IMPROVEMENTS IN TELEGRAPH APPARATUS
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by Laurentius Carlander at the Office of
the Commissioners of Patents on the 12th July 1877.
LAURENTIUS CARLANDER, of Stockholm, Telegraph Official. "IMPROVEMENTS IN
TELEGRAPH APPARATUS."
The purpose of this Invention is to effect not only like signals at the sending and
receiving stations through which the clerks quickly become familiar with the auto-
matic expedition, and greater security is attained, but also great quickness in for-
warding the messages, as well as simplicity and accuracy in the sending instrument,
which is not subject to those irregularities to which hitherto known automatic
instruments, by reason of the complicated manner of forming the writing at the
sending station, and through their intricate mechanism, are liable, namely, of often
getting out of order, and consequently often being useless. The system consists of
two apparatus, a perforator and a transmitter.
The perforator consists of knobs, say three, each of which is connected with a
lever. These levers operate the studs or punches which produce the writing by
piercing holes in the strip of paper, and also at the same time produce rack holes.
When the first knob is pressed down a bolt is pushed to the left, its studs or
punchers advance, and cut in the strip of paper a round letter hole, and above this
a small rack hole, at the same time the lever acts upon an arm, so that the latter,
by means of a stopping stud bell crank and lever pushes a pawl over a tooth of a
ratchet wheel. When the knob returns to its position of rest the studs are drawn
back by spiral springs, the bolt being drawn back at the same time by another
spring; a spring also draws back the arm or lever, carrying the pawl, which now
moves the ratchet wheel the space of a tooth; on the same axle as the ratchet wheel
is also placed a "dented" wheel, that is, a wheel with pins or teeth on its circum-
ference, which has a distance between its teeth equal to the distance between the
centres of the rack holes on the paper. When thus the ratchet wheel is turned a
cog, the paper by means of the "dented" wheel is pushed forward through a space
equal to the diameter of a letter hole.
When the second knob is pressed down, only one stud advances and cuts a rack
hole; the paper slip is in this case pushed forward in the same way, and also the
same distance as when the first knob is pressed down. This knob, which thus forms
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page_text: no signals (letters) whatever, tends only to form the distance between letters and
words. The bolt in this case remains stationary. When the third knob is pressed
down two studs advance and form together an oval letter hole thrice as long as the
diameter of a round letter hole, at the same time other studs advance, each forming
a rack hole. In this case the bell crank is drawn away by means of a spring, and
the pawl is pushed forward two cogs of the ratchet wheel, and thus the "dented"
wheel draws the paper slip the distance of the diameter of two letter holes, when
the knob returns to its position of rest. In this case also the bolt remains
stationary.
A spring is provided to act as a stopper for the ratchet wheel so that this
latter (and the dented wheel) is not shaken when either of the knobs is pressed
down.
By means of the above-described mode of cutting the holes, perfect Morse
writing is attained in the middle of the paper slip, not on the edge. The per-
forated slip thus receives two rows of holes, a lower one for the writing, and an
upper one for the rack.
The transmitter consists of two arms which, by spiral springs, are drawn towards
contact studs in metal discs. These metal discs are disconnected (insulated) from
one another by a piece of ebonite (through which passes an axle), on which is
placed a little writing piece, the ebonite disc (as well as the metal discs with the
contact studs), and the writing piece are firmly connected with the axle. The two
arms are in connection with the poles (each with its pole) of the battery; the contact
studs are through the metal discs in connection with line and with earth; a spiral
spring is provided to draw the writing piece towards the plane below (the paper
slip with the perforated writing running along under the writing piece).
The perforated slip is moved forward by clockwork constructed so that its speed
may be increased or diminished.
Whenever the writing piece by the spiral spring is forced down into a perforated
hole of the paper (pushed along by the clockwork) a positive current is sent into
the line, while at the same time a negative current goes to earth, and whenever the
writing piece slides along the paper without meeting a hole, a negative current is
sent into the line, while at the same time a positive one goes to earth. Between
each such change of current the line will for a moment come into direct con-
nection with earth, and has then a chance of leading away any superfluous
electricity unnecessary for forwarding the writing before an opposite (reverse)
current is let in.
To prevent unnecessary closing of the battery line and earth are in direct con-
nection; a screw is placed on one of the arms, this screw in such cases touching an
ebonite heel in the other arm.
It will be seen that according to this system the writing piece will copy and
forward the writing on the perforated slip in a most simple and correct manner;
and likewise, that according to this system (in a simple and practical manner) to the
same clockwork, one, two, or more current changers may be applied, which at the
same time forward the same or different messages to different stations. For
sending the same message to different stations the writing pieces have to be moved
so as to slide after one another on the same slip.