Year: 1888

page_text: United States of America, Electrician.
I ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex, M.I.M.E.
do hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:
This invention relates to an electrical type-writer capable of being used either as
a combined transmitter and
an independent electro-mechanical instrument or as
receiver for printing telegraphs.
As an independent electro-mechanical type writer, it consists, essentially, of a
mechanically arranged key-board carrying the ordinary letters, characters and
punctuation marks necessary for use in machines of this description.
The depression of any key thereof will mechanically arrest the rotation of a
revolving disk mounted on a shaft which carries the type-wheel with the type-letter
corresponding to such depressed key in the proper position to be imprinted on the
paper by means of certain auxiliary devices described hereinafter; and such depression
at the same instant will effect the closure of a local electrical circuit by means of
which the electro-mechanical printing and letter spacing mechanisms are operated.
When, as before stated, it may be found desirable or necessary to use this instru-
ment in the capacity of a combined transmitter and receiver, it is only necessary to
connect the same electrically with a line circuit by an ordinary lever switch, each key
being so arranged that its depression will cause an imprint of a corresponding type-
letter upon the paper-roll both of the local receiver and of the receiver or receivers
When desirable or necessary to
at the extremity or extremities of the line or lines.

page_text: connect or cut-out either the local receiving instrument or the receiver at the end of
the line, or both at the same time, certain means for accomplishing this result are
provided, as will be more fully explained hereinafter.
The construction and arrangement of the particular parts of this invention are
substantially the same when the instrument is used as a local type-writer, as when
electrically combined with the transmitter for printing-telegraphs, except as when
used as a combined transmitter and receiver for printing-telegraphs, that in the former
instance the key-board is operated mechanically with respect to the type letters and in
the latter it is operated electro-mechanically.
This invention consists, further, in certain details of construction, arrangements
and combinations of parts and electrical connections, all of which will be more fully
described hereinafter.
Referring to the accompanying drawings, which form a component part of this
application
Fig. 1 is a view in side elevation of this improved machinė; the travelling carriage,
its separate platform and the paper feeding machine all being removed to more clearly
illustrate the essential parts of construction.
Fig. 2. is a top plan view of the type-wheel; the escapement disc; the front
guide-rest of the platform for the travelling carriage; the ink-reservoir and the key-
board.
Fig. 3 is a detail inverted plan view of the escapement disc in which one stop is
employed for two key-levers and type-letters.
Fig. 4 is a similar view in which one stop is employed for each and every key-lever
and type-letter.
Like numbers and letters of reference indicate like or corresponding parts in all the
several views of the drawings.
Before entering into a detailed description of the construction and operation of this
invention, it is proper to here state that the major portion of the construction illustrated
and described hereinafter, is shown and described in the separate concurrent applica-
tion, filed August 21st 1888 No. 12063, which contemplates the use of these
several parts and organizations in connection with a suitable separate transmitting
instrument.
Therefore, it must be understood that the object of this application is to present an
improvement over the apparatus shown in the aforesaid pending application, by
utilizing the same parts with some changes in addition, as a combined transmitting
and receiving instrument in one organized machine. Consequently, those parts which
are described and claimed in the other application, will be claimed herein only as
co-operating to produce the result sought to be attained thereby.
"
And, furthermore, it will be hereinafter understood that this invention will be first
described as a combined transmitting and receiving instrument, respectively at two
extremities of a line circuit; and, moreover, it will be again understood that a complete
instrument such as is shown in fig. 1 is provided at each extremity of the line circuit ;
or, in other words, this figure can be made to represent two stations connected by a
line wire.
Referring to the drawings by numbers :-
1 designates the key-board, which consists of a series of pivotted metallic key-
levers 2, 2, having curved forward portions 3, 3, carrying the keys 4, 4, which latter
bear the symbols of the key-board; and the rear extremities 5, 5, of said key-
levers 2, 2, are all of the same length, and are each provided at their extreme ends
with enlarged weighted portions 6, 6, having the upwardly extending studs or
lugs 7, 7. (See Fig. 1.)
