IMPROVEMENTS IN OR RELATING TO ELECTRO-MAGNETIC PRINTING TELEGRAPHS
Year: 1883

page_text: LETTERS PATENT to William Phillips Thompson of the firm of W P Thompson
& Boult, Agents for Foreign Patent Solicitors, 6 Lord Street Liverpool in
the county of Lancaster Civil Engineer, for an Invention of "IMPROVEMENTS
IN OR RELATING TO ELECTRO-MAGNETIC PRINTING TELEGRAPHS" a communi-
cation to him from Henry Van Hoevenbergh a person resident at Elizabeth
in the state of New Jersey, United States of America, Electrical Engineer.
PROVISIONAL SPECIFICATION left by the said William Phillips Thompson
at the Office of the Commissioners of Patents on the 28th March 1883.
WILLIAM PHILLIPS THOMPSON of the firm of WP Thompson & Boult Agents
for Foreign Patent Solicitors 6 Lord Street Liverpool in the county of Lancaster
Civil Engineer " IMPROVEMENTS IN OR RELATING TO ELECTRO-MAGNETIC PRINTING
TELEGRAPHS" a communication to me from Henry Van Hoevenbergh a person
resident at Elizabeth in the State of New Jersey United states of America
Electrical Engineer
This invention relates to electro-magnetic printing telegraph systems.
It relates both to transmitting and receiving devices for such systems.
The principal object of the invention is to secure increased rapidity of operation.
To this end the type-wheel is caused to advance normally through consecutive arcs,
each subtending three characters, or in other words so as to skip two characters at
each step. When any one of the characters thus skipped is to be printed, the
wheel is brought to rest upon an adjacent character thereto, and one or other of
two devices is brought into action which mechanically imparts to the wheel a
supplementary movement independently of its shaft, and in the required direction
and extent to bring the desired character into exact position. The impression is
then taken therefrom.
The invention further includes a form of automatic transmitting mechanism for
operating the improved apparatus at the receiving station.
The several consecutive operations by which the printing is effected by the
apparatus at the receiving station, as herein described, may be set forth as
follows:-
First: A type wheel is caused to advance by successive steps, each subtending
three characters or circumferential divisions; secondly, it is arrested in position to
print either the desired character or a character adjacent thereto; thirdly, a further
or independent adjustment of said type wheel is then effected (in case the required
character is not already in position) by imparting a supplementary angular move-
ment thereto, in the direction and to the extent necessary to bring the required
D
037

page_text: character into the proper position for printing; fourthly, an impression is taken of
the character which has thus finally been brought into position.
The object of the third of the above mentioned operations, namely, that of
precisely adjusting the type-wheel, is to render it practicable to use the three-letter
step movement in place of the usual single letter step. The result produced is a
material diminution of a number of independent electric pulsations, and more
particularly of the time required for bringing the type-wheel into position for
printing any required character, and hence with this improved instrument great
speed in the transmission of electro telegraphic communications is attained.
The apparatus by which these results are accomplished may be briefly described
as follows:-
The transmitter:-This instrument may be constructed to be operated manually
or automatically. If it is to be manually operated it is provided with a key-board,
the office of which is twofold; first, to transmit to line by its normal continuous
action a series of alternate positive and negative impulses for causing the
progressive movement of the type-wheel at the receiving station; secondly, to
establish upon the line as required one or another of three electrical conditions,
which are as follows:-First, the condition in which the line is traversed by a
current of a given strength; second, the condition in which the line is traversed
by a current less than said given strength, and third a neutral condition or one in
which no current traverses the line. The keys upon the key-board are accordingly
divided into groups comprising three keys each. The first key of any group
throws the line into the first named condition; the second into the second named
condition, and the third into the third.
For rapid transmission the automatic form of transmitter will be preferred. In-
this instrument the passage of a peculiar form of prepared tape or pattern-strip,
over metallic surfaces and beneath a series of resilient springs, connecting with
the batteries and ground, causes the establishment upon the line of the three
electrical conditions mentioned above.
