AN IMPROVED MACHINERY OR APPARATUS FOR CALCULATING
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by Antoine Numa Durand at the Office
of the Commissioners of Patents on the 3rd August 1880.
ANTOINE NUMA DURAND, of Boulevard Saint Denis, 1, at Paris, Engineer.
"AN IMPROVED MACHINERY OR APPARATUS FOR CALCULATING."
My improved calculating machine has for its object to effect additions with
rapidity, thereby rendering it of great use for commercial houses, banks, and other
places. It is also adapted for executing other operations of arithmetic, and can advan-
tageously be employed for purposes of tuition. It consists in an arrangement of
barrels, say twelve in number, turning loose on an axle fixed in a wooden or metal
box. On these barrels are marked twice in reverse order the figures 1, 2, to 9, the
series to the right serving for the additions and those to the left for the subtractions,
so that by working always in the same direction either operation can be effected by
reading the results on one or the other series. For this purpose the openings of a
register or glazed groove or slot are presented, according to the case, in front of the
series desired. On their right the barrels are furnished with toothed wheels of
transmission which gear into double intermediate wheels loose on a fixed axle.
Each barrel as well as the intermediate wheels in lieu of turning on their respective
common axles may turn separately on short independent axles placed in bearings
fixed on a crossbar parallel to the shafts or fixed axles before named.
Each double intermediate wheel is composed of a toothed wheel joined with a
rack wheel of 10 teeth by a spring, which permits the drawing of the one by the
other without roughness in the case of carrying forward the tens. At the opposite
side of this gearing is a kind of ratchet on which presses a spring maintaining in
position the entire system of numbered barrels.
Opposite each rackwheel of 10 teeth and fixed to the preceding barrels at the
right is a small fillet or projection, which at each complete revolution of the
preceding barrel engages in the rack wheel and causes it to turn a half tooth, which
produces partly the carrying forward of the additions from a certain order to the
decimal order immediately superior, the complemental carrying forward being
caused by a system of cogs or tappets hereafter described. The numbered barrels
are acted upon by a crank plate keyed on a shaft, the transmission being made
through a succession of geared wheels from the shaft of the crank plate to the
double intermediate wheels before described. The gear wheels keyed on the
crank plate shaft are nine in number, and carry from left to right from one to nine
rD.

page_text: teeth, which permits of causing to pass automatically on the numbered barrels the
quantity of numbers corresponding to the amount to be added. For this purpose
the engaging gear wheel is movable, and should be placed in front of one of the gear
wheels (keyed on the crank plate shaft) of which the number of teeth represent
the number to be added. The transmission between this movable gear wheel and
the succeeding gear is made by means of two toothed wheels, one carrying 20 teeth
and the other 10 teeth; this doubling is necessitated by the number of teeth to the
numbered barrels which count 20 teeth or 2 teeth per number. The gear wheel
having 20 teeth may be placed inside the box and engage directly with the said
succeeding gear, which consists of a shaft having its teeth grooved or cut out of the
solid for its entire length, so as to give transmission to a movable pinion in whatever
position the latter may be. This movable pinion is slid in front of one of the
double intermediate wheels which acts upon the numbered barrel of the order of
units to be added. It turns in a case fitted with it on a longitudinal shaft, the
case being acessible from the outside by a knob or handle furnished with an index
or pointer.
The movable gear wheel before described is also fitted in a case and turns
therein by means of two lateral sockets; it is mounted on a shaft which is square
for its entire length, and therefore commanded by the wheel in all positions of the
latter. The rotation of the shaft is communicated to the numbering system
through the medium of the toothed wheel of 20 teeth before described, the lower part
of the wheel case being guided in its course by a dove tail groove cut the length of
a cross bar and drawn away by a click movement combined as follows:-
A small carriage guided in any desired manner between the cross bar and another
cross bar opposite carries on a pin or stud a spring click, which when at rest seizes
a tooth projecting from the side of the case, the tooth engaging in a notch of the
click. The drawing away is produced by a rack cut at the lower part of the
carriage. The pinion acting upon the notch is moved by conical gears, of which
that of command is mounted on a short axle carrying outside the box a right hand
pinion which engages with a second pinion of the same diameter but half the width.