At the junction of the front and rear portions and 5, of each key-lever 2, 2, is
formed a perforation through which is inserted the pivot-rod 8, which acts as the
fulcrum point or support of all the said key-levers.
9, represents a casting, two of which are screwed to the supplementary base 11, of
the instrument, as shown in figs. 1 and 2, and serve, respectively, as guide supports
for the key-levers 2, 2, and as bearings for the pivot rod 8, to which latter is

page_text: fulcrummed the series of key-levers, as before stated, and as shown clearly in Fig. 1.
Each casting constitutes a base 10, having an upright portion 12, of sufficient height
to support the pivot-rod 8, the requisite distance above the said base.
In the top edge or face of this portion 12, is formed a longitudinal hole extending
the entire length thereof, for receiving the pivot-rod 8, and sufficient space is provided
between the said pivot-rod and the bottom of the recesses 13 in which they work to
allow a certain play for each lever at its fulcrum-point. Transversely in the top edge
of the portion 12, are formed a series of these last mentioned inclined recesses 13, 13,
which correspond in number to the number of key-levers 2, 2, which latter are each
perforated at their fulcrum-points for receiving the pivot-rod 8, the said key-levers
fitting in and being guided by, the recesses 13, 13, (see Fig. 2) thereby forming an
approximately fan-shaped key-board for the purpose of affording convenience in
manipulation. However, it will be obvious that the key-board might be arranged in
any other desirable or suitable manner without departing from the spirit of this
invention.
The two castings 10, 10, are each of metal and are electrically connected together
by a suitable wire (not shown)..
Directly underneath the key-board, and upon the supplementary base 11, of the
instrument, is secured the guard-plate 16, which extends transversely under the said
key-board and forms a limiting medium for the play of the key-levers, which are, as
shown in. Figs. 1 and 2, provided with the adjusting screws 17, 17, so inserted in the
said key-levers between the keys 4, 4, and fulcrum-points thereof as to enable the
distance that any key-lever can be depressed to be readily adjustable. As before
stated, the rear free extremities of all the key-levers are each provided with an
enlarged portion 6, which serves as a retracting agency after the finger of the operator
has been removed from the key; and each portion 6, is provided with an upwardly-
projecting metallic escapement-pin or detent 7, which is tipped upon its upper surface
with insulation 17"; the sides of each of said detents being left bare (electrically.
exposed) so that the proper electrical contact may be made therewith in the manner
hereinafter explained.
A lip 19, projects from the inner side of the casting 9, and a binding post 18,
provided with a laterally-extending spring contact-plate 20, is screwed down through
the said lip 19, for electrically connecting the two castings with a battery 15, and the
plate 20, is designed to make contact with the pivotted switch lever 21 similarly to
the circuit-closer of the key of a Morse instrument when the machine is used as an
automatic receiver, as will appear subsequently.
A metallic vertical shaft 22, passes centrally through the machine, as shown in
Fig. 1, and is mounted in suitable bearings in the bases 11 and 23, and in the frame-
work of the elevated platform, which supports the travelling carriage (not shown),
Upon the upper extremity of this shaft 22, is secured the type-wheel 24, around the
periphery of which are disposed the letters, symbols or characters necessary for use in
printing, the said letters, symbols and characters being arranged equi-distant from
each other, and leaving at one point upon the periphery of the said type-wheel, a
space 24ª, (see Fig. 2) equal to the distance between two alternate letters, the object
of which will be described hereinafter.
This type-wheel is centrally perforated to receive the screw-threaded end of the
shaft 22, and rests upon and is supported by, the shoulder or collar 25. This type-
wheel is rigidly keyed upon its shaft between the nut 26, and the collar 25.
27 designates a horizontal journal bracket secured to the frame-work of the elevated
platform and provided at one end with the fastening screw 28ª, and at the other
extremity with the pointed screw 29, which latter fits in a diamond socket in the
upper end of the shaft 22 thereby forming the upper journal bearing therefor.
