Improvements in Computing Machines.
Year: 1890

page_text: Date of Application, 6th June, 1890-Accepted, 6th June, 1891
Improvements in Computing Machines.
A. communication from JOHN SHARPE, of 72, Robert Street, Toronto, in the
Province of Ontario, Canada.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
M.I.M.E., 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 relates to an improvement in computing machines adapted to be
used for purposes of addition and subtraction, and it consists in the peculiar
construction and combination of devices that will be more fully set forth
hereinafter.
In the accompanying drawings —
Fig. 1 is a front elevation of this improved computer.
Fig. 2 is a similar view of the same the front side of the enclosing case being
removed.
Fig. 3 is a top plan view partly in horizontal section.
Fig. 4 is a detailed perspective view of the trip bar.
Fig. 5 is an end view of the computing machine.
Fig. 6 is a vertical transverse sectional view of the same.
Fig. 7 is a detailed elevation of the gears and the tens operating keys.
Fig. 8 is a detailed perspective view of the guide bar, the ratchet tumblers and
the dog.
Fig. 9 is a similar view of one of the rocking detents.
Fig. 10 is a partial rear elevation of the gears and the keys forming part of the
hundreds registering mechanism.
Figs. 12, 13 and 14 are detailed elevations of the ratchet sleeves.
Fig. 15 is a detailed perspective view of the tens rocking detent.
Fig. 16 is a detailed perspective view of one of the weight arms.
The main shaft G of the registering machine extends through bearings in the
A coiled extensile
ends of the case and is adapted to move endwise therein.
spring a bears against one end of the case and against a shoulder or collar b on the
shaft and serves to hold the latter normally in the position shown. In the same or
opposite end of the main shaft is pivoted a levere having an eccentric cam d which
when the lever is moving outward is adapted to bear against the end of the case
and draw the main shaft end wise for the purpose to be presently described.
Arranged on the main shaft and loosely and independently revolvable thereon
are a series of discs 1, 2, 3, 4, 5, 6, 7, 8, 9, each of which is provided on its
periphery with a series of numerals from 0 to 9 arranged at suitable regular
distances apart. The numerals on the disc 1 indicate units, those on disc 2 indicate.
tens, those on disc 3 indicate hundreds, those on disc 4 indicate thousands, those on
disc 5 indicate tens of thousands, those on disc 6 indicate hundreds of thousands,
those on disc 7 indicate millions, those on disc 8 indicate tens of millions, and those
on disc 9 indicate hundreds of millions. The number of discs may be increased at
will to adapt the machine to register suns of any desired magnitude. The said
discs are provided with spur wheels 1, 2, 3, 4", 5", 6", 7", 8", 9", respectively the
said spur wheels being rigidly secured to or formed integrally with their respective
discs and the said wheels being all of the same diameter and provided with tho
same number of teeth.
Openings P¹ are made in the front side of the enclosing case through which the
numbers on the discs are presented successively as the discs are rotated.
A sleeve 1º extends from one side of the wheel 1* and is secured firmly thereto.

page_text: Said sleeve is loose on the main shaft and has at its outer end a spur wheel 1°
which is exactly similar to the wheel 1.
A shaft T is arranged parallel with the shaft Gand at a suitable distance
therefrom and has its ends rigidly secured in the end of the case. On this shaft T¹
are loosely mounted a series of spur wheels e, f, g, h, i, k, l, m, n, which are all of the
same diameter and have the same number of teeth.
The wheel e meshes with the wheel 1° the wheel meshes with the wheel 2, the
wheel meshes with the wheel 3ª, the wheel meshes with the wheel 4", the wheel i
meshes with the wheel 5, the wheel k meshes with the wheel 6ª, the wheel meshes
with the wheel 7", the wheel m meshes with the wheel 8, the wheel n meshes with
the wheel 9 The wheels f, g, h, i, k, l, m, n, are provided on one side with a
series of tappet pius o corresponding in number to the numerals on the discs, that
is to say there are ten of the said pins on each of the said wheels. Each spur
wheel 3, 4, 5, 6, 7, 8, 9, is provided with a radial tappet pin p which pins are
in the paths of the pins o and are arranged between the numerals 0 and 1 on their
respective discs. Pawls D' engage the wheels h, i, k, l, m, n, and serve to prevent
the same from turning in a reverse direction from that indicated by the arrow E2
in Figure 6.
