Improvements in and connected with Magneto Telephone Systems.
Year: 1890

page_text: Date of Application, 4th June, 1890-Accepted, 23rd Aug, 1890
COMPLETE SPECIFICATION.
Improvements in and connected with Magneto Telephone Systems.
I, ELIAS MUSHBACK GREENE of 79 Cedar Street in the City, County, and State of
New York, United States of America, Inventor, 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 relates to magneto telephony, and has for its object to provide means
whereby a subscriber on a magneto line may call up any other subscriber by ringing
or causing to be rung a definite signal, which shall indicate what particular subscriber
is called, and to these ends the invention consists in the improved construction of
parts and arrangement of devices substantially as hereinafter described.
In the accompanying drawing :-
Fig. 1 is a diagrammatic view showing a line equipped with the improved
apparatus.
Fig. 2 is an enlarged view of a signal box embodying the invention, showing the
arrangement of circuits and apparatus therein.
Fig. 3 is a cross section through said box.
Fig. 4 is an enlarged diagrammatic view showing the arrangement of circuits.
Fig. 5 is a detail showing the preferred arrangement of magnets in the generator.
Fig. 6 is a detail showing one form of circuit breakers.
Fig. 7 is a transverse section showing one form of receiving apparatus
Fig. 8 is a similar view showing a slightly modified form, and
Figs. 9 and 10 are side and plan views of an arrangement of magnets which may
be used therein.
In magneto telephony it is desirable to provide devices whereby one subscriber, or
when used in central office systems a central office operator can send a pre-
determined signal made up of a certain number of smaller signals or impulses
arranged in definite order so that any particular subscriber or other person may be
called by the operator simply rotating the armature of his call device.
In order that
this may be done and that the timing of the signals may be regulated, I provide a
signal box with a number of circuit breakers which can be connected by suitable
branch circuits to the line as desired. While this may be variously arranged, 1 have
shown in the drawing the preferred arrangement.
In Fig. 11 have represented a diagram of a line showing a number of stations,
each one of which is provided with a magneto call apparatus and a magneto tele-
phone, and I will now describe more in detail the construction of the call apparatus.
This apparatus is shown mounted in a box A, having a door B connected to the box
by hinges which form a medium for connecting the circuits between the switch C,
located on the box cover, and the apparatus located in the box. Secured in the box
is a magneto generator D which may be of any suitable construction, but preferably
one having a number of curved permanent magnets d connected by steps to the pole
pieces d', ', which pole pieces are joined by non-magnetic material d², as more
particularly shown in Fig. 5, and the magnets may be held in position by screws d³.
The armature shaft E is mounted in non-magnetic plates D₁, secured to the magnets
and pole pieces, and a brush or plate e insulated from said supports bears on the
shaft of the armature and forms a connection therewith. Also mounted in the non-
magnetic plates is a shaft F carrying a gear wheel ƒ meshing with a pinion e¹
the armature shaft E, and also carrying a pinion f¹ meshing with a gear ƒ³, mounted
on a stud or bearing secured to one of the plates D₁ and having a pinion 3 engaging
the pinion on a shaft G. This shaft Ġ carries a number of circuit breakers H,
which may be such as shown in Fig. 6, and there may be any number, as 1, 2, 3, 4,
Fig. 2.
upon

page_text: A number of brushes H' are mounted on the support, but insulated therefrom, and
their free ends are held adjacent to the circuit breakers and are adapted to make con-
tact therewith as they rotate..on, the shaft. It is desirable that the circuit breaking
shaft shall make one complete, rotation only at each call in order that a con.plete
signal may be sent, and in order to do this a sop device is provided which controls
the rotation of the shaft F, and is in turn controlled by the rotation of the circuit
breaking shaft G. Thus the shaft. F is provided with a disc 1 having two notches i
on opposite sides. The shaft G is provided with a disk J having a single notch jin
its periphery. Pivoted to the framework is an arm K carrying a stop k noriaily
engaging one of the notches in the disc 1, a spring L holding it in the locked
position. The armi K is provided with an extension carrying a wheel or disc M
which is adapted to fit into the slot. j, and a spring m surrounds the extension and
presses the disc M out wards against a stop m².
