IMPROVEMENTS IN TELEPHONIC
Year: 1881

page_text: LETTERS PATENT to George Lee Anders, of Boston, Massachusetts, in the
United States of America, but at present residing at No. 6, Lombard Street,
in the City of London, for an Invention of "IMPROVEMENTS IN TELEPHONIC
"
PROVISIONAL SPECIFICATION left by the said George Lee Anders at the
Office of the Commissioners of Patents on the 7th July 1881.
GEORGE LEE ANDERS, of Boston, Massachusetts, in the United States of America,
but at present residing at No. 6, Lombard Street, in the City of London.
IMPROVEMENTS IN TELEPHONIC APPARATUS, PART OF WHICH IMPROVEMENTS IS
ALSO APPLICABLE TO OTHER ELECTRICAL OR MAGNETIC APPARATUS."
My Invention relating to improvements in telephonic apparatus has reference to
the arrangement of the telephones themselves, and to the construction of signalling
apparatus to be used with the telephones for notifying from a central station to a
branch station, and also to the construction of the switch board to be used at the
central station; but a part of my Invention is also applicable to other electrical or
magnetic apparatus.
In carrying out my Invention, I combine both the transmitter (which may be
of the description known as Hanning's, for example), and the receiver at each
station in one and the same case with a mouth piece common to the two, and
which may be provided with a communicating tube or not, as desired, the
connections being arranged so that the current passes both through the transmitter
and the receiver.
By thus causing the sound waves to act upon the receiver as well as upon the
transmitter in the operation of transmitting, I not only eliminate the resistance of
the receiver, but am enabled to evoke the influence of the receiver in co-operation
with the transmitter in the operation of transmitting, whereby the clearness or
distinctness of the articulation is augmented or improved.

page_text: In the case of district telephone systems in which a number of telephones are
arranged upon the same circuit, I construct the signalling apparatus so as to admit
of a notification being sent to any one station in the circuit by ringing a bell at
such station without acting upon the bells of similar apparatus at the other
stations of the circuit with which it is not then required to communicate. In the
Specification to Letters Patent granted to Sidney Pitt, dated the 2nd July 1879.
No. 2674, for an Invention communicated to him by me, there are described
apparatus operating upon this principle, the bells, being rung by electric agency.
According to my present Invention, I employ a train of clockwork for actuating
the signal apparatus and ringing the bells, the escapement of which clockwork is
locked so that the motion of the apparatus is arrested by the automatic mechanical
action of the apparatus itself, whilst the escapement is released so as to start the
apparatus by electric agency; and I arrange the several parts of the apparatus
and combine them together in the following manner :-
The apparatus at each station is provided with a disc or its equivalent, having
an inclined or cam surface and a notch or recessed portion on its periphery, the
notches or recessed portions being at different positions in the discs of the respective
stations, whilst the inclined or cam surface is arranged in one uniform position in
all the discs. Each disc is fitted 'so as to be capable of rotating by means of a
spring barrel and a train of gearing, but is held out of action by a stop intercepting
the anchor of the escapement. It is released by the act of directing a current or
electric pulsation into an electro magnet, the armature of which is then caused to
impart an end or sliding motion to the anchor spindle. The whole of the discs in
the circuit then rotate, but the bells are prevented from sounding by reason of the
solid part of the disc obstructing the anchor spindle, so that the hammer is retained
out of the range of the bell.
When however the notch or recessed portion of any disc arrives opposite the
end of the anchor spindle, the latter is free to be moved so as to bring the hammer
within the range of the bell; and if another electric pulsation be then directed
into the electro-magnet, the anchor spindle will receive another increment of
motion, and the bell will be sounded and will continue to ring (the spindle by reason
of a notch with which it is provided remaining engaged with the disc) until the
inclined or cam surface arrives opposite the spindle, when the spindle is forced
back and the escapement is again arrested. It will thus be understood that
although the discs of the several apparatus are rotated synchronously and are
stopped simultaneously at the same union point, yet the bell of the particular
station only with which it is desired to communicate is sounded, the bells of the other
stations remaining inoperative; by graduating therefore the disc at the central
station in accordance with the positions of the notches or recessed portions in the
discs of the several stations in the circuit, or noting the interval of time requisite
to bring the notch or recessed portion of the disc of any particular station into the
required position, the operator is enabled to send the second electric pulsation at
the exact moment to operate the bell hammer at such station.
