Improvements in Printing Telegraphs.
Year: 1895

page_text: Date of Application, 5th Nov., 1895-Accepted, 14th Dec., 1895
COMPLETE SPECIFICATION.
Improvements in Printing Telegraphs.
I JAMES YATE JOHNSON, of 47 Lincoln's Inn Fields, in the County of
London Gentleman, do hereby declare the nature of this invention (which has
been communicated to me from abroad by Jonathan Edwards Woodbridge of
Duluth, Minnesota, United States of America, Electrical Engineer) 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 printing telegraphs and more particularly to systems
employing a type wheel having characters arranged on its periphery, and adapted
to be turned to bring any desired character to the printing position.
The general objects of this invention are first to increase the rapidity of
transmission by diminishing the movements necessary, and the time required to
bring the type-wheel to the printing position; and second to simplify greatly the
printing mechanism and other parts of the system.
More specifically the objects sought and results attained (among others) by this
invention are the following
(1) To operate over one wire with currents of uniform duration and uniform
strength, avoiding the uncertainties and complications attending the use of extra
strength and variable length currents.
(2) To avoid the use of synchronism unison devices, and specially constructed
relays.
(3) To give a wide range of characters with a small number of line impulses the
system herein described being capable of printing fifty-four characters with a
maximum of four line impulses per character.
(4) To reduce to a minimum the number and functions of magnets. By this
system the total number of magnets has been reduced to six (exclusive of relay-
magnets).
(5) To furnish a simple and reliable transmitting apparatus.
(6) To furnish a system in which the battery circuits are all normally open
(ie. when the system is in a state of rest) and one which is capable of being
organised and used for differential duplexing.
I will describe herein a system designed to accomplish the foregoing objects and
attended with other advantages as will be hereinafter pointed out.
It has been heretofore proposed, instead of advancing the type-wheel step-by-step
to give it a continuous movement and provide it with a series of stops and with
mechanism for selecting any of the desired stops and for throwing it into position
to arrest the type-wheel. Such systems are, for the most part, very elaborate and
complicated, and involve the use of a large number of circuits aud magnets.
It has also been proposed to employ a series of independent impelling devices,
operated respectively by separate magnets in various possible combinations, for
positively rotating or pushing the type-wheel to any one of its printing positions,
according to the impelling device, or combination of impelling devices which is
thrown into operation. Such system is much simpler than the ordinary step-by-
step or the synchronous mechanism but its use puts considerable work upon the
magnets, and it is necessary after printing each character to restore all parts to
their initial positions before operating a combination for the next character. Other
differences distinguishing this system from the foregoing will be hereafter
pointed out.

page_text: It has also been proposed heretofore to impel the type-wheel by a motor, thrown
into connection with the type-wheel by means of a magnet operated by a line
impulse, and to determine the extent of movement of the type-wheel by a series of
interacting stops, each controlled by a magnet adapted to be operated by a line
impulse. In the system here referred to, the type-wheel after each printing stroke,
with all the displaced parts of the arresting mechanism, had to be restored to zero
by a reverse movement of the wheel shaft.
Three main circuits were required to work the various releasing, arresting and
restoring mechanisms and extra strength currents were also utilized in the operation
of the system.
The present invention cambraces a printing-wheel whose point of arrest, after
release, is determined by a combination of stops (preferably three in number) each
controlled by an impulse from the transmitting station, and mechanism for operating
the stops singly and in combination so that the type wheel can be arrested at any
one of its printing positions. The operating magnets therefore have only to fix the
position of a stop which finally arrests the type wheel instead of impelling the
shaft of the type-wheel. The latter can be connected by a frictional or slip
connection with any constantly running motor, so that it is very sensitive and
prompt in action. Another gain in time is effected by reason of the fact that as
soon as one printing stroke is made, or indeed while it is being made, the com-
bination of stops for the next character can be set up. The wheel thus rotates
constantly in one direction and not only is the time saved which is usually consumed
in restoring it to the starting point, but all unison or retracting mechanism is
dispensed with. This non-restoring type-wheel is one of the important and
distinguishing features of the present invention.
The capacities or ranges of action of the shiftable stops are represented by the
powers of three instead of by the terms of the series of two, as heretofore. In
other words each stop may be regarded as having three possible positions one a
normal or resting position, one a positive current position the third a negative
current position. Thus with one such movable stop a wheel can be arrested (after
being started) at any one of three positions; with two such stops at any one of
nine positions, and with three at any one of twenty seven positions. A fourth stop
and operating mechanism therefore would provide for eighty-one positions; but it
is preferred to use only three stops, and to arrange the type in two lines of 27 each,
thus with suitable shifting mechanism the system provides for fifty-four characters
and requires only a maximum of four impulses for each character, one of which
impulses operates the shiiting magnet, and the other three operate the stop-
magnets. The use of combinations made up of three elements, and of shiftable
stops each having three functional positions, instead of two as heretofore employed,
is an important feature of this invention.
