Year: 1888

page_text: We, DORR EUGENE FELT, Machinist and ROBERT TARRANT, Machinist, both of
52 to 56 Illinois Street, Chicago, in the county of Cook and State of Illinois, United
States of America do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement :-
This invention has reference to certain new and useful improvements in adding
machines wherewith any amounts represented by figures may be rapidly added into a
total sum without any mental effort being necessary.
We now proceed to describe our said invention, reference being had to the
accompanying drawings and the figures and letters marked thereon, similar letters
of reference indicating like parts throughout.
.
Figure 1 is a longitudinal vertical section of our improved machine. Fig. 2 is a
partial plan and partial horizontal section of the same. Figs. 3 and 4 are partial
sections, showing the stop-motion devices employed with the carrying mechanism in
two different positions. Fig. 5 is a partial section, similar to Fig. 1, some of the parts
being broken away. Fig. 6 is a front elevation of two adjacent numeral-wheels,
showing the carrying part, and its stop.mechanism used with one of them. Fig. 7 is
a side elevation of one of said wheels, showing the cam and the spring-lever used in
carrying-Fig. 8 is a detail side view of one of the discs and ratchets accompanying
each numeral-wheel and the pawl for giving motion to the ratchet-Fig. 9 is a section
on line 99 of Fig. 7-Fig. 10 is a section on line 10 10 of Fig. 5-Fig. 10ª is a.
view of the ratchet shown in Fig. 8, the number of teeth being changed to adapt it to
use with fractions-Fig. 11 shows the carrying-stop-motion with some of the parts in
a slightly different position from those shown in the other figures-Figs. 12 to 18
inclusive, are modifications of portions of the machine, Fig. 17 being a section on
line 17 17 of Fig. 16-Fig. 19 is a detail horizontal section showing the junction of
the lowest key of one of the series with the cross-bar G2 and stop-lever G-Fig. 20.
is a perspective view, of the parts shown in Fig. 7.

page_text: In said drawings in which similar letters of reference indicate like parts,
A A represent the numeral wheels, whereof each stands for an order of numbers
or fractions of numbers, and all are mounted upon the single shaft B.
CC represent the operating-keys, there being a series for each order of numbers
or fractions and each key having the power noted upon it.
D. D. are the vibrating spring-levers operated upon by the keys, there being one
such for each series of keys-These levers are made of angle shaped metal, the
horizontal portion d being perforated for the passage of the keys, and the vertical
web d¹ serving to stiffen the lever and render it rigid-The keys are provided with
shoulders c, engaging with the levers D, whereby when they are struck they depress
the latter against the power of the springs S, the free ends of which are hooked under
the horizontal web of the levers D, as indicated by dotted lines in Fig 1-The levers
carry toothed segments 5, which mesh with and rotate pinions E' upon the shaft B-
Adjoining the pinions E¹, and either integral with or fast thereto, are discs E²,
carrying spring-depressed pawls e-These pawls, when the pinions and discs are
rotated by the downward movement of the levers, engage with and carry forward
ratchets F, but do not return the latter during the contrary rotation caused by the
return-stroke of the levers-The ratchets F are firmly joined to the numeral-wheels
and rotate with them, and the. extent of the rotation varies with the power of the
key struck, the throw of the segment-levers being in accordance with such power-
To obtain this variation the keys are graduated in length, and the levers are likewise
stopped at the proper point by suitable mechanism.
G. G. are the key-stop levers, there being one for each series of keys, placed
directly under the segment-lever of the different series-They are struck and operated
by those portions of the keys which project through the segment-levers as shown-
We pivot said stop-levers upon the cross shaft G at the rear of the machine, and
graduate the length of the keys so that all will impart about the same amount of
movement to them-For strength and rigidity the stop-levers are made of U shaped
or channel metal, as shown in Figs. 5, 10, 15 and 16.
The stop-levers are connected to the vibrating detents J' by the rods J, which are
joined to the detents at their upper ends, and are formed into loops j, enclosing the
stop-levers at their lower ends-(see Fig. 10)-When the stop-levers strike the
bottom of these loops j, they carry the rods and detents with them, and cause
the detents to engage the equispaced teeth or wires i, secured in the numeral-wheels
and their companion ratchets F, thereby absolutely stopping the rotation of the latter
parts The detents are lifted out of engagement with the wheels by the springs J³,
and the stop-levers are raised by the springs g-The cross-bar G2 forms a stop to
the upward movement of the stop-levers.