In lieu of using clockwork to actuate the apparatus and sound the bells, I may
employ the agency of electricity for the purpose, notched or recessed discs being
used as before with the notches or recesses arranged at different points in the
respective discs, so as to admit of any particular bell being sounded by sending a
current or an electric pulsation when the notch or recess arrives at a given position,
whilst the hammers of the other bells are intercepted by the solid part of their
respective discs. In carrying out this modification I employ an electro-magnet
with two polarized armatures, which are so arranged as to respectively respond to
currents of opposite polarity. One of these armatures when actuated by the
emission of electric pulsations of suitable polarity imparts intermittent rotary
motion to the notched or recessed disc, and also to (in the case of the instrument
at a central station) to a pointer which moves over a dial, the motion being
communicated to the disc and pointer through the intervention of a pawl and
ratchet wheel or wheels. The other armature carries the bell hammer, and when

page_text: the notched or recessed disc is in a suitable position may be moved by the trans-
mission of an electric pulsation or pulsations and caused to strike the bell; I prefer
to employ two ratchet wheels, so arranged that the pawl acts upon them alternately.
This method of using two ratchet wheels and a common pawl may also be applied
to other electric or magnetic purposes, as, for example, to the actuation of the type
wheels of printing telegraphs, the two ratchet wheels being made of such relatively
different diameters that the difference in diameter of the two wheels will neutralize
the effect of the sequential action of two type wheels, so that two parallel lines
may be printed, the one directly beneath the other, instead of one in the rear of
the other, without the necessity for devices of a complicated character.
The switch board for use at the central station consists of two sets of metal bars
at right angles to each other, say, for example, vertical and horizontal; the one
set, say, for example, the vertical ones, communicating at one end with the
respective telephones on the circuit and at the other end with earth, whilst the other
set of bars, viz., the horizontal ones, are capable of forming a connection by means
of pins between any two vertical bars. Switch boards constructed generally upon
this principle have been heretofore employed. According to my present Invention
however, I connect the vertical bars with earth by means of spring contact picces,
and I arrange such bars so that they shall be capable of sliding into and out of
contact with the said pieces so as to establish or cut off the communication with
earth as required, simultaneously with the act of connecting or disconnecting the
vertical and horizontal bars. I further form the pins for connecting the hori-
zontal and vertical bars of a conical, inclined, or wedge shape, and I provide the
holes for the reception of such pins in the vertical bars above each horizontal bar,
and make such holes of a suitable shape and size, so that the act of inserting the
conical, inclined, or wedge shaped pins in their holes will have the effect of imparting
a sliding motion to the corresponding vertical bars, and thus severing the connection
with earth, whilst at the same time ensuring a more perfect electrical connection
between the horizontal bar and the two vertical bars of the instruments to be
placed in communication.
In order to adapt the switch board for use in the direct working of tele-
phones, that is to say, where the battery for the operation of the telephones is
placed at the central office instead of at the stations where the telephones are used,
I arrange the horizontal bars in pairs and connect each pair with a separate battery,
so that any two telephones may have a battery at the central office placed in their
circuit. With each battery I combine a signal bell, so that either of the subscribers
in communication with each other can call the attention of the switch board
operator.
In some cases I place between the spring contact pieces before referred to and
earth a combined annunciator drop and circuit changer, so that the act of notifying
the switch board operator will change the circuit from earth to the switch board
operator's telephone circuit.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said George Lee Anders in the Great Seal Patent Office on the
6th January 1882.
GEORGE LEE ANDERS, of Boston, Massachusetts, in the United States of America,
but at present residing at No. 6, Lombard Street, in the City of London.
"IMPROVEMENTS IN TELEPHONIC APPARATUS, PART OF WHICH IMPROVEMENTS IS
ALSO APPLICABLE TO OTHER ELECTRICAL OR MAGNETIC APPARATUS."
My said Invention, relating to improvements in telephonic apparatus, has
reference to the arrangement of the telephones themselves and to the construction
for signalling apparatus to be used with the telephones for communicating or
notifying from a central station to a branch station, and also to the construction of
the switch board to be used at the central station.