The invention embraces mechanism of a very simple character for producing the
printing stroke, and also improved transmitting mechanism, though obviously any
transmitter capable of sending the positive and negative impulses to line in the
desired combinations could be employed.
The invention further embraces certain other improvements in details and
arrangements of devices and circuits, as will be hereafter explained and specifically
pointed out in the claims at the end of this Specification.
In the accompanying drawings
Figure 1, is a plan view of the receiving mechanism.
Figure 2 is a detail view of part of the operating mechanism for the printing
shaft.
Figures 3, 4 and 5 are elevations respectively of the three stops.
Figure 6 is an end view of the receiving mechanism.
Figures 7 and 8 are respectively a plan and elevation of the transmitting
mechanism.
Figure 9 is a diagrammatic view of the circuit arrangements and the different
elements of the mechanism.

page_text: Figures 10-15 inclusive illustrate certain modifications in the direction of
simplification, but within the principle of the main invention.
Figure 10 being a diagram illustrating a modified arrangement of apparatus and
circuit connections.
Figure 11 an elevation, partly in section shewing a portion of the key board and
pole-changing mechanism of the transmitter.
Figures 12 and 13 are respectively a plan view and an end elevation of part of
the modified printing and paper-feed mechanism.
Figures 14 and 15 are respectively an end elevation and a side elevation of a
double relay, which may take the place of two relays.
We will first describe the invention with reference to Figures 1-9.
A represents a printing wheel of ordinary construction having type arranged in
two rows. Attached to the printing wheel is a locking-wheel A' having a series
of notches a for purposes hereafter explained, and a collar A'. These parts are all
one piece, and are feathered on the shaft B so as to turn therewith, and also to be
capable of movement lengthwise thereof to bring either of the rows of type into
the printing position.
As shewn the right hand row is in the printing position and in the drawings all
the parts are shewn in their usual or normal position.
On the shaft B is a pulley b6 loose thereon but connected with a disc b¹ fast
thereon through a helical spring c.
Pulley b is driven by a cord e adapted to slip thereon when the spring acquires
a certain tension. Any other suitable driving mechanism may be used, but that
illustrated causes the type-wheel to start promptly, when released and to turn
quickly until arrested. The shift of the type-wheel is effected by a shift-magnet M
whose armature lever m is forked at the end, and carries pins engaging in a groove
in a collar A2, the construction being common and well known for the purpose
here in view.
MMM³ represent the three stop magnets which are shewn as electro-magnetically
polarized magnets. The armature lever m' of the first stop magnet is connected
(in the same manner as described above for armature lever m) with a sliding hub
or collar d also feathered on shaft B.
Collard carries the first of the stop arms D', and the shaft B ends just beyond
this arm, from which point an independent shaft B' extends in the same line. On
this shaft B is fixed the movable stop E¹ having three arms 1. 2. 3 (see Figure 3)
each with an angular finger (ff, f) on its extremity. It will be observed that
these fingers are in different vertical planes. Arm Di as shewn is resting against
and is arrested by finger f¹ the armature lever m¹ being in its intermediate position.
If the armature be attracted to the right, the arm D will move to the left out of
the path of finger f¹ and rotate until it encounters finger f³. A corresponding
movement in the opposite direction will bring the stop armm D' into the path of
the finger f. These three fingers or stops are arranged 120° apart, and by means
of this first of the series of stop mechanism, it is plain that by either a positive
impulse, a negative impulse, or no impulse at all the type-wheel inay be made to
assume one of three definite positions.
The other two of the series of stop-mechanisms are similar in construction and
operation to the first, differing only in the arrangement of the stop fingers.
Magnet M2 controls a stop-arm D, identical with the arm D', and capable of
assuming any one of three positions. Fingers ggg (see Figure 4) of the stop E
are in different vertical planes, and their angular positions with reference to the
shaft are such that they divide the arc between any two fingers f, f', (i.e. un
arc of 120°) into three equal parts. Stop. E is also fixed on a shaft B which
begins where shaft B¹ ends.
i
The third stop mechanism has the three fingers h¹³ of stop E³ (see Figure 5)
a distance of th of a circumference apart. Stop Es which is the last or final
stop, and fixes the ultimate point of arrest of the type-wheel is not carried by a
movable shaft like stops E E* but is fixed to a stationary support.

page_text: The action of the stop mechanism as a whole will now be readily understood.
For the purpose of explanation we will assume that positive impulses throw the
armatures to the right, and negative impulses to the left: The first impulse of any
combination operates the shift-magnet M. If this be a positive impulse there
would be no shift in the position shewn in Figure 1, since the armature is already
attracted to the right hand pole of the magnet: But this first impulse (whether
positive or negative) starts the commutator which successively brings the stop-
magnets into circuit with a generator as will presently be explained. Consequently
at the second impulse the circuit of the magnet M¹ is closed. If this impulse be
positive the arm D' shifts to the left; escapes from the finger, and shaft B rotates
i wo thirds of a revolution. If the desired character happens to be just eighteen
divisions from the starting point there will be no further impulses in the particular
:ombination transmitted, and consequently the second and third stop mechanisms
will not be operated. In like manner a negative impulse through magnet M¹ will
permit the type-wheel to rotate one third of a revolution and arrest it at the end
of nine divisions.