The receiver. This instrument is provided with a central shaft for carrying the
type-wheel, revolving under the action of a suitable constant force or maintaining
power and controlled by an escapement mechanism. The escapement mechanism
is actuated by a polarized magnetic system, the helices of which are in the main
circuit, and with every escape the type-wheel advances through an arc subtending
three characters.
The main line current also traverses the helices of a relay, the armature lever of
which may be brought to rest in any one of three positions, namely, two extreme
positions, one in each direction, and a central intermediate position. The position
which the armature lever will assume in any case depends upon the condition of
the main line as established by the transmitter, hereinbefore described.
With a
continuous current of definite strength the relay will pause on its front contact-
stop, with a weaker current it will assume the intermediate position, and when no
current is upon the line it will rest against the back stop.
In the intermediate position referred to, this armature lever closes the printing
circuit, and produces the impression upon the tape of the character then in place.
When upon the front stop a local circuit is closed including the printing mechanisın
and an electro-magnetically operated device, through the agency of which the type-
wheel is advanced through an are subtending a single character just before the
impression is taken. In the case of a pause upon the back stop the branch of local
circuit which is closed will include the impression of printing magnet and an
electro-magnetically operated device by which the type-wheel is set back a single
division just before the impression is produced.
Thus while the type-wheel normally advances three characters at a time the
impression of any one of three characters may be taken after it has come to rest.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Phillips Thompson in the Great Seal Patent Office on
the 28th September 1883.
WILLIAM PHILLIPS THOMPSON of the firm of W. P. Thompson and Boult, Agents
for Foreign Patent Solicitors, 6 Lord Street Liverpool in the County of Lancaster
Civil Engineer
"IMPROVEMENTS IN OR RELATING TO ELECTRO-MAGNETIC PRINTING
TELEGRAPHS." A communication to me from Henry Van Hoevenbergh, a person
resident at Elizabeth, in the state of New Jersey, United States of America,
Electrical Engineer.
This invention relates to electro-magnetic printing telegraph systems.
It relates both to transmitting and receiving devices for such systems.
The principal object of the invention is to secure increased rapidity of operation.
To this end the type-wheel is caused to advance normally through consecutive ares,
each subtending three characters, or in other words so as to skip two characters at
each step. When any one of the characters thus skipped is to be printed, the
wheel is brought to rest upon an adjacent character thereto, and one or other of
two devices is brought into action which mechanically imparts to the wheel a
supplementary movement independently of its shaft, and in the required direction
and extent to bring the desired character into exact position. The impression is
then taken therefrom.
The invention further includes a form of automatic transmitting mechanism for
operating the improved apparatus at the receiving station.
The several consecutive operations by which the printing is effected by the
apparatus at the receiving station, as herein described, may be set forth as
follows:-
First: A type-wheel is caused to advance by successive steps, each subtending
three characters or circumferential divisions; secondly, it is arrested in position to
print either the desired character or a character adjacent thereto; thirdly, a further
or independent adjustment of said type-wheel is then effected (in case the required
character is not already in position) by imparting a supplementary angular
movement thereto, in the direction and to the extent necessary to bring the
required character into the proper position for printing; fourthly, an impression is
taken of the character which has thus finally been brought into position.
The object of the third of the above mentioned operations, namely, that of
precisely adjusting the type-wheel, is to render it practicable to use the three-letter
step movement in place of the usual single letter step. The result produced is a
material diminution of a number of independent electric pulsations, and more
particularly of the time required for bringing the type-wheel into position for
printing any required character, and hence with this improved instrument great
speed in the transmission of electro-telegraphic communications is attained.