A shaft T is arranged lengthwise in the case and at a suitable distance in rear
of and below the shaft T. On this shaft T2 is loosely mounted a sleeve G2 which
has ten ratchets the width of which is equal to the length of the sleeve. Rigidly
secured to the said sleeve is a spur wheel H which engages the loose spur wheel f
on the shaft T; the latter wheel engages the wheel 2. Hence when rotating
motion is imparted to the said sleeve the disc 2 will be turned.
Arranged at a suitable distance above the shaft T and parallel therewith is a
shaft on which are loosely mounted a pair of ratchet sleeves L2 M² which are
similar to the ratchet sleeve G². The ratchet sleeve L² has a spur wheel N2 that
meshes with the idle wheel on the shaft T which idle wheel engages the wheel 1°.
The ratchet sleeve M² has a spur wheel 0 that meshes with the idle wheel
also on
shaft T which idle wheel meshes with the wheel 3*.
A
Loosely mounted on the shaft T' is a rocking detent T2 Fig. 6 which has a
horizontal engaging lip U of suitable length and from one end of which detent T2
projects an arm V A spring W2 is attached to the shaft at a point about midway
between the ends of the rocking detent and the free end of the spring bears against
the rear side of the lip and hence moves the same normally in one direction.
pivoted dog X2 is normally held in engagement with the arm V2 by a spring Y2 and
at the inner end of the dog is an arm Z2 which is in the path of the tappet pin A³
that projects from the ratchet sleeve L² at one end thereof. A spring pressed
pawl B engages the said ratchet sleeve to prevent the same from rotating in a
reverse direction.
On a suitable shaft C³ Fig. 7 is loosely mounted a rocking detent D³ which has a
horizontal engaging lip E³ of suitable length and from one end of the said detent
depends an inclined arm F3. A spring G³ is attached to the shaft C³ and its free
end bears against the rear side of the lip E' and moves the detent normally in one
direction. A spring pressed dog H³ normally engages and holds the arm F³ and
the arm I of the dog is in the path of a tappet pin K³ that projects from the
wheel H12 at one end of the ratchet sleeve G2. A. spring pressed pawl L³ engages
the ratchet sleeve and holds the same against reverse rotation, Figure 6.
A substantially semi-cylindrical ratchet tumbler sleeve M³ is loosely journalled
on a shaft M³ and has a series, say eight, of ratchet teeth O³ which extend its entire
length and are concentric with the shaft. That side of the tumbler which is
provided with ratchet teeth is necessarily heavier than the other or cut away side
thereof and therefore. the ratchet turn bler is normally in the position shown. On
the centre of the cut-away portion of the ratchet tumbler is a semi-circular web
or flange P3 which is provided with ratchet teeth R³.
Arranged on the same shaft with the tumbler M³ end to end are a pair of similar
ratchet sleeve tumblers S³ T³ Fig. 8. Gravity pawls U³ engage the flange or

page_text: web ratchet teeth R³ of the respective tumblers. The functions of gravity pawls
that engage the flange or web ratchet teeth are intended to keep the ratchet
tumbler from going backwards hence causing the ratchet bar to remain in an
elevated position until the said key has been depressed the full stroke when the
tumbler will tumble over and release the same as herein fully described.
On a suitable shaft V3 are pivoted three banks of finger keys 1° 2° 3° there being
nine keys in each bank and the said keys of each bank being numbered consecutively
from 1 to 9. Hubs or sleeves W³ are formed on the arms of the keys which bear
against each other end to end, and serve to space the said keys to the necessary
distance apart. The inward extending arms X3 of the finger keys pass under the
rod which serves to connect the weight arms the said arms X3 extending to
within a short distance of the back of the case. Each finger key is independent
of all the others and forms a lever of the first class.
