Improvements in Type-writers.
Year: 1890

page_text: Date of Application, 2nd Apr., 1890-Accepted, 3rd Jan., 1891
COMPLETE SPECIFICATION.
Improvements in Type-writers.
HUGH BERTRAM Cox, of 15 Barton Street, Westminster, Barrister at law, and JOHN
WILLIAM GORDON, of 2 Queensdown Road, Lower Clapton, Gentleman, 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 :-
Our first improvement relates to the mechanism used in typewriters for shifting the
Our object is to
paper carriage between the operations of printing successive letters.
cause the paper carriage to move through the exact distance required for the accurate
spacing of the different signs or combinations of signs which the instrument is designed
to print. For this purpose we employ modifications of the common escapement, pawl,
and fly, as hereinafter described and shown. For the better understanding of our
invention it will be convenient to state in general terms what are the mechanical
difficulties that have to he dealt with. The difficulty of securing variable spacing
results from the mechanical difficulty of producing either a rack or a wheel which can
be arrested at a sufficient number of points in its travel or rotation. Teeth can be cut
of such a size as to measure the average distance occupied by a letter; but this plan,
which is commonly adopted, necessitates giving one uniform space upon the paper to
every letter and thus leads to the undue compression of some letters and dispersion
of others.
The effect of our improvements is to provide a sufficient number of intermediate
stopping places, so as to render a rack or wheel having teeth of the average size,
mechanically equivalent to a rack or wheel furnished with teeth indefinitely small.
Our second improvement relates to an improved form of type wheel and type band
and the methods of operating the same.
In the accompanying drawings
Figure 1 Sheet 1 is a diagram of a series of pawls constructed and arranged to
subdivide a tooth space.
Figure 2 Sheet l' shows a modification of Figure 1.
Figure 3 Sheet 1 shows a ratchet wheel fitted with a series of subdividing pawls.
Figure 4 Sheet 1 shows the arrangement shown in Figure 3 with special modifi-
cations.
Figure 5 Sheet 2 shows an escape wheel 'fitted with a series of subdividing
escapements.
Figure 6 Sheet 2 shows a train of wheels controlled by an arm and pallet
Figure 7 Sheet 2 shows a train of wheels terminating in a fly controlled by an arm.
Figure 8 Sheet 3 shows our improved form of type band.
Figure 9 Sheet 3 shows a section of Figure 8 through the line 1-1.
Figure 10 Sheet 2 shows a means of operating the printing mechanism by means
of the type wheel.
Figure 11 Sheet 4 shows a vertial section of our eccentric printing mechanism.
Figure 12 Sheet + shows in detail part of the mechanism of Figure 11.
Figure 13 Sheet 4 shows a plan view of Figure 11, seen from beneath upon the
line 2-2 of Figure 11.
Figure 14 Sheet 5 shows a plan of the stop ring and stops.
Figure 15 Sheet 5 shows our improved spacing mechanism in connection with
a key.
Figure 16 Sheet 6 shows a view of the stop levers and keys.
Figure 17 Sheet 6 shows a plan view seen from below of the same arrangement of
paris.
Figure 18 Sheet 6 is a diagram illustrating our method of shaping the acting faces
of our serial nawls.

page_text: Like letters identify like parts in all the drawings.
Figure 1 Sheet 1 is a diagram in which five pawls of graduated lengths are shown
arranged so as to act serially upon every tooth of a broad escape or ratchet wheel.
Every one of these pawls may in succession arrest the wheel, and the space between
two teeth may thus be divided into as many portions as there are pawls.
Thus the wheel obtains five times the number of stopping places that it would have if
acted upon by only one pawl.
'
In Figure 2 the principle is further developed. Here every such pawl is formed
with a sloped acting face with the object, as hereinafter described, of furnishing the
said wheel with an indefinite number of stopping places intermediate between those
furnished by the pawls shown in Figure 1. The sloped faces acting in succession
maintain a continuous contact between the wheel and the detaining mechanism, that
is to say, the end of the face of a¹ with which the wheel is shown engaged will not be
withdrawn from contact with the tooth, until the upper end of a has come into
position to supply its place. The subdivision of the tooth angle by means of a series
of pawls, enables us to give so slight an inclination relatively to the tooth to each of
these successive faces, that the hold which they take of the wheel is perfectly sure,
and there is no danger of their being driven out of engagement by the pressure of the
tooth upon them. It is assumed throughout the following description that the form
of the acting faces of these pawls is determined by taking a centre slightly above the
centre of rotation of the pawl, and describing the arc of a circle from that centre
joining the uppermost and lowermost points of the face of the pawl required. This
method of determining the acting face of the pawls is illustrated at Figure 18
Sheet 6.