The apparatus by which these results are accomplished may be briefly described
as follows:
The transmitter.-This instrument may be constructed to be operated manually
or automatically. If it is to be manually operated it is provided with a key-board,
the office of which is two-fold; first, to transmit to line by its normal continuous
action a series of alternate positive and negative impulses for causing the pro-
gressive movement of the type-wheel at the receiving station; secondly, to establish
upon the line as required one or another of three electrical conditions, which are as
follows:-First, the condition in which the line is traversed by a current of a
given strength; second, the condition in which the line is traversed by a current
less than said given strength, and third, a neutral condition or one in which no
current traverses the line. The keys upon the koy board are accordingly divided

page_text: into groups comprising three keys each. The first key of any group throws the
line into the first named condition; the second into the second named condition, and
the third into the third.
For rapid transmission the automatic form of transmitter will be preferred. In
this instrument the passage of a peculiar form of prepared tape or pattern-strip,
over metallic surfaces and beneath a series of resilient springs, connecting with the
batteries and ground, causes the establishment upon the line of the three electrical
conditions mentioned above.
$
Various forms of transmitting apparatus may be devised to execute this work.
Two will be shown hereinafter, one of which may be operated manually, the other
automatically. The latter is the form which it is proposed to claim in detail in the
present application.
The receiver. This instrument is provided with a central shaft for carrying the
type-wheel, revolving under the action of a suitable constant force or maintaining
power and controlled by an escapement mechanism. The escapement mechanism
is actuated by a polarized magnetic system, the helices of which are in the main
circuit, and with every escape the type-wheel advances through an arc subtending
three characters.
The main line current also traverses the helices of a relay, the armature-lever of
which may be brought to rest in any one of three positions, namely, two extreme
positions, one in each direction, and a central intermediate position. The position
which the armature-lever will assume in any case depends upon the condition of
the main line as established by the transmitter, hereinbefore described. With a
continuous current of definite strength the relay will pause on its front contact
stop, with a weaker current it will assume the intermediate position, and when no
current is upon the line it will rest against the back stop.
In the intermediate position referred to, this armature-lever closes the printing
circuit, and produces the impression upon the tape of the character then in place.
When upon the front stop a local circuit is closed including the printing mechanism
and an electro-magnetically operated device, through the agency of which the type-
wheel is advanced through an arc subtending a single character just before the
impression is taken. In the case of a pause upon the back stop, the branch of local
circuit which is closed will include the impression or printing magnet and an
electro-magnetically operated device by which the type-wheel is set back a single
division just before the impression is produced.
Thus while the type-wheel normally advances three characters at a time, the
impression of any one of three characters may be taken after it has come to rest.
The particular subject-matter claimed will be hereinafter specifically designated.
In the accompanying drawings, Fig: 1 is a theoretical diagram designed to
explain the operation of the several parts, which are shown in perspective and so
distributed as not to interfere with each other; Fig. 2 shows in plan a manually
operated transmitter which may be substituted for the form shown in Fig: 1.
Fig 3 is a vertical view of the form shown in Fig: 2,
A is a transmitting cylinder or roller over which the prepared paper tape or
pattern-strip B passes. The cylinder A is divided into two parts A' and A³,
electrically insulated from each other at A³. The part A² is directly connected to
the main line L, while the part A¹ is in electrical connection by conductor 1 with
the earth at G. The brushes or contact-springs C1 and C2 press upon the division A²
or upon that portion of the tape B which is upon said division. A brush C³ rests
upon the division A', and is normally in contact therewith. The tape B is provided
at intervals, determined by the particular character to be printed, with lateral
projections B¹ B² etcetera. These pass between the spring C and the division A',
and serve to insulate them from each other during such passage. The spring C¹ is
connected to the positive pole of the battery E' and the spring C² to the negative
pole of the battery E². The remaining poles of both these batteries are connected by
a common conductor 4 to the spring C³, and thence to ground at G by way of the
division A¹ of the cylinder A, and conductor 1. In the event of the passage of one

page_text: of the lateral projections B' of the tape, insulating the spring C³ from the
division A', the batteries will still remain in connection with the earth but the
route of the earth circuit will then be by conductors 4 and 3, rheostat F, and
conductors 2 and 1. The tape B is provided with arbitrarily grouped perforations
of two classes, circular and elongated, as well as with the lateral projections B¹ B²
etcetera, upon one side.