On the shaft 22, is rigidly mounted a thin metallic disc 28, of larger diameter than
the type-wheel, having its under surface studded with a series of spirally disposed.
stops 30, which are so arranged as to have different radial distances from the centre,
no two stops occupying the same distance from the centre i of the disc 28 (see figs. 3

page_text: and 4). Thus it will be understood that while the disc 28, is revolving, should one of
the stops 30, come into contact with any obstruction or obstructions, say for example,
with one of the detents 7, 7, of the key-levers 2, 2, the said obstruction or obstructions
would only lie in the path of that particular stop, since the said stops are spirally
arranged each at a different distance from the centre of the disc.
Each stop 30, is intended to represent one or more type-letters on the periphery of
the type-wheel 24, and each of said stops occupies a certain relative position on the
under surface of the disc 28 with regard to its corresponding type-letter or letters on
the periphery of the type-wheel, as will be clearly explained hereinafter.
In one case, as shown in Fig. 3, each stop represents two letters on the type-
wheel 24; that is to say, any two respective type-letters which are represented by a
single stop 30, are arranged both with relation to each other, and with their corre-
sponding stop 30, on the periphery of the type-wheel. Suppose, for example, the
stop marked
in Fig. 3, is intended to represent two letter-type on the type-wheel,
such as "M" and "N." Now, in order to clearly comprehend the relative construc-
tion of these several parts, it must be first understood that all of the several key-
levers, 2, 2, terminate at their free rear extremities on a line corresponding to a
diameter of the disc 28, or, in other words, the ends of all the key-levers, when
viewed as illustrated in Fig. 1 are approximately in the same vertical plane, or their
longitudinal or basis line of that plane runs approximately diametrically through the
disc 28. Again it will be understood, that inasmuch as the disc 28, whose shaft is
designed to be revolved in unison with the corresponding shaft (not shown) at the
other extremity of the line, is rigidly keyed to the shaft 22, and that the type-wheel
is also similarly keyed to this shaft, the relative positions of the corresponding stops 30,
and the type-letters will be uniformly maintained during the revolution of the shaft ;
and furthermore, it will be apparent that when any one stop meets the detent 7, of
any key-lever, the type-letter, corresponding to such key-lever and stop must be
opposite to the impact-lever 29.
Now in order that these requirements may be fulfilled, the relative arrangement of
the key-levers, stops and letter-type, is as follows:-Take the stop marked g, in Fig. 3,
and designate the same as corresponding to both letters "N" and "M," then in this
instance, there will, of course be two key-levers of the key-board for engaging and
stopping the revolution of this one stop g, one key-lever bearing the letter "N
and
the other "6 M."
And inasmuch as the stop g, is farthest from the centre of the
disc 28, the end of each key-lever marked, respectively, M' and N¹ in Fig. 2 would
be separated from the other a distance equal to the diameter of a circle which has a
radius equal to the distance of the stop g, from the centre i of the disc 28. Conse-
quently, this stop g having been engaged and released by the key-lever marked M'in
Figs. 1 and 2, would not come in contact with the lever marked N₁ in Fig. 2, until it
(the stop) had completed one-half of its revolution i.e. a line such as x, x, (fig. 3)
drawn diametrically across the disc 28, from the stop g, which would intersect the
circle at the point where this stop g, would come into engagement with the key-
lever N¹. By an inspection of Fig. 3, it will be seen that the line x, x, passes
centrally between two stops on the opposite side of the disc 28, the object of which
construction will appear hereinafter.
