IMPROVEMENTS IN CALCULATING MACHINES
Year: 1883

page_text: LETTERS PATENT to William Robert Lake, of the firm of Haseltine, Lake,
"
and Co, Patent Agents, Southampton Buildings, London for an Invention of
"IMPROVEMENTS IN CALCULATING MACHINES communicated to him from
abroad by Karl Duschanek of Freiburg in the Empire of Germany.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 4th August 1883.
"
WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, and Co, Patent Agents,
Southampton Buildings, London, "IMPROVEMENTS IN CALCULATING MACHINES
[A communication to him from abroad by Karl Duschanek of Freiburg in the
Empire of Germany.]
This invention relates to apparatus for mechanically performing arithmetical
calculations.
Machines of this class have heretofore been more or less defective in their
construction. The object of this invention is to remedy these defects and to
produce a machine which shall answer in all respects the purposes for which it is
intended.
The improved machine comprises two main parts one of which is fixed, the
other one being movable.
In carrying the said invention into practice I provide a plate which forms the
base or foundation of the whole machine. Above this plate is fixed a second plate.
These two plates form the bearings for the various shafts of the fixed portion of
the machine. Over the second plate is placed a third plate upon which are
engraved or otherwise shewn the marks necessary for guiding the operator in the
manipulation of the machine. Behind the third plate is a fourth plate arranged
to be moved in various directions as hereinafter described. Below the fourth plate,
and attached thereto, is a fifth plate, which, together with the said fourth plate,
carries the various shafts of the movable part of the apparatus.
I also provide vertical shafts having upon them toothed sectors the teeth of
which gradually increase in length parallel with their axes.
TD 1011
Each of these sectors

page_text: has nine teeth which correspond to the figures 1 to 9. The said sectors are
movable longitudinally upon their shafts and give the multiplicand when two
numbers have to be multiplied or the divisor when they have to be divided. The
position of the said sectors is varied by rotating the shafts, hereinafter termed the
first shafts, which impart motion to bevel wheels attached thereto, toothed
wheels gearing with the said bevel wheels, racks, and arms secured to the said
racks when a first shaft is rotated to the left, the rack and with it the said arms
are raised thereby raising the toothed sectors in connection there with.
Each of the said first shafts carries a ratchet wheel having ten teeth; the said
ratchet wheel is held in position by means of a pawl mounted upon a shaft and
acted upon by a spring so that when the sectors have been raised to a certain
height they may be retained in that position. Upon the said first shafts are
mounted discs each of which has marked upon it the ten digits.
In the second and third plates which are close together apertures are formed of
such size as to shew only one figure at a time upon each of the said discs. The
said apertures are situated between the shafts of the said discs and those of the
sectors.
The figures which appear through the above mentioned apertures are varied
according to the position in which the toothed sectors have been set, that is to say
the said numbers indicate how many teeth of the sectors are in position to gear
with toothed wheels for a purpose hereinafter described.
The apparatus as hereinbefore described serves, as already stated, to arrange the
multiplicand or divisor, the said apparatus is therefore provided with as many
sectors and discs as there are figures required in the said multiplicand or divisor.
In order to bring the sectors and disc to the zero point after a calculation has
been made, I provide a shaft having a crank-handle which actuates, by means of
toothed wheels, a number of shafts hereinafter termed second shafts corresponding
to the number of sectors, and causes the said shafts to perform the same number
of revolutions. These second shafts each carry a cam. Upon theso cams bear
projections on the said pawls, so that when the said cams raise the pawls the
ratchet wheels are released, whereby the sectors are permitted to fall.
In order to prevent the said sectors from falling too suddenly, second shafts
carry partially toothed wheels, which, as soon as the pawls are raised, engage with
corresponding toothed wheels mounted upon the first shafts whereby the downward
movement of the said sectors corresponds to the rotation of the second shaft.
In the said toothed wheels spaces are formed between two of the teeth in such
a manner as to be opposite the teeth of the partially toothed wheels when the
discs are at zero.
As soon as the partially toothed wheels have caused the wheels engaging with
them to move far enough for the space between their teeth to come opposite the
teeth of the former, the wheels fall out of gear and the discs are placed at zero.