The lowest or first key of each series is connected to and actuates the detent
directly The detents for this purpose are provided with laterally-extending pins,
which are engaged by the forwardly-extending arms upon the keys, (see Fig. 5,)
whereby, when the keys are depressed, the detents are called into action-These
same keys-may, however, be called upon to serve a useful purpose in guiding the
stop-levers, the forked ends of the latter (seen at Fig. 19) receiving the prolonged
lower ends of said keys and sliding up and down the same.
The loops are elongated vertically, so that the stop-levers G. must move some
distance before they begin to actuate the detents-We find this is important, because
if the detents begin to move simultaneously with the levers the resultant action of
the detents is not quick enough when the keys are struck rapidly, and the over
rotation of the numeral-wheels is not effectually prevented; but by getting the
levers under way before they act the detents are caused to move with the celerity
needed to prevent the evil referred to.
The extent of the stroke imparted to the segment-levers by the various keys is
regulated by the engagement of the detents with the numeral-wheels, each key being
calculated to bring the detent into action when the numeral-wheel has been rotated
to the proper point-The set screws 15 are also useful in adjusting the stroke of
.

page_text: the segment-levers and determining their upper position-The lowest keys of the
several series pass through notches in the cross-bar G2, Fig. 19, so they are held
against lateral deflection at both top and bottom―This enables them to steady the
segment-levers at their moving ends, and the stop-levers also.
Spring-actuated stops K engage with the teeth i and prevent backward rotation of
the numeral-wheel.
In this our machine we store up power whereby to actuate the carrying mechanism.
The indicator-wheels are provided with cams L, (see Fig. 7,) and a pivoted
carrying-lever, M, is located adjacent to each wheel, and forced towards the wheels,
by the spring m (see Fig. 1.) Each lever M. has an arm, m³, riding upon cam L,
and also a push pawl, m², engaging with the teeth i of the wheel next higher in order,
the lever M being bent laterally, as shown in Fig. 6, to bring the pawl, m², in line
with the ratchet of the wheel next higher in order-The pushing back of the lever M
to the position indicated in dotted lines at Fig. 7 by the cam L, stores up power in
the spring m, which, when the arm of the lever has passed the highest part of the
cam, is utilised in returning the lever to its starting position and in carrying the
next higher wheel one point or number -Each of the wheels, except the lowest, may
be thus actuated, and several of them may be simultaneously actuated by this carrying
mechanism-It is not necessary that the cams should exert any pushing force against
the levers until the wheels have been rotated to indicate 4, or thereabout, and hence
the cams are circular for a portion of their outline.
It will be evident that in a machine having a series of keys for each numeral-wheel
the speed with which each wheel is moved will be much greater when a high
numeral-key is struck than when a low one is struck. In Fig. 7 the numeral-wheel
with its cam and the arm M are shown in their initial position-When the wheel
is rotated slowly, the spring m will promptly return the lever M as its arm passes
off the point of the cam; but when the wheel is rotated very rapidly the momentum
of the outward movement of the lever M is so great that the spring m is occupied
for a moment of time in overcoming and reversing this motion, and during that
moment the numeral-wheel will pass so far forward that the carrying part will
fail to act To prevent this over-motion, the cam L' is inserted to return the arm M
positively when the motion is too rapid for the spring m (see Fig. 20).
We may however construct the cams L by making grooves in the faces of the
numeral-wheels A corresponding to the outlines of the cams L, and providing the
extremity of the arm m¹ with a pin adapted to travel in said grooves-By this
arrangement the cams L' may be dispensed with inasmuch as a positive motion is
thereby attained.