As shown in Fig. 2, the diametrical line y, y, drawn from the end of the impact
lever 29, through the type-wheel 24, would be at right angles with the horizontal
line,, marking the vertical plane of the ends of the key-levers; and since each
stop 30, must engage each detent 7, of its respective key-lever, no matter on which
side of the disc 28, the engagement takes place, at a point coincident with this
horizontal line 2, 2; and since the particular type-letter on the type-wheel which
corresponds to its stop 30, which is engaged by any key-lever depressed, must be
coincident with the end of the impact-lever 29, at the time its respective stop is
arrested, it will be seen that each type-letter is located on the periphery of the type-
wheel at a point at right angles to its respective stop, provided that the two discs
were in the same horizontal plane, and the type-wheel was bounded by the disc 28,

page_text: as conventionally exemplified in Fig. 2; and inasmuch as each stop 30, of fig. 3,
represents two type-letters on the type-wheel 24, and as any two type-letters repre-
sented by a single lug are diametrically opposite to each other, to accord with the
relative location of the ends of the two key-levers which correspond to these two.
type-letters and one stop, it will be obvious that no other stop 30, on the opposite
side of the disc must be coincident with the horizontal line marking the ends of the
key-levers at the time a stop is engaged by a key-lever. Accordingly such provision.
is made by the construction shown in Fig. 3. However, in practice, it may be
desirable to have a stop 30, for each key-lever and letter-type and to meet such
requirement, the construction of disc shown in Fig. 4, has been devised.
From the foregoing description and accompanying illustrations, it will be clear:
First, that I am able to provide a key-board carrying both upper and lower case,
and a type-wheel having the corresponding type-letters or characters disposed there-
around; and Second, to thereby effect the imprint of both the upper and lower case
with stops equal in number to either one-half or the whole of the key-levers and
type-letters.
Each of the key-levers 2, 2, is made of metal, and, as before stated, is bent up at
its fulcrum point as shown in Fig. 1, the rear portion thereof being in a different
horizontal plane from the front portion, for the obvious purpose of being nearer to
the under-plane of the revolving disc 28, so that the depression of any key will not
necessitate much play or vertical reciprocation of its detent 7, in order that it may
engage an escapement-pin or stop 30, on the disc 28.
The impact-lever 29 is curved or hook shaped, as shown to conform to the size and
to the character and location of the adjacent parts of the instrument. This lever is
pivotally supported at its lower end by the screw 31, which is supported in the frame
or bracket 32. 33, designates a vertical plate which projects up from, and is formed
integral with, the lever 29, and carries the armature 34, of the electro-magnet 35,
which, in turn, is suitably supported opposite to its armature by the frame 32..
36, designates an adjusting screw passing through the vertical plate 37, for limiting the
movement of the impact-lever.
The binding post 18, is connected with one pole of the battery 15, by the wire 38;
and the switch-lever 21 which is adapted to make engagement with the plate 20, of
the binding-post 18, is electrically connected by the wire 39, with the brush 40, which
bears upon the collar 41, of the vertical shaft 22; the said brush 40, being in turn
connected with the electro-magnet 35, by the wire 42; and the electro-magnet 35, is
connected by wires 43 and 45 with the spacing magnets 44. The spacing magnets 44,
of the electro-mechanical step-by-step mechanism for advancing the travelling carriage
at a determinate instant after each imprint is made, is connected by wire 48, with the
electro-magnet 49. which, in turn, is connected with the binding-post 50 by wire 51.
The binding-post 50), is in circuit with the button-switch 52, by wire 53, and with the
switch terminal 54, by wire 55, the other switch terminal 56 being connected with.
the bell 57, by wire 58, and the bell itself is connected to the ground by wire 59.
The lever 60, which is adapted to make contact with the switch terminals 54, and 56,
is in circuit with the line.
Upon the base of the instrument is secured the electro-magnet 49, having its lower.
pole converted and brought up parallel with the side of the magnet helix, over, above,
and in close proximity to its upper pole as shown at fig. 1; and centrally in the
magnetic field, between the said poles of the electro-magnet 49, is designed to revolve
the soft iron armature-disc 61, which is rigidly secured to the shaft 22, by the
collars 62, this construction forming the electro-magnetic unison device for arresting
the revolving central shaft of one instrument at one end of the line simultaneously
with the depression of a key-lever of another separate instrument at a distant part of.
the line as will be clearly explained in the operation.