The revolution of the first shafts also causes at the same time the backward
rotation of the discs.
The cams and the partially toothed wheels act in such a manner that all the
various parts of the machinery are not compelled to move in the same time, but
this arrangement is not absolutely necessary.
If the crank and second shafts are caused to perform a whole revolution, all the
pawls will be raised and all the sectors and discs set at zero.
In order to prevent the crank-handle from turning to the left, a ratchet wheel
and a spring are mounted upon one of the second shafts.
I also provide shafts, hereinafter termed third shafts, carrying toothed wheels and
discs; the said shafts are placed opposite the sectors, and the toothed wheels are
placed at such a height as regards the said sectors, that when the discs are set at
zero, the longest teeth of the sectors are not in gear with the said toothed wheels.
The fourth plate has as many apertures formed in it as thore are discs.
The rotation of the sectors is effected at the same time as that of a crank
attached to a shaft carrying the toothed wheels, which actuates a train of gearing.

page_text: Additions and multiplications are therefore effected by revolutions of the said
crank to the right, and subtractions and divisions by revolutions of the same to
the left.
As soon as a disc has performed a completo revolution and the number 9 is
visible at its aperture the following number must be added, this is effected by
means of the following arrangement. One of the aforesaid shafts carries a pin
which in its revolution raises a lever by touching a projection with which tho
underside of the said lever is provided. In order to prevent the said lever from
falling below its horizontal position, a projection bearing against a pin is fixed
upon the said lever.
Upon somo of the shafts of the sectors and upon a shaft revolving at the
same time as the said sectors are drums, each of which has two arins.
"The said drum engages, by means of its arms, with a wheel placed above a
toothed wheel and moves the same one step forward and thus causes the movement
of the next disc.
In order that the said drum should remain in a raised position during the
revolution of the shafts the lever is lowered subsequent to the raising of the drum,
by means of a spring. Neither the said lever nor the spring is fixed to the
apparatus but to a piece which moves between rods and upon bearing pieces. The
to and fro movement of this piece is effected by means of excentrics impinging
against the studs and driven by one of the wheels of the aforesaid train of wheels..
The pin or stud allows only sufficient play to the spring for depressing the lever
below the drum, which depression allows the said lever to fall and again be ready
to rise when the "hundreds" disc is to be rotated.
For subtractions and divisions the arrangement for the tens and hundreds disc
is exactly reversed the discs being returned to zero by means of other arms.
In the above described operation the sectors are always in gear with the toothed
wheels which are in front of them, and the multiplication and division of units are
accomplished by the revolution of the crank. In order to effect multiplications
with tens the sector which is nearest the outside of the mechanism must be in
gear with the second wheel, and the next sector must be in gear with the third
wheel, a similar arrangement being extended to the other sectors.
This connection is effected by mounting the shafts with their bearings and discs
upon a part of the apparatus which can be moved to the right or to the left and
which is hereinafter termed a carriage.
The plates which carry the several parts of the machine rest, by means of
supports, upon small rollers which roll upon two bars fixed upon the foundation
plate
As the position of the said carriage must be fixed for the various positions of
the units and the tens so that the wheels should be placed precisely opposite the
sectors;
two notches in which pawls engage are formed in the plate. These pawls
rotate upon the shaft and can be raised by means of a rod and a lever, a spring
bearing upon the said rod to press it down again ready for the next movement.
.
This said rod consists of two parts firmly attached together, the left part pressing
upon the lever.
As many notches will be required in the foundation plates as there are numbers
in the multiplier or quotient.
In order to be able to perceive at the close of a multiplication how many
revolutions of the crank have been accomplished to bring the units, tens, or other
numbers in position, shafts hereinafter terined third shafts are arranged upon the
carriage above mentioned and upon them aro mounted the toothed wheels cach
provided with ten teeth and numbered dises the upper plate being provided with
corresponding apertures to show the numbers thereon. A shaft provided with a
pin which is in gear with the toothed wheel will rotato by means of the gearing of
all the wheels of the aforesaid train. In this rotation, the toothed wheel in gear
with the wheel mounted upon the shaft having the pin is rotated one tooth
further.

page_text: When a pultiplication [sic] is effected with the tens, the carriage is then brought
in its second position, in which case the said pin enters the teeth of another wheel;
a similar arrangement will correspond in the use of further numbers.