In carrying out my said Invention I combine both the transmitter (which is of
the type known as Hunnings or one of that class in which the handling ensures
its adjustment), and the receiver at each station in one and the same case with a
mouth piece, common to the two, and which may be provided with a communicating
tube or not, as desired, the connections being arranged so that the current passes
both through the transmitter and the receiver. By thus causing the sound waves
to act upon the receiver as well as upon the transmitter in the operation of
transmitting, I not only practically eliminate the resistance of the receiver, but am
enabled to evoke the influence of the receiver in cooperation with the transmitter
in the operation of transmitting, whereby the clearness or distinctness of the
articulation is augmented or improved.
In the case of district telephone systems in which a number of telephones are
arranged upon the same circuit, I construct the signalling apparatus so as to admit
of a notification being sent to any one station in the circuit, by ringing a bell at
such station without acting upon the bells of similar apparatus at the other stations
of the circuit with which it is not then required to communicate.
In the Specification to Letters Patent granted to Sydney Pitt, dated the
Second July, One thousand eight hundred and seventy nine, No. 2674, for an
Invention communicated to him by me, there are described apparatus known as
"Individual signal bells" operating upon this principle, the bells being rung by
electric agency. According to this part of my present Invention I employ a train
of clockwork or mechanical motor for actuating the signal apparatus and ringing
the bells, the escapement of which clockwork or motor is locked so that the motion
of the apparatus is arrested by the automatic mechanical action of the apparatus
itself, whilst the escapement is released so as to start the apparatus by electric
agency, and I arrange the several parts of the apparatus and combine them together
in the following manner-
The apparatus at each station is provided with a disc or its equivalent, having
an inclined or cam surface and a notch or recessed portion on its periphery, the
notches or recessed portions being at different positions in the discs of the respective
stations, whilst the inclined or cam surface is arranged in one uniform position in
all the discs. Each disc is fitted so as to be capable of rotating by means of a
spring barrel and a train of gearing, but is held out of action by a stop intercepting
the anchor of the escapement. It is released by the act of directing a current or
electric pulsation into an electro magnet, the armature of which is then caused to
impart an end or sliding motion to the anchor spindle. The whole of the discs in
the circuit then rotate, but the bells are prevented from sounding by reason of the
solid part of the disc or permit device obstructing the anchor spindle so that the
hammer is retained out of the range of the bell.
When however the notch or recessed portion of any disc arrives opposite the
end of the anchor spindle, the latter is free to be moved so as to bring the hammer
within the range of the bell; and if another electric pulsation be then directed into
the electro magnet, the anchor spindle will receive another increment of motion

page_text: and the bell will be sounded and will continue to ring (the spindle by reason of a
notch with which it is provided remaining engaged with the disc) until the inclined
or cam surface arrives opposite the spindle, when the spindle is forced back and
the escapement is again arrested. It will thus be understood that although the
discs of the several apparatus are rotated synchronously and are stopped simul-
taneously at the same unison point, yet the bell of the particular station only with
which it is desired to communicate is sounded, the bells of the other stations
remaining inoperative by graduating, therefore the disc at the central station in
accordance with the positions of the notches or recessed portions in the discs of the
several stations in the circuit, or noting the interval of time requisite to bring the
notch or recessed portion of the disc of any particular station into the required
position, the operator is enabled to send the second electric pulsation at the exact
moment to operate the bell hammer at such station.
This part of my said Invention is also applicable to other electrical or magnetic
apparatus than a telephonic apparatus where a similar system of signalling is
required.
The switch board for use at the central station consists of two sets of metal bars
at right angles to each other, say, for example, vertical and horizontal, the one set,
say, for example, the vertical ones, communicating at one end with the respective
telephones on the circuit, and at the other end or intermediately with earth, whilst
the other set of bars, videlicet, the horizontal ones, are capable of forming a connection
by means of pins between any two vertical bars. Switch boards constructed
generally upon this principle have been heretofore employed. According to my
present Invention however I connect the vertical bars with earth by means of
spring contact pieces, and I arrange such bars so that they shall be capable of
sliding into and out of contact with the said pieces, so as to establish or cut off the
communication with earth as required, simultaneously with the act of connecting
or disconnecting the vertical and horizontal bars. I further form the pins for
connecting the horizontal and vertical bars of a conical, inclined, or wedge shape,
and I make the holes for the reception of such pins of a suitable shape and size, so
that the act of inserting the conical, inclined, or wedge shaped pins in their holes
will have the effect of imparting a sliding motion to the corresponding vertical
bars, and thus severing the connection with the earth, whilst at the same time
ensuring a more perfect electrical connection between the horizontal bar or bars
and the two vertical bars of the instruments to be placed in communication.
