Year: 1887

page_text: Date of Application, 20th July, 1887
Complete Left, 18th May, 1888
Complete Accepted, 20th July, 1888
THOMAS ALEXANDER GARRETT B.A. 80 Abingdon Road Kensington London
Engineer do hereby declare the nature of this invention to be as follows:-
This invention has for its object certain improvements in apparatus or instruments
for transmitting and receiving electrical signals.
According to this invention the required current is produced in the transmitting
apparatus or instrument by electro-magnetic induction. One or more pieces of iron
bave an oscillatory motion imparted to them by means of a spring or springs made to
vibrate by being moved out of the ordinary position and then set free. The pieces of
iron by their movements cause stationary iron cores to be magnetized (and demag-
netized) either successively in the same direction or alternately in opposite directions,
and round these cores are wound coils of wire in electrical connection with the line,
so that the movements of the before mentioned pieces of iron cause currents in the
line which are alternately in opposite directions.
In one modification of transmitting apparatus one end of the stationary iron core
on which wire is wound is situated between the two opposite poles of a permanent
horse-shoe magnet, the other end being magnetically connected to the steel of the
permanent magnet about midway between its poles. A piece of iron is attached to
one end of a blade spring the other end of which is fixed so that when the piece of
iron is pulled to one side and then let go it vibrates in front of and very close to the
two poles of the permanet magnet and the end of the iron core which is between them,
and so causes the iron core to be magnetized alternately in opposite directions by the
opposite poles of the permanent magnet. This apparatus then when in action sends
currents to the line alternately in opposite directions.
In the receiving apparatus or instruments pieces of iron attached to springs are
made to vibrate by the action of the currents which pass through the lines, these
currents (or parts of them) passing through stationary coils of wire which either have
stationary iron cores or are without such cores. The pieces of iron either are
inductively magnetized by fixed permanent magnets (or electro-magnets) and act

page_text: therefore as if they themselves were magnets and are moved alternately in opposite
directions by the alternating currents in the lines, or they are inductively magnetized
alternately in opposite directions by the alternating currents in the lines and are
moved alternately in opposite directions by the attraction and repulsion of fixed
permanent magnets. The springs to which they are attached so constrain the
movements of the pieces of iron that their distances from the parts of the instruments
which have been said to inductively magnetize them are only very slightly if at all
altered by their movements, whether these parts of the instruments be permanent
magnets or coils of wire with stationary iron cores or coils of wire without such
cores.
In one modification of receiving apparatus a flat piece of iron is attached to the
free end of a blade spring between the poles of a permanent horse-shoe magnet and
a hammer to strike a bell, is also attached to the same end of the spring. The flat
piece of iron is magnetized inductively alternately in opposite directions by the
magnetic action on it near its middle of the end of an iron core, the other end of
which is magnetically connected to the steel of the permanent magnet about midway
between its poles. On the iron core is wound a coil of wire in connection with the
line, so that the alternate currents in the line magnetize the iron core alternately in
opposite directions, and this in turn magnetizes the movable flat piece of iron in such
a manner that its ends are successively both positive and both negative. When both
the ends of the movable piece of iron are positive it tends to move towards the
negative pole of the permanent magnet and when both the ends are negative it tends
to move towards the positive pole of the permanent magnet, and thus it alternately
receives impulses in opposite directions corresponding to the opposite currents in the
line.
An electro-magnet may be used instead of a permanent magnet in any piece of
apparatus made according to this invention.
The springs may be of any convenient shape.
The receiving apparatus may be made to indicate either to the ear or to the eye or
to both.
D
11

