Jaap's Mechanical Calculators Page

Hamann / DeTeWe

The Hamann Manus E The Hamann Manus F Hamann Delta



Hamann Manus E
   Video
Hamann Manus F
   Video
Hamann Delta
   Video
History
Books and Manuals
Promotional material
Advertisements and Articles
Patents
Links

Hamann Manus E

The Hamann Manus looks like a pinwheel calculator, but it uses a different mechanism. At the front is a carriage containing a 13-digit main register on the right and an 8-digit counter on the left. In the main body are 9 input levers with an input register that displays the current lever settings. There is a large crank on the right, and a clockwise turn of that crank normally adds the input to the register, and increments the counter. There is a switch to the left of the input that changes the direction of the counter.

The main noticable difference from a normal pinwhweel machine is that the crank cannot be turned anti-clockwise. To subtract you must instead flick a switch located below the crank to set the machine in subtraction mode. This shifts the carriage a half step, thereby reconnecting the carriage register through a set of intermediate gears. A clockwise turn of the crank then subtracts the number because it turns the register digits in the opposite direction. There is a very small tab just below the counter direction switch with which the crank can be reversed. If for some reason the mechanism locks up and the crank cannot move forward, then you can push the tab to allow the crank to move backwards into its cradle so that the problem can be fixed more easily.

The carriage can be moved a step left or right using the arrow buttons next to the crank, or any amount using the knob on the front of the carriage. The clearing levers for the register and counter are on the two ends of the carriage. The input can be cleared with the round button on top of the machine. When the button is pressed, the input pins spring up to zero. If the button is rotated so that its arrow points to the left, then the button is pushed down with every turn of the crank so that the input is cleared automatically after each addition or subtraction. The button can only be rotated while it is being pushed down.

Over the years that the Manus was in production, small improvements were made. These variations are unofficially denoted with the letters A to F. This is a type E with serial number 12,208, which dates it to about 1948.

Hamann Manus E
Hamann Manus E
Hamann Manus E
Hamann Manus E
Hamann Manus E
Hamann Manus E
Hamann Manus E
Hamann Manus E
Hamann Manus E
Hamann Manus E

This machine has automatic division. Set up the numerator in the register (as many decimal places to the left as possible). Then shift the carriage as far to the right as possible, and push in the carriage knob. Set the input to the denominator, again at the left end. Set the counter direction switch to subtract, and clear the counter. Then simply repeatedly turn the crank. Whenever the register underflows, the carriage is moved a half-step to the left so that the next turn adds the denominator back. This then overflows the register and moves the carriage another half-step, ready to subtract from the next decimal position. This repeats until the carriage arrives at the far left location, where the register is disconnected and further turns of the crank have no effect.

The latched gear mechanism of the Manus is somewhat reminiscent of the Marchant XA. Instead of pinwheels in which the number of teeth vary, it uses gear wheels that can connect to or disconnect from the central axle. While the crank turns the axle around, the stationary setting lever acts like a cam, and the cam follower on the rotating axle then either locks or unlocks the gear. In effect the gear rotates by an amount that is proportional to the lever setting.

Hamann Manus E
Hamann Manus E
Hamann Manus E
Hamann Manus E
Hamann Manus E
Hamann Manus E
Hamann Manus E
Hamann Manus E
Hamann Manus E

Video

Below is a video I made that demonstrates the Hamann Manus E.




Hamann Manus F

The Hamann Manus F is very similar to the Manus type E above, but it has several small improvements, mainly to the clearing mechanisms. The clearing lever for the counter has been moved to the right hand side of the carriage, next to the clearing lever for the main register. This allows both clearing levers to be operated simultaneously with one hand. Clearing the input is done by lifting a bar that pushes the input pins up to zero. The input pins are much easier to move since the they no longer need to be spring-loaded.

The Hamann Manus F
The Hamann Manus F
The Hamann Manus F
The Hamann Manus F
The Hamann Manus F
The Hamann Manus F
The Hamann Manus F
The Hamann Manus F
The Hamann Manus F
The Hamann Manus F
The Hamann Manus F

This machine has serial number 15421.