Three series of vertically movable ratchet bars 1'2' 3' are maintained in position
by guide bars Y3 or other suitable devices. There are as many of the ratchet bars
as there are finger keys and cach ratchet bar is pivotted at its lower end to the
rear end of the arm X of its respective finger key by means of a pin L¹³ which
operates in a slightly elongated slot A' made transversely in the ratchet bar. The
ratchet bars are arranged and maintained at a slight distance in front of the ratchet
tumbler sleeves and each ratchet bar has on its rear side a series of ratchet teeth B
which corresponds in number to and are adapted to engage the teeth O³ of the
ratchet tumblers when the ratchet bars are moved upward.
The said ratchet tumblers thus serve to keep the teeth F of the ratchet bars in
engagement with their ratchet sleeves while the ratchet bars are moving upward
and when the ratchet bars reach the upper limit of their stroke their teeth B will
meshing with the teeth O³ of the ratchet tumblers, have turned the latter about
half a revolution so that the heavier sides are uppermost and the impulse of the
ratchet bars causes the ratchet tumblers to complete their revolution. It will be
understood that while the teeth O³ are out of engagement with the teeth B the
ratchet bars will be free to descend by their own gravity and the assistance of
pivoted weight arms X which are connected by a rod L bearing on the finger key
levers the teeth of the ratchet bars slipping idly on the ratchet sleeves thus
restoring the bars, tumbler sleeves and finger keys to their initial position.
The upper guide bar 3 has on its front side a series of notches C which receive
the rear sides of the ratchet bars and maintain the latter at the required distance
apart and the inner sides of the said notches are inclined as shown at D Fig. 8.
On the rear side of each ratchet bar near the upper end thereof is an inclined off-
set cam E which is adapted to engage the inclined side D' of its respective guide
notch when the ratchet bar reaches the lower limit of its movement and thereby
move the upper end of the ratchet bar forward and move its ratchet teeth 14
forward into the path of its respective ratchet sleeve. The ratchet teeth F of the
ratchet bars of each bank of finger keys vary in number from 1 to 9 respectively
and correspond to the value of the nunerals on the said keys. That is to say if
the finger key numbered 9 that ratchet teeth of the ratchet bar attached to said
finger key will be nine in number and so on. The ratchet teeth of the bars of
each bank of keys are adapted and designed to engage different ratchet sleeves.
In other words the teeth on the ratchet bars 1 attached to the bank of keys 1° are
arranged to engage and rotate the sleeve L the teeth on the ratchet bars 21
attached to the banks of keys 2ª are arranged to engage and rotate the sleeve G³
and the teeth on the ratchet bars 3' attached to the bank of keys 3" are arranged
to engage and rotate the sleeve M². Hence the said ratchet teeth are differently
located on the different sets of ratchet bars.
At the lower end of each set of ratchet teeth F is a shoulder or stop G' which
by engaging its respective revolvable ratchet sleeve when the ratchet bar reaches
the upper limit of its stroke will absolutely prevent further rotation of the said
sleeve and hence prevent the numbered disc geared to and operated by the said
sleeve from moving too far and registering the wrong number.

page_text: At the upper end of each ratchet bar 1 is a forward extending arm 1 and
pivoted to the front end thereof is a depending link arm 1. Each of said link
arms has an off-set shoulder H on its front side near its lower end adapted to
be engaged by the lip of the rocking detent T2 and on the rear side of each of said
link arms at a suitable distance from the lower end thereof is a shoulder 1 which
is adapted to engage a tooth on the sleeve (as will be hereinafter more fully
described. A spring K see Fig. 6, attached to each arm 18 has its lower end
bearing against the side of one of the link arms the function of the said springs
being to normally hold the link arms forward in position to cause their shoulders 1
to be thrown out of engagement with the ratchet sleeve G².
At the upper end of each ratchet bar 2 is a forward extending arm 25 and
pivoted to the front end thereof is a depending link arm 2. Each of said link
arms has an off-sct shoulder I on its front side adapted to be engaged by the lip
of the rocking detent D³ and on the rear side of each of said link arms 2 at a
suitable distance from the lower end thereof is a shoulder M' which is adapted to
engage with the ratchet sleeve M².
The ratchet bars 31 attached to the last bank of keys are not provided with link
arms such as hereinbefore described.