All the discs have grooves or indentations formed in the peripheries, into which
indentations the springs fall as soon as a number appears at one of the apertures.
As by a sudden turning of the cranks a number inay easily be passed over, a
spring is arranged to fit into the concave indentations of the discs and a fork is
provided, upon one of the prongs of which is formed a pointed projection, whilst a
projection having the same shape as the concave indentations is formed upon
the other prong, at each movement of a disc an oscillating movement is imparted
to the said fork, and when a disc has to be secured the projection of the prong
which corresponds in shape to the indentations falls into one of the latter As
only a certain force is required to cause this projection to withdraw from the
indentation this mechanism will serve to effect the stoppage of the disc
The second and third discs are set at zero as follows that is to say. The shafts
of the said discs carry the wheels provided with nine teeth, room being left
vacant for a tenth tooth. These wheels are situated immediately above other wheels.
Opposite the said wheels are mounted partially toothed wheels which are rotated
by means of a crank together with a shaft and the toothed wheel mounted thereon.
In order to fix the crank in the zero position its shaft carries a disc segment,
upon the flat portion of which bears a spring.
Instead of toothed wheels, double cranks provided with connecting rods may be
employed.
By rotating the said shafts each wheel rotates until the part of a wheel_from_
-which a tooth is missing is brought opposite the same, when the wheels are thrown
out of goar.
At the same time every disc is placed at zero and a single rotation of
the crank is sufficient to place the product and the multiplier upon zero.
In the calculation of proportions.it is necessary that the row of figures appearing
in the apertures should not be placed at zero at the same time, by a revolution of
the crank. It is therefore necessary that the toothed wheel mounted upon the
crank should be divided into thirty six spaces and only provided with eighteen
teeth, which are arranged in such a manner that between each row of nine teeth
there is a vacant space equivalent to the space which would be required for nine
teeth. By half a revolution of the crank the row of figures in the second apertures
is placed at zero, and by another half revolution of the said crank the row of
figures in the third apertures is likewise placed upon zero.

page_text: Figure 6 is a plan view certain parts being removed.
Figure 7 is a view hereinafter described
Figure 8 shows two positions of mechanism for stopping some of the discs
Figure 9 is a plan and elevation of mechanism which may be used in lieu of
toothed wheels
Figures 10 and 11 each show in plan and elevation different portions of the
device for holding the drums in a raised position
Figure 12. shows the position of the parts when the movable part of the
apparatus is moved
Figures 13 and 14 each show in plan and elevation different positions of parts of
the apparatus when certain figure appear before the openings
The improved machine comprises two main parts, one of which is fixed the other
one being movable. As shown in Figures 1, 6 and 12 the plate a forms the base
or foundation of the whole machine. Above this plate a is fixed a plate b. These
two plates form the bearings for the various shafts of the fixed portion of
the machine. Over the plate 6 is placed a plate c upon which are engraved or
otherwise shown the marks necessary for guiding the operator in the manipulation
of the machine.
Behind the plate is arranged a plate d adapted to be moved in various
directions as hereinafter described. Below the plate d and attached thereto is the
plate d¹ which together with the plate d carries the various shafts of the movable
parts of the apparatus.
Referring to Figures 45. 6 and 12 e e indicate vertical shafts having upon them
the toothed sectors ff the teeth g, g of which gradually increase in length
parallel with their axes Each of these sectors has nine teeth which correspond to
the figures 1 to 9. The said sectors are movable longitudinally upon their
shafts and give the multiplicand when two numbers have to be multiplied or the
divisor when they have to be divided. The position of the said sectors is varied

page_text: by rotating the shafts h which impart motion to the bevel wheels i attached
thereto, the toothed wheels ¹, the racks i, and the arms secured to the said
racks as shown in Figure 1. When a shaft his rotated to the left, the rack, and
with it the arms ³, are raised, thereby raising the toothed sectors in connection
therewith. Each of the shafts h, as shown in Figures 5 and 6, carries a ratchet
wheel k having ten teeth; the said ratchet wheel is held in position by means of a
pawl mounted upon a shaft as shown in Figure 14 and acted upon by a
spring so that when the sectors have been raised to a certain height they
may be retained in that position. Upon the shafts h are mounted discs as shown
in Figure 2 cach of which has marked upon it the numbers 1 to 0
In the plates b and c which are close together, apertures
size as to show only one figure at a time upon each of the said discs.