Figures 1 and 2 are mere diagrams, in Figure 3 Sheet 1 we show how the principles
thus illustrated may be applied in a practical form.
In Figure 3 Sheet 1 A is a ratchet wheel, a', a³, a³, a* are detaining pawls arranged
in series and pivoted up a stationary plate B. The arrangement of these pawls in
series is such, that when as, for example, has just slipped over the point of a tooth,
a will be occupying a position intermediate between two teeth, and behind the
foremost of them at about one fourth of the distance which separates them; at the
same time a² will occupy an intermediate position midway between two other teeth,
while a will occupy a position between two other teeth, and behind the foremost of
them at about three fourths of the distance which separates them. These pawls are
cut, as shown, with sloped faces so shaped as to allow of a travel of the wheel A
while in contact with any such face through an angle not less than one fourth of the
angle between the points of two successive teeth.
C is a sector capable of angular motion about the arbor D. E is a toothed sector
which is rigidly attached to the sector C so as to move with it; a, a, a², as are
actuating pawls also arranged in series and pivoted upon the sector (. a, a, are
springs for holding the detaining pawls in contact with the wheel. Similar springs,
(not shown in the drawing), are fitted to the actuating pawls. The action of these
parts is as follows. The sector C is first moved into its starting position by means of
a rack engaging as shown in Figure 4 with the toothed sector E. The pawls a, a,
a', as are thereby drawn back over the ratchet wheel A, which is kept from moving
back with them by means of one or other of the detaining pawls a¹, a², a³, a². The
serial arrangement of the actuating pawls a, a, a, a, secures that whatever be the
position of the ratchet wheel A one or other of these actuating pawls must be in
position to drive it when the sector C is driven forward in the direction indicated by
the arrow. Thus the ratchet wheel is caused to rotate, and in so doing it passes over
the non acting faces of the detaining pawls a', a², a, a. It follows similarly from the
serial arrangement of these detaining pawls which has been already described, that in
whatever position the ratchet wheel A comes to rest, one or possibly more than one of
these pawls will be in a position to hold it there without allowing any appreciable
backlash. Thus the ratchet wheel A can be arrested at any point or driven through
any angle that may be desired. Such a wheel by reason of its freedom from back-
lash and the facility with which it can be moved through any desired angle and

page_text: arrested at any desired point, is peculiarly adapted to control the movement of the
paper carriage of a typewriter when it is desired to produce correct spacing of the
various signs printed. By way of illustration we will describe its use as applied to
the cylindrical paper carriage described and shown in our Specification No. 5948
of 1889.
Figure 4 shows this application. In this drawing the sector E is shown in contact
with a rack e which, on the depression of a key, is moved forward against the
pressure of a spring, (not shown in the drawing), the exact distance which corresponds
to the space required by the sign which the said key causes to be printed. The
release of the key permits the return of the rack and the sector, and consequently
the wheel A is driven forward through a corresponding angle. The wheel A being
fixed upon the square bar, in our said former Specification called the bar B, which
passes through the paper carrying cylinder, will give to the cylinder an angular
motion equal to its own.
To facilitate the mounting of the sectors C and E upon the said square bar, a
collare is interposed between the bar and the said sectors, as shown, which said collar
is squared upon its inner and cylindrical upon its outer surface.
In many typewriters the paper carriage is moved forward under the impulse of an
independent spring or other motive power, and in such a case the action of the key
is to release an escape wheel or rack or an equivalent device. The application of our
method of dividing the tooth angle to such a case as this is illustrated at Figure 5,
Sheet 2. In this figure C is a sector carrying actuating pawls a, a, a, a as in
Figure 3 Sheet 1. The detaining pawls a', a', as are to be understood to be pivoted
as in Figures 3 and 4 of Sheet 1 on a plate B, not shown in this figure, it being
supposed to have been removed to display the parts shown. It will be observed that
the parts in Figure 5 are viewed from the opposite side to that from which Figures 3
and 4 are viewed. These pawls act in this case upon the serrated edge of a metal
ring, hereinafter called the "cam ring" which is carried upon a centre, (not shown in
the drawing), about the shaft D. Within this ring, as shown, is a series of escape-
ments H¹, H³, H³. These escapements are pivoted upon the plate B. The interior
surface of the cam ring G is shaped to such a contour that its rotation by reason of
the pressure which it exerts upon the bearing studs h¹, hi², h³, h*, h², he will cause the
escapements to engage successively with the teeth of the escape wheel A. The internal
contour of the ring & shown in the drawing is determined in the following manner.