In Fig. 3 the machine is shown in its stationary position and before the shaft can
be rotated it is evident that some means must be provided for unlocking the device,
and in Fig. 2 such means are shown consisting of a push button N projecting through
the side of the box and operating a bell crank lever n which impinges on the end k²
of the rod, forcing the wheel M out of the notch in the disc J and thereby releasing
the projection from the notch i in the disc I. The shaft F can then be rotated,
operating the armature to produce the alternating currents which are controlled by
the circuits and switches hereinafter described so that the particular signal may be
sent over the line. When the circuit breakers have completed one rotation the
wheel M falls into the notch j, and the projection is thereby thrown into engage-
ment with one of the notches i and the apparatus is locked against further rotation.
The spring m allows the wheel M to yield slightly and to act as a break to
prevent too quick or sudden stoppage of the parts.
To prevent the shaft F being rotated backward and thereby sending the signal
in the reverse order from what was intended a ratchet wheel O is applied to said
.shaft into which a pawl o.engages. Suitably mounted in the box is a polarized
magnet. P operating an armature p, carrying the bell lever p¹ operating on the bells
in the usual way. The crank Q is provided with a sleeve Q', having a groove 9
engaging a ping on the shaft, and a spring 2 tends to maintain the sleeve in its
..outer most. position, but when the crank is turned in the proper direction the sleeve
will first travel around and. inwards on the shaft, compressing the spring 72 and
breaking the closed circuit 14, 15, and then the shaft will be rotated,,and when the
.crank is released it will normally return to its outer position.
1
,
Mounted on the cover of the box is the switch C, having a switch arm C.con-
nected with a thumb nut and having an index finger C3 passing over an indicator (.
The arm is of spring material.having a projection on its end which may be bevelled
to fit the cup, or other shaped contact. pieces c, c¹, c², c³, c¹. These pieces are con-
nected electrically with the different circuit breakers and with the frame of the
machine by conductors 1, 2, 3, 4, which are connected with the brushes of the respective
circuit breaking wheels, and the conductor 5 is connected to the frame of the generator.
The switch arm is connected. by a conductor 6. to the binding post-7.which may
lead to the ground, or line, as the case. may be. The binding post 8. is connected to
the line wire 9 and thence by a conductor.10 to the coils of the bell magnet,.from
which a conductor 11 leads to the conductor 12 and thence to the spring e.on the end
of the armature shaft. From the binding post 7 a conductor 13 leads to a spring: 14,
.normally bearing.on the sleeve Q, and another spring 15 bears upon the opposite
..side and is connected to the conductor.12. Thus the normal circuit when the machine
is at, rest is such that a signal, from a distant station may operate the bell P, passing
through the binding post 8; conductor 10 bell-magnet conductors 11 and 12,
springs 14, 15, conductor 13 and binding post. 7. When however,the,.generator.is
-operated the circuit, between the springs 14.and.15 is broken, and it may be traced
from the binding post. 7, conductor. 6, switchiarm! C"; to one of the.contact pinsias c,
thence by conductor 1 to the brush, over the corresponding circuit breaking wheel: to
the shaft of the same through the coils of the arinature out through the brush e,

page_text: through the conductors 12, 11, coils of the magnets, conductor 10, binding post 8,
and line 9.
It will be understood that the circuit as last traced will be broken or closed in
accordance with the construction and arrangement of the circuit breaking whee.
included therein. While these wheels may be variously arranged I have found it.
advantageous to cause a preliminary signal to be given before the signal representing
the number of the station is given, and each circuit breaker in such instance is.
provided with a projection X Fig. 6, which will cause a signal of the desired length
to be given, and will warn the hearer that a call is to be received. This is followed
by the desired number of projections Y arranged in groups at proper distances
apart as 1, 2. 3. When it is desired to send a continuous signal without interruption
the circuit is completed directly from the frame of the generator through the
conductor 5 and contact c, and as long as the armature is rotated a continuous signal
will be sent. It will thus be seen that by properly adjusting and constructing the
circuit breakers any number of signals may be sent, and they all being secured upon
the same shaft they can be arranged so that the intervals between the signals are
even and regular, and the listener can readily determine whether his particular call or
signal has been made or not. When the call is received at any station the operator
will listen at his telephone which may be arranged, if desired, in the usual way, so as
to open and close the circuit when taken from a hook or other place of support..