In order to adapt the switch board for use in the direct working of telephones,
that is to say, where the battery for the operation of the telephones is placed at the
central office instead of at the stations where the telephones are used, I arrange
the horizontal bars in pairs, and connect each pair with a separate battery, so that
any two telephones may have a battery at the central office placed in their circuit.
With each battery I combine a signal bell, so that either of the subscribers in
communication with each other can call the attention of the switch board
operator.
In some cases I place between the spring contact pieces before referred to and
earth a combined annunciator drop and circuit changer, so that the act of notifying
the switch board operator will place his telephone in communication with the
station from which the notification has been received.
And in order that my said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose shall refer
to the several Figures on the annexed Sheets of Drawings, the same letters of
reference indicating corresponding parts in all the Figures.
Figures 1 and 2, Sheet 1, represent respectively a plan and transverse section of a
combined telephonic transmitter and receiver constructed and arranged according
to my said Invention.
Figure 3 represents a front sectional elevation of a telephonic signalling
apparatus constructed according to one modification of my said Invention.
Figure 4 is a plan, and Figure 5, a side view of the same.

page_text: Figures 6, 7, 8, and 9, Sheet II., represent respectively a part front view, vertical
section, back view, and sectional plan of a central station switch board, constructed
and arranged according to my said Invention.
Figure 10 represents a similar sectional view to Figure 7, but shewing a
connecting pin introduced for the purpose of raising a vertical bar for establishing
electrical communication with a desired circuit, as hereinafter more fully described.
Referring to Figures 1 and 2, A is the casing of my combined telephonic
receiving and transmitting apparatus, which may be conveniently formed of wood
or other suitable non conducting material; a is a mouth piece having communi-
cation common to both the transmitter B and receiver C by means of the bifurcated
passage a, a, to which if desired flexible or other convenient forms of sound
conducting tubes may be attached.
The transmitter B, which is of the type known as Hunnings, is located in a
convenient recess formed in the casing A. The receiver C may be of any suitable
known kind, and similarly located in a recess formed in the framing, both instru-
ments being so arranged that their diaphragms b and c shall come over the
bifurcate passage before referred to.
The transmitter is connected up with the receiver by the wires 1, 2, 3, the latter
communicating with the foil diaphragm b and one terminal of the electro magnet
of the receiver, and the wires 4 and 5 are attached to the other end of the helix,
as represented in the Drawing. It is obvious that any other equivalent connections
may be employed, provided that they be so arranged that both the transmitter and
receiver are in circuit and therefore subject to the same electrical influences and
conditions.
By forming the mouthpiece, common to both instruments, as previously described,
the sound waves are caused to act upon the receiver as well as upon the trans-
mitter, so that during the operation of transmitting the resistance of the receiver
is practically eliminated, and the receiver is likewise enabled to evoke a reciprocal
influence concurrent with the transmitter, whereby greater clearness or distinctness
of the articulation is obtained.
Figures 3, 4, and 5 illustrate my improved telephonic signalling apparatus for
use in district telephonic systems. E is an escapement ratchet wheel fixed on the
spindle e, and capable of receiving when free intermittent rotary motion from a
train of clock work through the intervention of a pinion e'. The anchor F of the
escapement gearing into wheel E is fixed to a rocking spindle f capable of sliding
longitudinally in its bearings formed in the framing plates d, d, and with the anchor
is connected the bell hammer i, the arrangement being such that when the anchor
spindle is in one position the motion of the apparatus is arrested, whilst when it
is in another position the apparatus is started, and the bell I may then under
certain conditions be sounded, all as hereinafter more fully explained. Upon one
end of the intermediate spindle G is fixed a disc g, having an inclined or cam
surface g and a notched or recessed portion g² formed on its periphery. The
relative positions of these notches or recesses vary in the discs of the instruments
at the several stations, but the position of the inclined or cam surface is the same in
all the instruments. The disc g is capable of receiving intermittent rotary motion
from the train of clockwork by means of the pinion g³, but after making one
revolution its motion is arrested by a stop pin e², which intercepts the anchor F of
the escapement. The release of the train of gearing is affected by means of an
electric current influencing the electro magnet H, the armature h of which
becoming attracted causes an endwise movement to be imparted to the anchor
spindle by means of the tail piece h', so as to move the anchor clear of the stop
pin e
All the dises of the instruments in the different stations in the circuit are
then caused to simultaneously rotate, but no one of the bells can be sounded until
a second electric impulse is directed into the electric magnet, when the disc
corresponding to the said bell is in such a position that its notched or recessed
portion admits of the anchor spindle being further protruded, so as to bring the
hammer within the range of the bell I. As, however, the operator is cognizant

page_text: of the position of the notches or recessed portions on the several discs he is able
to time the second electric impulse according to the particular station with which
he wishes to communicate.
