The pencil insert

[Gunther]

When using drawing instruments such as compasses for pencil drawings, short pieces of 2 mm lead are mostly used. These are usually held in place by a clamping screw and have to be sharpened, which makes them inconvenient to use (there were also inserts where the lead piece was clamped by a sleeve, e.g. from Rotring in 1980, but these were not very practical either).

An easy-to-use alternative was registered by Dr Werner Beisel and Dipl.-Ing. Peter Gütig in November 1983 and published by the DPMA in May 1985 (the DPMA is the German patent and trademark office). The ‘drawing insert for drawing instruments’, designed as a mechanical pencil, accepts commercially available fine leads and can be screwed into the drawing pen holder of the drawing instrument.

Design as propelling pencil, mechanical pencil with push-button and mechanical pencil with push-button sleeve

An early (the first?) realisation of this idea was the Rotring R 538 23x pencil insert, which came onto the market in 1988.

The insert for three thin lead sizes and as a clutch pencil for 2 mm leads in the 1994 Rotring UK catalogue:

Here’s the Rotring R 538 235 in the STAEDTLER 556 58 drop bow compass:

However, this disclosure was not followed by the grant of a patent. The DPMA states briefly: ‘The application was withdrawn/the property right was waived’ (I would like to know more about this).

With the second thread facing the button, the pencil insert could be screwed into the barrel of a Rotring drawing pen and thus turned into a normal-length writing instrument (curiously, the disclosure document does not mention this possibility). This made the pusher inaccessible, but the solution to this problem was to come in 1987. Some will know what this solution looked like

[Alan]

Great discovery of the specification behind rotring’s pencil inserts! I’ll try not to drop any spoilers for what comes next, but following an earlier discussion of this topic off-forum I did a bit more research that might help explain why Beisel & Gütig’s patent didn’t stick.

Something very similar had already been the subject of a patent application and Gebrauchsmuster by Thomas Doser, instrument maker of Pfronten, almost a decade earlier in 1974.

This covered the use of a fine-lead mechanical pencil with compasses, drop bows, lettering devices and the like, stipulating a shorter body length (65 to 70 mm) for better handling.

Although the patent drawings show a pencil designed to fit into a special threaded sleeve for use with compasses, the patent text also makes provision for moulding the thread on to the barrel of the pencil itself:

"In a further embodiment of the invention, it is proposed to use a fineliner with a moulded threaded part, which threaded part is located near the writing tip, approximately in the area of ​​the rest of the handle.

The threaded part has an external thread that is adapted to the aforementioned internal thread on the drawing instrument.

This variant of the invention, which avoids the individual screw sleeve and combines it with the fine point pen into a single piece, allows for operation similar to the first variant of the invention described above.

In particular, this embodiment can be combined with the idea of ​​shortening the fine-point pen to a length of approximately 65 to 70 millimetres. A device of this type can easily be combined with a compass, as its dimensions are small enough. Working with a stencil pen is also possible."

It’s pretty clear that the later Beisel/Gütig application would have fallen foul of these specifications. However, it appears that although Doser’s Gebrauchsmuster may been granted, the associated patent application did not proceed.

While it’s possible that there was an even earlier patent for the use of fineliners as compass inserts, I wonder if the real obstacle was Haff’s ellipsograph, the 1972 invention of Willi Gaweji (Gebrauchsmuster/patent).

This was fitted with a socket that accepted standard technical pen points, which the patent specification described as:

“the holder [13] for the drawing insert, e.g. an ink insert, a pencil insert or an insert point”

In practice, the supplied pencil insert was a 0.5 mm fineliner of diminutive proportions, complete with integral thread to fit standard technical pen accessories.

Lead feed was via a knurled twist-advance tailpiece. From a comparison of numerous Haff ellipsographs, I believe the pencil inserts were made for the German firm by Uchida of Japan.

This, in turn, was an incremental update of the 2 mm leadholder insert linked to in the original post, sold by rotring since the late 1960s to accompany their “System Haff” compass, which was also made for them by Haff as its name suggests (the insert was No. 5608, seen at top right in the case below).

So, ironically, rotring’s pencil insert patent may have failed because similar designs had already been in use for years - by rotring!

[Leonov]

@Alan

From a comparison of numerous Haff ellipsographs, I believe the pencil inserts were made for the German firm by Uchida of Japan

Alas, I tried to find one of these after spotting one on a YouTube video demonstration of the ellipsograph, but all the listings for plastic ellipsographs from the Haff company I could locate were missing this crucial accessory. I even managed to get the extra-large version of the ellipsograph, but nothing was there.

Infinite sadness. O fine-point pencil inserts, where are you?

[Alan]

I feel your pain! It’s not entirely clear to me whether Haff included them as standard, or as an optional extra. My extra large Haff ellipsograph (98E) came with the Uchida point pictured on the right above, whereas the 97’s insert came in a plastic bag with handwritten “No 98” on it! The only other example I have come across was still screwed into the ellipsograph socket.

Either way, it is infuriating that such useful bits are so often missing from sets. The Haff ellipsograph fineliner insert is right up there with the Linex hatching apparatus template clamp for most wanted missing accessory.