The said apertures are situated between the shafts of the discs and the shafts e
of the sectors f
are formed of such
The figures which appear through the above mentioned apertures are varied
according to the position in which the toothed sectors f have been set, that is to
say the said numbers indicate how many teeth of the sectors f are in position to
gear with wheels 'o' for a purpose hereinafter described
Figure 13 shews, by way of example, the position of one of the sectors when
the number 4 is visible through an aperture 1, four of the teeth of the sector f
then being in position to gear with the corresponding wheel o'
The apparatus as herein before described serves, as already stated, to arrange the
multiplicand or divisor: The said apparatus is therefore provided with as many
sectors fand discs as there are figures required in the said multiplicand or divisor.
The apparatus shown in the drawings is-only arranged for two figures."
In order to bring the sectors f and dises to the zero point after a calculation
has been made the dovico shown in Figures 1 to 6 is employed. A shaft m¹
provided with a crank handle m actuates by means of the toothed wheels m³ m³ a.
number of shafts m corresponding to the number of sectors f, and causes the said
shafts to perform the same number of revolutions. These shafts m* each carry a
cam m³ Figure 6. Upon these cams bear projections on the pawls ³ so that when
the said cams raise the pawls the ratchet wheels karo released whereby the sectors f
fall. In order to prevent the said sectors from falling too suddenly the shafts m*
carry partially toothed wheels n Figure 6, which, as soon as the pawls k³ are
raised, engage with the corresponding toothed wheels n' mounted upon the shafts h,
whereby the downward movement of the said sectors f corresponds to the rotation
of the shaft m¹
In the toothed wheels n' spaces are formed between two of the teeth in such a
manner as to be opposite the teeth of the toothed wheels n when the discs are
at zero.
As soon as the toothed wheels n have caused tho wheels n' to move far enough
for the space between their teeth to come opposite the teeth of the former the
wheels nn fall out of gear, and the discs are placed at zero. The revolution of
the shafts m* also causes at the same time the backward rotation of the discs
The cams and the partially toothed wheels n act in such a manner that the
various parts of the machinery are not compelled to move at the same time, but
this arrangement is not absolutely necessary
If the shafts m' m' are caused to perform a whole revolution all the pawls l³,
will be raised and all the sectors and discs set at zero. Figure 14 shows the
position of these parts when the figure 4 is visible at the apertures.
In this case the partially toothed wheel n is allowed to rotato until its first tooth
is in gear with the fourth tooth of the wheel n¹. After a further rotation of four
teeth the wheel n coming to the untoothed portion of the wheel n¹ is thrown out
of engagement therewith, when the corresponding discs are set at zero.
In order to prevent the crank handle m from turning to the left, a ratchet
wheel is arranged upon the shaft m' with which a spring is adapted to engage

page_text: Referring to Figures 1, 7, 10, and 14 the shafts o with the toothed wheels o¹
herein before mentioned and the discs o³ are placed opposite the sectors f, and the
toothed wheels o' and the discs o' are placed opposite the sectors f, and the toothed
wheels o' are placed at such a height as regards the said sectors that when the
discs o³ are set at zero, the longest teeth g of the sectors are not in gear with the
said toothed wheels o¹.
The plate d has as many apertures as there are discs o³.
When the first named discs are placed so that the numbers 1, 2, 3 or others
show through the apertures, the corresponding sectors are raised proportionately
and by a single revolution of the said sectors a similar number of teeth g of the
same aro placed in gear with the toothod wheels o³ as shewn in Figure 13. By a
further rotation, the sectors f cause the tooth wheels o¹ to rotate for a distance
of four teeth, and the number four consequently becomes visible at an aperture o³
of the plate d.
The rotation of the sectors is effected at the same time as that of a crank p,
Figure 2, attached to the shaft 2 carrying the tooth wheel p³ which actuates
the gear wheels p³, p', p³, p² p² p³ p³ ³° ?" and pl
At each rotation to the right of the crank p the number appearing in the
apertures is added to itself in the apertures o³, and this same number is
consequently multiplied by the number of revolutions of the said crank.
