IMPROVEMENTS IN ELECTRO-TELEGRAPHIC APPARATUS
Year: 1869

page_text: LETTERS PATENT to William Alexander Lyttle, of The Grove,
Hammersmith, in the County of Middlesex, Engineer, for the
Invention of "IMPROVEMENTS IN ELECTRO-TELEGRAPHIC APPARATUS."
Sealed the 17th August 1869, and dated the 13th May 1869...
PROVISIONAL SPECIFICATION left by the said William Alexander
Lyttle at the Office of the Commissioners of Patents, with his
Petition, on the 13th May 1869.
I, WILLIAM ALEXANDER LYTTLE, of The Grove, Hammersmith, in
the County of Middlesex, Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN ELECTRO-TELEGRAPHIC APPARATUS,'
be as follows:-
I employ in the instrument known as the Morse printer or embosser
two separate levers with an inking roller, inking point, pen, or embosser to
cach; one of the levers being terminated with a soft iron armature, and
the other with an armature of magnetized steel or iron, kept constantly
polarized by the proximity or contact of a permanent magnet, and cach
lever having its armature end adjusted suitably for attraction by one or

page_text: more electro-magnets placed underneath. When a current in one
direction passes through the electro-magnet so as to produce the polarity
necessary for attracting the magnetized lever, both the levers will bo
attracted together and a double dot or two lines will be imprinted, whilst
if the opposite current is sent the soft iron lever only will be attracted
and a single mark only will be made. By this means dots and double
dots corresponding precisely to the dots and dashes of the Morse code
may be produced, and a record may be obtained of signals sent by the
common single needle instrument, or by the Brights Bells key, or any
other key working by change of current. If desired, the inking roller
disc of this printer may receive its ink by rolling against a larger disc
or wheel attached to the same lever. This larger disc or wheel should
alone become immersed in the ink on the descent of the lever. As dots
only are required under this plan, the levers of the armatures may be
terminated with wires hooked so as to dip underneath the ink in the
cistern, the free end of the hook being turned upwards. When the
armature of a lever so arranged is attracted the hook at the other end
of the lever rises out of the ink and stamps a point or dot upon the
paper riband. The end of the hook may if desired be split like a drawing
pen. It may also be made to play through a short tube attached to the
lid of the ink cistern, the diameter of the tube being such as to maintain
by capillary attraction a high level of ink around the inking hook even
when the supply of ink has run low.
In order to draw the paper band I either employ clockwork as at present,
or I accomplish the same result by electro-magnetic means, using the
local battery power at the receiving station as a "relay" for the purpose.
In the latter case the end of one of the inking levers furthest from the
cistern engages with a ratchet tooth into a ratchet wheel, and on the
axis of this ratchet wheel is coiled a piece of watch spring, the free end
of which engages by friction against or in the inside of the cylinder or
drum which serves to draw the paper band forward. The elasticity of
this spring should be adjusted so as to keep the cylinder moving some
time after the current has ceased. If a magnetized needle is placed over
or otherwise subject to the attraction of the coils of the line current
electro-magnet it will show the proper circulation of the current as
efficiently as the separate galvanometer now generally used. As
"dashes" are not required momentary currents only will be needed.
The secondary current from an induction coil may therefore be used
for signalling, the primary wire circuit of the coil being closed by the

page_text: sending apparatus or key at the sending station. The key which closes
the primary wire circuit must at the same time "short circuit" the
current devoloped in the secondary wire at the moment of making
contact, and must allow only the induced current set free on breaking
contact to pass out to line. This arrangement of one soft iron and one
magnetized lever affords a ready means of telegraphing by sound, because
by employing the levers as hammers the sounds produced on bells or
other sounding media, suitably placed either in proximity to the coils of
the aforesaid printer or in a separate arrangement (designed only to act
as an acoustic telegraph), will be double or single like the double or
single dots above described. If both levers are magnetized and have
opposite poles over the electro-magnets, only one will be attracted by
each kind of current according to the polarity developed in the electro-
magnet, and one or the other of the two bells or other sounding media
placed opposite the hammer heads of the levers will accordingly be
struck.