Hard to imagine , holding on my hands are the Mother of All Memovoxes.
Reference 3151 & 3150 , these were the very first Memovoxes , Jaeger LeCoultre released. Original adverts from Life Magazine ,1950 and 1951.
Translating the patent documents JLC submitted in 1949 , best way to say it is flared lugs , with a purpose.
If you look at the last image of both references , the lugs on each watch carry the case back raised not touching the ground , this ensures that the caseback never really rests on your wrist.. allowing for greater alarm resonance of the caliber 489. Caliber 489 , which being the first alarm caliber from JLC has and still holds an impressive full 46 hour power reserve with the alarm function.
Great pictures and write up. Caliber 956 one the new one has 45 hour power reserve so it still holds it ground. My flair kind of rests with the Memovox Parking because it’s a cool application of the alarm feature.