When the crank is turned to the left instead of the right, at each revolution of
the same the number in the apertures is subtracted from the number appearing
in the apertures o³.
Additions and multiplications are therefore effected by revolutions of the said
crank p to the right and subtractions and divisions by revolutions of the same to
the left.
As soon as a disc o³ has performed a complete revolution and the number 9 is
visible at its aperture o³, the following ten must be added; this intercalation of the
ten is effected by means of the following arrangement shown in Figures 1, 7, 10
and 11. The aforesaid shaft o carries a pin of which in its revolution raises the
lever o by touching a projection with which the underside of the said lever is
provided. In order to prevent the lover o from falling below its horizontal
position a projection bearing against a pin o¹º is fixed upon the said lever as shown
in Figure 7.
Upon some of the shafts e of the sectors f and upon a shaft e revolving with
the said sectors are drums of each of which has two arms o7 08.
When the shafts o and their discs o² have accomplished a revolution, the lever o³
and the corresponding drum oº are raised, and remain in this position until the
shafts e and e have accomplished their revolution. The said drum engages by
means of its arms with the wheel o° Figure 5 placed above the toothed wheel o¹,
and moves the same one step forward thus causing the movement of the
next disc.
In order that the drum o should remain in a raised position during the
revolution of the shafts e and eº I provide a device shown in Figures 6, 10 and 11.
Subsequent to the raising of the drum of the lever q¹ is depressed by means of the
spring g. Neither the lever q' nor the spring q is fixed to the apparatus, but to a
piece q which moves with the rods q³ and upon the bearing pieces q'. The to and
fro movement of this piece q is effected by means of the excentrics q³ impinging
against the studs q7 g and driven by the wheels pt. The pin or stud q allows only
sufficient play to the spring q for depressing the lever to the position shewn in
figure 11 below the drum, which depression allows the said lever to fall and be
again ready to rise when the next ten is to be inter calated.
In Figures 10 and 11 this device is shown in two positions.
For subtractions and divisions the arrangement for the tens and hundreds disc
is exactly reversed the discs being returned to zero by means of arms o³.
1

page_text: In the above described operation the sectors f are always in gear with the toothed
wheels o' which are in front of them, and the multiplication and division of units
is accomplished by the revolution of the crank p. In order to effect multiplications
with tens, the sector which is nearest the outside of the mechanisin must be in
gear with the second wheel o', and the next sector must be in gear with the third
whcel o', a similar arrangement being extended to the other sectors.
This connection is effected by mounting the shafts o with their bearing and
discs upon a part of the apparatus which can be moved to the right or to the left.
The construction of this movable part or carriage is illustrated in Figures 3, 5
and 12.
The plates & d' which carry the several parts of the machine are connected by
means of supports d² to a bar d³ which slides in two bars a' fixed upon the foundation
plate a.
As the position of the said carriage must be fixed, for the various positions of the
units and the tens, so that the wheels o¹ should be placed precisely opposite the
sectors, two notches a² a Figure 6 in which the pawls d' engage are formed in
the plate a. These pawls rotate upon the shaft ds and can be raised by means of
the push stud do and the lever d', a spring d³ bearing upon the said stud do to press
it down again ready for the next movement.
The stud de consists of two parts firmly attached together, one of which presses.
upon the lever d' Figure 3. It is therefore only necessary, in order to move the
carriage towards the next ten to raise the pawls d' by means of the stud dª and
push the said carriage sideways, when the said pawls after the sledge has reached
the end of its course will full automatically, and at the right-time-thus-securing the
said carriage. Figure 12 shews the position of the sledge or carriage when moved
to the right.
It is obvious that as many notches a³ will be required as there are numbers in
the multiplier or quotient
In order to be able to perceive, at the close of a multiplication how many
revolutions of the crank have been accomplished to bring the units, tens or other
numbers in position, the shafts are arranged upon the carriage above mentioned,
and upon them are mounted the toothed wheels each provided with ten teeth
and the discs 2, the upper plate & being provided with corresponding apertures ³
to show the numbers thereon.