The stop-motion mechanism for preventing over rotation of the carried wheels when
actuated by their carrying devices will next be described. There is, of course, a
mechanism of this sort for each of the carrying-wheels. Upon the shaft m³, whereon
the carrying-levers may also be journaled, are pivoted a series of detents, N, one for.
each numeral-wheel, and springs n press such detents toward the wheels at all times-
These detents are intended to engage with the teeth i, and are always in locking
engagement therewith when at rest, except when the numeral-wheel next lower stands
at 7, 8, or 9, or when released momentarily by the keys-It will thus be seen that
this part of the stop-motion mechanism serves a very useful and additional function,
and that by means of the detents N on the one side and the stops K on the other
all the wheels are absolutely locked during the major part of the time. To release
the wheels from this lock by the detents N, pins n¹ at the upper ends thereof are
provided to ride upon the peripheries of the discs E², and as such discs are notched, as
at n², the pins resting in the notches during the locking, it follows that the pins and
the detents are forced outward whenever the discs are rotated by the segment-
levers The detent N and its spring and pin are employed with the lowest
numeral-wheel; but the rest of the stop-motion mechanism is not necessary with
that wheel, as it is never actuated by carrying mechanism.
Upon the detents N are pivoted bell-crank levers O, the downwardly-extending
limb of which is acted upon by a spring, o, and the other limb whereof is provided

page_text: with catch o at its extremity-The spring o presses said lower limb toward the front,
and thus tends to lift the other limb.
The carrying-levers M are each provided with a laterally-projecting pin or stud, P,
which extends through the wide opening p in the detents N, as indicated, in position
to act upon the detent itself and upon the lower limb of the bell-crank lever O. The
catch o¹ engages at each carrying operation with a transverse bar, g, extending from
side to side of the machine, and the other limb of the lever O extends past said pin P,
upon the inside thereof-The bell-crank O and bar q serve to detain the stop-detent N
a sufficient time to permit the carrying-lever to move the numeral-wheel and prevent
said detent from engaging too soon. The stud P. strikes the downward-projecting
arm of the bell-crank O, and releases the catch from said bar q in time to permit the
detent to engage one of the pins i.
The parts just described constitute, in combination with the detents N, the stop-
motion of the carrying mechanism, and its operation is as follows: If the keys of any
column-as, for instance, the units column-be struck, the carrying lever M, actuated
by the cam of the units-wheel, will commence to move backward from the wheel from
the time said wheel indicates 4 until it has reached 9-In the backward movement of
the carrying-lever, the stud P comes in contact with the edge of the opening p in the
detent N of the wheel next higher in order at the moment when the wheel which
actuates said carrying-lover indicates 7, so that said next higher numeral wheel is,
when the time arrives for it to be moved, released from the locking-action of its own
detent N-During the latter part of the backward movement of the detent the upper
limb of the bell-crank lever comes in contact with the bar 9 and is deflected thereby
until, by the continued movement of the detent, the catch of said upper limb becomes
caught by the sharp edge of said bar-This takes place when the keys have brought
the units-wheel to 9. The parts are now in the position illustrated at Fig. 11, with
the pin P at the same side of the opening p occupied during the backward movement,
but the lower limb of the lever O stands toward the further side of said opening-The
continued rotation of the units-wheel from this point, whether due to a key stroke
already given, or to a stroke to be given, or to the action of the carrying part, will
result in carrying the highest part of the cam L of that wheel beyond the arm of th
carrying-lever, so that the lever is free to yield to its spring m and to move toward
the wheels and rotate the next higher wheel one number or point-The detent N is
detained momentarily from keeping company with the lever in this return movement
until the pin P strikes the lever O and disengages the latter from the bar
detention being due to such engagement-The detent N then resumes its normal
position quickly under the power of its spring, locking the carried wheel against
further movement-The operations of the carrying-lever M and the locking-detent are
relatively timed, it will be noticed, so that the former has somewhat the start of the
latter, thereby ensuring the carrying rotation before the locking takes place A
feature of value in this stop-motion contrivance is that it is at liberty to move into
locking position before the rotation of the carried wheel has been completed, it only
being necessary that it should allow the tooth previously held by it to pass-We
thus insure its being in position to engage the next tooth, while we prevent it
from re-engaging the same tooth it has just released by detaining it momentarily,
as specified. It will be understood that the operation of the stop-motion will be
precisely the same in the case of any other pair of adjacent wheels as that described in
the case of the units and the tens wheels.
the
The setting of the machine preparatory to commencing an operation is an easy and
quick performance-A rotatable bar, R, having a flat side, is placed transversely of
the machine in the position indicated, and provided with a crank-arm, ", whereby it
may be partially turned in its bearings-This arm r may be inside or outside the case
of the machine, as preferred, though we prefer to actuate it by a key, S', somewhat
similar to the numeral-keys, and to locate it inside, as shown at Figs. 3 and 4-The
flat side of the bar R, acts upon the projection s upon the lower end of the detents N
and forces said detents to release the numeral-wheels, so that the latter are all free to
be turned in the forward direction, and we actuate them in that direction through the
.