One of the stops 30, upon the disc 28, is arranged to correspond with the space 24*,
on the periphery of the type-wheel 24, in such a manner that the said space 24ª
will stop opposite to the impact-lever 29, when its corresponding stop 30, comes into.
contact with the upwardly projecting detent 7 of the spacing key 63.

page_text: 64, designates the front guide-rest of the elevated platform of the travelling carriage,
and 65 is a rectangular receptacle located underneath, and supported by, the front
guide-rest 64, and is provided with the lid 66, for gaining access to the conical
receptacle 67, which contains the ink for coating the rollers 68, 68, the said rollers
being in slight contact with the edge of the type-wheel 24.
For the sake of clearness I have shown the automatic electro-magnetic letter-
spacing motor for advancing the travelling carriage (not shown) step-by-step after
each type-impact has been made, together with other non-essential details of con-
struction. But these features will not be further dwelt upon herein, as they form no
essential part of the invention herein claimed.
The spacing magnets 44, being included in the main circuit, must be arranged to
operate the travelling carriage at a determinate instant after the action of the impact-
lever magnet, without impeding the passage of the current, which arrangement can
be effected in a variety of ways, but 1 prefer adjusting the electrical resistance of
the spacing magnets and the tension of the spring of the armature, so that the
mechanical action resulting from the magnetic force of attraction of said spacing
magnets will be subsequent to the action of the impact-lever.
The operation of this invention when used as a combined transmitting and receiving
instrument, is as follows:-
It is to be understood, as before stated, that the apparatus illustrated in Fig. 1, is
duplicated at two distinct and separate stations, and with this understanding, the
operation will now be described.
The instrument being in the condition shown in Fig. 1 with the switch lever 21, and
the button-switch 52, thrown open, and the arm 60, upon the switch-terminal 54, and
the operator desires to convey a message, say for example, the words "Dynamograph
Machine," over the line to a distant station, he successively depresses the keys of the
instrument composing the stipulated message. Now, in order to clearly follow the
operation, we will suppose that the first key depressed is the "D" key. Consequently,
the depression of said key elevates its rear extremity 5, of said key lever until its
detent 7, is in line with the particular stop 30, which corresponds to the letter "D"
on the type-wheel; then the revolving disc 28, will force its stop 30, against the
detent 7, of this lever, thereby stopping said disc with the letter "D" opposite the
impact-lever 29. Now, at the same time that this stop 30, engages and is arrested by
the end of the lever, the circuit is instantaneously closed from the battery 15, wire 38,
binding-post 18, lip 19, casting 9, rear portion 5 of the key-lever, stop 30, shaft 22,
brush 40, wire 42, to the magnet 35, energizing said magnet, and causing the attraction
of its armature 34, and consequently, forcing the rubber tipped end of the impact-
lever against the paper (not shown), and effecting the imprint of the letter "D"
thereupon. Then the same impulse discharged from the battery 15, through the
magnet 35, passes instantaneously through the wires 43, and 45, to the spacing
magnets 44, and energizes the latter and effects the operation of the letter-spacing
mechanism at a determinate instant after the imprint is made upon the paper, said
spacing magnets being of a higher resistance and therefore more sluggish than the
magnets 35. Now the impulse imparted by the depression of the "D" key having
as just described, energized the magnets 44, it will pass through the wire 48, into the
magnets 49, energizing the same and effecting the attraction of the disc 61. But, the
shaft 22, having been previously arrested in its revolution this latter action will be
unnecessary at this station, and the same impulse after energizing the magnet 49, will
traverse the wire 51, binding post 50, wire 55, switch-terminal 54, switch-arm 60,
over the line to the instrument located at the other extremity of the line. Now, it
being understood that Fig. 1 conventionally represents the instrument at the distant
station, the impulse, which has passed over the line, will enter through switch-arm 60,
switch-terminal 54, wire 55, binding-post 50, wire 51, to the magnet 49, energizing
said magnet, and arresting the rotation of shaft 22, at the same instant that the
impulse was imparted at the other end of the line with the letter "D" upon the
type wheel opposite to the impact-lever 29, in the same manner as described with
reference to the first mentioned station. Then the current instantaneously traverses

page_text: wire 48, spacing magnets 44, wires 45 and 43, into magnet 35, energizing said
magnet, and causing the attraction of its armature 34, and the consequent stroke of
the impact-lever 29, thereby effecting another and similar imprint of the letter "D"
upon the paper. Then, the spacing-magnets 44, being constructed as before stated,
to be more sluggish than the magnet 35, the travelling carriage will be advanced onc
letter space at a determinate instant after this imprint is made at such distant
extremity, the impulse passing simultaneously from the magnet 35, through wires 42,
and 39, switch-lever 21, binding-post 18, wire 38, battery 15, to ground, the said
switch-lever 21, being closed at such distant extremity in order that the impulse may
find a closed circuit through the distant instrument.
