
Passed to me from within the family, the typewriter came with a case and was in working condition apart, from two inoperative keys (question mark and percentage) and some keys sticking.
The serial number B4A02505 at the rear bottom of the frame indicated that it was bult in 1930 with the ‘B’ denoting the colour – DuPont DUCO® Channel Blue with contrasting panels having a crackle finish in same color. In 1927 the Corona 4 was priced at $60.

To right – typewriter mounted in the case with an arrow pointing to a metal arch which holds the keys in place when being transported.





Repairing the inoperative keys
Following general cleaning of the machinery, fitting a new black only ribbon and rubbing down the platen with Platenclene, attention was focussed on the inoperative keys – the question mark and percentage. Examination of the mechanism showed that a link between two of the levers was either loose or missing.


The front ‘Corona’ plate was removed to gain access to the key levers. Attempts to rejoin the existing very rigid link to the appropriate lever failed as there was not enough space for manoeuvre. So it was removed and it was decided to try fashioning two links from the metal of a paperclip. This was too stiff to crimp around the levers within the space available.

So finally a thinner but stiff garden wire was chosen. This was relatively easy to fashion to the required shape and to fit and should withstand normal typing operation.
A useful video of this type of repair is available, although for a different model of Smith Corona.
Corona 4s are normally fitted with ribbon spool covers as shown on the left from of another machine.

Instruction and Repair Guidance
Two guides on the use of the Corona 4 were found – ‘How to Use Corona 4‘ and ‘Instructions for Operating Corona 4‘
Also a guide to Smith-Corona portable parts and to Corona Portable Typewriter Repair.
Guide to fitting a ribbon through the slots
Guide to winding a new ribbon onto the specifically designed Corona 4 spool (the method I used)
Replacing carriage string
Fixing Stuck and Dirty Typewriter Keys
History of L C Smith and Corona
Lyman Cornelius Smith with his brother Leroy William H. Baker formed W.H. Baker & Co in 1877 and went into firearm manufacture. The mechanical production processes were noted to be similar to those employed in the production of typewriters. A typewriter design from inventor Alexander T. Brown spurred the bothers’ interest leading to the creation of the Smith Premier Typewriter Company in 1877.

The business developed until in 1926 when L. C. Smith & Bros. merged with the Corona Typewriter Company who were producing popular portable machines.
As for many manufacturing companies the coming of World War II had them concentrate on producing goods to support the war effort. Afterwards Smith Corona lead with the first electric typewriters and continued developments into the 1960s. In the 1970s and 80s, Smith Corona diversified further into such products as typewriter cartridges, ribbons, electronic typewriters, and word processors. However the typewriter business collapsed from the 1980s and the company now applies its print know-how into the label market.
Additional Sources of information
Corona Portable Typewriter Repair AMES OAMI Mechanical Training Manual for Standard and Portable Typewriters