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Today, Admiral Shark's Keyboards is celebrating the 70th anniversary of two important patents being filed pertaining to the iconic IBM Selectric electric typewriter! On the 17th November 1955, engineers at IBM Poughkeepsie submitted two patent applications for the future Selectric's type element and most of its supporting assembly that would largely define what the then-future Selectric was to become. The Selectric is known for its "golfball" type element that moves across the typewriter instead of having the entire carriage move, and of course for outwardly typical IBM industrial design and class. Selectrics would go on to dominate offices for the following two decades, and serve as a major influence for the many IBM keyboard designs that came after and feature throughout this website.

Contents

Some background

A photo of an original IBM Selectric typewriter
The IBM Selectric[1]

A big part of what made Selectric so special is that it is a single type element typewriter. Most typewriters before it - including the Electromatic/IBM Electric family - use typebars, a system comprising a semicircle of arms, each with a character and aimed towards a central printing position. Pressing a key actuates the arm towards the paper. Typewriters with such a mechanism are susceptible to jamming if more than one key is pressed at once, which potentially causes the typebars to become entangled.

Most typebar typewriters are not designed to have their font routinely changed. Typewriters that can do it, such as the Imperial A through D downstrike typewriters, may require changing their entire type basket (a combination of the keyboard assembly and typebars).[2] Some typewriters supported individual typebar removal, but typically for a servicability context rather than for changing font.

A patent drawing of a Blickensderfer single type element typewriter design
Blickensderfer's type writing machine (US472692A)

Having a single type element as the typewriter's print head can directly address those two issues. Having just a single type element means there are no others that can interfere and jam it, and there is a single, smaller 'thing' that needs to be changed to switch fonts. Selectric was not the first single-element design, though. The Crandall 1 (introduced in 1883) is considered the earliest known commercial single-element typewriter, and even featured proportional spacing[3] when most Selectrics did not. Other examples include the Hammond typewriter family (and its Vari-Typer successors) that entered production in 1884 with its "typeshuttle" element and impression hammer that pushes the paper and ink ribbon towards the element rather than the element moves towards the paper[4], and the Blickensderfer typewriter family and its type cylinder that was patented on 12th April 1892.[5]

Selectric type element carrier[6]
Selectric type element[6]

I think what the Selectric got right was a combination of the single type element, the fact that the carrier with the element moves instead of the entire carriage, and the ingenious design of its internals and electromechanical speed it can achieve. Selectrics also got heavily augmented for various phototypesetting (Selectric Composer family) and neo-word-processing (e.g., Magnetic Tape and Mag Card) roles. Not to mention that Selectric technology or simply the use of spherical elements empowered by electromagnets/solenoids found its way into printers such as the IBM 1053 Console Printer and terminal I/O devices such as the 1052 I/O Printer-Keyboard, 2740 and 2741 Communications Terminals and 3210 Console Printer-Keyboard.

Of interest to this website is, of course, the keyboard, which had a significant reputation behind it and is what IBM tried to recapture with various clicky keyswitch technologies in the following two decades after the Selectric's release. Even in the '90s, when IBM was developing laptops and notebooks such as the IBM PS/2 Model L40 SX and ThinkPad family with Model M3 and M6/M6-1 keyboards (respectively), the people behind those projects looked back fondly on their IBM Selectric keyboard heritage:

We started with certain advantages. One was that our keyboards were descendants of the old IBM Selectric electronic [sic] typewriter, another piece of technology that many young people today have never seen. Keyboards were designed by the keyboard manufacturing division in Lexington, Kentucky, which is where the Selectric used to be made.

The element

IBM's single element printing head (US2895584A)

The first patent of interest that is having its "birthday" today is the "single element printing head" (US2895584A), filed 70 years ago. As explained in the background section, the idea of a single type element is not novel by this point. Whilst the "prior art" had mostly been fairly solid cylinders, this design is a spherical-shaped element with a separable hollow "top shell". This is the iconic 'typeball' part of a Selectric we now love to call a "golfball" today.

The top shell has a grid of characters around its surface that can be moved into a printing position to be struck, requiring a rotation and tilt force to do so (but what generates those forces is not within the scope of this patent). However, both forces are intended to be 'governed' via detents to ensure the character is struck "squarely" without sliding or smudging the print. The top shell can be removed and swapped to allow different typefaces without replacing the entire mechanism.

The invention also intends the sphere to be a relatively small one, which is advantageous compared to a potentially larger design:

  • On a small sphere, characters get naturally angled further apart and cannot inadvertently touch/smudge on the paper.
  • To achieve the same effect on a larger sphere, the spacing of characters would need to be larger, and thus more rotation and tilt force is required to access them.

The main difference compared to the production Selectric element design is that the top shell is screwed into place rather than clipped on, an innovation for a future patent.

The machine

IBM's single element printing machine (US2879876A)

The second patent turning 70 today is the "single element printing machine" (US2879876A). Whilst this patent was filed before the element's, I wanted to talk about that before the whole machine. This patent explains how a spherical single type element machine can be constructed and work in principle.

Code chart of required forces per key/character[7]

The whiffletree mechanism that Selectrics are famous for is not yet present; it uses direct wire-and-cam control of both required forces, but it establishes the general selection process from key levers to actually manipulating the element, and that the element carrier is what moves rather than the entire carriage. But the patent does provide an example code chart showing how each key and character can have a specific rotation and tilt code that needs to be achieved. It also claims that during testing, it was found that the machine could "satisfactorily" print at 19 characters per second, versus the general 14.8 to 15.5 characters per second upper limit for production Selectrics.