A circle g¹ is first drawn in which the points of all the studs h¹, h³, h³, h, h³, h° will
lie if the escapements H1, H2, H3 are so disposed that their studs are all equidistant
from a common centre. This circle is then divided into quadrants, and each quadrant
is subdivided into six approximately equal parts. Referring to one of these quadrants
which is shown between the dotted lines gag x as an example, the first subdivision gl
is a segment being one twenty fourth part of the original circle. The second sub-
division g' which lies next adjacent to the subdivision g¹ and above it, projects
inwards towards the centre of the circle to such a distance as will hereinafter be
defined. The third subdivision g' brings back the curve to the original circle g', in
which circle the fourth subdivision g¹ wholly lies. The fifth subdivision g' projects
outward from the circle to a point which will also be hereinafter defined. The sixth
subdivision g brings back the figure to the circle gl at the starting point of the next
quadrant, in which this whole preceding figure is repeated. It is the last sub-
division 9 which is the important part of the curve upon which the form of the whole
mainly depends. Its operation will be easily understood by supposing the cam ring G
to be moved through an angle of about fifteen degrees in the direction shown by the
arrow. The stud would then be pressed down from the position shown in the
drawing to the level of the circle g¹. The depression of this stud will cause
the pallet to move out of engagement with the escape wheel A and the two
studs h3, h4 having both then reached the circle g¹, the further revolution of the cam
ring G through a similar angle will cause no additional movement of the escapement H³
but both its pallets will stand clear of the escape wheel A in the position occupied in

page_text: the drawing by the escapements Hand H³. It is assumed that in the present instance
it is desired that the motion of the escape wheel A across the face of the pallet ³
shall be sensibly uniform and therefore the curve is drawn of such a shape as to
produce this result. An approximation to this shape sufficiently close to serve the
present purpose may be obtained by joining the two points which the segment 9 has
in common with the segments 9 and g¹ respectively by means of the arc of a circle
having the same radius as the segment g'. The convexity of this curve is somewhat
exaggerated in the drawing. Should any other than uniform motion of the escape
wheel be desired the curve must be modified accordingly. The highest point of the
curve 9 must be at such a level as will allow the paliet is to engage at its full working
depth with the escape wheel A. Similarly the lowest point of the curve 9² must be
placed at such a level, that by its action on the stud hit will drive the pallet ³ into
this position. The curves g¹ have been already defined. Their action upon the studs
is merely to hold the escapement out of contact with the escape wheel. The contour
of g², g and g need not be particularly described. They only satisfy the condition of
permitting the cam ring G to glide over the studs ³, and of the escapements with
the least possible friction, since the movement of the escape wheel is in no way
affected by the motion which they give to the escapement. The point at which the
subdivisions and g³ meet, must project inward from the circle g¹ to such a
distance that the passage of one stud over this point forces the opposite_stud h³
into the lowest point of the recess formed by the subdivisions g* and 9. Each of
the remaining quadrants having been planned out in the manner above described, the
interior of the entire ring G is cut to the shape thus delineated. The three
escapements H1, H2, H3 are arranged within the cam ring G in such a manner that
the rotation of the cam ring causes them to act one after the other upon the escape
wheel as follows. In the position shown in Figure 5 Sheet 2, the pallet h' has just
cleared the escape wheel, the pallet 8 is engaged at its full working depth and is
just about to commence its rise as the cam ring rotates. The pallet his standing
clear, but will by the same rotation of the cam ring be forced into a position of
engagement. The continued rotation of the cam ring will cause the pallet h³ to
move out of engagement, and the pallet 10 to move into engagement; and if rotation
be further continued the pallets hand will in their turn he caused to operate in
the same way. Thus the turning of the cam ring through an angle of 90 degrees
will cause all six pallets to act in succession upon the escape wheel. The distance of
these pallets from the pivots of their respective escapements are so varied as to form
in themselves a series analogous to the series of pawls already described, and operating
like them to subdivide the tooth angle, which in this case is so subdivided into six
parts. The acting faces of the pallets are shaped upon the principle already laid
down in the description of the slope faced pawls in Figure 4, so as to subtend this
subdivided angle and produce a gliding motion of the escape wheel instead of the
dropping motion with which an escape wheel ordinarily rotates. Consequently it will
be seen that whenever the cam ring G is moved through any angle, the escape wheel A
will move through a corresponding angle. In the actual case described the
angular motion of the escape wheel will be one ninth of the angular motion of the
cam ring. It will of course be understood than our invention is not confined to
the proportions actually shown and described, but that both the number of escapements
used, and the number of times that the cam figure is repeated on the interior contour
of the cam ring G, may be indefinitely varied.