The specific manner in which this tape or pattern-strip is formed does not
constitute any part of the subject-matter of the present invention.
The functions and objects of the perforations may be best explained by considering
what takes place when the tape is made to pass beneath the contact-springs. As
shown in the drawing, the part of the tape crossed by the transverse dotted line a
is beneath the springs. Hence the spring C² is in contact with the division A*
through an elongated perforation, and the negative pole of battery E' is conse-
quently to line. The spring C¹ in connection with the battery E' is insulated,
leaving the battery circuit open. As the lateral projection B¹ upon the tape
intervenes between the spring C³ and the division A', the battery E' is grounded
through the rheostat F, as heretofore explained. There is therefore sent to line a
current, diminished in strength by the resistance of the rheostat which it is
compelled to traverse, and which may be represented by the symbol - 1. If now
the tape be caused to advance in the direction indicated by the arrow, or reaching
the part b of the tape, the spring C³ will come into contact with division A³ of the
cylinder through one of the circular openings, and the spring C³ simultaneously
into contact with the division A¹, and hence the battery E¹ will be put to line by
its positive pole, the negative pole being at the same time to earth directly through
the division A¹. The resulting electric impulse may now be conveniently repre-
sented by +2. Similarly, when the part c is reached, an impulse represented by
the expression 2 will be sent to line. At da current represented by the
expression + 2 will be sent to line which will be prolonged in consequence of the
elongated shape of the slot. When the part e passes, both contact-springs C¹ and
Ca will be withdrawn from the line and an elongated pause produced during which
there will be no current upon the line.
-
Reviewing what has been said, it will be seen that by reason of the passage of
the tape arbitrarily punctured in the manner described, the line is traversed by a
series of short pulsations of alternate polarity, and also at intervals, prolonged
pauses occur, during which the line will be traversed, either by a current of given
strength, or by a weaker current, or by no current whatever.
Passing now to the receiving mechanism, the electric currents entering by line L
pass first through the electro-magnetic system H, where they produce to-and-fro
oscillations of an anchor-escapement mechanism I of well-known construction. The
scape wheel I¹ of this mechanism is provided with five teeth, and as both pallets of
the anchor engage with each tooth, the shaft 12 makes one advance revolution for
every ten reversals of current. The shaft I also carries a ten-toothed wheel I³ and
type-wheel I' provided with thirty characters. These wheels are both mounted on
a loose sleeve 15. A pin 1 projects from the shaft I2 and is flexibly attached by
means of springs I7 and 18 to the face of the wheel I³. Under the action of these
springs the wheels 13 and I tend to retain a constant fixed position upon the shaft I²,
but both wheels may be revolved slightly in either direction under the influence of
independent mechanism, as hereinafter explained.
The main line passes from the electro-magnetic system H to the relay K, by
conductor 5, and thence to the earth at G. The armature-lever N¹ of the relay K
plays between contact-stops O' and 02. At an intermediate position between
these stops it makes contact with the spring P¹. The forward motion from this
point removes the spring P' from its resting contact-point P2; the backward motion
breaks contact between the armature-lever N¹ and the spring P¹.
The three positions thus described serve to transmit the current of the battery Q
through three different channels respectively. These may be traced as follows:-
First In the intermediate position, which is the position shown in the figure,

page_text: the current passes from battery Q by conductor 6, lever N¹, lever P¹, contact-
point P2, conductor 7, printing magnet R¹, conductor 8 to battery Q. When the
lever N¹ is on its forward contact-stop O¹, the local current will traverse the
conductor 6, armature-lever N', stop.O', conductor 9, electro-magnet R², conductors
10, 11 and 7, magnet R' and conductor 8 again to battery. When on the rear
contact-stop 02, the current passes from battery by conductor 6, lever N¹,
stop 03, conductor 12, magnet R³, conductors 11, 7, magnet R', conductor 8 again
to battery Q.