When therefore the notched or recessed portion g² of the disc of the instrument
at the said station arrives opposite the end of the anchor spindle f the second
electric impulse is communicated by the operator at the central station, whereby
the anchor spindle f is moved forward, so as to bring the hammer i within range
of the bell I, and the latter is sounded under the action of the clock work and
continues to ring by the uniform periphery of the disc engaging in a guiding notch
or slit f' formed in the end of the spindle, so as to retain it in such position until
the inclined cam surface g' arriving opposite the spindle forces it back again to its
normal position, and the escapement and train of clock work is thus arrested.
It will therefore be understood that although the discs or permit devices of the
several instruments are actually simultaneously rotated and arrested, yet the bell
of the particular station only with which it is desired to communicate is capable
of being sounded. For, as before described, the first electrical impulse sets the
various instruments in action by moving the spindle with its anchor F clear of the
escapement stop e², but it is a second impulse which brings the hammer in range
of the bell, and this result can only be accomplished by the further end motion of
the anchor spindle through a notch on the disc definitely arranged for each station.
in the circuit.
By graduating therefore the disc at the central station in accordance with the
positions of the various notched or recessed portions provided in the discs of the
several stations in the circuit, or by noting the interval of time required to elapse
to bring the notched portion of a disc of any particular station into the requisite
position relatively to the sliding anchor spindle, the operator is enabled to transmit
the second electric impulse at the exact moment necessary to operate any signal bell
at a particular station with which it is desired to telephonically communicate.
This part of my said Invention may also be applied to other electrical or
magnetic apparatus than telephonic apparatus where a similar system of signalling
is required.
The switch board for use at the central station consists of two sets of metallic
bars, the one set fixed and the other capable of receiving reciprocating or sliding
motion, and which are placed at right angles to each other, as represented in
Figures 6 to 10 of the Drawings.. P is a series of vertical metal bars communicating
at their upper ends with the connections of the respective telephones in the circuit,
and by an intermediate contact with the earth when in their normal position, as
hereinafter explained, and Q is a series of horizontal metal bars arranged so as to
be capable of forming a connection by means of pins R between any two of the
vertical bars P. The connection of the vertical bars P with earth is formed by
means of spring contact pieces p¹ and studs p², and I arrange such bars so that they
shall be capable of sliding, so as to form and break the contact between the said
springs and studs, and thus establish or cut off communication with "earth' as
required.
"
I further form the pins R for connecting the horizontal and vertical bars Q and P
respectively with conical, inclined, or wedged shaped ends, and I provide suitable
holes p, q, for the reception of such pins in the vertical and horizontal bars, such
holes being in their normal position in slightly different relative planes, as shewn
clearly in Figure 7, so that the act of inserting the tapering pins in these holes will
have the effect of imparting a sliding motion to the vertical bars, thus severing the
connection with earth, and establishing communication with the desired telephonic
circuit through the medium of the contact springs T and horizontal bars; at the
same time a more perfect electrical connection is ensured between the horizontal
and the two vertical bars of the instrument to be thus placed in electric com-
munication.
It will now be understood that such change of circuit from earth to line or
conversely is automatically and simultaneously effected by the act of inserting and

page_text: withdrawing the connecting pin R from the holes provided in the vertical and
horizontal bars. The spring contacts T are always in communication with the
vertical bars, and assist their return to the normal position after the pins are with-
drawn so as to connect them with earth. The horizontal bars Q are arranged in
pairs with separate and independent batteries U, so that the switch board may be
used for the direct acting of the telephones. By this arrangement the battery for
the operation of any individual telephone circuit is placed at the central station
under the charge of the attendant, who is thus enabled to place any two telephones
in circuit.
