Type the text to search here and press Enter.
Separate search terms by a space; they will all be searched individually in all fields of the database.

Click on Search: to go to the advanced search page.

Rolex - 2940 - Oyster Perpetual - Bubbleback

Please help support TroveStar. Why?
Name 2940
Family Oyster Perpetual
Subtype Bubbleback
Movement Rolex 630 (Details)
Years in Production 1945 - 1947
Case Diameter (mm) 32
Lug Width 17
Mechanism Automatic
Chronometer No
Hacking No
Date Function No
Quickset No
Power Reserve (Hours) 41
Frequency (bph) 18,000
Jewel Count 17
Second Hand Sweep
Case Material Stainless Steel
Hour Marks Arabic
Crown Position 3 O'Clock
Crystal Material Acrylic
Band Replaceable Yes

Notes: The 2940 Rolex was produced in the 1940s and featured the 630 automatic movement. The 2940s come in a stainless steel case with a leather strap band. The bezels are usually stainless steel but also are occasionally made from 14K yellow gold. The dial face comes in various configurations with both Arabic and Roman numerals as hour marks.

Th 630 was Rolex's second automatic mechanism. It was an evolution of the 620. It is a self-winding movement with unidirectional winding rotor, 18,000 A/h, 17 jewels, small seconds, shock protection. Escapement: Stone lever, Yoke winding system. Sweep second. first automatic with rotor winding. Breguet hairspring.

Family Notes: In 1926, Hans Wilsdorf introduced the Oyster watch which used a waterproof case, hence the name. He added "Perpetual" to the name when in 1933 he introduced a reliable automatic self-winding watch. Hence the name means "Waterproof, Self-Winding" in Rolex-speak and generally means the watch is water resistant to a depth of 100 meters.

Type: The Rolex Bubble Back or Bubbleback was first manufactured in 1933. These watches got their name due to the fact that the auto wind mechanism appeared to simply be bolted onto the basic Rolex movement. This attachment was rather large so it was necessary to round out the case back in order to accommodate the mechanism in order to allow proper functioning of the oscillating weight which made complete 360 degree rotations within the case. The Rolex Bubble Backs were produced possibly as late as the early 1960's. Many good examples exist to this day possibly due to the simple and durable basic 18 jewel design of the movement.

Most of these watches were time only and also had a sweep second hand. Later models included a date mechanism and were possibly the first DateJust models produced by Rolex such as the model 6075 which was manufactured in 1948. Some of these early Bubble Backs also had subsidiary seconds bits and many also had the popular California dials which had both Roman numerals and Arabic numerals. None of the Bubble Back cases had bezels that could be removed. Rather than the watch crystal being held in by compression using a bezel crystals were installed by the constriction method. The most common crystal used for these watches is the Tropic 30 crystal. It measures 2.6mm in height. The inside diameter is 24.6mm and the outside diameter is 25.5mm. The Bubble Back shown below has a Registered Design of 6015. Case sizes for the gents watch is 31mm, the ladies is 24mm. Lug sizes for the gents watch is 16mm and the ladies is 13mm.

Item created by: gdm on 2018-09-29 19:59:38. Last edited by gdm on 2019-07-29 17:23:17

If you see errors or missing data in this entry, please feel free to log in and edit it. Anyone with a Gmail account can log in instantly.