In the front side of the upper portion of the case is a longitudinal opening
which is covered with a sheet of transparent glass. .
7'
Arranged from end to end of the case one above the other, and at suitable
distance in rear of and below the opening rare a pair of horizontal guide bars R.
In openings in the said guide bars are arranged three sets of vertical tumbler
rods 1, 2, 3, which are equal in number to the ratchet bars.
A series of tablets 1 are attached to the upper ends of the rods 1" and similar
series of tablets or indicators 2" 3" are attached to the upper ends of the rods 2" 3"
respectively. Said tablets are normally below the level of the opening out of
sight. The tablets 1" are numbered from 1 to 9 and indicate tens and the
tablets 3 are numbered from 1 to 9 and indicate hundreds. Each tablet corresponds
in value to its respective finger key.
From the foregoing it will be understood that the highest value or number that
may be indicated by the tablets 1m 2m 3m when the tablet of highest value of each
series is presented behind the opening is 999 the nine appearing thus 9 hundreds,
9 tens, 9 units.
When a finger key is operated its respective ratchet bar as the latter rises
strikes the lower end of its respective tumbler rod and thereby causes the appropriate
tablet corresponding to the value of the sum to be noted to appear before the
openings in the case.
Springs S are coiled on those portions of the tumbler rods between their guide
bars R and the lower ends of the said springs bear on collars T on said tumbler
rods and thereby normally force the latter down and hence move the tablets below
the opening in the case.
A trip bar is arranged lengthwise in the case and has vertical arms Y at
its ends which are pivoted to the ends of the case and adapt the trip bar to
oscillate. Studs A limit the forward movement of the trip bar and springs B
which bear against the rear side of the arms Y¼ keep the latter normally in
engagement with the studs.
As
When a finger key is operated the force of its ratchet bar is sufficient to
strike the lower end of the tumbler rod with such force as to drive the collar
on the tumbler rod upward entirely across the cam face of the trip bar.
soon as the collar passes up beyond the trip bar the springs of the latter force
it back under the collar thereby retaining the latter and its tumbler rod at the
upper limit of their stroke and consequently the tumbler rod will be maintained
in such position as to display its tablet before the opening until another finger
key is operated. When this is done the instant the next ascending tumbler rod
collar engages the trip bar and the latter is moved rearward the collar on the
tumbler rod which has since the last key was operated been supported in an

page_text: elevated position will be released when its spring will instantly force it down to its
normal position and withdraw its tablet from display.
The mechanism hereinbefore described is adapted for computing sums in addition
and the operation thereof for this purpose is as follows;-
Before the initial operation of the machine all of the discs 1, 2, 3, 4, 5, 6, 7, 8, 9,
must be turned with their 0 or zero marks opposite the openings P and this
must be effected by the means hereinafter described. We will assume that the
first sum to be noted is of the value of five units. The operator touches the
key 5 of the bank 1" and by so doing causes the ratchet bar attached to said finger
key and having five ratchet teeth to ascend said teeth engaging the ratchet
sleeve Land turning the same on its shaft through a space equal to the width of
five ratchet teeth or 5 tenths of its circumference. This sleeve being geared to
the disc 1 by the wheels N° 1° sleeve 1 and wheels 1ª causes the said disc to also
rotate through the same proportion of its circumference and thereby presents the
number 5 indicating units to the appropriate opening P. At the same instant the
said ratchet bar operates the tumbler rod having the tablet 5 in series 1" to be
moved to display five units.
The same initial impulse of the finger key which operated the ratchet bar and
registering mechanism will also cause the bar I to rise and lift the weight arms X.
