Corona No.3 (Prototype)
Standard Folding Typewriter Co., Inc.
Before the Corona's Standard Folding No.3 officially replaced the Standard Folding No.2 (SF2), there was the prototype seen on this page. It is what engineer Otto Petermann originally envisioned for the future of the brand. Unfortunately upper management felt it was too expensive to produce so it was scaled down. Luckily for us the prototype has survived. You'll note that it is the machine represented in patent no.1,088,924 which Petermann filed in 1909 and assigned to the Standard Folding Typewriter Co.
Obviously, the prototype lost its carriage. It was lost some time prior to 2009 which was when the typewriter was deaccessioned from the collection of the Onondaga Historical Association in Syracuse, NY and offered at public auction. However, based on the patent drawing and on a photo of Otto Petermann next to the actual prototype, which has been generously provided by the descendants of the inventor, we can see that its carriage had two platen knobs whereas the eventual production model had just one.
Other major differences between the prototype and production model included:
Larger, more angular steel frame
Placement of mainspring under left ribbon holder
Placement of bell under right ribbon holder
Keytops like those of SF2
Keyboard with 30 keys
L-shaped folding arms
Solid type segment
Ribbons spool drive shafts
More robust escapement
Otto Petermann started working on the prototype even before production of the SF2 commenced so it should not be surprising that some attributes, like the form of the typewriter and its keytops, more closely resemble the SF2 than the Corona No.3. Other attributes, like the solid type segment and the L-shaped folding arms, were not found on the original No.3 but were adapted later in 1912 and 1919, respectively.
Click here to see an experimental faux woodgrain Corona No.3.
Need an Instruction Manual for you Corona? I have them available here...