If the desired character be not at one of the three positions controlled by the
first stop mechanism, one or both of the other mechanisms must be called into
operation.
Thus, if the next impulse be positive (the circuit of the magnet M' being then
closed) the arm D2 will shift to the left, the shaft B' will be free to turn, and the
shaft B will turn as far as permitted by the first stop-mechanism and ths of a
revolution farther. If the third impulse be negative the additional movement of
the shaft B and type-wheel will be th of a revolution.
In like manner the third stop-mechanism may allow a further revolution of th
or ths of a revolution; and by a single or combined action of the several
mechanisms the wheel can be turned to any desired oue of 27th angular positions,
the magnets having no work to do except to shift the stops.
Conversely stated, for the shortest movements (one step or two) the stop-
magnet Malone is actuated, there being no impulses at the time when the
magnets M2, Mi are in circuit.
For movements of greater range (4 to 9) the magnet M' alone, or the
magnets M and M³ are actuated. For movements of the greatest range the
magnet Malone, or in combination with one or both the other magnets is
actuated.
The mechanism for giving the printing stroke is also of very simple construction.
The printing magnet M' is brought into circuit, as will be presently explained, just
after the four impulses comprising a signal have passed over the line. Armature m*
of this magnet throws the movable member of an ordinary clutch into engage-
ment with the relatively stationary member k' the latter being carried by a shaft k*
which also carries a constantly rotating pulley n driven from any suitable motor.
Member of the clutch is feathered on the printing shaft F which therefore
immediately begins to rotate. On this shaft is a disc G having an annular cam
surface G (see Figure 2) cut away or grooved at j. In this groove a projection i
on the armature lever m' rests when the parts are in their normal position, but as
soon as the shaft F begins to revolve the cam G' engages this projection keeping
the two parts of the clutch together, so that, although the circuit of the magnet M
is immediately opened, the printing shaft makes one complete revolution it being
arrested when the groovej once more comes opposite the projection i and the
armature lever can be retracted by its spring H.
N represents the printing lever, pivoted at N₁ and carrying the strap N' (see
Figures 1 and 6) which bears on an eccentric N' on the shaft F so that at each
revolution of the shaft F the printing lever is vibrated positively in both 'directions.
Lever N carries a wedge shaped point or tooth n which at its upward movement,
enters one of the 27 notches in the locking wheel A heretofore referred to, both
momentarily arresting the type-wheel and also bringing it accurately to the printing
position. Lever Nalso carries a printing pad 'n over which passes a strip of

page_text: paper n which passes between feed rolls N' No. The latter has a ratchet wheel n³
worked by a pawl n* ou the printing lever N and a detent no is provided to engage
the said ratchet wheel. The type wheels may be inked by a brush nº.
Obviously the printing and paper-feed mechanism can be of any suitable
description.
Shaft F is also utilized to bring the armatures of the stop-magnets to their
normal or intermediate position ready to be properly operated by the next impulse
which passes through the magnets. To this end the extremity of each armature
lever (m', m³, m) lies between the faces of two cams O O¹on shaft F. Normally
(as shewn in the drawings) the end of each lever is between the curved faces of the
cams where the groove or space between them is widest, and hence is free to move
in either direction. When an armature has been shifted the curved face of one of
the cams rotates it gradually to its normal position as the cam is rotated with
shaft F.
It will be observed that as soon as the tooth n releases the type-wheel (which it
detains only for a small fraction of a second) the latter is free to continue its
movement to the next resting point, and that in the meantime the stops may be set
or be in process of being set, for the next character, there being no need of
restoring the type-wheel to its initial position between successive printing opera-
tions, as in most systems. After a message has been printed the type-wheel will
simply continue to rotate until it reaches its initial point, since all the stops will in
that case return to their normal positions shewn in Figure 1.
To fully understand the operation of the receiving mechanism it is necessary to
refer to Figure 9 in which the circuit arrangements and the different elements of
the mechanism are illustrated diagrammatically.
The circuits of the shift magnet M and the stop magnets M¹ M' M³ are controlled.
by an ordinary revolving switch arms (operated by clockwork or otherwise) which
makes contact successively with the four contact plates 10, 11, 12, and 13 of a
commutator.
These magnets are in multiple arc branches of a local battery L B the
magnet M being connected with commutator plate 10, the magnet M³ with plate 11,
the magnet M2 with plate 12, and the magnet M³ with plate 13. The arbor p³ of
the switch arms also carries an escapement wheel p, a second switch arm s¹ and a
pinion q. The main line L passes through the polarized relays R RI, which may
be of ordinary construction, and thence to ground. M' represents the polarized
escapement-magnet which operates the escapement lever p' the latter co-operating
with the double-escapement wheel p to permit its shaft to complete one revolution
in eight steps. Magnet M³ is a differential double wound magnet as indicated, the
reason for which will presently appear.
