An Improved Adding Machine.
Year: 1892

page_text: Date of Application, 9th June, 1892
Complete Specification Left, 7th Mar., 1893-Accepted, 2nd June, 1893
PROVISIONAL SPECIFICATION.
An Improved Adding Machine.
I, DAVID LINDSAY COUPER SWAN, of Carron, in the County of Stirling, N.B.
Clerk, do hereby declare the nature of this invention to be as follows:-
The object of my invention is to sum up columns of figures or numbers, in an
improved manner and by means of improved apparatus. My improved apparatus
is applicable to numbers which represent values of any kind.
In carrying out my invention, propose to show the answer or result by means
of a series of fixed dials and moveable pointers, somewhat similar to that used on
an ordinary gas meter, or otherwise I may use an engine counter.
According to one modification, I propose to actuate the pointers by means of a
series of levers or keys-placed so as to suit one or both hands-and numbered
from one to ten in such a manner, that on striking say key three, the pointer will
show that number on the index dial, and on thereafter striking say key two, the
pointer will stand at five, on thereafter striking key eight, the second or tenths
pointer will stand at ten, and the unit pointer at three, on their respective dials,
and so on.
The pointers and the wheels may be so constructed that they will be
brought to 0. or zero at the commencement of each operation of addition, by a
touch of the finger of the person operating the machine.
The pointers may be actuated in the following manner :-
The spindle upon which the pointer of the unit dial is mounted projects beyond
the back plate of the index, and has keyed upon it a ratchet wheel. Close to the
ratchet wheel is a pinion which can run loose upon the spindle when turned in the
one direction, but when made to rotate in the other, it carries with it the ratchet
wheel by means of a pawl, thus turning the pointer of the unit dial a definite
distance; the pointers for the other dials moving proportionately. In order to
actuate the pinion a large wheel is geared into it. By turning the large wheel in
one direction through a certain definite distance the pinion on the unit dial spindle
is made to rotate a whole or a part of a revolution, and to carry with it the unit
pointer; but when moved in the opposite direction, it merely makes the pinion to
rotate on the spindle. The wheel is made to have a varying amount of travel by
means of the aforesaid series of levers, marked from one to ten, and they are so
designed as to move the wheel through varying distances, with as nearly as possible
an equal pressure upon each. As before stated the unit spindle projects through
the back plate of the index and has upon it a ratchet wheel or other device to act
as a brake when the pointer has made the requisite travel. A little further from
the back plate is the other ratchet wheel previously referred to. The remaining
projecting part of the spindle carries a tube having at the end next the ratchet
wheel, a ratchet box and pawls which act upon same.
65
To more particularly show how the apparatus works, I shall describe how
figure one is shown on the index, and how the pointer is stopped at the correct
place.
Underneath the ten levers there is an arm working about a centre on one side of
the levers, and attached on the other side to the previously described large wheel.
The levers pressing on this arm turn the wheel. Beneath the key levers are
another series of ten levers placed at right angles to them. The lever which is
being actuated presses down the arm thus turning the wheel, the pinion, the ratchet
wheels and the pointer. Simultaneously therewith the lever which is being
depressed pushes down one end and up the other of the lever which is at right
angles to it, in this manner raising a barrier against the further motion of the
pointer when it has made the required travel. The operators finger being then