When the operator removes his finger from the key the weight arms by causing
the rod to depress the inner end of the finger key return the latter to its normal
position and cause the ratchet bar to descend with it. When another key of the
value say of 4 units, has been operated, the sleeve L² will have been turned through
nine-tenths of its revolution and will have brought its tappet pin A³ to a position
adjacent to the upper side of the arm Z2 of the dog X2 and the disc 1 will have
been turned to bring the number 9 or the sum of 5 plus 4 before the appropriate
opening PI
We will assume that the key of the value of 1 unit is now operated which will
cause the appropriate ratchet bar of the series 1' and having only one ratchet
tooth F to engage the ratchet sleeve L on its ascent and turn the same through
a distance equal to one space or the width of one tooth and thereby complete the
rotation of the said sleeve. As the latter effects this complete rotation the tappet
pin A being in engagement with the arm 72 of dog X as before stated will depress
said arm and cause the dog to release the arm V of the rocking detent T when
the spring W2 will instantly move the said detent rearward. On the succeeding
descent of the ratchet bar the said detent will engage the link arm 1h attached to
said ratchet bar and said link arm will be moved rearward thereby against the
resistance of the spring K and the shoulder 1 of said link arm will engage one
of the teeth of the ratchet sleeve G2 geared to the tens disc 2 by the mechanism
herein before described and as the ratchet bar and link arm complete their descent
the shoulder I of the link arm will rotate the sleeve G through a space equal to
one-tenth of its circumference and hence cause the tens disc 2 to turn through one-
tenth of a revolution from 0 to 1 and present the latter number to the appropriate
opening Pl
The shape of the shoulder 1 is such that as soon as it has moved the sleeve G²
one space the next succeeding ratchet tooth of the said sleeve will engage the rear
side of the link arm and push the shoulder I thereof out of engagement with the
said sleeve G2 and hence the latter will be only moved the required distance and
as the link arm continues to descend after thus disengaged from the sleeve C² its
off-set shoulder or cam H will continue to engage the detent T and in moving
down across the lip thereof will return the said detent to its initial position and
cause its arm V2 to be engaged again by the dog X2 which will retain the rocking
detent T in its initial position until the sleeve L has been moved through another
complete revolution.
From the foregoing it will be understood that as often as the sum of the values
registered by the bank of units key 1 exceeds 10 the sleeve L' will be automatically

page_text: operated to cause the tens disc 2 to be moved one space and present its next highest
number to the appropriate opening P¹.
When a key in the tens bank is operated say the key of the value of three tens
or 30, its ratchet bar 2 is caused to operate the sleeve G, through a space equal
to 3 tenths of its circumference and consequently the tens disc 2 will be moved a
corresponding distance by the gear wheels which connect it to the sleeve G²
We have assumed that the said disc 2 has been already moved one space by the
previous operations of the link arms of the ratchet bars attached to the unit keys
of bank consequently the three spaces through which the said disc 2 is now
turned by the aforesaid appropriate key and ratchet bar of the bank 2° will cause
the number indicating 4 tens or 40 or the sum of 3 tens plus 1 ten to appear on said
disc 2 through its appropriate opening P₁
It is understood from the description hereinbefore given of the tablets.or indi-
cators that the appropriate one of the latter will be displayed whenever a finger
key of any bank is operated. The highest number that may be registered by the
discs 1, 2 is 99, when the figures 9 of said discs are displayed. Each time that
the sleeve G is caused to make a complete revolution either by the ratchet bars
attached to the keys 2 or by the link arms of the ratchet bars attached to the
key's 1°, that is to say either by registering tens or the sums in tens of units, its
tappet pin K³ will engage the arm 13 of the dog H³ and cause the latter to
disengage its arm F3 of the rocking detent E³, and consequently on the succeeding
descent of one of the ratchet bars 2' the said detent will engage the off-set
shoulder M on the link arm 2h attached to said ratchet bar and said link arm will.
be moved rearward thereby against the resistance of its spring, and the shoulder M
of said link arm will engage one of the teeth of the ratchet sleeve M² geared to the
hundreds disc 3 by the mechanism hereinbefore described, and move said sleeve M²
one space and thereby operate the disc 3 one space and cause its next highest
number to appear before the appropriate opening Pl
When one of the finger keys in the bank 3 is operated, the ratchet bar
attached to said key is caused to partly rotate the disc 3 the required number of
spaces to indicate the sum in hundreds, plus the sum in units and tens previously
indicated.