The Hamann Manus F
The Hamann Manus F
The Hamann Manus F
The Hamann Manus F

Video

Below is a video I made that demonstrates the Hamann Manus F.




Hamann Delta

The Hamann Delta is an electrically driven calculator with a full keyboard. Its mechanism is otherwise very similar to the Hamann Manus.

At the front right are four buttons: Two buttons for shifting the carriage, as well as buttons for subtraction and addition. The latter buttons will set the carriage into subtraction or addition mode and then activate the electric motor. The motor will keep running while the button is depressed, so this performs repeated addition making multiplication easy. There is a second addition button to the right of the keyboard, and this is purely for adding because the motor stops after one addition, and the keyboard is is automatically clears. On the left there is a switch lever that sets the counter direction, i.e. whether it counts the net additions or net subtractions. The carriage has a knob that allows the carriage to be released and shifted any amount, or pushed in to set division mode.

As with the Hamann Manus, this machine has automatic division. It is is performed in almost exactly the same way. You set the numerator in the register as far to the left as possible, and the divisor in the input. Set the counter direction to subtractions, shift the carriage to the right, and push in the carriage knob to set division mode. Pressing the subtraction button then starts the process.

The machine is supplied with a detachable crank handle. It is normally stored in a holder on the back of the case, but it can easily be inserted in a hole on the right when no electricity is available.

Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta

This machine has serial number 1368. The Hamann Delta is a rare model. Very few can be found online, such as #1231, #2307, #????. Probably fewer than 1500 were made, but it is hard to be sure with so little data.

Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta
Hamann Delta

Video




History

Christel Hamann (1870-1946) was a highly prolific and inventive designer of calculating machines. He founded his own company in 1896, at which his first machines were made. The full range of his lesser known early work is somewhat unclear. It is possible that he started with troncet adders and pinwheel machines, as his name has been linked to the Trick (troncet adder) and the Berolina (pinwheel machine) due to some of his patents. His first proper machine design was called the Gauss, and was a cylindrical machine with a single stepped drum at the centre and number wheels arranged around it. He patented this in 1902. This principle had been used by Philipp Matthäus Hahn in the 1770s to make a handful of machines, but the Gauss was simpler, and about a thousand were made. The culmination of the principle was the Curta calculator from 1946 by Curt Herzstark.

In 1905 he developed and patented an entirely new principle, proportional levers. Similar to stepped drum machines the input is done by sliders, one for each digit, and the slider shifts a gear along an axle so that it engages with the mechanism. In this case that is not a stepped drum for each digit, but a set of ten parallel toothed racks shared by all the input digits. These toothed racks are pivoted to an arm, and when one end of that arm swings out, the racks move different amounts, varying from 0 to 9 units. The register wheels move in one direction only, so when the racks have returned to their starting position the input has been added to the register. For subtraction the other end of the arm is moved so that complementary digits are added. Hamann called this machine the Euklid.

In 1907 Hamann's company was bought by Mercedes Bureaumaschinenwerke. They continued to make the Gauss for a few years, and made the Mercedes Plus which was an adding machine that Hamann designed, but it was mainly the Euklid machines that became successful and were developed further. Mercedes-Euklid models, all based on the same principle, were produced until the 1960s.

In 1922 Hamann started working for Deutsche Telephonwerke GmbH, or DTW, which later became Deutsche Telephonwerke und Kabelindustrie AG, or DeTeWe. It seems that he essentially ran a daughter company Hamann Rechenmaschinen. There he developed the Hamann Manus, of which the model A was released in 1925. Before then only Madas had made machines with fully automatic division, but they were much larger machines. This was the first compact calculator with automatic division. There followed models B to F, and finally R. See the description of my Manus E above for more details about the mechanism. Below is a table with information about these Hamann Manus models. Unless otherwise specified, later models in the table also have all the characteristics of the previous models.

