Sticky keys on the Royalite 120

Guest post by owner of Royal Royalite 120 - that does have a few sticky keys :)

Straight-line mechanism (in Meccano, with a little mystery)

With a wonderfully descriptive title, the 1924 Dutch edition of Meccano Book 1 contains a straight-line mechanism; 'a device to convert a circular motion into a rectilinear motion'.

In English with a more abbreviated title, this same model here also in a 1930 instruction book; 'geometrical apparatus'.

The manual ascribes the mechanism to M. Pierre Th. Dufour who, it is stated, designed this as part of his thesis work for Doctor at the University of Paris. It is also explained that that point C will move in a straight line, perpendicular to line through F and E.

This Meccano model first appears in 1918, so Monsieur Dufour's thesis will likely have been around 1917 (indeed it probably was).

The illustration still shows the long 3/4" version of the double-angle brackets part nr. 11 that was updated in 1917 by the half-inch version. The illustration is made from a photographed model that was thus likely made in the model room in 1917 or perhaps early 1918.

Now reproduced in nickel Meccano also using long, pre-1918 double-angle brackets:

Some minor modifications were made to the illustrated model. A few hinge-points were changed to use round pins instead of screws - these give less play. The mechanism does work, but Meccano still has noticable play on the joints; so point C has a few mm leeway from the straight. It does work, but is more of a straight-ish line mechanism perhaps.

This straight-line mechanism is known as the Peaucellier mechanism of 1864, rather than the Dufour mechanism of 1917. For example, it is shown here in the chapter on straight-line mechanisms in the book 'Ingenious Mechanisms for Designers and Inventors':

It is also known as the Peaucellier-Lipkin linkage or the Peaucellier Inversor.

The Meccano model is indeed the Peaucellier linkage, showing the same point having the linear motion. One difference however is the extra linkages GHK of the Meccano model which seem entirely unneccesary. These links play no role at all in the straight motion, as was already noted in a description of this model in number 39 of the Meccanoman's Journal of July 1975:

This does raise a question; why would Meccano Ltd. in 1918 show this mechanism as a design of M. Dufour and why the extra superfluous linkages? 

Reflecting on the alleged creator; it would be highly unlikely for M. Dufour or the Faculty of Science in Paris to not be aware of the Peaucellier mechanism. It is much more likely that M. Dufour simply used the mechanism as part of his work. Considering this, it is then possible that Meccano Ltd. enthusastically created this model, unawares of it being a Peaucellier Inversor. It is also very much possible that M. Dufour expanded on the Peaucellier Inversor - that would perhaps account for the linkages GHK.

Toying a bit with the mechanism (it really is fascinating); could it be that M. Dufour expanded the mechanism with a point H? It (almost?) makes a straight-line motion parallel with C. Or perhaps its deflection from line EF is of interest, relative to the deflection of point C? And that in writing the description, Meccano did not realise and/or omitted the addition that M. Dufour made to the Peaucellier linkage?

Astonishingly, today it is possible to identify the proibable thesis that this mechanism was created for. Monsieur Pierre Th. Dufour most probably was a Swiss student, who after studying in Lausanne obtained a degree at the Paris University's Faculty of Science in June 1917. His thesis is stored in several university libraries - its content has however not (yet) been digitized. Al least, a digitized version could not readily be found.

(If deeply curious, a copy is available online from an antique books seller.)

Its title "Les perspectives-reliefs : nouveau procédé permettant de les obtenir par simple transposition automatique en projection oblique des formes du terrain représentées sur les cartes hypsométriques" does however give clues what it is about. It is about methods to apply transformations from oblique projections to obtain depth/altitude maps in geography (hypsometry). Linkages seem a logical tool to use for such an undertaking.

Pierre Dufour probably used Meccano to prototype various mechanisms. Maybe he corresponded with Meccano (France?) on the subject, or his work was picked-up on by Meccano.