When the sum of all the operations is more than 999, the dise 3 indicating
hundreds will be turned by the mechanism hereinbefore described to such
position as to cause its pin p to engage one of the pins of the wheel hand move
the latter one space and hence cause the said wheel which meshes with the wheel 4"
to move the latter and its disc 4 one space, and thereby cause the figure I on said
disc indicating thousands to appear before the appropriate opening P¹ and so on
until the said ise 4 has been caused to make a complete revolution when the pin p
on said disc will engage one of the pins o on wheel i and cause the latter to move
the disc o one space, and thereby indicate ten thousand plus the thousands in units,
the hundreds in units, the tens, and the units indicated by the discs 4, 3, 2, 1.
This operation will be repeated throughout the series of discs and tappet wheels
geared thereto each complete revolution of a disc indicating values of a lower
denomination causing the disc of the next higher denomination to be moved one
space and thus units of a lower denomination will be carried to units of the next
higher denomination throughout the series.
The highest sum that may be indicated by all of the registering discs is 999,999,999
but by increasing the number of discs and the operating wheels and pius the machine
may be adapted to indicate sums up to any amount.
From the foregoing description it will be clear that three sums exclusively in
units, tens and hundreds, may be registered simultaneously by depressing the
appropriate finger key of each bank.
A machine constructed with three banks of keys such as shown is capable of
registering at a single operation any sum less than 1000 but by increasing the
number of banks, ratchets, sleeves, ratchet bars, link arms and rocking detents, the

page_text: machine may be rendered capable of registering at a single operation a sum of any
desired amount.
In order to prevent more than one key of each bank from being operated at the
same instant provide a rectangular open frame E' which is arranged in the rear
side of the case. Vertical bars G divide the said frame into as many divisions
as there are keys. The rear ends of the finger key arms extend through the said
divisions and at the end of the latter are stops or studs H³. A series of eight
rolling discs I are arranged in seats or ways 15 in each division of the same and
above the spaces between the pairs of said arms. The combined width of all the
discs in a single division plus the width of one of the key arms X³ is equal to the
space between one pair of the stops or studs H. Hence when the rear end of one
of the finger key arms X2 is moved upward when the key is operated said arm rolls
the discs laterally and the latter open only a sufficient distance to clear the said
arm before they come in contact with the stops or studs H³ and consequently render
it impossible to operate another key of the same bank.
Arranged across the case near the rear side thereof is a lock-plate L' which has
its end provided with pivots M that bear in the ends of the case. The said lock
plate is at a slight distance in rear of the frame E' and has the depending flange N³
and the inclined off-set 05 the latter extending towards the frame E and the said
flange No of the lock plate has its lower edge in a plane slightly higher than the
upper sides of the finger key arms when the latter are at rest. The flange N
is below the pivots M³ and the off-set 0 is above the same. A spring P
bears against the rear side of the lock plate at a point near its centre and
normally retains the lock plate in the position shown with its flange N inclined
rearward a sufficient distance to clear the rear ends of the finger key arms.
The operation of this portion of the machine is as follows:-
When a finger key of one or more banks is depressed the inner ends of the arms
thereof arise, and by engaging the inclined off-set 05 partly turns the lock plate
on its pivot and causes the flange N³ to move forward over the arms of the
remaining keys and hence lock them and prevent them from being operated until
after the pressure on the finger keys in use has been removed, and the said keys
have returned to their initial position, when the spring P³ restores the lock plate to
the position it formerly occupied.
I will now describe this improved mechanism whereby the computer is adapted
to be used for the purposes of substraction, multiplication and division.
A shaft B which is exactly similar to the shaft G is arranged parallel with the
latter and at a suitable distance in front of and. below the same and has its
ends journalled in bearings in the ends of the case and adapted to move endwise
therein.
A coiled extensile spring C is arranged near one end of the shaft B and bears
between a shoulder D thereon and one end of the case and to the projecting end of
the shaft is pivoted a cam lever E which is adapted to be used for moving the shaft
end wise this cam lever being in all respects similar to the cam lever on the shaft G¹
previously described.
ܐ܂
Loosely journalled on the shaft B are a series of discs 1, 2, 31, 41, 51, 61, 71, 81, 91
which are of the same size and construction as the adding discs on the shaft G
their numbers being in the same order as those on the adding discs and have spur
wheels 1 2 3 4 5 6 7 8 9 respectively which are adapted to mesh with the
respective wheels on the said discs on the shaft G¹.