In each of these cases the local current traverses the coils of the electro-magnet R'.
In the first case it traverses them alone, in the second it traverses said coils and
also in conjunction therewith the coils of electro-magnet R2, in the third case it
traverses the coils of electro-magnet R¹ and in conjunction therewith those of
electro-magnet R³.
Each of the electro-magnets R2 and R³ operates an independent mechanism for
imparting a supplementary movement to the type-wheel I* The mechanism
operated by the magnet R2 advances the wheel while that operated by magnet R³
gives it a retrograde movement. The lever devices operated by the magnets *R*
and R³ are practically similar to each other and may be described as follows:-
The attraction of the electro-magnet is exerted upon an armature R* actuating
an armature-lever R5 fulcrumed at R and normally kept at a distance from the
magnet by a spring R7 abjustable by a screw Rs. The excursion of the armature R*
is determined by the adjustment of the screws R2 and R10, the former limiting its
forward motion toward the magnet and the latter its backward motion away from
the magnet. A pin R" carried by the armature-lever R5 articulates with the bent
lever R2, which turns in eyelets R¹³ and R, projecting from the side of the main
printing lever S, which is actuated by the electro-magnet R¹. To permit the rise
and fall of the said bent lever, the articulating pin R" traverses a slot in the end of
the bent lever R12, so that the latter may be operated by the motion of the lever R³
regardless of its vertical position. The ends of the bent levers are bevelled. In
the case of the lever actuated by the magnet R2, the bevel is in such form as to
cause the advancement of the wheel I³ by impinging upon one side of the tooth
acted upon. In the case of the lever actuated, by the magnet R³ the action is
precisely similar in nature but in a reverse direction.
The printing mechanism may be of any convenient form and need not therefore
be minutely described. It preferably consists of an armature-lever S carrying the
armature S¹ actuated by the poles of the magnet R¹ and carrying a platen S², over
which passes the paper-tape S³ upon which the impressions are to be taken.
The advance movement is imparted to the type-wheel shaft 12 when released by
the escapement, by means of a drum T, suspended weight T' and cord T2, or other
equivalent mechanism.
The operation of the receiving instrument as thus described, under the action
of the several conditions of the line, caused by the pauses of the transmitter as
herein before described, is as follows:-
All the prolonged currents represented by the expression + 1 as hereinbefore
described, bring the relay armature-lever NI to its central position, and therefore
cause the actuation of the printing mechanism only. The pauses in which the
condition can be represented by the expression + 2 cause the actuation of the
printing mechanism and of the magnet R2, thus setting forward the wheel a
single division. The pauses represented by the expression O cause the actuation of
the magnet R and magnet R³, and hence take an impression immediately after
setting back the type-wheel. The alternating pulsations caused by closing the
circuit through the circular punctures upon the tape, while causing the advance
movement of the type-wheel through divisions subtending three characters each,
are not of a sufficient duration to operate the printing mechanism.
Figs. 2 and 3 show in diagram a convenient form of hand-transmitter. It
comprises a pole-changing device U provided with two circuit-wheels U' and U²
provided with alternating circumferential notches. These wheels are mounted on

page_text: a vertical shaft U³ and are insulated therefrom by a sleeve U* The lower wheel
is connected to the negative pole of the battery V by means of the spring or
brush V. The positive pole of this battery is connected with the upper plate by
brush V2, shaft U³, conductor Us, and contact-points W' and W2 upon the arm W.
When these contact-points are closed, the circuit-wheels may be regarded as the
electrodes of the battery, and as said wheels revolve with the shaft, alternating
pulsations of opposite polarity will be transmitted to the line, via the brushes Xi
and X2 which press upon the extensions between the circumferential notches upon
said circuit-wheel. In this manner the current upon the line will be reversed ten
times in each revolution.