The shaft provided with the pin which gears with the toothed wheel r¹ is
rotated by means of the movement of all the wheels 2 to p₁ by the crank p. In
this rotation the toothed wheel in gear with the pin 70 mounted upon the shaft 7
is rotated one tooth further.
When the carriage is in its first position that is to say when operations are
performed with the units only the pin enters the teeth of the last wheel r to
the right.
When a multiplication is effected with the tens, the carriage is then brought in
its second position, in which case the pin enters the teeth of the second whicel ¹;
a similar arrangement will correspond to the use of further numbers. The direction
in which the shaft and the shaft of the discs rotato is reverse to that in which
the crank p revolves. The multiplier has therefore to be arranged upon the discs
and when a revolution of the crank p is effected in the right direction, all the
numbers are placed at zero in the apertures ™³.
For divisions, the revolution of the crank will be effected in a reverse direction,
the numbers of the above mentioned discs being thus placed at zero, and the
quotient will appear, as the result of the operations, in the apertures 2³.
All the discs have grooves or indentations formed in the peripheries into which
indentations the springs o9 and 7 fall as soon as a number appears at one of the
apertures. As by a sudden turning of the cranks a number may easily be passed
over, the arrangement shewn in Figure 8 is utilized in order to avoid such an

page_text: occurence. The spring 7 is arranged to fit into the concave indentations of the
discs and a fork is provided, upon one of tho prongs of which is formed a
pointed projection 10, whilst a projection having the same shape as the concave
indentations is formed upon the other prong. At each movement of a disc an
oscillating movement is imparted to the said fork and when a disc is secured the
projection of the prong which has the shape of one of the indentations fits into the
same. As only a slight forco is required to cause this projection to withdraw from
the indentation this mechanism will serve to effect the stoppage of the disc.
The discs o and are set at zero, as follows, that is to say:-The shafts of tho
said dises o³ and carry the wheels s' provided with nine teeth, room being left
vacant for a tenth tooth. These wheels are situated as shown in Figures 6 and 12
immediately above the wheels o' and 7. Opposite the said wheels are mounted
partially toothed wheels 82 which are rotated by means of a cranks together with
the shaft 8, the toothed wheel mounted thereon, and shafts 8, 81, 8, 8, 87, and 8.
In order to fix the crank s in the zero position its shaft carries a disc segment 8 9
upon the flat portion of which bears a spring 810 as shown in Figure 2.
8
The toothed wheels which transmit the rotation and which are mounted upon
the shafts 80, 8, up to 8 8 are not shewn in the figure their shafts being represented
thus O.
Instead of toothed wheels, double cranks provided with connecting rods may be
employed,ns shown in Figure 9.
By rotating the said shafts, each wheel 8¹ rotates until the part of the wheel 83
from which a tooth is missing is brought opposite the same, when the wheels are
thrown out of gear. At the same time every disc is placed at zero and a single
rotation of the crank s is sufficient to place the product and the multiplier
upon zero.
In the calculation of proportions it is necessary that the row of figures appearing
in the apertures o³ and should not be placed at zero at the same time, by a
revolution of the winch crank 8. It is therefore necessary that the toothed wheel
mounted upon the shaft of the crank s should have room on its periphery for thirty
six teeth, but only have nine teeth, the remaining space being left vacant. By
half a revolution of the crank s the row of figures in the apertures o³ is placed at
zero, and by another half revolution of the said crank the row of figures in the
apertures is likewise placed upon zero.
The various calculations are effected in the following manner that is to say :-
For addition the number which is to be added to a number placed in the apertures o³
is shown in the apertures 1, the crank p is then turned once round to the right
when the said number is added to that which was in the apertures o³.
"
For Subtraction-the number which is to be subtracted from a number shown in
the apertures o³ is shown in the apertures , the crank is then turned once round
to the left and the result of the operation is shown in the apertures o³.
For multiplication. One of the factors is shown in the apertures and the other
in the apertures, the carriage & d' being in its norinal position. The crank p is
then rotated to the right until zero appears in the aperture to the right where-
upon the multiplication of units is accomplished. The carriage d d' is then pushed
to the right until the pawl d' falls in the notch a². The crank p being revolved
to the right until the figure zero appears in the second aperture 7. This operation
is continued in a similar manner for greater numbers. The product is seen in the
apertures o³.