A. shaft 1 is journalled in suitable bearings in the case has a spur pinion 1' at its
inner which engages the wheel 1 and at the outer end of the said shaft is a circular
milled head 1 by which the shaft may be readily turned by the fingers to cause the
disc 1' to revolve.
A similar shaft 2 has a spur pinion 2 engaging the wheel 2 and has also the
head 2".
A similar shaft 3* has a spur pinion 3 engaging the wheel 3 and has also
the head 3.

page_text: nead.
A similar shaft 55 has a spur pinion 5 engaging the wheel 5* and has also the
head 5".
A similar shaft 6' has a spur pinion 6 engaging the wheel 6 and has also
the head 6".
A similar shaft 7 has a spur pinion 7
head 7".
A similar shaft 8 has a spur pinion 8
head 8.
engaging the wheel 7' and has also the
engaging the wheel 8 and has also the
A similar shaft 9 has a spur pinion 9t engaging the wheel 9 and has also
the head 9.
Thus the discs 1 2 3 4 5 6 7¹ 81 91 are adapted to be revolved independently
of each other and in either direction. The spur wheels of said discs are of sufficient
width to enable the said dises and spur wheels to be moved laterally by the
end wise movement of the shaft B without disengaging said spur wheels from said
pinions.
The numbers on the discs 1 2 3 4 5 6 7 8 9 appear successively when said
discs are rotated before a series of openings R' in the front side of the case below
the openings P¹.
1 will now describe the operation of this invention to perform examples in
subtraction.
We will assume that it is desired to subtract the sum of 27777 from 45835. To
accomplish this the shaft G' must be first moved endwise by its cam lever in the
manner herein before described so as to disengage the spur wheels of the adding
discs from the spur wheels on the shaft T and thereby render them capable of
rotation in either direction.
The cam lever when turned outward from the end of the case maintains the shaft
in this position as will be readily understood. The shaft B must also be moved
simultaneously with the shaft G to keep its dises in gear with the adding discs.
Then by turning the appropriate discs 1 2 3 4 5 by means of their respective
shafts and pinions the discs 1 2 3 4 5 must be turned to cause the number 45835 to
appear before the openings P₁. The discs of higher value than those involved in
the example should not be operated.
Having thus brought the number 45835 before the openings P¹ the operator
causes the shaft B to move endwise so as to disengage its discs from the adding
discs and he then tums the said discs on shaft B to the 0 or zero mark and moves
the shaft B so as to re-engage its discs with its adding discs. To facilitate the
description of the operation of the machine 1 will designate the discs on shaft G¹
as the adding or primary discs and those on the shaft B as the secondary discs.
Having arranged the discs involved in the computation in the manner just described
the operator turns the secondary discs in progressive order of their numerals until
the lesser sum 27777 involved in the computation appears on the recording dises
before the openings R'. By thus turning the secondary discs the primary discs
geared thereto will be moved in reverse order and cause numerals of decreasing
value to appear before the openings P' and when the lesser sum 27777 shall have
been indicated by the secondary discs as before stated the remainder 18058 will
appear before the openings P1.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me by my
foreign correspondent 1 declare that what I claim is :-
1. In a computing machine the primary discs the carrying devices connecting
the same for the purpose set forth, and the secondary discs geared to the primary
dises said primary and secondary dises being numbered in the same order all in
combination substantially as described and illustrated in the accompanying
drawings.

page_text: 2. In a computing machine the combination of the adding or primary discs the
carrying wheels geared thereto the secondary discs numbered in the same order as
the primary discs and means substantially as set forth to shift said secondary and
primary discs into and out of gear with each other substantially as described and
illustrated in the accompanying drawings.
3. In a computing machine the primary registering discs having carrying devices
in combination with the secondary indicating discs numbered in the same order
means substantially as specified to move said primary and secondary discs into_and
out of gear with each other and devices to independently revolve the secondary
discs.