Ergo - the model as described in the Meccano instructions is actually the Peaucellier mechanism. M. Dufour is likely to have made modifications to obtain specific properties. The superfluous linkages shown, but not described, in the Meccano instructions may be such a Dufour-modification, but its meaning for now unclear.

Perhaps after reading his full thesis the meaning of linkage GHK would become clear. 

Until then - it is anyhow an intriguing mechanism (and remains a bit of a puzzle mystery :)

The Burroughs Portable ribbon spools; the 7/16" keyhole type

The common Burroughs Portable adding listing machine that was introduced in 1925 uses a narrow, 7/16" ribbon. The spools are also narrow, small-diameter and have a Burroughs-specific keyhole driving hole/slot.

This spool was not created for the Portable line, but it was a carry-over from the Class 3 machines. The Burroughs Class 3 machines in turn are originally the Pike adding machines made by the Pike Adding Machine Company of 1904. 

(Above image from bss1250's video on a Class 3 machine.)

The Pike company started around 1904, their machine was perhaps first sold commercially around 1906. These Pike full-keyboard adding-listing machines were probably selling well enough for Burroughs to notice. By 1909 Burroughs had taken control of Pike; in industry press it is reported late 1909 that the sales of the Pike company are now controlled by Burroughs.

In January 1910 a new model, the Pike Visible is announced. The 7/16" ribbon and keyhole spool may have its origins in this ~1909 Visible design-effort, but probably it dates right back to the original Pike design of ~1904.

The Burroughs Pike Visible Model production starts as/when the Pike operation is moved from their orginal Orange, NJ factory to a new-built factory in Detroit. The stated plan at the time is to make 7000 machines a year in the new, expanded facilities. That would account for a quarter of Burroughs output for 1912. By volume, that is - by value it would be a lot less, the Pike was at the lower end of the Burroughs machines price-range.

The Burroughs Visible is included in the company naming system as their Class 3 machine and continues until it is superseded by the more modern and modular design of the Portable (Class 8 and 9 machines). Judging by the number of these 'Pike Visible' machines still turning up today on classifieds and auction sites, it really did sell in large numbers. 

The Portable of 1925 sold in even larger numbers over ~40 years. It kept the Pike's spool and ribbon; keeping the 7/16" ribbon with the keyhole spools in production for more than half a century!

When Burroughs introduces a typewriter for office work in the '30s, they however conform to the 'industry expectations' and use a regular half-inch ribbon. The original Class 1 and 2 machines used a very wide ribbon, so for a time there were (at least) three different sizes of ribbons sold by Burroughs for their machines.

In the 1950s, the Pike spools are used in the Rooy portable typewriter. An astonishingly thin 'ultraportable' typewriter; a design where 1/16th of an inch saving would be relevant. The smaller diameter of the spool would help as well. 

(Above image shows keyhole spool on this Rooy on The Typewriterdatabase.)

Using the Burroughs adding machine ribbon and spool design meant that availability was not an issue; the Burroughs Portable was in production until the 1960s (as P-Series machines) and the enormous installed base of machines meant that replacement spools and ribbons were widely available. Rooy thus could get the benefit of a 'custom' smaller size part without having to support an own proprietary format.

(Above on the site of Ribbons Unlimited)

And even today these keyhole spools with narrow ribbon are still available! Not just the narrow ribbon, but even complete with appropriate spools. Stocks won't last, but there may still be a lot of these floating around. As a business-only item not very visible to the general public, but the keyhole spool will have been fairly common. 

A succesful design, like the Portable itself :)

Marchant Pony transfer levers - adjusting

The Marchant Pony calculator did basically work after re-assembly, but not very well. It was noisy and 'rough' to operate, although it is hard to tell what these machines would've been like when new. Setting numbers was fine, but adding to the result-register required quite some force and especially the carries would sometimes block the machine. I.e. small calculations worked, but anything with several carries or larger numbers blocked - that for sure is not what it would've been when new.