Figure 6 Sheet 2 shows an illustration of the second method whereby we secure
a sufficient number of stopping places in the travel of a rack or wheel to provide-
accurate spacing of the different signs or combinations of signs which a typewriter
may be designed to print. This method, we call the method of multiplication, the
distinguishing feature of this methed as compared with the method already described,
being the use of an ordinary train of wheels and pinions controlled by special devices.
Figure 6 Sheet 2 shows such a train of wheels controlled by an arm and pallet. In
this figure. I shows the wheel the travel of which it is desired to control, which is

page_text: mounted upon the arbor i¹ and which can be driven by a weight or spring or by any
convenient means. If it is desired to control the travel of a rack, the rack may be
made to gear with the wheel I. The wheel I by means of a pinion drives the wheel i
which by means of another pinion drives the wheel, which last wheel in this case is
shown as the escape wheel, though any convenient length of train may be used. The
escape wheel and the wheel I travel in the direction shown by the arrows. Upon
the arbor of the wheel I is placed, as shown, an arm. This arm is not fixed
rigidly upon the said arbor but grips it by means of a friction clutch, as shown, in
such a manner that when the arbor rotates the arm it is carried round with it while
nevertheless the arm can be independently moved round the arbor i. The arm
carries at one end a pallet suitably shaped to catch and hold the escape wheel ³.
When the said pallet is so engaged with the wheel, the wheel and the rest of the
train are prevented from rotation. If however the arm is lifted, and the pallet
disengaged from the wheel, the train will be free to travel intil the arm (which
by means of the friction clutch will be carried round with the arbor i¹), has once more
reached the wheel 3, when the pallet will reengage with the said wheel and the
further travel of the train will be arrested. It is obvious that the time of travel of
the train and the angular distance through which the wheel I will rotate depends on
the distance to which the pallet on the arm is raised relatively to the escape
wheel, and the consequent length of travel permitted to the train before the said
pallet reengages with the escape wheel in the manner described. It is also clear
that by raising the pallet to varying distances from the escape wheel 3, a corre
sponding variable angular travel can be secured for the wheel I. The action of these
parts when applied to a typewriter is as follows.
Depression of a key upon the keyboard is caused by means of the mechanism
hereinafter shown at Figure 15 Sheet, or by any convenient means, to lift the pallet i*
to such a height, that before it reengages with the escape wheel 3, the paper carriage
the travel of which is controlled by the wheel I, will have moved forward the exact
distance which is required to space the sign or signs which the said key prints. If the
raising of the arm and pallet is synchronous with the printing of the letter, the
wheel may be held as hereinafter shown and described, or by any convenient
means, until the printing operation is completed, when the train is allowed to travel
and the paper carriage accordingly moves on until the train is brought to rest by the
reengagement of the pallet with the escape wheel ³.
An alternative method of mounting the arm is to place it on an independent
pivot. The distance which the train will run when released by the withdrawal of the
pallet will then depend upon the time which is allowed to elapse before the return of
the pallet to its position of engagement. This may be regulated in various ways, for
instance, it may be left to the control of the operator, or to the automatic action of
gravity or of any other calculable force. It is for some purposes desirable to allow
the train to run through a relatively long distance. In order to provide for this the
following modification of the parts is shown at Figure 7 Sheet 2. A pinion is added
to the train and placed upon an arbor i which carries the radial arms. These arms.
may be flattened to serve the purpose of a fly for preventing the mischievous
effects of excessive speed. They have moreover the advantage of additional lightness
as compared with a toothed wheel.
Our second improvement consists in a new and improved form of type wheel, for use
in that class of typewriters in which the printing letters are placed upon the circum-
ference of a wheel or segment of a wheel, which is rotated in order to bring the
requisite type to the point at which its impression is to be delivered. The object of
our said improvement is to enable the said wheel, although rotated at any required
speed, to be instantly arrested at any given point so as to enable the desired impression
of the type to bo given, and as soon as that impression has been given, to be again
rotated without any delay so as to bring the next letter which it is required to print
opposite to the printing point.
For this purpose we mount upon a spindle La metal wheel shown at Figure 9
Sheet 3, this wheel, (hereinafter termed "the type wheel"), may be either rigidly

page_text: fixed to the said spindle Las shown at Figure 9, or may be connected with it as shown
at Figure 10 Sheet 2, or at Figure 11 Sheet 4. This type wheel l may if desired
for purposes of lightness be made with a hollow interior as in Figure 9. Round it and
fitting closely to its shape is placed a rim or band M of thin metal hereinafter called
the type band" so adjusted as to be carried round with the wheel when the said
wheel is rotating, while it slips round the surface of the wheel when arrested during
the rotation of the said wheel. This type band M is shown in plan at Figure 8
Sheet 3. On its edge at any convenient point is fixed a cam or projection m¹. The
type band M is used for the purpose of carrying upon its outer surface the letters or
signs to be printed such letters or signs being fixed at the ends of shanks or rods m²
projecting from the exterior surface of the said band as shown, or otherwise as for
example upon the edge of a flange projecting from the type band.
