largest diameter: 22 - 31 mm
• Shape: Round
• Winding: Manual (Crown)
• Hands Setting: Crown
• Seconds Hand: None
• Escapement: Pin Lever
• Date, Day, Month...: None
• Other Functions: Alarm
• Jewels: 0
• Setting Lever Screw/Pin Position: Left
• Balance Position: Bottom (120 - 240°)
• Shock Protection: None
• Beats per hour: 18,000
• Balance Type: Nickel
• Power Reserve: Approx. 36 hours
• Production Period: 1963 - 1990 (whole movement family)
• Country: Germany
• Identification: Dial side marked with 24-00. Original datasheet available. Listed in the Flume K3 catalog from 1972.
• Contributor ©: Uhrforum.de member Badener (Andreas Kelz)
• External Link: https://uhrforum.de/threads/identifizierte-uhrwerke-die-weder-bei-ranfft-lorenz-noch-im-watch-wiki-zu-finden-sind.86322/page-77#post-10671722
• External Link 2: https://watch-movements.eu/blog/en/2024/12/01/the-umf-24-39-for-ruhla-sumatic-and-midimatic-alarm-clocks/