For Division. This operation is performed in an exactly reverse manner to that "
above described. The dividend is shown in the apertures o³ and the divisor in the
apertures, whereas the number in the apertures 7 is left at zero. The carriage is
then pushed to the right and the winch crank is rotated to the left. If the number
nine appears on the left in the apertures it shews that the said carriage is moved
too much to the right, the crank p is then turned one revolution backward, the
carriage is pushed back to its next position and the crank is turned on again to

page_text: the left until the figure appears, when the winch crank is turned back again
to the right as before. The rest of the operation is repeated as above until zero
appears in the row of apertures o³, or a smaller number than the divisor which is,
in this case, the remainder of the division, whereas the quotient appears in the
apertures 1-3.
Having thus fully described the said invention as communicated to me by my
Foreign Correspondent, and the manner of performing the same, I wish it understood
that I Claim.
First. The arrangement of the toothed sectors mounted upon vertical shafts, and
of the vertical shaft operated by means of a crank handle, in combination with
intermediate gearing between the said shafts, whereby as the said crank is moved
in one direction or the other the toothed sectors will move in a corresponding
direction, as set forth.
Second. The arrangement of racks, toothed wheels and arms, for vertically
moving the toothed sectors, in connection with the vertical shafts h of the discs
upon which the multiplicand is shown, whereby each toothed sector, when the
said discs are moved, is brought simultaneously into a corresponding position, so
that when the crank is turned a suitable number of the teeth of the said toothed
sector are engaged with the toothed wheels o' of the product shafts o.
Third. The intercalation of the tens in products by means of pins of placed in a
horizontal position upon the shafts o of the discs o³, and which at every revolution
of the said shafts raise a lever ob provided with a projection, whereby a drum o
provided with two arms o' and o" (for multiplication and division) is raised to such
a height that one or the other of the said arms gears, when the drum is rotated
by means of the crank used for operating the same, with the corresponding toothed.
wheel o° of the next cypher disc of the product and advances or moves it back one
tooth, substantially as described.
Fourth. The employment of a lever 91 pressed by a spring upon the body of
the said drum for the purpose of maintaining the same in a raised position until
the intercalation of figures is completed, the said lever being mounted upon a slido
and moved under the said drum after it is raised and drawn back to allow the
drum to fall again, the movement of the lever being limited in such a manner that
it ceases to be in contact with the body of the druin when the slide is drawn back.
Fifth. For the purpose of effecting arithmetical calculations with tens, hundreds
and thousands, the arrangement of the product shafts o upon a slide which
moves to and fro in a horizontal direction, whereby the wheels of the said shafts
can be placed in a position to gear with other sectors by a simple movement
of the said slide, which is held in position by means of a spring pawl which enters
corresponding notches in the fixed foundation plate.
Sixth. The arrangement of the shafts r, carrying the discs upon which the
multiplier is shown, upon the above mentioned slide, the said shafts being operated
by means of a shaft placed outside the slide and provided with a pin r", substantially
as described.
Seventh. The employment of a crank and partially toothed wheels &² rotated
thereby provided with nine teeth, which wheels gear with wheels s¹ (provided with
nine teeth and a vacant space equal to one tooth) on the shafts of the discs o³ for
simultaneously setting the said discs at zero.
Eighth. For simultaneously setting at zero the discs and o' of the multiplier
and product with one and same crank, the arrangement of the toothed wheel &
between the wheels 81, 8' of the shafts and o, carrying the discs for the
multiplier and product, so that a wheel & should gear simultaneously with two
wheels 8¹.
Ninth. In order to place at zero either row of discs o³ or the employment of
toothed wheels divided into thirty six parts but provided with only nine teeth,
which wheels at the first half of their rotation turn the discs o to zero and at the
second half rotation the discs 7² to zero.

page_text: Tenth. For the purpose of allowing the toothed sectors to drop out of engagement
with the wheels o¹, the release of the pawls k³ from the ratchet wheels k by means
of cams m³ mounted upon the shafts m*.
In Witness whereof I the said William Robert Lake have hereunto set my
hand and seal this second day of February in the year of Our Lord one
thousand eight hundred and eighty four.
W DORDT TAKE hel