The action of these parts is as follows. Rotation being given to the spindle I, and
type wheel by any convenient means, the type band is carried round with the said type
wheel by reason of the friction between their surfaces. When it is desired to deliver
an impression, the depression of a key upon the keyboard causes a stop of any
suitable kind to project into the path taken by the cam m¹ on the type band M at any
desired point in the course of its revolution. The type band M is thus held by the
stop while the type wheel continues to revolve. The friction between the surfaces
of the type band and type wheel thereupon keeps the cam firmly pressed against the
stop and prevents the recoil of the type band, while the said stop prevents its further
revolution and the type band is thus arrested at any given point for the purpose of
stopping the required letter opposite the printing point. The paper can then by any
suitable means be projected against the type, or the type band itself may as herein-
after described and shown at Figuros 11, 12, 13, on Sheet 4, be caused to project
against the paper. As soon as the said impression has been thus delivered, the stop
can be released by the return of the key or otherwise as desired, and the cam m
being thus freed from the stop, the type band M is carried round in the manner
already described by the revolving type wheel, and resumes its rotation to be again
arrested when and where desired as hereinbefore described.
Figure 10 Sheet 2 shows an arrangement of parts by which the stopping of the
type band M may be caused automatically to set in motion any required mechanism
for impelling the paper against the type, or for setting in motion any other mechanism
which is required to operate at the moment when the letter about to print has arrived
opposite the printing point. In this Figure L is the spindle hereinbefore described
carrying the type wheel, which may be cone shaped, as shown, for the purpose of
receiving the type band M. This wheel is not made fast to the spindle L but is
attached to a sleeve which embraces the spindle L but is prevented from falling by
means of a slot in the sleeve through which passes a projection * fixed on
the side of the spindle. Fixed at one end to the under surface of the wheel and at the
other to the projection 1, is a coiled spring which keeps the sleeve and the wheel
in their most advanced position upon the spindle L. For convenience in placing
the sleeve upon the spindle, the slot 13 may if required, be carried up to the top of the
sleeve and spindle shouldered, or the projection carried up to serve as a shoulder
in order to support the cone upon the spindle. If this is done the projection should
be duplicated so as to support the cone on both sides. The upper sleeve is thus free
to rotate upon the spindle through a small angle but cannot move vertically. The
lower edge of this sleeve is helically shaped as shown and exactly fits the upper
zurface of another sleeve / which embraces the spindle L and the lower surface of
which sleeve rests upon a ring 18 which also embraces the spindle. On opposite
sides of the sleeve are cut vertical slots 17 in which fits a pin driven through
the spindle L. The sleeve is therefore carried round with the spindle L when it
rotates and is at the same time free to move vertically. On to the ring is hinged
a rod 10 as shown. This rod 10 forms the end of a lever the other end of which
may by any suitable means be made to actuate or release the mechanism by which
the paper is brought into contact with the type.
The action of the above described mechanism is as follows. When the spindle L

page_text: is revolving, the wheel and type band M are carried round with it by means of the
spring. When however the type band is arrested for the purpose of printing, the
friction between its inner surface and the surface of the wheel 1, tends to arrest
the motion of the said wheel, and the sleeve slips round upon the spindle until the
projection is brought to the forward end of the slot P. This motion of the upper
sleeve causes its lower edge to travel over the upper edge of the lower sleeve l which
has travelled round with the spindle. This relative motion of the two sleeves causes
a depression of the lower sleeve which in its turn depresses the ring 18 and the
lever 10. When the type band is released the spring immediately returns the
upper sleeve and wheel to their original positions.
For
Figure 11 Sheet 4 shows the spindle L furnished with a plate N for carrying the
wheel which, as hereinafter described, is made capable of assuming an eccentric
position relatively to the spindle L. For this purpose it is pivoted upon the pin n¹
which projects from the plate N at a point situated, as shown, at some little distance
from the centre of the plate N. The bearing is made, as shown, longer than the
mere thickness of the metal of the wheel in order to obviate any tendency
which there might otherwise be in the wheel /¹ tilt out of its truly horizontal
position when acted upon by external forces such as the shock of the type on the
paper in printing, or the pull of the type band on its edge when slipping.
the purpose of this long bearing the wheel is fitted with a small tube n² as shown.