page_text: main shaft B-The latter for this purpose is extended through the side of the case and
provided with a thumb-wheel, b, whereby power may be applied-Adjacent to the
cam side of each numeral-wheel we insert in said shaft a pin, T, which, when the
shaft is rotated, comes in contact with the abrupt face of a depressible 'stop, U, pro-
jecting from the side face of each of the cams-As these pins are all in the same plane
and the stops are located at the same point in all the wheels, it necessarily results that
all the wheels may be rotated to indicate the same figure by rotating the main shaft,
the pins coming in contact with the stops at some point in the course of the revolution,
such point depending upon the position occupied by the wheel when the setting is
commenced To avoid the engagement of the pins T and the stops U when the wheels
alone are rotated, as in adding, the stops are made sloping upon one side and inserted
in recesses which allow them to sink out of the way when the pins pass over such
sloping sides-The construction we prefer for these stops and their holding recesses is
clearly shown at Fig. 9. The stops are shaped, and when placed in position are
securely held without being pivoted or otherwise attached to the cam or wheel-At
one extremity the stop, is provided with a nib, u, which passes under the cam L, and
another nib, u, which enters the recess, u², in the web of the wheel-This end of the
stop is effectually held by these nibs, while they do not prevent the necessary motion
at the other end-At said other end is an enlargement, u³, which engages with the
L and prevents the throwing out of the stop under the pressure of the spring, ut,
by which it is returned to its normal position after it has been depressed by the
pin T-A recess, u³, allows the enlarged end, u³, to pass inward when the stop is
depressed.
cam
The steps involved in the setting operation are, first, the drawing back of the
detents N by the crank, r, and the bar R, and then the rotation of the main shaft B
until all the wheels have been brought into line at the zero position-The pressure
upon the crank, r, should be continued until the wheels have been rotated to indicate 7,
or thereabout, when it may be released, and the detents N will then automatically
catch and stops the wheels at the zero position.
It will be noticed that we have provided in our machine for the adding of
fractions,,, etc.-The only changes necessary to adapt the machine to this work
are the provision in the ratchet F of eight teeth instead of ten, a like number of
teeth i, seven keys instead of nine, a proper graduating of the keys, and the changes
in the numerals upon the wheel; but in principle the machine for adding fractions is
unchanged from that used for whole numbers, and it will be understood that other
fractions than the particular ones illustrated may be added in the machine if similar
changes to those mentioned be made.
A feature of great importance in our machine is the provision for excess motion by
the discs E-I have shown at Fig. 8 the relative position of the pawl carried by said
disc and the ratchet F when at rest, and it will be noticed that the pawl must move
some distance before it engages with the ratchet and moves the latter-This
preliminary or excess movement upon the part of the disc and pawl, while not
necessary so far as actuating the ratchet is concerned, is essential to enable the disc to
release the ratchet and number-wheel from the lock of the detent N before movement
is imparted to them, as will be readily understood.
At Figs. 12 and 13 a modification of the carrying stop-motion is illustrated-The
spring-actuated detent N¹, corresponding to the detent N, already described, is
provided with a similar pin, n', intended to engage with the notched periphery of
dise E2, and is detained for the same purpose as detent N is detained by a spring-
catch, V, and released from said catch by providing the lever M with a flange, m³,
which will act as a cam to force said catch away from the detent―The detent is
drawn back by the carrying-lever M through the medium of a pin, P¹, upon the
latter.
In Fig. 14 the detent N2 corresponds with detent N in that it locks the numeral-
wheel in a similar way, is provided with a similar pin, n², engaging with the notched
disc E2, and is drawn back by a pin, P2, upon the carrying-lever passing through an
elongated opening, P, in the detent-With this detent we have shown no detaining

page_text: device, and we regard it, therefore, as a less desirable construction than the forms
wherein the detent is held back to give the carrying lever time to do a part at least of
its work.