The keys of the transmitter are divided into three series, each series comprising
ten keys. These may be conveniently arranged in circular concentric rows Z¹ Z2 Z³
as shown in the diagram. The depression of any key in the outer row Z' causes
the arm W to be arrested in a position depending upon the particular key depressed.
The current then traversing the line will accordingly be prolonged during
the period of arrest. Such current will be conveniently represented by the
expression +2, the effect of which will be to cause a pause of the relay armature N'
at the receiving station on its forward contact-stop.
When any key of the second series Z2 is depressed, not only will the arm W bo
arrested, but the contact-points at W₁ will be separated, and the current then
traversing the line will be diminished in strength by having to traverse the coils
of the rheostat W3. The current thus established may be represented by the
expression ±1. Such current will cause the arrest of the relay armature-lever N
in a central position.
If any key of the third series Z³ be depressed, the arm W will be arrested and
the contact-points W2 separated and the line accordingly left in a neutral condition.
This will throw the armature-lever N¹ of the relay on its back-stop.
Thus by this transmitter the same conditions are established upon the line as by
the automatic transmitter described above in detail.
Having thus described the nature of this invention, and the manuer in which
the same is to be performed, as communicated to me by my foreign correspondent,
I would have it understood that I claim :-
=
1. The combination, substantially as hereinbefore set forth, of a transmitting
cylinder, mechanism for sending to line alternating electrical pulsations, and
mechanism for establishing upon the line prolonged conditions of three kinds,
namely, a condition of definite strength of current, a condition of lesser strength,
and a neutral condition.
2. The combination, substantially as hereiubefore set forth, of a transmitting
cylinder, a tape arbitrarily punctured to establish the conditions as hereinbefore
set forth, the contact-springs, the batteries, and the electrical conductors.
3. A metallic cylinder, a spring resting thereupon, and a transmitting tape or slip
provided with lateral projections upon one of its edges, for separating said
spring from said cylinder and thereby insulating them from each other.
4. The combination, substantially as herein before set forth, of a cylinder divided
into two divisions insulated from each other, and a tape provided with
perforations passing over one of said divisions, and lateral projections traversing
the other.
5. The combination, substantially as herein before set forth, of a cylinder
comprising two divisions insulated from each other, a tape provided with
arbitrary perforations, two springs making contact through said perforations upon
one of said cylinder divisions, and a spring normally in contact with the other of
said divisions but which may be temporarily insulated therefrom by the passage
of a lateral projection upon said tape.
6. The combination, substantially as hereinbefore set forth, of the cylinder divided
into two insulated sections, one of which is in contact with the earth and the
other with the line, contact springs for pressing upon said sections, batteries of

page_text: alternating polarity thereby connected to line and to earth, and a shunt-circuit
whereby the line may be put to earth through an artificial resistance.
7. The combination, substantially as hereinbefore set forth, of a transmitting
mechanism, establishing upon the line three distinct electrical conditions, a
relay pausing in three different positions by virtue of said conditions, and three
local circuits completed respectively by said relay armature-lever, one including a
printing mechanism only a second including said printing mechanism and a
mechanism for advancing a type-wheel through a definite arc, and the third
including said printing mechanism, and a device for retrograding said type-wheel
through a similar definite arc.
8. An armature-lever making three contacts, namely, a central contact at which
point it closes the local printing circuit, a forward stop at which point it
closes the local printing circuit and includes therein a device for advancing the
type-wheel and a back stop at which point it closes a local printing circuit and a
device for retrograding said type-wheel.
9. The combination, substantially as hereinbefore set forth, of a type-wheel
normally advancing through arcs subtending three characters each, mechanism
for advancing said type-wheel through an arc subtending one character, and
mechanism for retrograding said type-wheel through an arc subtending one
character.
In witness whereof I the said William Phillips Thompson have hereunto set
my hand and seal this twenty sixth day of September in the year of our Lord
one thousand eight hundred and eighty three.
TYT
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