Improvements in Telephone Call Devices.
Year: 1890

page_text: COMPLETE SPECIFICATION.
Improvements in Telephone Call Devices.
I HERBERT JOHN HADDAN of the firm of Herbert & Co. Patent Agents of
18 Buckingham Street Strand W.C. in the County of Middlesex Civil Engineer
do hereby declare the nature of this invention a communication to me from abroad
by Francis Rollin Spalding of Brookline in the County of Norfolk State of Massa-
chusetts, United States of America, Merchant, 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 improvements in call devices for telephones and it has for
its object to enable the operator at the central station to ring up any one of the
telephones on the line (in a block of from two to about ten) without ringing up the
others and this I do by means of a magneto generator of variable strength at
the central office or exchange and individual call bells on the telephones in the block
system, which bells are actuated and sounded according to the strength of the magneto
electric current sent through their respective electro magnets as will hereinafter be
more fully shown and described, reference being had to the accompanying drawings
where,
Fig. 1 represents a side view of the magneto generator partly shown in section, the
commutator and the keyboard.
Fig. 2 represents a vertical cross section of the magneto generator.
Fig. 3 represents a side elevation of one of the individual call bells in the block
system.
Fig. 4 represents a longitudinal section of the commutator.
Fig. 5 represents a diagram showing the magneto generator and individual call
bells in the block system connected together for operation and
Fig. 6 represents a diagram showing the commutator and the coils of the armature
on the magneto generator.
Similar letters refer to similar parts wherever they occur on the different parts of
the drawings..
a in Figs. 12 and 5 represents the permament horse shoe magnets of the magneto
generator at the central office or exchange and a', a represent the field magnets as
usual. B represents the rotary armature having its shaft journalled in suitable
bearings and preferably provided in one end with a pinion B' meshing in the teeth of
the wheel B having a crank B³ as is usual in magneto generators.
By turning the crank B³ the armature B is set in a quick rotary motion as usual
or said armature may be rotated by power applied to its shaft in any other suitable
or equivalent manner without departing from the essence of this invention.
In the drawings I have represented the magneto generator as connected to five
individual call bells on as many telephones on the line but more or less telephones
may be thus connected in practice I prefer to connect the telephones to the improved
magneto generator.
B in Fig. 4 represents the shaft of the armature to one end of which is attached a
sleeve B of hard rubber or other suitable insulating material. Said insulated sleeve B
is surrounded by a number of metal rings or conimutator bands 6 6 6 6 and 6*
which are connected to the respective coils of wires C¹ C C3 C4 and C³ on the
armature B by means of the wires cell cc and c as shown in Fig. 6.
The coil Cis connected to the coil C₁ and wire c" by means of the wire d', the
coil is connected to the coil C³ and wire ca by means of the wire d", the coil C³ is
connected to the coil C and the wire c by means of the wire d³, the coil (is
connected to the coil and wire c' by means of the wire d' and the coil (³ is connected
by means of the wire d³ to the ground G as shown in Fig. 6.
el elle and e represent metallic brushes the free ends of which are held in

page_text: metallic contact with the respective commutator rings b₁₁13 and 6 and having
their rigid ends secured in a suitable manner to the insulated bar or plate e as shown
in Fig. 1.
The brushes e e e e e are connected respectively to the keys E¹ E" E³ E¹ and E'
by means of wires as shown in Figs. 1 and 5.
E represents the key board with which either of the keys E E E E and E³
may be connected by depressing their ends as is common in telephonic exchanges.
From the keyboard E leads a wire F to the individual call bells I K L M and N
on the telephones in the block system as shown in Fig. 5.
The individual call I consists of the electro magnet i and its metal frame i¹; to
the free end of the said frame is pivoted the arm and on said arm is hinged the
armature as shown in Fig. 3.
The arm is provided with a screw threaded lever on which is adjustably
secured the weight as shown in Figs. 3 and 5.
is a spring interposed between the electro magnet i and arm for the purpose
of holding the armature away from the electro magnet when no current passes
through the electro magnet i, and 7 is a regulating set screw on the arm ¹ for.
limiting the outward movement of the armature arm as shown in Fig. 3.
23 is an electrode secured in a suitable manner to the individual telephone on which
the bell call is used and is the wire leading from the electro magnet i to the
electro, is the wire leading from the electro magnet to the next individual
magnet in the block system.
The wire F is connected to the coil of the electro magneti and its frame i¹ connected
to said wire F by means of the wire as shown in Figs. 3 and 5. 18 represents the
clapper lever secured to the armature and I" represents the bell or bells as is
common in telephone calls.
k¹¹K¹KL¹L" m² m¹ M₁ M" n¹ ni N¹ N¹¹ represent corresponding
parts on the respective individual call bells K L M and N as shown in Fig. 5.
10 represents the wire leading from the electro magnet n to the ground G as shown
in Fig. 5.
By adjusting the weights 1 m³ and n³ on the respective call stations I KLM
and N the armature resistance on such call stations will be made according to the
magneto generating power of the respective coils C¹¹³ C and C³ and consequently
that one only of the bells in the line will be sounded that corresponds to the key on
the key board that is depressed by the operator at the central office or exchange which
corresponds to the coil on the revolving armature of the magneto generator.
Others in the circuit will not be operated owing to absence of power sufficient to
attract the armatures or the excess of power by which the levers are brought
in contact with the electrodes 88 causing the current to be cut off from the corre-
sponding electro magnets and so on.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is.
1. In an individual call system the combination of the electro magnet the armature
hammer and bell, the arm to which the armature is connected, the electrode or contact
which co-operates with the said arm and the weighted lever connected to said arm as
described.
2. In an individual call system the combination of the magneto generator the
commutator and the keys, the electro magnets, the armatures the arms to which said
armatures are connected, the levers connected to said arms the weights adjustable on
said levers and the electrodes adjacent to said arms as described.
Dat
DAVI
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C., Agents to Applicant.