Jaap's Mechanical Calculators Page

Dacometer

Dacometer 908


The Dacometer 908
Video
History
Models
Advertisements and Articles
Patents
Links


The Dacometer 908

The Dacometer 908 is quite a rare key-driven adding machine with a full keyboard, similar to the Burroughs Calculator. It has 8 columns of keys, and a 9-digit register that is located beyond the keyboard. Above the register is a row of carry suppression buttons, and to the right of the register is a clearing lever. After clearing the register, the clearing lever stays in the down position. It pops back up the first time a key is pressed, triggering a bell.
It has serial number 5348, was made in about 1951 in Copenhagen, Denmark by Rich. Müller A/S, and distributed by Dacorema A/S. On the rear is a faded decal of the logo of The Imperial Import Company of Amsterdam.

Dacometer 908
Dacometer 908
Dacometer 908
Dacometer 908
Dacometer 908
Dacometer 908
Dacometer 908
Dacometer 908
Dacometer 908


The carry mechanism is quite interesting. When a number wheel turns it winds a spring, and when the wheel rolls over to zero a catch is released so that the spring rotates an axle through a full rotation. This rotation is reduced by a 10:1 ratio and turns the next wheel one step. The interesting part is that the 10:1 reduction is done by an excentric gear system. There is a 9-toothed excentric gear with a fixed orientation. It is surrounded by a 10-toothed ring fixed to the number wheel. The driving axle pushes the excentric gear around the ring once, thereby moving the ring forward by one tooth. It is also constructed in such a way that the carry can be performed even if the receiving wheel is being rotated due to a key press.

On my machine, the carry springs are broken on two of the number wheels (the third and sixth from the right). I am not able to disassemble the register without disassembling the whole mechanism, so am unable to repair it easily. Those same springs are used in the clearing mechanism too, so those two wheels do not clear properly.

Dacometer 908
Dacometer 908
Dacometer 908
Dacometer 908
Dacometer 908
Dacometer 908
Dacometer 908
Dacometer 908
Dacometer 908
Dacometer 908
Dacometer 908
Dacometer 908
Dacometer 908



Dacometer video

Here is a video where I demonstrate my Dacometer.




History

The company Rich. Müller A/S was founded in 1901 by Richard Müller. He was a German toolmaker who had emigrated to Denmark a few years earler. After his death in 1925, his son Ernst Müller took over. The company made a variety of things made from metal. Between 1947 and about 1955 they made a series of mechanical calculators.
Dacorema A/S seems to be an independent company that sold office equipment, and they had exclusive rights to market these Dacometer calculators during the 7 or 8 years that they were made.
It is unclear what relationship these two companies had, other than both being based in Copenhagen, but it is notable that Dacorema registered Dacometer as a trademark 3 years before the machine came to market.

The Rich. Müller company still exists today as RMIG (Richard Müller International Group) and is specialised in making perforated metal sheets. Dacorema seems to have ended in the mid 1970s.


Models

There were two main types of Dacometer. One type had a half-sized keyboard similar to the Contex A, another Danish machine, while the other had a full-sized keyboard with carry suppression buttons. The table below lists the variations that these two types went through. The serial number ranges are based on known serial numbers taken from various online sources.

YearsHalf-size keyboardFull-size keyboard
1947-1949 Dacometer 5
Ser. No: 1148-2522
Dacometer 98
Ser. No: 5039-5161

8-column keyboard, 9-digit register
Boxy black or dark brown bakelite case
Works on downstroke
Serial numbers probably started at 1000 and 5000.

