T E C H N I C A L D A T A of the Mechanical Calculator WALTHER » RK « ************************************************************************* (* There is NO MODEL NAME on the calculator ) Serial Number: 4484 Dimensions: (ca.) Width = 10_1/4" / 26 cm Depth = 5_1/2" / 14 cm Height = 5_1/2" / 14 cm Weight: (ca.) 10_3/4 lbs / 4.9 kg Mechanics: Pin-Wheel / Sprossenrad 10s Carry Mechanism Counter Stepping Mechanism + Animation Functions: Add, Subtract, Multiply, Divide Registers: Input = 6 Decimals Counter = 6 Decimals (NO Carry; Neg.Figures RED) Arithmetic = 10 Decimals Manufacturer: CARL WALTHER Waffenfabrik Zella-Mehlis in Thueringen Germany 1926 H O W T O U S E the WALTHER » RK « ******************************************* BASIC SETTINGS: =============== (A) Crank: ---------- For addition (+) the crank is turned clockwise; for subtraction (-) the crank is turned counter-clockwise. In the idle position the crank is DOWN & LOCKED. To make one or more turns with the crank, pull out the handle to unlock. When finished the turn(s), let the handle snap into lock again. The locked down position only makes other functions (ex. clearing) accessible. REMARK: Every started turn has to be finished completely! Accidentally started turns are correctible somehow. (B) Clearing Registers: ----------------------- The input: With the BIG LEVER the INPUT can be cleared simultaniously. (It is intended to use the thumb for.) **) The KNOB ON TOP - See Remarks ... The counter unit will be cleared with the CRANK on the LEFT SIDE of the carriage The arithmetic register will be cleared with the CRANK on the RIGHT SIDE of the carriage (C) Shifting the Carriage: -------------------------- The SILVER LEVER under the crank will shift the carriage one step to the left - The BLACK LEVER right in front of the carriage will shift the carriage one step to the right - Pressing the SILVER KNOP left on the carriage let the carriage jumps left in position "1" by force of a spring. Position "1" is the "Start Position". The carriage can be shifted quick to the right by hand. ADDITION & SUBTRACTION: ======================= Example: 123 + 45 - 6 = 162 Clear input, counter & arithmetic units. Carriage in position 1. ADD: Enter the first number (123) in the far right of the input unit. Make a positive (clockwise) turn with the crank to transfer the number into arithmetic unit. The counting unit displays the figure 1. Enter the second number (45). Make a positive (clockwise) turn with the crank to add the number. The arithmetic unit displays the intermediate sum (168) and the counting unit displays the figure 2. SUBTRACT: Enter the third number (6). Make a negative (counter-clockwise) turn with the crank. The arithmetic unit displays the result (162) and the counting unit is decreased by 1. REMARK: NEGATIVE RESULTS are displayed in the arithmetic unit as the COMPLEMENT of the next higher 10, 100, 1000, ... Example: -12 = 99...9988 MULTIPLICATION: =============== Example: 123 x 45 = 5535 Clear input, counter & arithmetic units. Enter the multiplicand (123) in the far right of the input unit. The multiplicator (45) has two digits, so the carriage is shifted to position 2. Make positive (clockwise) turns with the crank, until the first figure of the multiplicator (4) will appear in the 2nd position of the counter unit. Shift the carriage to position 1. Repeat making positive turns with the crank, until the second figure of the multiplicator (5) appears in the 1st position of the counter unit. The multiplication is done: The multiplicand (123) stays in the input unit, the multiplicator (45) in the counter and the result (5535) is in the arithmetic unit. DIVISION: ========= Example: 22 : 7 = 3.14285 Remainder 5 Division requires 3 steps: (1st) To Set the Dividend into Arithmetic Unit: ----------------------------------------------- For the maximum number of decimals, pull out the carriage to the far right position. Enter the dividend (22) in the far right of the input unit. Make a positive (clockwise) turn with the crank to transfer into arithmetic unit. (2nd) To Set the Divisor into Input Unit: ----------------------------------------- Clear the counter. Enter the divisor (7) above the dividend (22). (3rd) To Divide: ---------------- Make negative (counter-clockwise) turns with the crank until the arithmetic unit shows an "underflow". Make one positive (clockwise) turn with the crank. Move the carriage to the next left position. Repeat this procedure until the required number of decimals ... The result (3.14285) is in the counter unit ( in RED ), and the remainder (5) is in the arithmetic unit. The divisor (7) stays in the input unit, therefore an additional decimal can be estimated ... ( 7, cause 7 x 7 = 49). R E M A R K S : ========================================================================= The COUNTER-FIGURES ( WHITE/RED ) follows the "ODHNER-TYPE"-Scheme ... The SPRING of the INPUT-CLEAR LEVER was broken and is now home-made ... *) Model »RK« according to the WALTHER CLASSIFICATION found in ... http://www.rechenmaschinen-illustrated.com **) The KNOB ON TOP ... ----------------------- I asked the Calculator Experts H.Schneemann / M.Reese & E.Anthes and was informed ( "Thank you!" ) , that ... " There is no special functionality known / documented - probably it is invented to re-synchronize input levers & input displays if necessary " In this case do the following ... (1st) Set ALL INPUT LEVERS to 00 .. 00 (2nd) Unlock the Main-Crank (3rd) TURN THE KNOP CLOCKWISE until the DISPLAY SHOWS 00 .. 00 (4th) Lock the Main-Crank impressum: ************************************************************************* © C.HAMANN http://public.beuth-hochschule.de/~hamann 10/11/12 |