On the periphery of the crank plate are two toothed arcs of convenient length, but
not situated in the same plane and placed one following the other. One of these
arcs engages with the right hand pinion and the other are with the second pinion,
this combination producing at each turn of the crank plate the travel and return
of the carriage and the movable wheel. A spring click engaging in a notch of the
crank plate marks each turn of the latter. The movable gear wheel during its
travel from right to left is locked opposite one of the gear wheels on the crank
plate shaft, of which wheel the number of teeth correspond to the number of units
to be added; this is produced by means of keys similar to those of a pianoforte,
the black keys carrying the even and the white the odd numbers.
The key lowered causes to vibrate a lever, the extremity of which is presented
in the course of the click of the carriage, which continuing to travel and its large
arm bearing against the lever, causes the click to vibrate aud lock, and the movable
gear wheel is stopped ready to engage with the gear wheel before named
on the crank plate shaft, and is maintained in position by a spring which bears
against the periphery of a ratchet at the side of and solid with the movable gear
wheel. This ratchet during the passage of the teeth of the gear wheel (on the
crank plate shaft) enters into notches cut in the cylindrical part of the gear wheel
Behind the double
and stops any other movements of the movable wheel.
intermediate gear wheels is a shaft which carries opposite the said wheels tappets
or peg cams with only one tooth; these peg cams are keyed at an angular distance
of the thickness of a tooth and are commanded by gearing. They are designed to
finish the carrying forward the additions commenced by the fillets or projections
on the numbered barrels; this movement is thus softened and inade without
roughness. For bringing back all the barrels to the zero at the end of an operation,
each numbered barrel engages with a pinion which only occupies a part of the
width of the barrel wheel; these pinions are keyed on a shaft furnished with a

page_text: knob or handle projecting at the exterior, and serving to produce the recall to
zero. In front of each of these pinions, in the position corresponding to zero, one
or two teeth of the barrel wheel are removed, so that the pinions can turn without
drawing the wheels; consequently for bringing back the wheels to zero it suffices
to turn the knob or handle until no further resistance is felt. On the other hand,
for permitting the independent rotation of the barrels, one or two teeth are removed
from the pinion following the same line for giving passage to the teeth of the
barrels. Two slates are applied on either side of the keys. The operation of the
apparatus is as follows, say for example, to add 5 and 7-The machine being
brought back to the zeros, and the movable pinion with its handle and index placed
opposite the units, the key corresponding to the number 5 is lowered and the
crane plate turned. The movable gear wheel engaging with the gear wheels on
the crank plate shaft is placed opposite the gear wheel with 5 teeth on the latter,
which causes the numbered barrel to turn to the extent of 5 numbers, the figure 5
appearing at the first opening in the glazed register; then lowering the key for
number 7 the turn of the crank plate causes the same barrel to turn 7 numbers
further, which causes the figure 2 to appear at the opening.
But when the barrel has made a complete revolution and arrives at 0 its fillet
or projection and the corresponding tooth carry on the tens to the following barrel,
and the figure 1 appears at the second opening of the register. The number 12
is therefore read at the two openings, the operation being repeated according to
the numbers to be added.
Subtraction. As we have said above for subtracting it suffices to slide the
glazed register opposite the contrary barrels and bring at first to the openings the
larger number, placing successively the movable pinion with the handle and index
under the figures; that done, the keys marking the figures to be subtracted are
lowered as for addition.
Multiplication. For multiplying the multiplicand is brought to the openings,
say for example, 345 x 27, then sliding the movable pinion and index under the 5,
the key for number 5 is lowered and the crank plate turned 7 times; the same is
done for the hundreds; one then multiplies by the figure of the ten by placing
successively the movable pinion and index at first under the tens of the multiplicand,
then under the hundreds and the thousands. The product appears at the
openings; the separate products of units can also be effected mentally and entered
on the apparatus which shortens the operation.
Division. For dividing one operates by subtraction by sliding the glazed
register opposite the inverse series. Then commencing from the left one forms a
partial dividend containing the divisor at least once and less than ten; one subtracts
this as many times as possible from the preceding by entering in the quotient the
number of subtractions.
One operates in the same manner with the dividend formed with the remainder
and the figure following, the operation being continued until at last the remainder
is entered at the openings.