Whenever the type band M is arrested by a stop and caused to slip backwards upon
the rotating wheel 1, the friction between them will exact a retarding force upon the
wheel and cause it to slip backward over the plate N, if free so to move; in that
case it must rotate about the pin n' and thus take up an eccentric position relatively
to the plate N and spindle L. The extent of this motion is limited by the pin n
which is attached to the underside of the wheel and passes through a slot n in the
plate N as shown.
For the purpose of returning the wheel to a position in which it will be concentric
with the spindle L, the plate N is provided on its under side with a lever n³. This is
a lever of the third order having its fulcrum at n³. The other end operates on the
back of the pin n³, and serves by this means to restore the wheel to its place. The
power is applied to it at the point n by means of the cam n against which it presses.
An anti-friction roller shown in Figure 13 is placed at this point n° to facilitate the
travelling of the lever over the cam. The lever is curved as shown in Figure 13, to
accommodate the figure of the cam n. The cum n' does not revolve but is fixed, as
shown, and serves as a bearing for the spindle L. Hence the revolution of the lever no
about the cam n causes the lever n³ to receive an impulse similar to that which it
would receive if it were stationary, and the cam revolved in the opposite direction.
This impulse transmitted by the lever to the pin n³ serves to restore the wheel to its
concentric position at the instant when the anti-friction roller is passing the point of
the cam.
As soon as this point has been passed, the wheel is free to take up an
eccentric position and if at that instant the type band is dragging upon the said wheel
it will do so, and carry the type band M with it. The cam therefore should be so
disposed with respect to the printing point, that the resulting stroke of the type band
will be in the direction of the paper to be printed upon.
To secure precision in this stroke and to prevent any movement of the type across
the face of the paper at the moment of impact or withdrawal, the type band M is
furnished with a ring m³ provided with serrations upon its outer edge. The ring m³
is made of such a breadth as to extend nearly to the same distance from the type
band M as the ends of the shanks m³ which carry the type. A pad m* of india rubber
or other suitable tissue is interposed between the surface of the paper and the ring m³.
The thickness of this pad is so adjusted that the ring m² will press upon it before the
type reaches the paper, and by its contact will prevent any such rubbing movement of
the type upon the paper as is above referred to.
Figure 14 Sheet 5 shows an arrangement of parts whereby the type band M can be
arrested at any required point by means of stops projected into the path of the cam m¹
which is fixed upon it.

page_text: In this figure shows a ring of metal surrounding the type band M which is
indicated by dotted lines. This ring O is screwed into the table of the type writer.
The interior surface is cut into a serrated or ratchet form as shown. Into these
serrations are fitted in such a manner as to be capable of vertical but of no other
motion, thin plates of metal o' which we call the stops, and which are so arranged as
to lie clear of the path taken by the cami m' upon the revolving type band M previously
described, so that they do not interfere with the cam in its revolutions. The plates or
stops o¹ are connected by any suitable means with the keys upon the keyboard, in
such a manner that the depression of a key raises from its position of rest the stop o'
to which the said key corresponds, so that the said stop when so raised, projects into
the path taken by the cam upon the type band and the cam when it comes round is
arrested by the stop which has been so raised,-the blow of the type band being by
and through the stop o¹ transmitted to and borne by the serrated ring 0. Each of
the stops o' must correspond in size to the breadth of the sign or combination of signs
which, when interposed in the path of the cam m³, it arrests opposite the printing
point. The ring O may be provided with as many serrations as there are stops, but
we consider it more advantageous to arrange the stops in groups as shown in
Figure 17 and to place one such group in each of the said serrations of the ring O.
This enables us to use coarser serrations which are better able to resist the blow of
the cam m of the type band M. It will be observed that the ring O shown in the
figure, is designed to operate with a type band carrying upon its outer edge a larger
number of signs than are shown in the Figures 8 and 13.