It will be seen that this system requires the use of ouly six magnets in all
(exclusive of relay-magnets) and the work of each is comparatively slight,
permitting the use of a small amount of energy and tending towards certainty and
promptness of action.
Pinion q drives a gear-wheel q' having twice as many teeth as the said pinion,
and whose arbor carries the arm q' of a "three-point" switch. The arm of a
similar switch is carried by the shaft of a gear 9 driven from a pinion q (having
half the number of teeth) on the printing shaft F (see also Figure 1). Printing
magnet M is in the circuit of these switches, which circuit has a local
battery L B
Assuming that R is the positive relay, and that the first impulse of a signal is
positive the following actions will occur. Armature of relay R touches its front
contact 15, and a circuit is made from the positive pole of battery L B by wire 16,
point 15, armature r, wire 17 through one winding of escapement magnet M,
passing from one coil to the other by wire 18; thence by wire 19 to switch arm 8,
commutator plate 10, shift magnet M, and by wire 20 to the battery L.B.
The operation of the shift magnet is understood, but the excitation of the

page_text: escapement magnet M' draws lever to one side releasing the tooth of the outer
rim of the escapement wheel p, into position to engage with the inner teeth of the
Baid double escapement wheel and permitting the latter and shaft p to turn
oue eighth of a revolution. This leaves the switch arm s still on plate 10, but as
the armaturer at once returns to its back contact, a circuit is closed, as presently
described, through the auxiliary battery L B' carrying a current in the opposite
direction through the escapement maguet M, the effect being to vibrate the arm p¹
back to the position to engage with the outer teeth of the escapeinent wheel as
shown in the drawing, the shaft p' turning another step, and carrying the arms over
to plate 11 of the first stop-magnet M'. The circuit of the auxiliary battery above
referred to is as follows: The rotation of shaft p has carried the switch arm s¹
from the dead plate v of the auxiliary commutator to the first live plate ol (and it
will be seen that there are eight of these plates, including the dead plate while the
main commutator has but four). Starting at the back-stop of the positive relay R
the circuit proceeds by the wire 28 to the switch arms s', plate ¹, wires 30 and 31
to the positive pole of the battery L B', bywire 32 to the back stop of the negative
relay R, over armature lever r¹, wire 27 to one winding (represented by the
wire 29) of the differential escapement magnet M³, back through the other
winding 18, to wire 17, and armature lever to the point of beginning. It may be
observed that winding 18 of the magnet M is connected with the positive relay,
and winding 29 with the negative relay; and that when the armatures of both
relays are on the back or resting contacts the current after passing through one of
the windings returns through the other (the currents being in opposite directions in
the reversely wound coils thereby reinforcing each other) and that only when one
relay armature is on its front contact does the local battery L B come into circuit
through one of the stop magnets. The same movement of the escapement wheel
which carried the arms to plate 11, carried the arms to the second line plate v³,
If now no
which is connected to the opposite pole of the auxiliary battery L B³.
main line impulse immediately follows the first, as is the case when the first stop
mechanism in the combination is not to be shifted either to the right or left, the
auxiliary commutator and battery are in position to work the escapement arm, thus
performing the function of a line impulse. That case will be considered presently,
and it will first be assumed that in the combination being transmitted another
impulse immediately follows the first and that its sign is minus.
In such case the negative relay R responds, attracting the lever to front
stop 25. The circuit can then be traced from point 25 by wire 26 to battery LB;
thence by wire 20 through magnet M', by wire 26" to commutator plate 11 through
the switch arms wire 19, winding 29 of escapement magnet M³, wire 27 and
armature lever r¹ to the point of beginning. The current through the escapement
magnet is in this case in the opposite direction to that of the current produced by
the action of relay R, but as the windings 18 and 29 are reversed as already stated,
the effect is the same; namely to draw lever p₁ from engagement with the outer
row of teeth of the wheel p into engagement with the inner row of teeth.
Shaft p thus turns another step bringing the arms into engagement with
plate and the auxiliary battery is brought into operation as before, returning the
lever p¹ and moving the arm s to plate 12. Thus, if the combination consists of
four line impulses, of whatever sign, the escapement arm is actuated in one direction
by currents from the local battery L B and returned by currents from the auxiliary
battery LB until the shaft p2 has completed a revolution.
