Rare Square Case "ROLEX PERPETUAL BULGING BACK Ref.4643" Arrives. Sales Begin for a Rare 18K Rose Gold Model Tracing the Origins of the Early Perpetual Mechanism.

ROLEX PERPETUAL BULGING BACK 18k Rose Gold 1950s

PRINCIPE PRIVE - Epoca d’Oro, highly acclaimed by domestic and international watch collectors and fashionistas for its unique aesthetic selection of vintage watches from the 1940s to the 1990s, has acquired a ROLEX PERPETUAL BULGING BACK Ref.4643.

In 1929, Rolex filed patent "144350" concerning automatic winding mechanisms. Subsequently, patent "160492" for the oscillating weight mechanism, and further patent "170803" filed in 1933, established the foundation for what would later be known as the “Bubbleback” structure.

These mechanisms, designed to efficiently transmit the rotor's power to the mainspring, required height in their internal structure, resulting in the formation of a case back that bulged outwards.

The Ref.4643, now in stock, is a model born from this early era of the Perpetual mechanism.

ROLEX PERPETUAL BULGING BACK 18k Rose Gold 1950s

A Model Inheriting the Structure from the Birth of the Bubbleback

In 1933, Rolex unveiled the first Bubbleback. At that time, the automatic winding mechanism employed a unique rotor structure different from today's, and some individual pieces even had disassembly guide engravings for technicians on the inside of the case back.

Subsequently, after the introduction of Caliber 620, the miniaturized Caliber 520 was born in 1936. Rolex continued to miniaturize movements while developing a variety of case designs.

Our Ref.4643, which we are introducing today, is an extremely rare square-shaped model produced within this lineage.

Ref.4643 Perpetual Bulging Back

Ref.4643 was manufactured for only six years, from 1946 to 1952.

It features an 18K solid rose gold case, boasting a deep hue and substantial weight.

Despite its 28mm size, the unique sculptural quality of the square case gives it a presence greater than that of a round case.

This timepiece is also equipped with a Perpetual mechanism, but unlike typical Bubblebacks, it adopts a “Bulging Back” structure with a convex case back on a square case.

While sometimes treated as a Bubbleback, its structure and origins are distinctly different.

A bulging case back, waterproof structure, automatic winding mechanism. This is a timepiece that expresses Rolex's Perpetual concept of the time, in a square case.

Rare Individual Piece Equipped with Cal.520AR

This particular piece is equipped with the Cal.520AR, which appeared in 1936.

From its early days, Rolex managed its inventory by utilizing the discrepancy between the number of movements manufactured and the number of cases, mounting movements from different manufacturing years into later cases.

In this individual piece, a movement manufactured in 1936 is used in a case from 1946.

Such specifications are not merely a difference in age, but also demonstrate Rolex's rational production management system established at that time.

This piece allows one to understand the technical background of the early Perpetual mechanism and Rolex's unique manufacturing philosophy.

Model: ROLEX PERPETUAL BULGING BACK 18k Rose Gold 1950s

Sales Price: ¥1,920,000 (tax included)

Brand: ROLEX Ref: 4643 PERPETUAL BULGING BACK Year of Manufacture: 1950s

Condition ・Overall good, with slight signs of use

Dial ・Original, untouched ・Original hands and indices

Strap and Buckle ・Aftermarket metal strap

Case ・18K solid rose gold ・28.2mm (excluding crown) / 37mm (lug to lug)

Movement ・Cal.520AR ・Automatic

Accessories ・"PRINCIPE PRIVÉ" Appraisal Certificate ・"PRINCIPE PRIVÉ" Box

Sales Store

PRINCIPE PRIVE - Epoca d'Oro - OMOTESANDO

3-5-19 Kita-Aoyama, Minato-ku, Tokyo

Business Hours: 12:00 - 19:00

PRINCIPE PRIVE - Epoca d'Oro - Official Website

https://principe-prive-epocadoro.com/ja/products/rolex-perpetual-bulging-back-18k-pose-gold-1950s?variant=53283540107571

PRINCIPE PRIVÉ Epoca d’Oro

Keywords: