IMPROVEMENTS IN TELEGRAPHIC PRINTING INSTRUMENTS, AND IN APPARATUS CONNECTED THEREWITH
Year: 1872

page_text: LETTERS PATENT to Edward Augustine Calahan, of Brooklyn, New
York, United States of America, now of No. 8, Southampton
Buildings, London, Telegraphic Engineer, for the Invention of
"IMPROVEMENTS IN TELEGRAPHIC PRINTING INSTRUMENTS, AND IN APPARATUS
CONNECTED THEREWITH
"
Sealed the 8th November 1872, and dated the 3rd August 1872.
COMPLETE SPECIFICATION filed by the said Edward Augustine
Calahan at the Office of the Commissioners of Patents, with his
Petition and Declaration, on the 3rd August 1872, pursuant to
the 9th Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
AUGUSTINE CALAHAN, of Brooklyn, New York, United States of
America, now of No. 8, Southampton Buildings, London, Telegraphic
Engineer, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
TELEGRAPHIC PRINTING INSTRUMENTS AND IN APPARATUS CONNECTED THEREWITH,"
and have petitioned Her Majesty to grant unto me, my executors, admi-

page_text: I
nistrators, and assigns, Her Royal Letters Patent, for the same, and
have made solemn Declaration that I am the true and first Inventor
thereof.
NOW KNOW YE, that I, the said Edward Augustine Calahan, do
hereby declare that the following Complete Specification, under my
hand and seal, fully describes and ascertains the nature of the said
Invention, and in what manner the same is to be performed, in and
by the following statement, reference being had to the accompanying
Drawing forming a part of this Specification:-
The first part of my said Invention relates to printing telegraph
instruments.
These instruments have heretofore been constructed with two type
wheels placed in line with each other, but revolved independently so
that one can be operated while the other remains quiescent. In instru-
ments of this character it is usual to stop one type wheel at the zero
or unison point while the other is made use of, but sometimes a letter
will be missed and the type wheel will not properly print when again
set going.
This part of my said Invention consists in a method of setting the
type wheels in their correct positions and also in connecting latches or
catches so positioned and operated that the type wheel moved by the
step-by-step motion keeps turning the type wheel that would otherwise
be quiescent until it is set or arrives at the zero or unison point. By
this construction it becomes impossible for either type wheel to remain
out of unison while the other wheel is being operated, because a
movement given to either one brings the other to its proper place and
there leaves it.
7
The second part of this Invention relates to a simple and reliable
switch instrument whereby one of two or more telegraphic printing
nstruments may be conveniently connected with the battery and the
emainder detached from the same.
t
In working with several telegraphic printing instruments it is
frequently desirable for one operator to use them in rapid succession
for different matter without changing the different keys or using a
separate battery for each, and this object is accomplished by the use of
my Invention. .

page_text: Figure 1 is an elevation of a portion of a telegraphic machine showing
the said type wheels in transverse section; Figure 2 is an end elevation
of the same parts; Figure 3 is a section of the said type wheels illus-
trating a modification of their connecting and disconnecting devices.
Figure 4 is a plan of my improved switch instrument showing it
connected with one printing instrument and provided with a wire
leading to another printing instrument; Figure 5 is a side elevation of
the said switch instrument.
Figures 6 and 7 show detached portions of my improvements drawn
to an enlarged scale. Like letters indicate the same parts throughout
the Drawing.
I
The type wheels a, b, are mounted upon independent shafts or sleeves
and operated by a step-by-step movement of any desired character, the
usual ratchet wheels c, d, being shown upon which the pawls work. Upon
the wheel a is a pawl d' with an arm 2 contiguous to the pin 3 on the
wheel b or equidistant from the centre so as to come in contact there-
with; upon the wheel b is a pawl e with an arm 4 taking the pin 5 on
the wheel a. Two arms fand project from the frame of the machine
into the path of the inclined ends of the spring pawls d'and e, and as the.
wheels and pawls come around the inclined ends of the spring pawls.
come into contact with these fixed arms. If the wheel 6 has been in
use the operator manipulate the wheel a, and as it comes around the
arm 2 on the pawl d¹ takes the pin 3, and the two wheels move together
until the pawls d¹, e, arrive at the stationary arms f, g; the arm g then
arrests the wheel 6 while the wheel a is moved forward and the arm 2
lifted over the pin 3 to allow the wheel,6 to remain stationary, this will
be the result every time the wheel a is brought around, therefore the
wheel 6 will remain at the zero or unison point and be in proper position.
to start when required with all the other wheels in the various. instru-.
ments in the line that are operated simultaneously. If power is applied.
to the wheel b and the wheel a should not have been stopped at the
zero or unison point, the wheel 6 will carry the wheel a around to.
that point and leave it as before described, the armg lifting the pawl-e.
clear of the finger 4 and the pin 5. The same operations are performed
by the contrivances shown in Figure 3, but the pawls d and e' are
provided with a V shaped point. 6 and notch 7, and these pawls are