ModelYearsSerial NumbersCharacteristics
A1925-1926 501- 1000Black colour; DTW logo; Wingnuts for clearing; Input clearing button at top-left; Carriage left-shift lever on the right, no right-shift lever; Overflow bell on outside.
B1926-1927 1001- 1500Carry mechanism in counter; Crank reverse tab
C1927-1937 1501- 8200Carriage right-shift lever on the left; Overflow bell internal
D1937-1944 8200-12000Both carriage shift buttons next to crank on right; Wingnuts replaced by clearing levers at each end of carriage.
E1948-195312001-15000No toothed rack visible in base; At some point changed to green colour, DeTeWe logo.
F1953-195515001-16000Green colour; DeTeWe logo; Both clearing levers on right of carriage; External input clearing bar
R1953-195940001-54000Back transfer mechanism

There is some disagreement on what constitutes the model D, as some consider only the machines with serial numbers 8200-8230 to be of that model, with the rest being model E.

In his time at DeTeWe Christel Hamann also developed many other machines such as the Delta, Elma, Selecta, and various Automat models. These were electrically driven machines that were based on the same mechanism as the Hamann Manus. He also experimented with relays used by telephone industry, and in 1931 patented one of the earliest electric calculators using that technology. Hamann died in 1946. The company developed the Hamann 300, a calculator model with a 10-key number pad. In 1958 DeTeWe sold off Hamann Rechenmaschinen GmbH to Marchant. This occurred at the time that Marchant fused with Smith-Corona to become SCM, so Hamann Rechenmaschinen GmbH became a wholly owned daughter company of SCM. Further calculator models followed until the end of the 1960s (models 350, 400, 450, 500, 505, 1630).


Books and Manuals

Handhabung der Hamann Manus Rechenmaschine    (PDF, 10.7 MB or archive.org)
Deutsche Telephonwerke und Kabelindustrie A.-G.
1937-1944
21 page stapled booklet
226mm × 156mm

This booklet is the manual for the Hamann Manus in the German language. It has no copyright year, but the pictures are of the model D so it was presumably printed between 1937 and 1944.

Hamann Manus Manual
Hamann Manus Manual
Hamann Manus Manual
Hamann Manus Manual

Handhabung der Hamann Manus R Rechenmaschine    (PDF, 7.73 MB or archive.org)
Deutsche Telephonwerke und Kabelindustrie A.-G.
March 1953
12 page stapled booklet
210mm × 148mm

This booklet is the manual for the Hamann Manus R in the German language. It has the same contents as its predecessor above, but is written much more concisely so has fewer pages. It has no copyright year, a printing code suggests it was printed in March 1953.

Handhabung der Hamann Manus R Rechenmaschine
Handhabung der Hamann Manus R Rechenmaschine
Handhabung der Hamann Manus R Rechenmaschine
Handhabung der Hamann Manus R Rechenmaschine
Handhabung der Hamann Manus R Rechenmaschine

Rechne schnell + einfach mit Hamann Manus R
Deutsche Telephonwerke und Kabelindustrie A.-G.
1953?
77 page softcover book
209mm × 149mm × 7mm

This book contains a brief explanation of the four basic operations, followed by many practical calculation examples that can be performed using the Hamann Manus R. The book has no copyright date.

Rechne schnell + einfach mit Hamann Manus R
Rechne schnell + einfach mit Hamann Manus R
Rechne schnell + einfach mit Hamann Manus R
Rechne schnell + einfach mit Hamann Manus R
Rechne schnell + einfach mit Hamann Manus R
Rechne schnell + einfach mit Hamann Manus R

Die Hamann 300 in der täglichen Rechenpraxis    (PDF, 31.2 MB or archive.org)
Deutsche Telephonwerke und Kabelindustrie A.-G.
1953?
Folder with 36 loose leaves, 72 pages.
Folder 154mm × 219mm, leaves 148mm × 210mm

This booklet gives examples of many different types of calculation that can be performed on the Hamann 300. It consists of a folder containing loose pages, and the pages of each section have their own page numbering, so any sections deemed irrelevant can be removed. It has no copyright year, but model 300 was released in 1953.

hamann300manual01
hamann300manual02
hamann300manual03

Reparaturanleitung Hamann Automat S    (PDF, 46.1 MB or archive.org)
Hamann Rechenmaschinen GmbH
1955?
52-page strip-bound book
226mm × 320mm × 3mm

This is the repair manual for the Hamann Automat S. It contains brief descriptions of how to disassemble various parts of the machine, and some of the common faults. The book has no copyright date but the model Automat S was made in the second half of the 1950s.