ן,
The system, however, provides that the omission of impulses shall have a
significance in the code of siguals; in other words the signals are all compounded
of three elements namely (1) positive impulses, (2) negative impulses, (3) no
impulses. When, therefore, in the transmission of a signal the "no impulse
element is used, the auxiliary commutator comes into play to perform the usua
function of a line impulse and work the escapement magnet forward. Wha
actually happens at such time is that there is an extra-long interval between the

page_text: signals, an interval equal to the usual duration of an impulse plus the usual duration
of two breaks. It will be seen that after a line impulse has worked the escapement
arm and the auxiliary commutator has returned it, the switch arm s¹ will be in
contact with one of the plates which are connected with the positive pole
of the auxiliary battery L B while the plates v vv, which send the current
for returning the escapement arm, are all connected with the opposite pole of the
battery. Hence in case no impulse immediately follows the first, the auxiliary
battery L B sends a current through the escapement magnet in a direction
opposite to that whose course was traced above, producing the desired effect.
The auxiliary commutator always tends to perform this function but when
impulse immediately follows impulse over the main line (the breaks being
relatively short, as explained) the current from the auxiliary battery does not act,
since its circuit is broken at one or the other of the relay armatures. In case of
the extra long interval due to the omission of an impulse, the auxiliary battery has
abundant time to reverse itself through the escapeinent magnet and to shift the
switch arms from one plate to the next. In case of two omissions of line impulses
together, the auxiliary commutator will repeat its action. In the case where the
type-wheel is already in the position to print the desired character, the combination
consists of but a single impulse, the other three elements being represented by
blanks, or no impulses. In such case the first impulse, which operates the shift-magnet,
starts the escapement shaft, and the auxiliary commutator works it entirely aroun.l.
Thus the escapement shaft p' makes one complete revolution for each combination,
however composed.
At the end of each revolution the circuit of the printing magnet M* is closed
through its battery L B' through the operation of the three-point switches already
referred to. We will now describe their operation. Arm has two contact
strips 36, 37, and arm q' has two similar strips 38, 39. Contacts 36 and 38 are
connected by the wire 40, and strips 37 and 29 are connected by the wire 41.
A wire 35 connects one pole of battery L B' to the arm q3 and another wire 42
connects through magnet M' the other pole of the battery to arm q. In the
position shown in Figure 9 the circuit of battery L B₁ is open. When, however,
the pinion has made a complete revolution with the shaft p³, arm gỗ, turning in
the direction of the arrow, will have made a semi-revolution, and come into contact
with the strip 37. This completes a circuit as follows:-From the negative pole
of the battery L B¹ current passes by wire 35 to arm q³ to strip 37; thence by
wire 41, strip 39, arm q* and wire 42 through magnet M back to battery L Bi.
The printing shaft now operates as above described, and in doing so it turns the
arm q one-half a revolution into contact with the strip 38 which is now out of
circuit by virtue of the fact that its companion strip 36 is no longer in contact with
the arm . When the arm q makes another semi-revolution, which it does when
the next signal has passed over the line, it again touches the strip 36 closing the
circuit of printing magnet M which is immediately broken again by the move-
ment of the printing shaft F. Thus the switch arms of the two three-point
switches operate in alternation, one to close the circuit of the printing-magnet at
cach rotation of the escapement shaft and the other to break the circuit at each
rotation of the printing shaft.
For producing the required combinations of impulses a simple form of trans-
mitting apparatus, illustrated in Figures 7 and 8 and by diagram in Figure 9 is
provided. This transmitter is of the key-board type, and by its operation, the
depression of any of the keys has the effect of sending to line from the main
battery M B a particular combination of impulses corresponding to the character
which such key represents. For this purpose an ordinary commutator, comprising
a switch arm S and four plates or segments 50, 51, 52, 53 are provided. These
plates are respectively connected with the four plates 60, 61, 62, 63 of a pole-
changing apparatus while the switch arm S is connected to line L. Adjacent
to these plates are two conducting bars 54, 55, the former connects with the

page_text: positive pole of battery M B and the latter with its negative pole. while a
wire 56 runs from the middle of the battery to ground. Between the bars 54, 55,
is an insulating strip 57. Each contact plate has a movable contact-inaker,
designated respectively 70, 71, 72, 73 these being the real pole-changers. Their
contact points normally bear on the insulating strip 57, when no current goes to
line. If a pole-changer is moved up, a positive current goes to line through
the corresponding commutator segment, if down, a negative current.
will be perceived that to properly operate the transmitter it is only necessary that
the depression of a key should operate the proper combination of pole-changers
and cause the switch arm S to make one revolution.
Thus it
The shaft of the switch arm S, carries a pulley S' (Fig. 8) driven by a constantly
running cord which engages it with light friction. The arm is normally held from
rotation by a stop lever 65 engaging a finger 66 connected with the switch arm.
This lever 65 has a cross-bar 67 extending under all the key-levers, U so that the
depression of any key releases the switch arm permitting it to make one revolution.
sending to line a combination of four-elements, the character of which depends on
the positions of the four pole-changers.