Figs. 15 to 18 illustrate a modification of the construction of the connection
between the stop-levers G and the vibrating detents J-The rods J are here
employed, but they are attached to the detents by looping their upper ends and
passing such loop over guide heads Z, the loops allowing the rods to move some
distance with the stop-levers before they actuate the detents, thus accomplishing the
result dwelt upon above of getting the stop-levers under motion before they begin to
actuate the detents-The attachment of the rods to the levers is also different from
that previously shown and is a rigid one-It consists in bending the ends of the rods
at right angles and passing the extremities thereof through openings in the vertical
webs of the levers-Retaining loops or staples, z, are then passed around the rod and
soldered to the upper surface of the levers-By making the heads, Z, oblong, as
shown, the loops of the rods may be slipped over them while held horizontally, and by
then swinging them to the vertical position they become fastened or movably held-
This same result would follow, of course, if the heads could be partially rotated upon
their axes; but we prefer to rivet them to the detents, so they cannot be detached or
moved The springs, n and'o may both be formed in one piece and are so indicated in
the drawings.
In sheets 5 to 6 we have shown a modification of our invention, and in which
Fig. 21 is a longitudinal vertical section. Figs. 22 and 23 are respectively enlarged
front and side elevations of the numeral-wheels and their controlling devices. Fig. 24
is a detail view of one of the numeral-wheels, showing the cam for storing up the
power, and Fig. 24" is a partial section of the same wheel-Fig. 25 is a cross-section of
the levers for actuating the wheel-stops, and Fig. 26 is a partial plan of the same, both
being enlarged Fig. 27 is a longitudinal vertical section showing the position
assumed by the wheel lever and stop-lever-Fig. 28 is a section similar to Fig. 27,
showing a suitable substitute for the stop lever shown in previous figures-Fig. 29 is
a section of the numeral-wheel and the companion ratchet and disc, and Fig. 30 shows
a modified form of the wheel-stop.
In the drawings, A, A', A² etc. represent the numeral or indicator wheels-CC, CC¹,
C2 C2 etc. represent the several series of depressible keys-Below these keys are
located the vibrating segment-levers D, D1, D2 etc. each provided with a retracting-
spring S, but in this case pivoted upon bar d, there being one such lever for each
series of keys and indicator-wheel.
We will next describe the device for preventing over rotation by the indicator-
wheels.
G, G, are the stop-levers-There is one for each series of keys, and they are placed
under the same, so as to be actuated thereby-They are made to yield slightly when
struck by the keys, and such yield is obtained by providing them with laterally-
extending arms g at each end and pivoting such arms at g' to stationary cross-bars G₁-
From these stop-bars links or connecting-rods J, extend upwardly and are joined to
vibrating detents J₁ pivotally hung upon a cross-wire, J2, and adapted to engage
with the equispaced wires or teeth i, secured in the indicator-wheels and companion
discs F, to form ratchets-Springs Jlift the detents to their normal position after
each operation, and with them the stop-lever also-This construction results in the
absolute stopping of the rotation of the indicator-wheel whenever any key has
depressed its stop-bar sufficiently to bring the detent into operation with the
ratchet, i, of the wheel-It also results in limiting the down stroke of the keys, so
that no special device for this purpose is necessary.
During the backward rotation of the pinions E¹ and discs E2, caused by the
upward motion of the segment-levers, there is a tendency upon the part of the
wheels and their actuating ratchets to move with the pinions and discs-To prevent
this we provide spring-stops K, having nibs or teeth k, adapted to engage with the
ratchets, already mentioned-The nibs, k, are given a gradual slope upon their
neutral side, as shown, to enable the ratchet teeth to lift the stops easily-The 'tension

page_text: of springs K is regulated by screws k¹ in cross-bar 2-The stops, K, are also useful
in bringing the indicator-wheels into line when they move a fraction, too far, as they
are usually in contact with two pins, i, at a time when the wheels are at rest, and exert
a lifting power upon the one beyond the centre of revolution of the ratchet i-By
these stops the indicator-wheels are positively held against backward rotation, and are
also caused to present their numbers at the openings, h, in true alignment with each
other.
