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Mechanical Pencil Month – Day 11: Side-knock pencils

Today’s post takes a quick look at three examples from the small sub-genre commonly referred to as “side-knock” pencils. Unlike most conventional mechanical pencils in which the lead is advanced by pressing a button on the end, the side-knock’s button can be found – yes, you’ve guessed it – on the side.

Side-knock mechanical pencils comparative view with centimetre scale

The most obvious benefit of this arrangement is the ability to feed more lead without changing the position of the pencil in the hand, useful for continuous writing. It also frees up the end of the pencil for other uses, such as a larger eraser or more accessible lead reservoir. For people who like to rotate their pencil while drawing (me included), the side-knock is rather less attractive.

Mitsubishi Pecker side-knock mechanical pencil montage

Historically, the first side-knock pencil is often stated to have been the curiously-named Mitsubishi Pecker. This design was patented by the Mitsubishi Pencil Co. in 1972 and went through several designs of which I believe this model to be the earliest.

Mitsubishi Pecker side-knock mechanical pencil four view

The mechanism, with a bent spring driving the clutch, is easily understood from the patent drawing.

Mitsubishi Pecker side-knock mechanical pencil patent drawing

Better known than the Pecker, and with a more intelligible name, Pentel’s Quicker Clicker brought the side-knock concept to the masses.

Pentel Quicker Clicker PD345TA side-knock mechanical pencil montage

Pencils bearing the Quicker Clicker name are still sold today, Pentel’s website claiming it to be “The original side advance mechanical pencil”, in apparent ignorance of Mitsubishi’s effort. Many of the early models were made of transparent plastic, which has the benefit of revealing the simple linear cam design used for the side-knock feature.

Pentel Quicker Clicker PD345TA side-knock mechanical pencil grip detail

However, the question of which was the first side-knock design is moot, as a much earlier example can be found in the Belfor Clicker, an English-made pencil with a button on each side of the barrel.

Belfor Clicker mechanical pencil montage

In this design, the lead is advanced by alternately clicking one button and then the other, not the most convenient arrangement (you have to remember which button you last clicked), but with a very positive action that justifies the pencil’s onomatopoeic name.

Belfor Clicker mechanical pencil three view

Unfortunately I have been able to discover nothing whatsoever about the pencil’s inventor, maker or date of manufacture. There is a certain belligerence about the instruction sheet, which directs in all caps to “USE ONLY BELFOR CLICKER REFILL LEADS (1.19mm) WITH THIS PENCIL”, when the standard lead at the time was 1.18 mm (fortunately the box included a glass tube of the precious 1.19 mm refills).

Belfor Clicker mechanical pencil with box, instructions and spare leads

Even so, it is an undeniably beautiful pencil of reassuring weight and solidity, although I dare not disassemble it to inspect the mechanism for fear of never getting it back together again.

While the Belfor Clicker clearly predates both the Mitsubishi and Pentel pencils, it cannot claim the title of earliest side-knock design. That honour would seem to belong to a German patent cited by Mitsubishi’s 1973 US application for the Pecker. It was filed in 1913 by Ernst Weiler of Berlin and describes a pencil very much like the later Mitsubishi one (Weiler is also named in a 1924 US patent for a pencil sharpener).

Ernst Weiler side-knock pencil 1913 patent drawing

As with Belfor, I have no further information about Ernst Weiler’s activities, so am unable to say if the 1913 side-knock was ever produced. There is a certain naivety about the patent drawing that reminds me a little of the early Penkala automatic pencil introduced a few years before in 1906.

Penkala automatic pencil patented by Eduard Slavoljub Penkala in 1906

With any luck, an example of Weiler’s side-knock will turn up somewhere and help to shed some light on the origins of this interesting branch of the mechanical pencil family.

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