page_text: positioned nearly at right angles to the radial lines; the arms f, g, act
as before and draw back the point or notch to clear the other pawl and
allow the wheel to stop at the zero or unison point. These stops and
pawls may be applied to arms or discs upon the type wheel shafts
instead of to the type wheels themselves.
'
I will now describe the part of my Invention illustrated in Figures
4, 5, 6, and 7. represents the electro-magnet of the switch instrument
connected by a wire i with the battery, and by another wire j with the
earth. The wire j leads through a suitable key, which must be touched
in order to establish a current, provided the connection with the battery
is uninterrupted. The wire i leads to a cup k, whence it is branched at
1, l', one branch leading to a spring m on one of the printing instru-
ments. The printing lever n of each printing instrument when raised
or attracted by its magnet o comes in contact with the spring m, as
indicated by dotted lines in Figure 7, and establishes metallic connection
between the wire a¹ and another wire p leading immediately from the
battery to the supports of the said lever n. When this lever is lowered,
as shown by full lines in Figure 7, it is disconnected from the spring m.
Therefore to complete the circuit through the magnet the lever n
must be raised and the before-mentioned key touched at the same time,
either of them alone being insufficient. q is the armature lever of the
switch instrument; it carries at its upper end a pawl r, which engages
in a notched or toothed wheels that has its bearings in a fork or post.s'
projecting from the bed or base of the switch instrument. A wheel t
is mounted upon the axles of the toothed wheel s. This wheel thas
a metallic inner part in contact with the axle s*, and a series of
equidistant radial arms 2 projecting from the said inner part. Between
the arms 3 are fitted pieces of non-conducting material. Metal
springs u, u¹, are connected by wires u², u³, with the electro-magnets
v, vl, of the type wheel turning instruments. The ends of these springs
are in contact with the periphery of the wheel t, but are so spaced that
only one can be in contact with a metal arm t2, the other or others
being in contact with the insulating pieces t³. A suitable number of
such springs according to the number of instruments to be connected may
thus be in contact with the wheel t. The printing lever in when at rest
is in metallic contact with a spring x, which is by a wire x' connected
with the post s', and is therefore in metallic contact with the axle s³
and metal arms of the wheel t.

page_text: The operation of this instrument is as follows: As long as the lever n .
is at rest, that is to say, in contact with the spring x, that printing
instrument which by its connection with the spring u or u¹ is in metallic
connection with one arm of the switch wheel will have a circuit
established through its magnet. All the other printing instruments
connecting with the same switch wheel have their circuits broken by
the insulating pieces of the same. The instrument whose magnet is
thus charged can be worked by the keys in the ordinary manner, the
printing lever being caused to vibrate by a separate key each time a
type has been set in position for printing. Whenever the printing
lever is thus raised it interrupts momentarily the connection with the
spring x, and establishes through the spring m metallic connection with
the magnet of the switch instrument. The operator can then by a mere
touch of the appropriate key establish a circuit through the said magnet,
causing the armature q' to be attracted and the lever q to be swung to
move the wheels & and t, and bring another spring in metallic contact
with the wheel t. The key to the magnet h may be touched once or a
number of times to obtain the desired position of the wheels 8, t, if more
than two instruments are connected with the switch. Any printing
instrument thus brought into metallic contact with the wheel t may
be worked, and all the others will be out of gear. If during the eleva-"
tion of the lever n the key to the switch instrument is not touched, the
printing instrument having this lever remains in circuit after the descent
of the same.
While the key to the switch instrument is being worked,
if more than one motion of it is necessary the hand must remain on the
key which operates the printing lever in order to retain the same in the
elevated position.
I prefer that the printing instruments used in connection with this
switch instrument should be constructed like those above described, but
other printing instruments may be'used if desired.
Having thus fully described the said Invention, and the manner of
performing the same, I wish it understood that I claim,-
First. The method herein specified of causing one type wheel to set
the adjacent type wheel by moving it around to the designated point and
there leaving the same, as herein set forth.
Second. The printing lever arranged between the springs to establish
by its movements alternate connections with the magnets, as hercin
specified.

page_text: Third. The said printing lever arranged between the springs in
combination with the switch instrument and the various printing
instruments on the same line, as herein set forth, and for the purpose
described.
In witness whereof, I, the said Edward Augustine Calahan, have
hereunto set my hand and seal, this Second day of August, in
the year of our Lord One thousand eight hundred and seventy-
two.
Witness,
GEORGE HASELTINE.
EDW. A. CALAHAN. (L.S.)