Figure 15 Sheet 5 shows a method by which the depression of a key upon the key-
board may be caused to actuate and control the spacing mechanism. K shows a key
placed at the end of an ordinary key lever k¹. Through this lever passes an adjustable
screw the end of which when the key is depressed impinges upon a lever ³ moving
about the centre k. The lever k³ is fixed to a shaft, not shown in the drawing, to
which the armis ko, ke, are also attached. The arm serves under pressure of the
spring to hold the lever ³, (which may be made to extend along the whole length
of the keyboard so as to be actuated by any key that may be struck), in the position
of rest against the underside of an abutment ks, the upper side of which may be used
to form an abutment for arresting the descent of the lever k¹. Upon the depression
of the key K, the lever and arm k will be correspondingly depressed through a
distance determined by the adjustment of the screw upon the particular key lever
selected. By means of the link k the setting lever 410 is caused to strike the arm i
and thus to raise the detent the required distance. In order to prevent the
premature movement of the train the descent of the link is caused to raise a pad
on a brake lever so as to hold the escape wheel during the depression of the setting
lever 10. The brake lever k¹ has an elastic arm so as to yield to the pressure of the
link . Upon the release of the key the setting lever 10 is lifted out of the way of
the arm and by the same motion of the link the pad k is withdrawn from the
escape wheel and the train allowed to travel through the required distance.
It will therefore be seen that the arm and the pad k constitute the two arins or
pallets of an escapement for the purpose of controlling the escape wheel and allowing
it the required motion. The adjusting screw and levers and k¹ and link ko may
be used to operate the rack e' in Figure 4 Sheet 1 if those methods of spacing are
employed. In such a case the depression of the key may be caused to draw back the
rack e against the pressure of a spring, the wheel A being held meanwhile by the
detaining pawls a¹-a and on the release of the key the spring will drive forward
the rack e and turn the wheel A, (which may be made by any convenient means to
gear with the paper carriage), the correct distance required by the particular letter
or combination of letters which the key causes to be printed.
Figures 16 and 17 on Sheet 6 show, upon a smaller scale than the preceding
figures, a means whereby the stops o' in Figure 14 may be lifted by the key K upou
the keyboard, so as to arrest the type band M shown at Figure 8 Sheet 3 by means
of the cam m¹. In this figure the letters KK show two keys, k¹, k¹ two key
levers, k³, k³ two other levers depressed by screws as described, and shown

page_text: at Figure 15 Sheet 5. O shows the serrated ring previously described, o' the stops
raised by the depression of the keys upon the keyboard into the path of the cam m¹
upon the revolving type band. p², p², p³, are rods of wood or metal fastened by
springs p to the underside of the table of the typewriter in which the serrated ring
is fixed. At the end of the said rods which is opposite to the springs p, is fixed one
of the stops o' which upon the raising of the rod will be lifted against the pressure of
the spring into the path of the cam m³. In Figure 17 the ring O and stops o¹ and
rods ppp are shown as viewed from beneath. p p show thin plates of metal,
of which is fastened to the underside of the rod p³ as shown at Figure 17,
and overlaps the rod p', while the plate p' is fastened to the rod p and overlaps the
rod p. If the rod p¹ is raised it will raise the stop o' to which it is fixed into the
position required in order to arrest and will arrest the type band by means of
the cam m², the shock of impact being transmitted to the back of the serration in the
ring O against which the stop o' will rest if raised. If the rod p* be raised it will, by
means of the plate p, lift also the rod pl, and similarly if the rod p³ be raised it will,
by means of the plates p and p*, raise both the rods p¹ and p³ with it. By this
means the stop which is fixed to the rod p³ and receives the blow of the type band,
will always have the stop which is fixed to the end of the rod p¹ to form an abutment
between it and the end of the serration in which it rises; and similarly, the stop at
the end of the rod p will always have the stops at the ends of the rods p' and p² to
forio abutments, between it and the end of the said serration.
The action of these parts is as follows. Depression of a key lifts the rod p² p³ or p³
to which the key corresponds, by means of a key lever k¹ or ³, which may be curved
as shown by the dotted lines at Figure 17 or of any suitable shape so as to correspond
to the curve of the ring O. The lever k¹ or then by means of the links " raises
the rod pl por 3, as the case may be, to which the key corresponds, into the position
required to arrest the type band. On the release of the key the said rods return to
their position of rest below the level of the path taken by the cam m¹ upon the
type band.
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: :―
1. In a typewriter, the combination of a toothed wheel with a series or with more
than one series of pawls having their acting faces so sloped as to maintain a continuous
contact between the wheel and the detaining mechanism, or between the wheel and
the driving mechanism, or between the wheel and both the detaining and driving
mechanisms as the case may be, the said pawls being arranged about the said wheel
so as to engage with it at different points in its rotation within the limit of a single
tooth space, for the purpose of subdividing the tooth angle in order to secure the accurate
spacing of various signs or combinations of signs substantially as described and shown.
2. In a typewriter, the combination of a toothed wheel with a number of driving
pawls arranged serially about the wheel so as to subdivide the tooth angle as herein
described and shown, with a similar series of pawls arranged to prevent backlash of
the said wheel, and a sector and rack suitably arranged to move forward the said wheel
by means of such driving pawls, in the manner and for the purposes substantially as
herein described and shown.