The operator at such distant extremity of the line is notified to close the switch-
lever 21, by having his switch-arm 60, normally on the switch-terminal 56, of the
bell 57. Thus, when a preliminary impulse is sent from the local station to a
distant extremity, such impulse will ring the bell 57, and thereby notify the
receiving operator to close his switch 21, and to change his switch-arm 60, upon
the switch-terminal 54.
Thus the operation is repeated until the end of the word " Dynamograph" is
reached. The operator now being desirous of making a space between the word
(Dynamograph) completed and the next word (Machine) to be printed he depresses
his spacing key 63 (Fig. 2) thereby causing the stop 30, which corresponds to the
space 24, on the type-wheel, to come into contact with the upwardly projecting
detent 7, upon the said lever 63, thereby stopping the type-wheel with the space 24ª,
opposite the impact-lever 29; the path of the electrical current will now be identical
with that hereinbefore described in connection with the depression of a. letter-key,
and the operation of the several parts will be the same as in that instance, with the
exception, that the impact-lever 29, cannot force the paper against the type, and the
said impact-lever being so adjusted that it can move forward only a sufficient distance
at each stroke to come in contact with the face of the type, it will be seen that it
will not force the paper against the type-wheel, but will simply strike the back thereof
and produce no imprint whatever, while the space will be made in the same manner
as when a letter-key is depressed.
Thus, it will be understood that the operator transmits the desired message over
the line, and at the same time records the said message at both extremities thereof
by means of the instrument shown in Fig. 1. Should it now be desired to use the
instrument locally, it is only necessary to change the switch-arm 60, to the switch-
terminal 56, and close the button-switch 52.
When the travelling carriage reaches the end of a printed line, through the agency
of the electro-mechanical letter-spacing motor, it is automatically returned or run
back to its line starting position and the paper-feeding and line-spacing devices
are instantaneously operated. However, the mechanism for accomplishing these
results, although partly illustrated, will not be described in detail, for reasons above
stated.
Of course it will be understood that the shaft 22, of the instrument, is rotated in
unison with the shaft or shafts of the instrument or instruments at any terminal or
intermediate stations by means of a synchronal motor, which may preferably be of
the construction shown and described in the patent No. 11200, dated August 16th
1887; but any operative unison device may be employed.
As the type-wheel is revolved, it is continually in contact with the ink roller shown
in Fig. 1.
Having now particularly described and ascertained the nature of the said invention
as communicated to me by my foreign correspondent and in what manner the same
is to be performed, I declare that what I claim is :-
1. An electrical type-writer, comprising a circuit-controlling key-board; a current-
conducting revolving stop-disc, controlled by said key-board; a local circuit also
controlled by said key-board; a main line circuit; and switches and connections for
connecting and disconnecting the main and local circuits.

page_text: 2. An electrical type-writer, comprising a circuit-controlling key-board; a current-
conducting revolving stop-disc, controlled by said key-board; a local circuit including
printing mechanism, and also controlled by said key-board; a main line circuit; and
switches and connections for connecting and disconnecting the main and local
circuits.
