Jaeger-LeCoultre Caliber 409 – Technical Overview from Document 1098_JLC

The Jaeger-LeCoultre Caliber 409 is a distinguished manual-winding mechanical movement, notable for its precision, compact design, and reliability. Document 1098_JLC provides an in-depth technical description, highlighting the movement’s architecture, functional features, and guidelines for servicing.

Technical Specifications

• Type: Manual-winding

• Functions: Hours, minutes, small seconds

• Jewels: 17

• Frequency: 21,600 vibrations per hour (3 Hz)

• Power Reserve: Approximately 40 hours

• Diameter: Approximately 22.5 mm

• Height: Approximately 3.5 mm

Caliber 409 is appreciated for its slim profile and accuracy, making it suitable for refined dress watches requiring a reliable small seconds complication.

Movement Architecture and Features

According to document 1098_JLC, Caliber 409 features:

• Small seconds subdial at 6 o’clock, powered by the fourth wheel and pinion

• Compact and robust gear train and barrel design, optimized for energy efficiency

• Shock protection on the balance staff, ensuring durability against impacts

• Manual winding mechanism designed for smooth operation and reliable time setting

The movement’s construction facilitates both precision and ease of maintenance.

Servicing Notes

• Lubrication: Synthetic oils should be applied sparingly to escape wheel pivots, pallet fork jewels, and balance staff; light grease on barrel arbor and winding components

• Regulation: Aim for a stable amplitude between 250° and 280° with a beat error under 0.7 ms

• Small seconds function: Ensure proper mesh and clearance of the fourth wheel and seconds pinion to prevent hand stutter

• Keyless works: Inspect and service the setting lever spring and sliding pinion to maintain smooth crown function

Applications

Caliber 409 was typically used in:

• Mid-sized Jaeger-LeCoultre dress watches emphasizing classic aesthetics with small seconds

• Models crafted from stainless steel or precious metals, generally ranging from 33 to 35 mm in diameter

• Timepieces favored by collectors for their combination of elegance and reliable mechanics

Conclusion

The Jaeger-LeCoultre Caliber 409, as detailed in document 1098_JLC, exemplifies the brand’s commitment to precision manual-winding movements with compact dimensions and traditional complications. Its robust design, ease of servicing, and refined timekeeping make it a valued caliber among vintage watch enthusiasts and professional horologists. It reflects the enduring quality and engineering excellence characteristic of Jaeger-LeCoultre.