Reparaturanleitung Hamann Automat S
Reparaturanleitung Hamann Automat S
Reparaturanleitung Hamann Automat S
Reparaturanleitung Hamann Automat S
Reparaturanleitung Hamann Automat S

Promotional material

36-card deck of playing cards
DeTeWe, and Max Kranz, Augsburg
1930s
Box 62mm × 102mm × 12mm; Card 56mm × 100mm

This is a deck of playing cards promoting Hamann calculators. The box has a picture of some type of Hamann Automat on one side, and a type of Hamann Selecta on the other, which probably dates this to the 1930s. The cards are a 36-card German deck, so it has the values 6 to 10, O, U, K and A of the four suits bells, hearts, leaves and swords. The card design is a Bavarian pattern of a Stralsund type.

German Playing Cards
German Playing Cards
German Playing Cards
German Playing Cards

Hamann leaflet
DeTeWe, Deutsche Telephonwerke und Kabelindustrie AG
1938?
6-section folded leaflet
Folded 101mm × 148mm, unfolded 600mm × 148mm

A German leaflet for many of the Hamann models. It shows the Manus, Elma, Automat V, Delta, and the Selecta.

Hamann Leaflet
Hamann Leaflet
Hamann Leaflet

Hamann Leaflet
Hamann Leaflet
Hamann Leaflet
Hamann Leaflet

Hamann Folder
DeTeWe, Deutsche Telephonwerke und Kabelindustrie AG
1950s
Large cardboard documents folder
223mm × 310mm

A large cardboard folder for storing documents, with the Hamann and DeTeWe logos on the front.

Large Hamann folder
Large Hamann folder

Flyers for various Hamann calculator models
DeTeWe, Deutsche Telephonwerke und Kabelindustrie AG
1950s
Double-sided large flyers
210mm × 298mm

These are German flyers for the various Hamann calculator models. Each has an illustration of the particular machine on the front, and a descriptive text on the reverse. They flyers are for:
Hamann Automat S, December 1954
Hamann 300, 1953?
Hamann E, January 1955
Hamann E, January 1957
Hamann Manus R, May 1954
Hamann Manus R, 1954?

Flyer for the Hamann Automat S
Flyer for the Hamann Automat S
Flyer for the Hamann Automat S
Flyer for the Hamann Automat S
Flyer for the Hamann 300
Flyer for the Hamann 300
Flyer for the Hamann 300
Flyer for the Hamann 300
Flyer for the Hamann E
Flyer for the Hamann E
Flyer for the Hamann E
Flyer for the Hamann E
Flyer for the Hamann E
Flyer for the Hamann E
Flyer for the Hamann E
Flyer for the Hamann E
Flyer for the Hamann Manus R
Flyer for the Hamann Manus R
Flyer for the Hamann Manus R
Flyer for the Hamann Manus R
Flyer for the Hamann Manus R
Flyer for the Hamann Manus R
Flyer for the Hamann Manus R
Flyer for the Hamann Manus R

Cristel Hamann article
DeTeWe, Deutsche Telephonwerke und Kabelindustrie AG
June 1956
3-page folded leaflet
210mm × 298mm

Reprint of a biographic article of Christel Hamann, used for advertising.

articlecristelhamann01
articlecristelhamann02
articlecristelhamann03
articlecristelhamann04
articlecristelhamann05
articlecristelhamann06

Hamann 300 article
DeTeWe, Deutsche Telephonwerke und Kabelindustrie AG
1958
Double sided flyer
222mm × 311mm