page_text: removed, the whole of the parts brought into action again spring back to their
original positions with the exception of the pointer: which remains where it was
placed.
The appliance for determining the limit of travel of the pointer consists
essentially of a tube upon which are a series of stops pitched equally in the
direction of the axis, and arranged spirally round its circumference, one stop for
each key. Should it be found necessary I may employ springs, or other means to
equalize the power required to actuate the keys.
Dated this 6th day of June 1892.
GEO. C. DOUGLAS & Co.,
41, Reform Street, Dundee, Agents for Applicant.
COMPLETE SPECIFICATION.
An Improved Adding Machine.
I DAVID LINDSAY COUPER SWAN of Carron in the County of Stirling N.B.
Clerk, 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 :-
The object of my invention is to sum up columns of figures or numbers in an
improved manner by means of improved apparatus. My improved apparatus is
applicable to numbers which represent values of any kind.
In carrying out my invention I propose to shew the answer or result by means
of a series of fixed dials & moveable pointers, somewhat similar to that used in an
ordinary gas meter, or otherwise I may use an engine counter.
According to one modification I propose to actuate the pointers by means of a
series of levers or keys-placed so as to suit one or both hands—& numbered from
one to ten in such a manner, that on striking say key three, the pointer will shew
that number on the index dial, & on thereafter striking say key two, the pointer
will stand at five, on thereafter striking key eight, the second or tenths pointer will
stand at ten, & the unit pointer at three, on their respective dials, & so on.
pointers & the wheels may be so constructed that they will be brought to 0 or zero
at the commencement of each operation of addition by a touch of the finger of the
person operating the machine.
The pointer may be actuated in the following manner :-
The
The spindle upon which the pointer of the unit dial is mounted projects beyond
the back plate of the index & has keyed or otherwise fitted upon it a ratchet wheel.
Close to the ratchet wheel is a pinion which when turned in one direction carries
with it the ratchet wheel by means of a pawl thus turning the unit pointer a
definite distance. When the pinion is turned in the opposite direction the pawl
rides over the ratchet wheel. In order to actuate the pinion a large wheel or
segment rack is geared into it. By turning the rack the pinion is set in motion as
above described. The rack is made to have a varying amount of travel by means
of the aforesaid series of levers & they are so designed as to move the rack through
varying distances with as nearly as possible an equal pressure on each. As before
stated the unit spindle projects through the back plate of the index & has upon it
another ratchet wheel or other device to act as a brake when the pointer has made
the requisite travel. A little further from the backplate is the other ratchet wheel
previously referred to.
65
To more particularly shew how the apparatus works I shall describe how
figure one is shewn on the index & how the pointer is stopped at the correct
place.
Underneath the levers there is an arm working about a centre on one side of the
levers & attached on the other side to the previously described rack. Anyone of
the levers pressing on this arm turns the wheel. Beneath the key levers are
another series of 10 levers placed at right angles to them. The lever which is
1

page_text: being actuated presses down the arm, thus turning the wheel, the pinion, the
ratchet wheels & the pointer. Simultaneously therewith the key lever which is
being depressed pushes down one end & up the other end of the under lever which
is at right angles to it in this manner raising a barrier against the further motion
of the pointer when it has made the required travel. The operators finger being
then removed the whole of the parts brought into action again spring back to
their original positions with the exception of the pointer which remains where it
was placed.
The appliance for determining the limit of travel of the pointer_consists
essentially of a spindle (being a continuation of the line of the unit spindle) upon
which is a series of ten stops pitched equally in the direction of the axis, &
arranged spirally round its circumference, one stop for each key.
being actuated presses down the arm, tous turning the wheel, the pion, the
ratchet wheels & the pointer. Simultaneously therewith the key lever which is
being depressed pushes down one end & up the other end of the under lever which
is at right angles to it in this manner raising a barrier against the further motion
of the pointer when it has made the required travel. The operators finger being
then removed the whole of the parts brought into action again spring back to
their original positions with the exception of the pointer which remains where it
was placed.
The appliance for determining the limit of travel of the pointer consists
essentially of a spindle (being a continuation of the line of the unit spindle) upon
which is a series of ten stops pitched equally in the direction of the axis, &
arranged spirally round its circumference, one stop for each key.
DRAWINGS.
In order that my invention may be properly understood & readily carried into
effect I shall now describe the drawings hereunto annexed :-
Drawing Sheet I Figure 1 is a side section shewing index & spiral range of
stoppers & parts connected therewith.
Drawing Sheet I Figure 2 is a front view shewing dial & keys.
Drawing Sheet II is a plan shewing upper & under levers driving arm and parts
connected therewith.
Drawing Sheet III is a drawing shewing in section the spiral range of stoppers
& the relation of the stopping levers thereto.
Referring to the whole of these drawings the following letters refer to the same
parts in each drawing. Thus A represents the keys which are to be pressed by
the fingers of the operator. B the levers which when pressed down operate the
index & so turn the pointers. C is the index. D the portion of toothed wheel
gearing into pinion E. FFF are the ends of the ten underlevers shewing
position they occupy in relation to the spirally arranged stopping levers G G G on
the spindle H H.
On referring to Sheet II & to Sheet I Figure 2 it will be seen that the driving
arm K has been so shaped & cut away that while some of the key levers act on
the arm at the commencement of their stroke, others only act during a portion of
their stroke. In this way the strokes have been equalized.
Having now fully described & ascertained the nature of my said invention & in
what manner the same is to be performed I declare that what I claim is :-
1. An adding machine with equal or almost equal depression of the keys arrived
at by the system of construction above described & illustrated.
2. A method of determining the limit of travel of the pointer of the index
arrived at by the system of construction above described & illustrated.
Dated this 4th day of March 1893.
D. L. C. SWAN,
Applicant.