An interesting observation of the depiction is that the Selectric keyboard at this point uses keycaps akin to that of IBM Models A through C Electric Typewriters, rather than the spherical-style keycaps Selectrics popularised for IBM keyboard designs until the early 1980s.

The names involved

Both patents refer to John E. Hickerson and Ralph E. Page as inventors, with Leon E. Palmer being unique to the machine patent and James A. Weidenhammer to the element patent. All four are said to be of Poughkeepsie, New York, in one of the two patents, with Hickerson being of Wappingers Falls, New York, specifically in the machine patent. Poughkeepsie was the location of a major IBM factory (plant number 2), which indeed produced typewriters.

Hickerson is considered the "lead inventor" of the element patent, whereas Palmer is such for the machine patent. IBM considers both men amongst those pivotal to the Selectric, with Hickerson specifically credited as transforming IBM's single type element design from a mushroom shape (shown later) into the iconic spherical shape, and Palmer later pioneered its character selection system. Whilst not referenced in either patent, Horace S. "Bud" Beattie is credited with coining the "golfball" element concept, while noting the shape of a ligthbulb as he changed it in his Lexington home."[8]

Other notable patents

The two patents celebrating their anniversary today do not make a complete Selectric on their own, and there are several other patents before and after worth noting.

"Mushroom" type element[9]

The "high speed printing mechanism" (US2661683A) filed on the 17th April 1948 is the most notable pre-Selectric IBM design that is on the path towards our beloved Selectric. The final figure in the filing shows the "mushroom" design that Beattie had been working on until the "spherical" idea came to be. The element is in turn inspired by an even earlier, non-IBM patent for a "type-writing machine" (US393259A) filed by Charles H. Perry on 23rd May 1887.[10]

Displacement mechanism[11]
Typewriter mechanism (partly sectioned)[11]
Rotate selector links[11]

The aforementioned character selection system is the next big step, the "selection mechanism for a single printing element typewriter" (US2919002A) applied on 19th April 1957 and credited solely to Palmer. The character selection system is what processes a pressed key into a certain amount of rotation or tilt force. It most notably describes its whiffletree, used as a linkage-style binary-to-analogue converter.

Revised spherical element[12]

On 27th October 1960, the "printing mechanism" (US3001628A) patent by Russel W. Rice, Jr. was filed that refined the element itself. It shows an element design much closer to that of the final production version, which compared to the earlier element, uses a clip for securing the shell rather than a screw.

IBM Selectric I design[13]
IBM Selectric I/O Keyboard Printer design[14]

The actual ornamental exterior design is credited to Eliot F. Noyes, an architect and industrial designer who worked with IBM for 21 years.[8] Before Selectric, he had worked on the IBM Model A electric typewriter (USD160139S). The earliest two Selectric design patents were of the Selectric I (obviously, USD192829S) and the Selectric I/O Keyboard Printer (USD194856S). They are utterly fantastic; even without any fill or colour, Noyes' brilliance is apparent. I think the original Selectric is one of IBM's most beautiful products. When I was compiling my Keyboard Patents database earlier this year, I would often be mesmerised by some of the illustrations I was seeing, and Noyes' were the main culprits!

A word from me

This is the first article I have attempted to write solely about typewriter technology rather than just keyboards. Whilst I hope I got most things right, I am still learning. If you believe there are any mistakes and corrections to be made, I welcome any polite feedback via email as I wish to not only improve but also cover more typewriter topics in the future.

I also want to give my thanks to Mr. Haelscheir and shoggot of Discord for answering my queries about typebar-based typewriters that could change font and pre-Selectric single-element typewriters. I didn't want to make a sweeping statement that either was entirely Selectric innovation, and they helped me do just that!

Internal

External

  1. Tekniska museet - TEKA0007180 [accessed 2025-04-14]. License/note: public domain.
  2. The Virtual Typewriter Museum - Imperial D (portable) [accessed 2025-11-17].
  3. The Martin Howard Collection - Antique Typewriters - Crandall 1 Typewriter [accessed 2025-11-17].
  4. Haelscheir's Haven - Hammond Multiplex Typewriter Deep-Dive Part 1: Comparison, Mechanics, and Repair [accessed 2025-11-17].
  5. George C. Blickensderfer - Type-writing machine [accessed 2025-11-17]. License/note: provided by Google Patents.
  6. IBM - IBM Selectric [accessed 2025-10-22]. License/note: uploaded to the Internet Archive by okeefe1996, photos used under fair dealing.
  7. IBM - Single element printing machine [accessed 2025-11-17]. License/note: provided by Google Patents.
  8. IBM 100 - The Selectric Typewriter - The Team [accessed 2025-11-17]. License/note: retrieved via the Wayback Machine (2014-01-03 capture).
  9. IBM - High speed printing mechanism [accessed 2025-11-17]. License/note: provided by Google Patents.
  10. Charles H. Perry - Type writing machine [accessed 2025-11-17]. License/note: provided by Google Patents.
  11. IBM - Selection mechanism for a single printing element typewriter [accessed 2025-11-17]. License/note: provided by Google Patents.
  12. IBM - Printing mechanism [accessed 2025-11-17]. License/note: provided by Google Patents.
  13. IBM - Typewriter [accessed 2025-11-17]. License/note: provided by Google Patents.
  14. IBM - Intelligence transmitter and receiver [accessed 2025-11-17]. License/note: provided by Google Patents.