Reprint of a short article from September 1957 about using the Hamann 300 to solve difficult formulae.

articleformula-01
articleformula-02
articleformula-03
articleformula-04

Hamann 300 article
DeTeWe, Deutsche Telephonwerke und Kabelindustrie AG
December 1956
One-sided flyer
210mm × 298mm

Reprint of a short article from September 1957 about the growth of German industry in West Germany, and the production of the Hamann 300 in particular.

articlehamann300-01
articlehamann300-02

Hamann 300 article
DeTeWe, Deutsche Telephonwerke und Kabelindustrie AG
December 1957
4-page folded leaflet
210mm × 298mm

Reprint of an article describing how the Hamann 300 was used to calculate the processes involved in steel production.

articlehamann300-03
articlehamann300-04
articlehamann300-05
articlehamann300-06
articlehamann300-07
articlehamann300-08
articlehamann300-09
articlehamann300-10

Hamann 300 article
DeTeWe, Deutsche Telephonwerke und Kabelindustrie AG
1958
Double-sided flyer
210mm × 298mm

Reprint of an article describing the uses and advantages of the back transfer functionality that the Hamann 300 has.

articletransfer-01
articletransfer-02
articletransfer-03
articletransfer-04

Hamann 300 Flyer
DeTeWe, Deutsche Telephonwerke und Kabelindustrie AG
1953-1959
2-sided small flyer
83mm × 126mm

A small German flyer for the Hamann 300, an electrically driven calculator with a 10-key keyboard, automatic division, and back transfer from both the main register and the counter.

Hamann 300 Flyer
Hamann 300 Flyer
Hamann 300 Flyer
Hamann 300 Flyer

Hamann E Flyer
DeTeWe, Deutsche Telephonwerke und Kabelindustrie AG
1953-1959
1-sided small flyer
105mm × 148mm

A small German flyer for the Hamann E, essentially an electrically driven version of the Hamann Manus.

Hamann E Flyer
Hamann E Flyer
Hamann E Flyer
Hamann E Flyer

Hamann Folder
SCM Hamann-Rechenmaschinen GmbH
1963?
Large cardboard documents folder
226mm × 320mm

A large cardboard folder for storing documents, with the SCM logo on the front. It contains many flyers for various SCM products together with a cover letter. Those related to Hamann calculators can be found on this page, and the Marchant calculator flyers on the Marchant page. Most of the flyers are of other SCM products, such as Smith-Corona typewriters, electrostatic photocopiers, data processing machines using punched tape, etc.

SCM Hamann Folder
SCM Hamann Folder
SCM Hamann Folder

SCM Hamann Automatic 505 Flyer
SCM Hamann-Rechenmaschinen GmbH
1963?
4-page folded flyer
210mm × 297mm

A large German flyer for the Hamann Automatic 505. This calculator can do automatic multiplication and division, and was the last mechanical calculator that Hamann made.

SCM Hamann Automatic 505 Flyer
SCM Hamann Automatic 505 Flyer
SCM Hamann Automatic 505 Flyer
SCM Hamann Automatic 505 Flyer
SCM Hamann Automatic 505 Flyer
SCM Hamann Automatic 505 Flyer

Articles and Advertisements

I have not found many articles and advertisements relating to the Hamann machines in online archives.

Here is the entry in Ernst Martin's 1925 book Die Rechenmaschinen:

1925 Ernst Martin 1
1925 Ernst Martin 2
1925 Ernst Martin 3

Here are a few other articles that mention Hamann.

1927-09-08 Linzer Tagespost
1931 Moderne Buero-Maschinen
1959-10-22 Aktiv

Lastly, here are some advertisements. The first one is for the Gauss, the last includes a Marchant Hamann.

