Circa 1950s - many would simply call this a bullet bra However
ELLECyclopedia: Bullet Bras Were All The Rage Back In The 50s And
Vintage Late 1940s Pink Rayon Bullet Bra - Raleigh Vintage
Final product (maybe) for my sister's 70s themed birthday party! : r/VintageFashion
A Beginner's Guide to Bullet Bras - The Breast Life
Circa 1950s - many would simply call this a bullet bra However, this example by Hollywood Maxwell used the trademark whirlpool because of the company's proprietary spiral stitching on the cups.
Shop 1950s Style Bullet Bras at What Katie Did - What Katie Did
The Good News Journal: I Miss The 50's Bullet Bras
Vintage Late 1940s Pink Rayon Bullet Bra - Raleigh Vintage
Vintage 1950s Bullet Bras - Behind the Bizarre Trend — Classic
A History Of The Iconic Bullet Bra – The Endless Night
My daily wear vintage undergarments per request : r/VintageFashion
From corsets to cone bras: an undergarment retrospective
List of bra designs - Wikipedia