The next feature of this machine to be described is the carrying mechanism, which
is in all respects similar to that aforedescribed, with the exception that the spring-
lever M located adjacent to each wheel and pivoted at m is kept towards the wheels
by the spring m¹ which in this case is attached to the casing, and further that
the cams L of the wheels have guards, m³, which answer the purpose of the cam L¹'
aforesaid.
The screws, a¹, in the stop-levers may be employed to receive the impact of the
keys, and, being adjustable, may be set at any point required to compensate for
levers not exactly the proper length-The rods J should preferably be either
adjustable as to length or be adjustably secured at one end, as by a screw, a².
At Fig. 28 we have shown a stop-lever, much like the segment-lever-that is to
say, it is pivoted at one end only, the other end being free-With this lever the keys
will require to be somewhat different in length from those used with the stop-lever
previously described; but the modified form is on some accounts to be preferred.
The pivoted detent, J', may also be dispensed with by attaching to the stop-lever a
hook, N, as illustrated at Fig. 30-Where this hook is employed, a spring (not
shown) should be used to bring the lever back to its normal position after each
operation.
In machines of this character, when the power required by the carrying operations
is obtained from the key, it becomes very difficult and sometimes impossible to operate
the machine, because enough power to operate all the wheels involved in the carrying
cannot be put upon any one key-In our machine, an independent power being relied
upon, no such objection pertains.
The operation of the machine is as follows: Suppose we are presented with numbers
to be added. as follows:
with the wheels all presenting the zero-mark, the operator begins with the units and
successively depresses the keys 7, 6, and 3 in the unit-column. At the first of these
operations the unit wheel will rotate and present the figure 7, the cam L of said
wheel acting to push back the lever M as the rotation proceeds-The second
operation, the depressing of unit-key 6, causes the rotation of the unit-wheel to
position indicating 3, and at the same time its cam L completes its first revolution,
so that the spring-lever is released from the larger or outermost part of the cam, and
is allowed to move toward the wheels under the force of its spring, m¹²-This permits
the push-pawl M¹ to carry the next higher wheel, that of the ten-column, one space
or figure, so that said wheel indicates 1, instead of 0-We now have represented by
the unit and the ten wheels the sum 13-The next operation which is the depressing
of unit-key 3, rotates the unit-wheel to 6, giving as the total sum of the unit-
column 16. We are now. ready to commence operation upon the column of, tens, and
the operator strikes successively the 2, 4, and 8 keys of that column, resulting in
rotating the ten-wheel first to 3, then to 7, then to 5, the last operation also causing
the turning of the hundred-wheel one point, and the machine now indicates 156 as
the sum of the tens and units-The operator then proceeds with the hundreds,
depressing in their order keys 3, 9, and 1 of that. column, the first depression carrying
the wheel to 4, the next to 3, (carrying 1 at the same time to the thousand-
wheel,) and the last to 4. The four wheels mentioned now show the total result to
be 1,456.

page_text: Instead of adding by vertical columns, the numbers may be added by horizontal
columns-Thus, in the example supposed, after first setting the machine to repre-
*sent 327, the next operation may be to add 946, striking first the 9 key in the
hundreds, and then the 4 key in the tens, and lastly the 6 key in the units; or this
order may be reversed and the units, added, first, then the tens, then the hundreds, as
preferred, and after this is done the remaining number, 183, may be added in the
same way In this manner the operator, who is required to add one number or
amount at a time to another, or to the sum of the others- -as is the case with cashiers
at stores etc., who note the sums of money they receive as the same are paid-will
thus be enabled to keep the account as the business progresses, and be able to tell at
any time the amount of cash received by them.
Having now particularly described and ascertained the nature of our said Inven-
tion, and in what manner the same is to be performed, we declare that what
we claim is:
ist. In an adding machine, the combination of the several parts comprising the
mechanism, all substantially as and for the purposes hereinbefore described and
shown in the drawings with reference to Figs. 1 to 20 of the drawings hereunto
annexed..
2nd. In an adding machine the combination of the several parts comprising the
mechanism, all substantially as and for the purposes hereinbefore described, with
reference to. Figs. 20 to 30 of the drawings hereunto annexed.
Dated this 24th day of N 1000'
HORN & SON,
Agents on behalf of Applicants.