1903-01-30 Der Bautechniker
1931-01-02 De Maasbode
1931-01-08 Arnhemsche courant
1940-05-18 Salzburger Volksblatt
1948-01-16 Berliner Zeitung
1954-11-08 Algemeen Handelsblad
1956-08-20 Algemeen Dagblad
1961-03-30 De Tijd De Maasbode

Patents

PatentFiling datePublished dateNameDescription
DE 88,22311-06-189510-09-1896Christel HamannPlanimeter
US 703,78502-07-190001-07-1902Christel HamannGauss predecessor
US 705,83828-03-190229-07-1902Christel HamannExtra register for pinwheel calculator
US 772,93513-10-190325-10-1904Christel HamannPinwheel calculator improvements
DE 179,24626-11-190430-11-1906Christel HamannSubtraction using complements on pinwheel calculator
DE 194,52723-03-190506-02-1908Christel HamannGauss calculator
See also: US 832,666
DE 209,81731-05-190613-05-1909Mercedes Bureau-Maschinen-Gesellschaft m.b.H.Euklid calculator
See also: US 1,011,617
DE 210,52430-10-190703-06-1909Mercedes Bureau-Maschinen-Gesellschaft m.b.H.10-key input
DE 210,66111-02-190807-06-1909Ch. Hamann, Math. Mech. Institut, G.m.b.H.Subtraction mode on Gauss calculator
DE 228,56304-06-190912-11-1910Ch. Hamann, Math. Mech. Institut, G.m.b.H.Calculator for products of more than two factors
DE 234,98415-09-191029-05-1911Ch. Hamann, Math. Mech. Institut, G.m.b.H.Calculation device for trigonometric functions
DE 242,66513-04-191116-01-1912Mercedes Bureau-Maschinen-Gesellschaft m.b.H.Trick, troncet with sliding cover for subtraction
DE 253,52524-06-191113-11-1912Ch. Hamann, Math. Mech. Institut, G.m.b.H.Printing mechanism
US 1,221,31820-04-191203-04-1917Ch. Hamann, Math. Mech. Institut, G.m.b.H.Calculator with fast multiplication
DE 268,72912-04-191327-12-1913Mercedes Bureau-Maschinen-Gesellschaft m.b.H.Trick, version for British currency
DE 278,68012-04-191302-10-1914Ch. Hamann, Math. Mech. Institut, G.m.b.H.Calculator with totaliser
DE 287,77017-02-191405-10-1915Ch. Hamann, Math. Mech. Institut, G.m.b.H.Euklid with automatic multiplication and division
See also: US 1,566,961
DE 367,72624-10-192025-01-1923Deutsche Telephonwerke G.m.b.H.Latched gear mechanism
DE 384,15024-02-192327-10-1923Deutsche Telephonwerke und Kabelindustrie A.G.Latched gear mechanism
US 1,528,01817-01-192103-03-1925Mercedes Bureau-Maschinen- und WaffenwerkeCombined typewriting and counting machine
US 1,566,96201-06-192322-12-1925Mercedes Bureau-Maschinen- und WaffenwerkeCalculator with fast multiplication
DE 418,44529-01-192511-09-1925Deutsche Telephonwerke und Kabelindustrie A.G.Electric drive
See also: SE 64,082 C; US 1,912,133
DE 432,43519-12-192405-08-1926Deutsche Telephonwerke und Kabelindustrie A.G.Automatic division
See also: SE 64,634 C; US 1,788,192
DE 443,47904-03-192629-04-1927Deutsche Telephonwerke und Kabelindustrie A.G.Revolution counter
DE 468,27504-03-192609-11-1928Deutsche Telephonwerke und Kabelindustrie A.G.Carry mechanism for revolution counter
DE 470,33924-10-192611-01-1929Deutsche Telephonwerke G.m.b.H.Shortcut multiplication
DE 502,27604-03-192612-07-1930Deutsche Telephonwerke und Kabelindustrie A.G.Electric drive
DE 531,17814-07-192907-10-1931Deutsche Telephonwerke und Kabelindustrie A.G.Automatic multiplication
See also: SE 76,452 C