There was also the Dacometer 9 which was identical to model 98 except that it had some kind of extra register in front of the keyboard (possibly to show the last keypress in each column), but it was much more expensive, and therefore rarer. I found a Norwegian newspaper ad that includes this model so it was sold commercially, but have not found any still existing examples of the machine online.
1950-1952 Dacometer 508
Ser. No: 2845-3205
Dacometer 908
Ser. No: 5348-5382

8-column keyboard, 9-digit register
Rounded brown steel case (possibly some in bakelite)
Works on downstroke
Serial numbers probably follow on from the previous model.
Dacometer 511
Ser. No: 4023-4396
Dacometer 911
Ser. No: 10077-10170

11-column keyboard, 12-digit register
Rounded brown steel case (possibly some in bakelite)
Works on downstroke
Serial numbers probably started at 4000 and 10000.
1952-1955 Dacometer 508
Ser. No: 15112-15765; 30305-31470

8-column keyboard, 9-digit register
Rounded green-grey steel case
Works on upstroke
Serial numbers probably started at 15000 and 30000.

It is unclear whether the jump to a new range of serial numbers introduced any other changes.
Also rebranded as by Torpedo as "Torpedo Schnelladdiermaschine" from 1952. Previously Torpedo made licensed copies of the Bell Punch Plus adders (or their predecessor, the Petometer).

Advertisements and Articles

I found a few text-only advertisements in Dutch newspapers, and a nice one with a picture in an Australian newspaper.

1947-03-08 Algemeen Handelsblad
1947-04-09 Algemeen Handelsblad
1947-05-16 Nieuw Israelietisch weekblad
1947-07-16 Algemeen Handelsblad
1948-12-20 Nordlys
1949-09-30 Leidsch Dagblad
1953-04-09 The Courier-Mail (Brisbane, Qld)
1953-07-23 Upper Hutt Leader
1953-11-21 The Mercury (Hobart, Tas.)


Here are some Dacorema trademarks, shares notices and other records found in the Danish royal library.

1943-04-08 Registreringstindene for vare- og faellesmaerker
1944-03-23 Registreringstindene for vare- og faellesmaerker
1944-06 Registreringstidende for aktieselskaber forsikringsselskaber og foreninger
1957-10 Registreringstidende for aktieselskaber forsikringsselskaber og foreninger
1963-04-30 Registreringstindene for vare- og faellesmaerker
1967-07 Registreringstidende for aktieselskaber forsikringsselskaber og foreninger
1968-12 Registreringstidende for aktieselskaber forsikringsselskaber og foreninger
1969-10 Registreringstidende for aktieselskaber forsikringsselskaber og foreninger
1971-05 Registreringstidende for aktieselskaber forsikringsselskaber og foreninger
1974-08 Registreringstidende for aktieselskaber forsikringsselskaber og foreninger



Patents

The mechanism of the Dacometer 9 is almost identical to the one described in a patent by George C. (Clinton) Chase from 1915. The patent references J.A. Turck's calculator, the Mechanical Accountant as its reference point, and improves on it by having a carry mechanism that works even when the receiving wheel is being turned by a key press. The patent also describes the rest of the mechanism, including the carry suppression buttons, the keyboard and actuating mechanism, and clearing mechanism, all of which were used in the Dacometer. He also had an earlier patent which describes a carry mechanism that uses a planetary gear system.
By 1930 George C. Chase was working for Monroe, where he became the chief designer.

PatentFiling datePriority dateNameDescription
US 1,011,15629-06-191112-12-1912George C. ChaseRegistering Mechanism for Calculating-Machines
US 1,329,26220-03-191527-01-1920George C. ChaseCalculating-Machine

Links

Rechnerlexikon has a pages for the Dacometer 5, Dacometer 9/98, Dacometer 508/511, and Dacometer 908/911, as well as a page for the Dacorema company and a nice article (pdf) about these machines.
Rechenmaschinen-Illustrated has a little info about the Dacometer.
John Wolff has various key-driven machines including the Dacometer 508.
Rechnen Ohne Strom shows a Dacometer 508
Arithmeum has in its collection the Dacometer 5, Dacometer 508, and Dacometer 908.
François Babillot's site has nice pictures of an early Dacometer 5.
Jens Aperdannier's site has a picture of a Torpedo Schnell-Addiermaschine .
The Danish Royal Library has some public records about about companies such as registered trademarks, including an entry for the Dacometer trademark from 1944.
RMIG (Rich. Muller International Group) has a company history page, which makes no mention of their brief foray into calculators.


© Copyright 2020 Jaap Scherphuis, .