4. In a computing machine the combination of the laterally movable primary
discs the finger keys and connecting devices to operate the same the relatively
fixed carrying wheels adapted to gear to the primary discs the detents to prevent
retrograde rotation of the carrying wheels the secondary discs adapted to be shifted
into and out of gear with the primary discs and the trip device to release the
detent from the carrying wheels substantially as described and illustrated in the
accompanying drawings.
5. In a computing machine the combination of the laterally movable primary
discs the finger keys and connecting devices to operate the same the relatively
fixed carrying wheels adapted to gear to the primary discs the detents to prevent
retrograde rotation of the carrying wheels the secondary discs adapted to be shifted
into and out of gear with the primary discs the trip device to release the detents
from the carrying wheels and the devices to be independently rotate the discs
substantially as herein described and illustrated in the accompanying drawings.
6. The combination of the end wise movable shafts the primary and secondary
registering discs thereon and capable each of independent rotation the finger keys
and connecting devices to operate the primary discs the relatively fixed carrying
wheels adapted to gear to the primary discs the detents to engage said carrying
wheels for the purpose set forth and the trip device to release said detents sub-
stantially as described and illustrated in the accompanying drawings.
7. In a computing machine the combination of the endwise movable shafts the
independently revolvable primary and secondary registering discs thercon and
adapted to gear, the levers, to move the shafts and thereby throw said primary and
secondary discs into or out of gear with each other the independently revolvable
shafts geared to the secondary discs the relatively fixed carrying wheels adapted to
gear to the primary discs the finger keys and mechanism to operate the primary
discs the detents or pawls to engage the carrying wheels for the purpose set forth
and the trip devices to disengage the pawls or detents from the carrying wheels
substantially as described and illustrated in the accompanying drawings.
8. In a computing machine the combination of the primary discs the secondary
discs means to shift said primary and secondary discs into and out of gear with
each other and the independent shafts having the pinions engaging the secondary
discs whereby the latter may be independently rotated substantially as described
and illustrated in the accompanying drawings.
9. In a computing machine the combination of the ratchet sleeves geared to the
primary indicating discs the ratchet bars to engage the sleeves when moving in one
direction and the weighted ratchet tumbler sleeves engaging the ratchet bars and
cut-away on one side for the purpose set forth, substantially as described and
illustrated in the accompanying drawings.
10. In a computing machine the combination of the ratchet sleeves and gears to
operate the primary discs the ratchet bars attached to the finger keys and operating
the ratchet sleeves in one direction and the ratchet tumbler sleeves to maintain the
ratchet bars in gear with the ratchet sleeves when moving in one direction and
release them therefrom when moving in the reverse direction substantially as
described and illustrated in the accompanying drawings.
11. In a
computing machine the combination of the ratchet sleeves and gears to
operate the primary discs the ratchet bars connected to the finger keys and
B

page_text: operating the ratchet sleeves in one direction the revolvable ratchet tumbler sleeves
engaging said ratchet bars to maintain the latter in engagement with the ratchet
sleeves when moving in one direction and having the eccentric or cut-away faces to
release said bars from said sleeves substantially as described and illustrated in the
accompanying drawings.
12. In a computing machine the combination of the ratchet sleeves the ratchet
bars to operate the same the ratchet tumbler sleeves to alternately engage and
disengage the ratchet bars substantially as and for the purpose described and
illustrated in the accompanying drawings.
13. In a computing machine the combination of the ratchet sleeves the ratchet
bars to operate the same the ratchet tumbler sleeves to alternately engage and
disengage the ratchet bars and the pawls or detents to prevent retrograde
rotation of the ratchet tumbler sleeves substantially as described and illustrated in
the accompanying drawings.
14. The combination of the finger keys arms and the rolling discs having limited
lateral movement and arranged one between each pair of arms substantially as
described and illustrated in the accompanying drawings.
15. The combination of the finger keys arms the frame having guides therefor
and the rolling discs or stops having limited lateral movement and travelling in
ways or scats in the frame substantially as described and illustrated in the accom-
panying drawings.
16. The combination and arrangement of parts constituting the complete
computing apparatus substantially as described and illustrated in the accompanying
drawings.
Dated this 6th day of June 1890