US 1,968,20115-03-193031-07-1934Deutsche Telephonwerke und Kabelindustrie A.G.Automat calculator
DE 615,33431-10-193303-07-1935Deutsche Telephonwerke und Kabelindustrie A.G.Short-cut automatic multiplication
See also: US 2,170,406
DE 648,13712-11-193122-07-1937Christel Hamann; Deutsche Telephonwerke und Kabelindustrie A.G.Selecta calculator
See also: GB 437,743; SE 82,799 C; US 2,081,008
DE 649,08316-02-193125-08-1937Deutsche Telephonwerke und Kabelindustrie A.G.Casing
DE 691,20924-02-193720-05-1940Christel Hamann; Deutsche Telephonwerke und Kabelindustrie A.G.Electrically driven carriage
DE 711,64122-04-193114-10-1941Christel Hamann; Deutsche Telephonwerke und Kabelindustrie A.G.Electric calculator
DE 724,33027-08-193731-10-1942Christel Hamann; Deutsche Telephonwerke und Kabelindustrie A.G.Electrically driven calculator
See also: SE 100,538 C
DE 728,51503-11-193328-11-1942Deutsche Telephonwerke und Kabelindustrie A.G.Selecta calculator improvement
See also: GB 437,743; SE 82,799 C; US 2,081,008
DE 741,55921-03-193118-11-1943Deutsche Telephonwerke und Kabelindustrie A.G.Electric calculator
DE 742,46407-09-193925-04-1944Christel Hamann; Deutsche Telephonwerke und Kabelindustrie A.G.Calculator
DE 742,46605-11-194019-04-1944Christel Hamann; Deutsche Telephonwerke und Kabelindustrie A.G.Revolution counter
See also: SE 106,919 C
DE 746,80411-03-193825-08-1944Christel Hamann; Deutsche Telephonwerke und Kabelindustrie A.G.Keyboard Input
DE 748,50023-10-194003-11-1944Christel Hamann; Deutsche Telephonwerke und Kabelindustrie A.G.Backtransfer
See also: SE 106,999 C
DE 756,99907-09-193921-06-1954Christel Hamann; Deutsche Telephonwerke und Kabelindustrie A.G.Calculator
DE 759,32123-10-194022-02-1954Christel Hamann; Deutsche Telephonwerke und Kabelindustrie A.G.Calculator
DE 819,59229-10-194905-11-1951Christel Hamann; Deutsche Telephonwerke und Kabelindustrie A.G.Carry delay mechanism
DE 861,93502-07-194108-01-1953Christel Hamann; Deutsche Telephonwerke und Kabelindustrie A.G.Backtransfer copy
DE 862,52431-08-194312-01-1953Christel Hamann; Deutsche Telephonwerke und Kabelindustrie A.G.Multiple registers
DE 866,26821-01-193909-02-1953Christel Hamann; Deutsche Telephonwerke und Kabelindustrie A.G.Automatic carriage movement for shortcuts
See also: SE 107,529 C
DE 866,56315-11-193912-03-1953Christel Hamann; Deutsche Telephonwerke und Kabelindustrie A.G.Extra register (Selecta SP)
DE 867,01011-09-194212-02-1953Christel Hamann; Deutsche Telephonwerke und Kabelindustrie A.G.Carry mechanism for extra register
DE 869,87605-03-193809-03-1953Christel Hamann; Deutsche Telephonwerke und Kabelindustrie A.G.Transfer mechanism
DE 909,26012-10-194115-04-1954Christel Hamann; Deutsche Telephonwerke und Kabelindustrie A.G.Transfer mechanism
DE 919,78729-10-194904-11-1954Christel Hamann; Deutsche Telephonwerke und Kabelindustrie A.G.Backtransfer Manus R
DE 919,79028-08-193704-11-1954Christel Hamann; Deutsche Telephonwerke und Kabelindustrie A.G.Quotient transfer mechanism
DE 924,71702-03-194107-03-1955Christel Hamann; Deutsche Telephonwerke und Kabelindustrie A.G.Printing mechanism
DE 1,799,980 U29-03-195812-11-1959Hamann Rechenmaschinen GmbHHamann Automatic 500

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