The actuating mechanism for the pole-changers will be understood by reference
to Figures 7 and 8. Each key lever U carries two uprights U U each of which
has projections w for operating the pole-changers. It will be understood that the
arrangement of these operating projectious differs for each key. Each of the pole
changers is carried by a tilting frame T, T', T2, T3. These frames are pivoted on
shafts t and have each two parallel horizontal cross-bars t' t2 extending across the
apparatus so as to be in the range of all the operating projections 10. The
explanation of the action of one key will suffice for all. The key shown in
elevation in Figure 8 is supposed to have been last depressed and returned by its
spring. In this action the projections w¹ has depressed frame T carrying pole
changer 70 which controls the first line impulse, which is to actuate the shift-
magnet M. Hence the first impulse is negative. Frame T¹ has been tilted in the
opposite direction by projection to sending a positive impulse to line through the
commutator strip 51. Frames T2 T3 have not been tilted at all, the positions of
the projections w³ ³ and wo wo being such as merely to touch the cross-bars of
their respective frames if the latter happen to be in a horizontal position. Hence
no current goes to line, through the pole-changers 72, 73, and therefore the signal
transmitted by this key consists of the elements negative, positive, zero, zero.
The
projections to act as restorers, in case the frames T2 T3 have been shifted by
the preceding key. This obviates the necessity of providing special means for
returning the frame after each key has been struck, since each key positively sets
its combination of pole-changers, in whatever position it may find them.
The key-levers after being depressed and released are at once restored by their
springs y and not detained in their depressed condition until the commutator has
made a complete revolution. Spring restoring mechanism for the pole-changers
being dispensed with and positive setting devices substituted therefor renders it
unnecessary to keep the keys depressed for a definite time, since the pole-changer
will remain wherever placed until shifted by the depression of another key.
The modifications illustrated in Figures 10 to 15 inclusive will
described.
now be
The pole-changer 70 which determines the nature of the first line impulse which
operates the shift magnet M is connected directly with a key U2 which may be
termed the shift key, instead of being connected with and operated by a tilting
frame. When so connected each character key had to be provided with means for
operating the tilting frame of pole changer 70, since an impulse must always
go to line when the switch arm S is on the plate 50. By connecting the pole-
changer 70 directly with a special key, one of the tilting frames and its actuating
devices can be dispensed with leaving only three frames T¹ T' T'.
Moreover the number of keys is reduced to half it not being necessary to provide

page_text: :
a separate key for each character as before. Each key can, by this arrangenient
have two characters assigned to it, the pair of characters being those occupying
corresponding positions in the two rows of type on the type-wheel.
As shown the contact plate of pole-changer 70 normally connects the line
terminal 60 with the plate 54 connected with the positive pole of main battery M B,
so that the first line impulse will be positive. At the receiving end the letters of
the, alphabet with the character "&" may be arranged in one row on type wheel A,
and the figures, punctuating marks and characters less frequently used, in the other.
The first row will be in the printing position when the shift magnet M has
responded to a positive impulse. Hence, in transmitting, the shift key is only used
for characters in the second row of type.
The other pole-changers 71, 72, 73 which respectively control the stop-
magnets M¹ M³ M' normally rest as before on an insulating strip 57 between the
positive and negative terminal plates (54 and 55) of the main battery. The
terminal plates 61, 62, 63 are connected respectively with the commutator
plates 51, 52, 53 and the centre of the main battery is connected to ground, as
before, by a wire 56.
Referring to the apparatus at the receiving end of the line, the shaft B of the
printing wheel A (Figure 12) has a sleeve B¹ loose thereon, and, on the latter is
the pulley b held by frictional contact (due to the pressure of spring c¹) between a
collar and a nut a² on the said sleeve. The pressure of spring c can be adjusted
by the nut a Arm B fast on the sleeve B' is attached at one end to a spiral
spring c which is the driving spring, the other end of the latter being attached to
the shaft B. Pulley 6 is continuously rotated by a cord, as heretofore, keeping
the spring wound up, the pulley slipping against the pressure of its frictional
holding devices when the spring c is at its utmost tension.
Printing shaft F, also carries a constantly driven pulley loose thereon, but
connected with the shaft by the frictional contact of a collar f* and nut f* main-
tained by a spring f* adjustable by means of the nut f. This shaft carries a
finger G which normally engages the hooked end of one branch of the forked
armature m of the printing magnet M*. Obviously, when the armature m* is
in its normal position the pulley f rotates idly, but when the armature is
attracted by its magnet, which occurs as soon as the type wheel has turned to
its printing position, the shaft F is released and makes a complete revolution,
during the first part of which an eccentric n thereon, actuates printing the lever N,
causing the printing roller n' on the end thereof to press the paper against the
type..
Shaft F also carries the finger of a "geneva-stop" mechanism, the notched
wheel P thereof being on a short shaft O' which carries a serrated feed-roller 0².
The paper strip passes, as indicated, between this roller and the companion roller o³,
carried on the end of an arm P². Consequently, during the last part of the
revolution of the shaft F the paper is fed forward one step. During this part of
the revolution also, the finger G makes contact with the other branch mⓇ of the
forked armature, restoring it positively, but it may be restored by a spring m.