While any form of telephone can be used, it is preferred to use one illustrated
herein, in which a strong magnetic field is produced between the diaphragm and core
of an electro-magnetic, which renders it more sensitive and loud-speaking.
In Fig. 7 A represents a number of permanent magnets bent into a U-shape,.
having one of the poles of each magnet that is of the same name connected to a
common plate H2 which is provided with an annular flange I, into which fits a
core G¹ made up of fine wires forming an intense magnetic pole or extension of the
permanent magnets A¹. The diaphragm B¹ rests upon an iron ring B2 connected to
the magnets, and is provided with a mouthpiece E2 preferably in the form of a
trumpet. In order to make the core as powerful as possible I provide three
cores G2, G3, G4, mounted on Y shaped pieces K2, and the, coils F1, F2, F³, thereon
are preferably connected in series. The Y shaped pieces being in intimate contact
with the main core G₁ concentrate the magnetism of the cores G2, G3, G4, in the
extremity of the main core, so that the pole piece is in a highly magnetic condition.
The diaphragm B being opposite this core piece, also becomes highly magnetic, and
in this way a strong magnetic field is produced between the centre of the diaphragm
and the main core, and any vibration or movement of the diaphragm in this field
will produce greatly increased magnetic changes in the core, and on the contrary
varying changes in the magnetic condition of the core will in turn intensify the
effects in the diaphragm in the strong magnetic field.
In Fig. 9 the same principles are embodied in an L shaped magnet.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what 1
claim is:-
1. In a system of magnetic telephony, the combination with the line and telephones
connected thereto, of magneto signal devices provided with circuit controllers
arranged to send predetermined signals over the line, substantially as described.
2. In a system of magneto telephony a magneto signal device having a generator,
a number of circuit controllers, a switch and circuits and connections whereby any
predetermined signal may be sent, substantially as described.
3. In a system of magneto telephony, a magneto signal device provided with a
generator, a number of circuit controllers, a switch and circuit connections whereby
a certain predetermined signal may be sent, each circuit controller being arranged to
first send a preliminary signal and then a particular individual signal, substantially as
described.
4. In a system of magneto telephony, a magneto signal device having a generator,

page_text: a driving shaft for the same, a series of circuit controllers connected to the driving
shaft, and a switch and circuits connecting the circuit controllers and arranged to
send predetermined signals, substantially as described.
5. In a system of magneto telephony, a .magneto signal device having a generator,
a series of circuit controllers, a driving shaft therefor, and a stop device for the
driving shaft controlled by the circuit controllers, substantially as described.
6. In a system of -magneto telephony, a magneto signal device having a generator
and circuit controllers, a driving shaft therefor.. a disc on the shaft, and a disc
connected to the controllers, and an arm provided with a detent and stops engaging
said discs, substantially as described.
7. In a system of magneto telephony, a magneto signal device having a generator
and circuit controllers, brushes connected to the circuit controllers, a switch
connecting the brushes and circuits, and another circuit connected with the generator
whereby a prolonged continuous or predetermined interrupted signal may be sent
over the line by adjusting the switch, substantially as described.
8. In a system of magneto telephony, a magneto call box in which the generator
is composed of a series of permanent ring shaped magnets connected to pole pieces,
the pole pieces being provided with projections corresponding to the shape of the
ends of the magnet, substantially as described.
9. In a system of magneto telephony, a magneto call provided with a generator
and circuit breakers, a driving shaft for the circuit controllers and armature arranged
to rotate the circuit controllers at a slower rate of speed than the armature,
substantially as described.
10. In a system of magneto telephony, a telephone having a number of permanent
magnets, a plate connecting all the poles of one name, a core supported by said
plate, a ring connecting the poles of the opposite name, and a diaphragm supported
- on the ring substantially as described.
11. In a system of magneto telephony, a telephone having a compound electro
magnet, consisting of a central core, yoke pieces connected to said core and
supporting independent cores, coils surrounding the independent cores, the connected
pole pieces being all of the same polarity, substantially as described.
12. In a system of magneto telephony, a magneto telephone consisting of a
plurality of permanent magnets, a compound core therefor, connected to one of the
poles of the magnets, and a diaphragm supported on the other poles, substantially. as
:described.
Dated this 4th day of June 1890.
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London, Applicant's Agent.