page_text: and Receiving Electrical Signals.
I, THOMAS ALEXANDER GARRETT B.A. 80 Abingden Road, Kensington, London,
Engineer, 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 has for its object certain improvements in apparatus or instruments
for transmitting and receiving electrical signals.
According to this invention the required current is produced in the transmitting
apparatus or instrument by electro-magnetic induction.
One or more pieces of iron have an oscillatory motion imparted to them by means
of a spring or springs made to vibrate by being moved out of the ordinary position
and then set free.
The pieces of iron by their movements induce magnetism in stationary iron cores
round which are wound coils of wire in electrical connection with the line, so that
the movements of the before mentioned pieces of iron cause varying electrical currents
in the line.
In one form of transmitting apparatus one end of the stationary coiled core is
situated between the two opposite poles of a permanent horse-shoe magnet, the other
end being magnetically fixed to the magnet about midway between its poles. A piece
of iron is attached to the free end of a blade spring so that when it is pulled to one
side and then let go it vibrates in front of and very close to the poles of the magnet
and to the end of the iron core between them, so causing magnetic variations in the
iron core whereby electrical currents are sent to the line.
In the receiving apparatus or instrument a piece of iron attached to a spring is
made to vibrate by the action of the line currents which or parts of which pass
through a coil on a stationary iron core.
The piece of iron being inductively magnetized by a fixed permanent or electro
magnet is caused to move to and fro in a magnetic field.
In one form of receiving apparatus according to my invention a piece of iron
attached to the free end of a blade spring lies between the poles of a permanent horse-
shoe magnet and has attached to it a hammer to strike a bell. The piece of iron is
magnetized inductively alternately in opposite directions by the magnetic action on
it, near its middle, of the end of an iron core, the other end of which is magnetically
connected to the magnet about midway between its poles. On the iron core is wound
a coil in connection with the line, so that the varying currents in the line vary the
magnetism of the iron core and of the piece of iron attached to the spring in such a
manner that the piece of iron is caused to move to and fro in relation to the poles
of the magnet.
Electro magnets may be used instead of permanent magnets in apparatus such as I
have described.

page_text: The receiving apparatus may be made to indicate either to the ear or to the eye or
to both.
Figure 1 of the accompanying drawings is a front view and Figure 2 is a vertical
section of a transmitting instrument according to my invention. Figures 3 and 4 are
corresponding views of a receiving instrument arranged to give audible signals, and
Figure 5 shows how a similar instrument may be applied to give a visible signal.
Referring to Figures 1 and 2, A is a magnet of horse shoe form and B is an iron
core magnetically attached to the magnet A about midway between its poles, the end
of the core B being situated in the space between the poles of the magnet. C is a
spring to the free end of which is attached an armature or piece of soft iron D which is
bent in a trough form so as to embrace without touching the end of the core B. To
the spring is attached a handle E by which the iron D can be pulled aside. On E
being let go the iron D vibrates in presence of the two poles of A and of the end of
the core B thus causing electrical impulses in a coil F of insulated wire which is
wound on the core B and is connected to the line.
Referring now to Figures 3 and 4 in which the magnet A and core B with its
coil F are arranged as in Figures 1 and 2. The spring has attached to it a stem C¹
to. which is attached the armature or piece of iron D that is bent round so as to
embrace the end of the core B, between which and the poles of A there is room for
the sides of the piece D to move to and fro in obedience to the varying electrical
impulses arriving from the line and passing through the coil F. A hammer G may
be attached to the stem C¹ so as to strike a bell H, or, as shown in Figure 5 it may
strike a lover K and so release a catch on a loaded disc L allowing the disc to move
and so to give a visible signal. In both the transmitting and the receiving instruments
electro magnets may be used instead of the permanent magnets A. Also the coils F
might be wound on cores having the position of the magnets A and in that case
instead of the middle core B there would be a permanent or an electro magnet. It is
generally preferable that the springs of the connected transmitting and receiving
instruments should be such that the armatures in both instruments vibrate
synchronously.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I hereby declare that I make
no general claim to transmitting apparatus wherein electrical variations are caused in
a coil made to vibrate in a magnetic field, nor to receiving apparatus wherein a coil
subject to electrical variations is caused to vibrate in a magnetic field, but what I
claim is :-
1. Electrical signal transmitting instruments wherein there are in the presence of
magnetic poles and of the ends of stationary iron cores coiled with wire armatures or
pieces of iron attached to springs which when caused to vibrate produce electrical
variations in the wire coils and in the line with which these coils are connected,
substantially as described.
2. Electrical signal receiving instruments wherein pieces of iron attached to
springs are made to vibrate in the presence of magnetic poles and of the ends of
stationary iron cores coiled with wire when electrical variations are transmitted
by the line through these coils, substantially as described.
Dated this 18th day of Mo. 1900
ABEL & IMRAY,
Agents for the Applicant.