The double-relay, which is to take the place of the two relays, has the two main
line coils R R' and the magnetizing coil R2. At one end of the coils R R' is the
positive armaturer and at the other end the negative armature r'.
These armatures are biased in opposite directions. Each armature is between
pole pieces which are extensions of the cores of the line coils R R and each
is magnetized by a polar projection or of the core of the magnetizing coil.
The armatures are separately pivotted so as to act independently, this being the
chief structural difference between this relay and the Wheatstone relay. Obviously
this relay will perform all the functions of two Wheatstone or other polarized
relays in a system such as described, or in other systems where two relays are
required. The connections may be reversed coil R³ being the line coil and R R¹
the magnetizing coils.

page_text: .
Referring to the diagram, Fig. 10 the principal change is in the construction
of the main and auxiliary commutators.
The main commutator which controls the circuits of the shift magnet M, and
stop magnets M M M through the local battery L B, has eight contact plates,
instead of four, and the auxiliary commutator has sixteen plates instead of eight.
For each character the switch arms ss' of the main and auxiliary commutators
make half a revolution, the contact. plates of each being duplicated, or composed
of two series, the corresponding plates of each series being electrically connected
as shown.
Thus the plate 1 of the main commutator is connected by a wire to
the plate 10 both being in the circuit of the shift magnet M, plate 11 is connected
to the plate 11 and both to stop magnet M¹, and so on. Escapement magnet M
and its mechanism is the same as before in construction and operation. This
magnet, through the lever pl and escapement wheel p, permits a step-by-step
movement, in a well known manner, to the shaft p', on which the switch arms s s¹
are mounted. Switch arms of the auxiliary commutator normally rests on the
plate v, but at the first movement of the shaft it passes to the plate v¹ which as
heretofore sends a current from a local battery LB through the escapement
magnet M, reversing the movement of the lever p₁ permitting the shaft p³ to
move another step. It will be observed that the plate and every alternate
plate (and so on) until we reach the plate directly opposite the starting
plate v, are connected together and to a wire 28 leading to the back stop of the.
armature r, while the plates and so on arc connected in like manner to the
wire 26 lending to the back stop of armature r'. Switch arm s' is itself connected
by a wire 50 to one pole of the battery L B¹.
Hence the circuit, when the switch arm is on the plate v', is from battery L B'
by the wire 50 to switch arm s¹, to plate v¹, wire 28, armaturer wire 17 through
magnet M³, to the other pole of the battery L B'. The only new feature in the
commutator is the use of the plate v (heretofore a dead plate having no electrical
. connection) and its companion plate for controlling the circuit of the printing-
magnet M. As shown the plate v is connected by wire 40 to one terminal 38 of a
three-point switch, and wire 41 leads to the other terminal 39, the moveable arm q*
thereof being controlled as heretofore by the printing shaft. One of the three
point switches is thus dispensed with." Arm is, as shown, resting upon
terminal 39, and the circuit of the printing magnet M is consequently open until
the arms reaches plate v, which will occur when the arms has reached the
plate 10 setting all the stop magnets. At this time the circuit of the magnet M
is closed through local battery L B', as is obvious from the diagram.
The printing shaft then rotates, performing the operations heretofore described,
and also transferring the arm q' to the terminal 38, so that the circuit of the
magnet M will again be closed when the arm & reaches the resting plate t.
Battery LB' is thus used both to operate the printing magnet M¹ and also to
energize the escapement magnet M' to throw back the lever p' and to work it
forward in the absence of a line impulse.
The foregoing description has set forth with minuteness the details of a system
embodying the principles of the invention; but it must be understood that this is
done ouly for the purpose of explaining fully the manner in which the invention
may be carried into effect and not with the object of giving undue importance to
details which may be varied and modified within wide limits. The invention
involves certain features which are believed to be broadly new, and therefore it is
designed to cover them broadly.
For example, no type-wheel system has heretofore been devised, as far as I am
aware, in which the combinations representing different characters of the code are
made up of three elements. All similar systems heretofore have utilized only
the powers of two elements represented by positive and negative impulses. The
use of controlling mechanism for the printing devices, each having three
functional positions is also believed to be new. This feature of the invention can

page_text: be applied, by one skilled in the art, to mechanism widely different from that
described herein.
...f.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In a telegraph system, and in combination with suitable receiving apparatus
adapted to respond to signals compounded of three impulses, represented by
positive impulses, negative impulses, and no-impulses, a transmitting apparatus
comprising a generator, a series of pole-changers and mechanism for shifting each
pole changer, to connect either pole of the generator to line, or to leave the line
open, thus sending to line signals compounded of positive impulses, negative impulses,
and no impulses, as set forth.