Adjusting the drum position relative to the carriage already helped a lot with the required force - there are no dowel-pins on this machine to lock the side-brackets, so these can be adjusted a mm or so. Distance adjusted to create the smallest pressure-angle of pinwheel to the intermediate gears, whilst still no parts clashing that shouldn't.

The carries were likely blocked by the transfer levers requiring too high a force to push out. Feeling by hand, some were very hard to move.

These levers are held with a spring-loaded pin against a rod through their slot, toggled between out- and in-position. An extra tooth on a numeral wheel pushes it out, a cam on the drum pushes it back in. In the transfer-lever's out position, it causes an extra count on the next-up numeral wheel by the drum.

Taking the carriage off the machine, the force needed to push out and back in every transfer lever was measured. This confirmed that these forces were indeed very high and also varied a lot per position!

Pushing over 900 gram-force via that tooth by a single pin of the pinwheel is of itself worrying - risk of damage to that single pin. The variation in forces is likely caused by the springs and pins of a position being too stiff and/or rough.

The hole for the spring-loaded pin is (well..., should be) on the centre-line of the lever and centred in the slot, as per drawing. Differences between in- and out-forces then from an irregularly shaped pin, or maybe small deviations of a part. This calculator had very few of the original pins (or springs) left; most are 'crafted' replacements made when it was completely rebuilt sometime in the past. Whatever the reasons; the forces were too high.

With the force-meter at hand to test a position, all transfer-levers were re-assembled one-by-one. I.e. for every position the spring and also the little beveled pin trimmed to bring the forces somewhere between 200 and 400 gram-force. Lower forces to push out would be even nicer, but it became more difficult to make the levers 'snap' to their end-positions when pushed over the centre of their toggle.

After the re-fixing of the side-walls with improved drum-distance and tuning of the transfer-levers the calculator is noticeably lighter to operate. As bonus it's a bit less noisy too. The machine is now capable of doing zero minus one with a ripple-carry over 13 positions - still a challenge, but it can be done. Carries no longer block the machine! All that having been said; it is not as smooth and light-running as e.g. a 1930s Odhner or Thales. This of course may simply be wear of this particular specimen and not its design.

During some more testing, one position started to fail doing a carry. This was caused by the lever not 'flipping' fully to the out position. By pushing in a rod from the right, some 'minimally invasive surgery' was possible on this single position. The offending lever was rotated off the rod to get at the spring and pin. Then re-assembled with a stronger bevel filed to the pin of position 10 - the bevel helps it 'flip' to the end-positions when toggled.

The Marchant Pony B Special calculator; now with adjusted carriage slightly less noisy and capable of 13 carries in a row :-)

Sighting of an old Adler on a shelf

During a trip last week, did a stop-off at a local thrift shop. On a shelf were a well-used Hermes standard and an old Adler. That Adler was surprising; pre-war machines rarely show up in thrifts stores anymore.

The decal on the cover was in great condition with cover-nuts present as well as original spools.

 

This may actually be a pre-pre-war machine; the serial number was I think 4-digits and that'd make it a pre-1914 specimen. (Serial number 6639 ? -should've taken a better picture.)

The drawband was disconnected (still present) and one keylever had been mistreated (bent?), but overall the machine looked complete and rustfree. The nickel should polish up fine, and the wide ribbon looked usable too.

Overall a decent machine with lots of potential to be a very fine ancient typewriter; at 45 Euro an entirely reasonable asking price too. (Left on their shelf :)

Marchant Pony B calculator coming together

Now that the main functional blocks of the calculator, i.e. the carriage, the setting-drum and the carriage-shifting are all re-built, the whole machine was put together again. A 'test fitting' , with all the covers on too.

The carriage cover had the 18th position blocked off, an old 'fix-up' of a severely damaged machine:

This blocking-off had been very neatly done with a soldered-on bit of brass. Now de-soldered and the hole cleaned-up:

The covers of Marchant machine 70049 are all stamped with '49', i.e. the last two digits of the serial number. For now, only the carriage back-cover was swapped-out with the part from the donor-machine (serial number unknown). The original of machine '49 was really very mangled - oddly so.