3. An electrical type-writer, comprising a series of circuit-controlling key-levers;
a current-conducting disc provided with a series of stops, and arranged to be arrested
by the movement of any key-lever; an electric circuit including said key-levers and
disc, and operated also by a movement of any key lever; an electro-magnetic unison
brake also included in said electric circuit; and a revolving armature-disc controlled
by said brake.
4. An electrical type-writer, comprising a circuit-controlling key-board; a current-
conducting revolving stop-disc, controlled by said key-board; a local circuit including
letter-spacing mechanism and also controlled by said key-board; a main line circuit ;
and switches and connections for connecting and disconnecting the main and local
circuits.
5. An electrical type-writer, comprising a series of circuit-controlling key-levers;
a revolving current conducting disc provided with a series of stops and arranged to
be arrested in its rotation by a movement of any key-lever; an electric circuit
including said key-levers and disc; electro-magnetic printing mechanism, substantially
as described, included in, and controlled by said electric circuit; and electro-magnetic
letter-spacing mechanism, substantially as described, also included in said electric
circuit, and arranged to be operated thereby at a determinate instant after the printing
mechanism.
6. An electrical type-writer, comprising a series of circuit-controlling key-levers;
a revolving current-conducting disc provided with a series of stops, and arranged to
be arrested in its rotation by a movement of any key-lever; an electric circuit
including said key-levers and disc, and operated also by a movement of any key-lever;
electro-magnetic printing mechanism, substantially as described, included in and
controlled by said electric circuit; an electro-magnetic unison brake, also included in
and controlled by said electric circuit; a revolving armature disc controlled by said
brake; and electro-magnetic spacing-mechanism, substantially as described, also
included in said electric circuit, and arranged to be operated at a determinate instant
after the operation of the printing mechanism.
7. In a printing telegraph two or more instruments located respectively, at two or
more stations of a line circuit, and each comprising essentially, a series of circuit-
controlling key-levers; a rotary current-conducting disc, and type-wheel upon a
common shaft; an electro-magnetically actuated printing lever; an electro magnetic
unison brake controlling the rotation of said shaft; electro-magnetic spacing-mechanism,
substantially as described; in combination with a line circuit, including said key-
levers, disc, and the actuating electro-magnets of the brake, printing-lever, and spacing
mechanism, and a synchronal motor for revolving the shafts of the respective
instruments.
8. In a printing telegraph, two or more instruments located respectively at two or
more stations of a line circuit and each comprising essentially, a series of circuit-
controlling key-levers, a rotary current-conducting disc and type-wheel upon a
common shaft, an electro-magnetically actuated printing lever, an electro-magnetic
unison brake controlling the rotation of said shaft, electro-magnetic spacing mechanism,
substantially as described; in combination with a line circuit, including said key-
levers, disc, and the actuating electro-magnets of the brake, printing-lever, and
spacing mechanism, a synchronal motor for revolving the shafts of the respective
instruments, switches, annunciators and circuit connections for the line circuit.
9. In a printing telegraph, two instruments located respectively at two stations of a
line circuit, and each comprising a series of circuit-controlling key-levers, a revolving
current-conducting disc provided with a series of stops, whereby it may be arrested
in its rotation by a movement of any key-lever, an electro-magnetic unison brake
controlling the rotation of said stop disc; in combination with a line circuit including

page_text: the said key-levers, stop-disc, and the actuating electro-magnets of said brake, and
switches and circuit connections for said line circuit.
1. In a printing telegraph, two instruments located respectively at two stations of
a line circuit, and each comprising a series of circuit-controlling key-levers, a revolving
current-conducting disc provided with a series of stops and a type-wheel rotating in
fixed relation to each other upon a common shaft, said disc being arrested in its
rotation by a movement of any key-lever, a synchronal motor for said shaft, an electro-
magnetic brake also controlling the rotation of said shaft; in combination with a line
circuit including said key-levers, disc, and the actuating electro-magnets of the said
brake, and switches and circuit connections for the said line circuit.
1000
W. P. THOMPSON & BOULT,
Agents.