2. The combination with the telegraphic receiving apparatus adapted to respond
to signals compounded of three elements, as specified, of a transmitter comprising a
commutator, pole-changers, one for each commutator plate and adapted to assume
any of three positions, a generator, and circuits and connections whereby a pole
changer in one position connects the positive pole of the generator to its
commutator plate, in the second position connects the negative pole with said
plate, and in the third disconnects the said generator and plate, substantially as
described.
3. The combination in a telegraphic transmitter, of the commutator, the pole
changers, one for each commutator plate, carried each by a moveable support, and
key levers having actuating devices, different for each lever, for positively setting
all the pole-changers from whatever position normal or otherwise they may be in
substantially as described.
4. In a telegraph receiver, the combination with signal-receiving devices
including a shaft and means for rotating the same always in one direction, of a
series of interlocking stop mechanisms whereby the point of arrest of the said
shaft is determined, the said stop-mechanism comprising arms rotatable in the
direction of rotation of the said shaft, and electro-magnets controlling the several
stop-mechanisms, substantially as described.
5. In a telegraph receiver, the combination with a non-restoring type-wheel and
means for rotating the same in one direction only, of stop-mechanism comprising
a series of interlocking arms, carried each by rotatable supports, and electro-
magnetic controlling devices, whereby the stops can be shifted axially to arrest the
said shaft at any desired point, substantially as described.
6. In a telegraph receiver, the combination with a shaft and means for rotating
the same, of a series of interlocking and independently movable stops, having
each three functional positions, and electro-magnetic mechanisms, whereby the
stops are independently controlled, substantially as described.
7. The combination with the type-wheel and means for rotating the same, of a
series of stop mechanisms, each comprising three stop-fingers in different planes
and carried by a rotatable support, an engaging arm on an independent support
and an electro-magnet and connections for shifting the arm to one position when
influenced by a positive current, and to another when influenced by a negative
current, said arm occupying a third position when the magnet is not excited,
substantially as described.
8. The combination with the printing wheel, having two rows of type, and the
motor for rotating the same always in one direction, of the shift magnet for shifting
the printing wheel lengthwise of its shaft, and a series of interlocking stop-
mechanisms, having each a controlling magnet, whereby the point of arrest of the
wheel is determined, substantially as described.
9. The combination with the printing-wheel, and motor, of a series of interlocking
stop-mechanisms, for determining the arrest of the wheel, each stop mechanism
being actuated by a lever connected with the armature of a maguet, a printing

page_text: :
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shafty printing mechanism actuated thereby, and restoring devices for the said
armature levers actuated from the said printing shaft, substantially as described."
10. The combination with the type-wheel, a series of magnets controlling stop-
1"
mechanism, therefor, a commutator for bringing the stop-magnets successively. into
circuit with
a divided local battery, an auxiliary battery, a differentially. wound
escapement magnet having two similar reversely wound coils in circuit respectively
with the two parts of the said local battery, both of tlie said coils being Serially
connected in the circuit of the said auxiliary battery, relays in the main line.
responding respectively to positive and negative impulses and controlling the circuit
connections of the said local battery, and an auxiliary commutator in circuit with
the said auxiliary battery, substantially as described.
11. The combination with the type-wheel, a series of stop-magnets, mechanism
controlled thereby for determining the range of movement of said wheel, a
commutator to the plates of which the said magnets are respectively' connected,
a printing magnet and mechanism controlled thereby, a switch operated by the
: commutator shaft to close the circuit of the printing magnet when the said
cominutator has completed a revolution, and a second switch operated by the said
printing shaft to break the said circuit when the said shaft has completed' a
revolution, substantially as described.
12. In the transmitter, the combination of the commutator; the series of pole-
changers, the key-levers, one of the said pole-changers being connected directly
with a key-lever, and actuating devices for the other levers, different for each key-
lever, for setting the other pole-changers, substantially as described.
13. The double relay, comprising two main line coils having polar projections,
at each end, and two armatures at opposite ends of the said coils, pivoted' and
movable independently of each other and a magnet for polarizing the said armatures,
substantially as described.
14. The combination with the printing shaft, and the type-wheel of a constantly
driven pulley having a frictional connection with the said shaft, an armature
normally holding the said shaft stationary; a printing lever and paper-feed
mechanism actuated by the rotation of the said shaft, substantially as described.
15. The combination with the type-wheel, the printing shaft and means for
rotating the printing shaft, of paper-feed mechanism comprising a geneva-stop, the
finger being actuated by the said shaft, and the notched-wheel being connected
with the paper feed rolls, substantially as described.
16. In a telegraph receiver, the combination of the distributing commutator
controlling the circuit of a local battery, and having two series of contact plates,
escapement mechanism for actuating the switch-arm of the commutator, an auxiliary
commutator having two series of contact plates connected in circuit with the
escapement magnet, and two resting plates, a printing magnet, and a three-point
switch having its stationary terminals connected' respectively with the said resting
plates, and its movable part with the said printing magnet, substantially as
described.
Dated this 5th day of November 1895.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.