Several bits were also tackled or transplanted - the decimal-pointers and bars were taken from the donor-machine -and of course the wooden baseplate.

When putting the cover on the carriage, the counter register did not align properly with the openings - the left digits drop below the viewing holes.

Some checking found that this was not due to a wrong assembly or the carriage itself being bent, but simply because the holes in the cover are misaligned! The cover part is manufactured over many separate stamping steps, so there is a risk of the plate not being fully seated against the alignment pegs on one of these steps. A small misalignment in the tool this time (i.e. back in 1920) resulted in a slight misalignment in the counter-holes. Not major, but still unexpected that this got past final-inspection - these were very expensive machines! A Pony B Special sold new for well over 300 dollar in 1920.

For the whole 'typical look' of the Marchant, a quick-fix reproduction nameplate was mounted on the top-cover and a bit of felt was cut to size to put between baseboard and machine. The long-lost factory original felt probably was black or dark purple/blue, but green is nice too.

To try make the calculator work smoother and as a test, the right sidewall here swapped out with the donor-machine's sidewall (that does not have the brass weld repair) - it really is a luxury to have so many spare parts to choose from! :-)

There still remain many small items to be worked out, but this Marchant Pony B Special calculator basically works again. It does not work very well yet, but it's a start :)

Agelist for Underwood frame numbers (left-foot numbers re-visited)

Spurred on by extra datapoints of Underwood typewriters left-foot numbers on The Database (Thank you James!), and now looking only at the Underwood 5 samples, there are enough points to reasonably map a relation.  [Updated graph; showing 24 Underwood 5 numbers.] 

It is not quite a linear fit (the portfolio mix of Underwood was evolving), but a polynomial fit gives a pretty good correlation. Using that fitted relation and the serial numbers from the agelist, then an 'auxiliary' agelist based on frame numbers can be created:

year frame number

1905    75,000

1906   115,000

1907    154,000

1908   206,000

1909   260,000

1910   329,000

1911      410,000

1912   515,000

1913   639,000

1914   769,000

1915   883,000

1916   998,000

1917 1,141,000

1918 1,287,000

1919 1,422,000

1920 1,601,000

1921 1,812,000

1922 1,948,000

1923 2,130,000

1924 2,323,000

1925 2,520,000

1926 2,768,000

1927 3,005,000

1928 3,214,000

1929 3,386,000

This agelist from frame numbers (a.k.a. the front-left foot numbers) probably has a margin of about a quarter-year either way. Note that after 1926 the first digit of the frame number can be missing, but the full number likely still stamped on the carriage side.

This 'auxiliary' agelist very likely can also give a year-estimate for Underwood typewriters that fall in other serial number ranges than the 5, but were built from the same frame-casting and assembly line.

There's more information still to be had from more data - e.g. there are hints that 1916 saw a significant, sudden shift in the Underwood portfolio -or factory set-up. Also there are hints on batch-sizes, and production buffering was not completely first-in first-out either.

I.e. as more frame-numbers become known, the data will improve and more information can be extracted. 

But already possible is a rough "front-left foot agelist"  :-)

[Update: volume estimates.]

After 1929 the data becomes hazy; maybe because of portfolio shifts or because of the market upheaval from the October stock market crash. After October the sales of expensive business equipment such as typewriters (or Elliot Fisher bookkeeping machines!) probably collapsed.

Nevertheless, between about 1905 and 1929 there seems a robust set of numbers; both for Underwood 5 serials and for all Underwood frames (on that typewriter-frame line, at least). This means an estimate can be made of the volumes and volume-share of the ubiquitous Underwood 5 for the company:

This shows the fluctuations of the overall sales, and also that the share of Underwood 5 (and 4) machines is more than 90% of machines in 1905, but by the end of the 1920s has dropped to about 60% of sales. It has become a less dominant product for the company - typewriter sales have become more diversified; the business market perhaps becoming more receptive to special features such as wider (and more costly) carriages.