3. The combination of parts substantially as shown at Figures 3 and 4 for the
purposes herein described and shown.
toothed wheel with a number of
4. In a typewriter, the combination of a
escapements so arranged about the said wheel as to engage therewith in series in
such a manner as to subdivide the tooth angle thereof, in order to secure the accurate
spacing of various signs or combinations of signs substantially as herein described
and shown.
5. In a type writer, the combination of a toothed wheel with a series of escape-
ments having their acting faces so sloped as to maintain a continuous contact
between the wheel and the detaining mechanism, the said escapements being so
B

page_text: arranged about the said wheel as to engage with it at different points in its rotation
within the limit of a single tooth space for the purpose of subdividing the tooth
angle in order to secure the accurate spacing of various signs or combinations of
signs substantially as herein described and shown.
6. In a typewriter, the combination of a toothed wheel with a number of escape-
ments so arranged in series round the said wheel as to subdivide the tooth space in
the manner hereinbefore described and shown, together with a ring surrounding the
said wheel and having its inner surface so shaped as when rotated to cause the said
escapements to come successively into position to engage with and control the rotation
of the said wheel for the purpose of securing the accurate spacing of various signs or
combinations of signs substantially as herein described and shown.
7. In a typewriter, the combination of a number of escapements arranged to
operate serially upon a toothed wheel in the manner and for the purposes herein
described and shown, with a cam ring arranged to bring the said escapements into
engagement with the said wheel, and a number of driving pawls so arranged as
to engage serially with teeth cut upon the outer edge of the said cam ring, and a
number of detaining pawls similarly arranged to prevent backlash of the said cam
ring, and a sector upon which the said driving pawls are fixed, all substantially as
herein described and shown at Figure 5.
8. In a typewriter, the combination of a train of wheels with an arm constructed
to detain an escape wheel or fly, the said arm being so carried upon the arbor of
one of the wheels of the train as to be turned by the said arbor into its position
of engagement but capable nevertheless of independent motion about the said
arbor for the purpose of liberating the said escape wheel or fly, or being otherwise
so pivoted as to be capable, after having been displaced by suitable mechanism
through a regulated distance, of being restored to engagement with the said escape
wheel or fly by the action of gravity or other calculable force, in order to secure the
accurate spacing of various signs or combinations of signs in the manner substantially
as herein described and shown.
9. The combination of the parts substantially as herein before described and shown
at Figure 6.
10. The combination of the parts substantially as herein before described and shown at
Figure 7.
11. In a typewriter, the combination of a type wheel mounted upon a sleeve with
a spindle connected with the said type wheel by means of a spring so constructed as
to allow of the rotation of the spindle after the stoppage or partial stoppage of the
said type wheel and sleeve, for the purpose of depressing a sleeve or other
mechanism rotating with the said spindle substantially as hereinbefore described
and shown.
12. In a typewriter, the combination of the spindle and the type wheel land
the connecting spring and the sleeves 12 and 18, fitted upon each other as shown, and
the ring as shown and described.
13. In a typewriter, the use of a type carrying wheel having a separate band or
rim upon which are placed the characters to be used in printing, which said band can
be arrested without stopping the wheel, in the manner and for the purposes
substantially as herein described and shown.
14. The combination of the parts constituting the revolving wheel and type band
substantially as described and shown at Figures 8 and 9.
15. In a typewriter, having a type wheel with a separate type band, a type wheel
so pivoted as when the said type band is arrested by means of a suitable stop or
otherwise, to be capable of rotating eccentrically for the purpose of striking in the
direction of the paper carriage in the manner as herein before substantially described
and shown.
16. In a typewriter, having a type wheel fitted with a separate type band and
capable of eccentric motion upon a spindle, the use of a cam actuated lever for the
purpose of controlling the motion of the said wheel, in the manner and for the
purposes substantially as hereinbefore described and shown.

page_text: 17. The combination of the parts substantially as hereinbefore described and shown
at Figures 11 and 13.
18. In a typewriter, the use of a ring with serrations upon its inner edge for the
purpose of affording abutments for moveable stops interposed between the said ring
and a rotating type wheel, the said stops being constructed and arranged to arrest a
separate rim or band carried by the said type wheel in suitable positions for printing
with various signs or combinations of signs, substantially as herein described and
shown.
19. The combination of the parts substantially as hereinbefore described and
shown at Figure 14.
20. The combination of the parts as hereinbefore described and shown at Figure 15.
Dated this 2nd day of April 1890
HUGH BERTRAM COX.
J. W. GORDON.