[Leonov]

@Alan

with the Linex hatching apparatus template clamp

Yes, another little piece I dearly miss. I found the machine, even with box and papers, but the clamp? Gone — or possibly, never been there.

I also contacted Haff directly, a few years ago, while they were in the middle of their transition from drafting implements manufacturers to high-precision machinists, but many accessories had already been lost for years; I snagged a large lot of items (compasses, trammels, ruling pens, prickers) with a very convenient discount, including some of their legendary magnifying lenses with attachments for prickers, pencils, and even technical pens, but the ellipsograph insert is a unicorn.

I still hope to be lucky, but even luck reaches its end, ultimately.

[Alan]

I’ll have a look for that third one I got, but I’ve a nasty feeling I might have sold it with the ellipsograph. In the meantime, eyes peeled!

[Gunther]

This is incredible! Thank you for these amazing details. Yes, it’s very obvious why Beisel & Gütig’s patent didn’t stick. However, I’m surprised that the application has made it through the review. – By the way, I have not yet found a connection between Beisel & Gütig and Rotring, and I’m not sure of the Rotring pencil insert was the first of its kind.

I have the Haff ellipsograph too but unfortunately without that accessory.

[Gunther]

@Leonov

but all the listings for plastic ellipsographs from the Haff company I could locate were missing this crucial accessory

The same here – after hearing of it the first time I have found quite a few ellipsographs but none came with than accessory.

[Gunther]

@Alan

Linex hatching apparatus template clamp

What an amazing device! I haven’t heard of it before.

[Alan]

That’s what I love about drawing instruments - it’s like mechanical pencils with the Heath Robinson dial turned up to eleven.

[Gunther]

Great! By the way, do you know the book “Drawing Instruments 1580–1980” by Maya Hambly?

[nimrodd]

From the Pentel Timeline, it looks like Pentel may have had some come out about 1986.

[Leonov]

Do you mean the tiny, metal twistaction leg attachments typically found in medium-to-large drafting sets, or something more similar to the plastic, threaded attachment Gunther was referring to in his first post?

I know of many European (re-)sellers for these plastic accessories (Ecobra, Faber-Castell, Staedtler, rOtring, Kern, etc.), but very few had full-metal inserts imported from Japan — Haff, for instance, used to have one in his all-metal elliptical compass.

[nimrodd]

All I have to go on is the drawings in the presentation. Most everything else is identifiable, but at the bottom of S60 & S63 (Showa 60 & 63, which should be 1986 & 1989), are two small short items.

As I say, I don’t know for sure what they are as 8 don’t recognize them. I believe someone in this group may be able to translate this.

There were 4 pictures on the timeline, and they are in my public Catalog directory as _Pentel Timeline.pdf.

Dropbox

[Leonov]

Thank you very much for the image and explanation; regretfully, I don’t speak, read, or write Japanese, so I will not be helpful with the possible translation.

As for the details you pointed at, the one below S60 might be closer in shape to the Haff ellipsograph accessory mentioned by Alan, whereas the one below S63, given the shape and profile, seems a different part. Still, I think the metal Haff/Uchida twistaction pencil inserts discussed should be older than 1986, so the pictures might even contain a reference to an internal part of some pencils, developed around those years.

Once again, the issue is with missing catalogues: I have a few scanned documents from Haff, but either they are too recent, or too old to show the pieces I am chasing; the 0.5mm twistaction compass leg attachment can only be inferred by a single image of their 1971 catalogue (p.32, “Haff-Elliptical Trammel”), and only because the pencil attachment has been traded for a nylon-tip pen insert now sitting where the thin-lead pencil attachment was originally positioned in the presentation box.

If anyone is willing to attempt a translation of the timeline, we may get an inch closer to the final solution.

[Leonov]

@Gunther

This made the pusher inaccessible, but the solution to this problem was to come in 1987. Some will know what this solution looked like

Did anybody say “Staedtler Mars Circofix”?

[drifand]

Those 2 small items say 'プロッター’ / PLOTTER 0.3 / 0.5

[Gunther]

That could well be possible

[Alan]

I did a quick search using the characters above plus the word “pentel” and ended up here:

https://mouhitotsuno.pentel.co.jp/about/story/chemical/

The first paragraphs translate as:

In the second half of the 1980s, as more women worldwide began to enter the workforce, there was a growing need for portable cosmetics that were easy to carry around, and inquiries about incorporating stationery technology into cosmetics increased sharply. At the same time, there were also a number of requests for special pens for the output devices (plotters) of CAD systems, which were beginning to spread.
In order to respond to such needs from other industries, Pentel established the OEM Division (now the Chemical Products Division) in 1985. It entered the OEM business in earnest, and as its first product, it began selling “CAD plotter pens” made to various companies’ specifications.

This date would seem to fit with the 1986 attribution to the first “plotter” on the timeline. It’s not clear who Pentel was making them for, but the plotter points illustrated do not appear to match any of rotring’s products of the time. They also seem to have Pentel branding on the cartridge.

Tangentially, I have never seen a pencil point for a plotter, although with auto-feed and a cushioned tip it should be possible.

[nimrodd]

These would be pencils, as that is all that this presentation was about; the development of pencils up to the Orenz.