0
A signal bell of suitable construction is combined with each battery, so that the
subscribers desiring to communicate with each other can call the attention of the
attendant in charge of the switch board. When it is necessary or desirable, I
place annunciator drops V₁ between the contact springs p₁ and earth, so as to
visibly indicate to the switch board operator the station desirous of having its
circuit changed from earth to a definite telephone circuit for the purposes of com-
munication, and I combine with the annunciator drops a circuit changer, consisting,
for example, of a longitudinal metal rod Y connected by a wire Z with the
telephone of the switch board operator, and otherwise connected up in the manner
shewn in the Drawing, so that the annunciator drop by the act of falling shall
automatically place the said telephone in circuit with the telephone from which the
notification has been received.
Now assuming that a certain subscriber, say at station 37, is desirous of commu-
nicating with station 40, as given as an example in the Drawings, then 37 will
notify the fact by sending an electrical impulse to the central office, which will be
transmitted through one of the contacts T and vertical bars P to earth via the
contacts p, p, and helices of the electro magnet, so as to cause the annunciator to
fall, as shewn at V1 (Figures 6 and 10), thereby placing the central telephone in
circuit with the telephone from which the notification has been received.
The operator in charge of the switch board will then enquire by telephone with
whom 37 is desirous of conversing. Taking station 40 as that which is to be
placed in communication, the operator informs such station of the fact, the warning
being acknowledged by the annunciator V2 falling out in a corresponding manner,
previously described.
The operator at the central office then inserts the tapering pins R, R¹, into the
proper respectives boles in the bars, as shewn at 2, 3, Figure 6, so as to raise the
vertical bars clear of their earth contacts, and bring the two telephone stations into
circuit by means of the horizontal bar connections, as illustrated in section at
Figure 10 of the Drawings. The established "line" communication between the
stations 37 and 40 would then be as follows:-t, normal line wire from 37 in
connection with contact springs; T¹, vertical bar 1 through pins R, R', to the
horizontal pair of bars 2 and 3, and by the vertical bar 4 and contact T2 to the
normal "line" wire of station 40.
When the automatic circuit changer is not employed one pair of the horizontal
bars may be appropriated for the use of the central telephone.
It will be readily understood that the sliding action of the bars may be obtained
by any equivalent means without departing from my Invention; for example, holes
may be provided only in the vertical bars above the horizontal ones, and the
wedging action of the pins against the sides of the latter will serve to raise the
former and still maintain the electrical connection.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried into
effect, I would observe in conclusion that what I consider to be novel and original,
and therefore claim as the Invention secured to me by the herein before in part
recited Letters Patent is,―
First. The combination of a telephonic transmitting apparatus (of the type of
what is known as "Hunnings transmitter ") and a telephonic receiving apparatus
in one and the same case, so that the sound waves shall act upon the receiving

page_text: apparatus as well as upon the transmitting apparatus in the operation of trans-
mitting, the connections being arranged in such a manner that the current passes
both through the transmitting apparatus and the receiving apparatus, all
substantially as and for the purpose herein before described.
Second. A series of individual signal bells, each provided with clockwork or a
mechanical motor arranged to be started by an electric impulse, and provided with
a notched disc or permit device which at predetermined intervals, differing in each
signal bell, admits of the clock work or mechanical motor ringing the bell on the
passage of a second electric impulse, substantially as herein before described.
Third. The combination in an individual bell of a rotary disc or equivalent device
having an inclined or cam surface and a notched or recessed portion of a clock
movement or mechanical motor for directly actuating the said disc or equivalent
device at a uniform velocity under the action of a combined pendulum and bell
hammer, and of an electro magnet for starting the clockwork by giving an end
movement to the pendulous bell hammer, and at a predetermined time (corresponding
to the position of the notched or recessed portion of the disc) giving a second end
movement to carry the pendulous bell hammer within range of the bell in order for
the latter to be mechanically sounded during the remaining portion of the rotation
of the disc until the incline or cam surface removes the hammer from the bell and
stops the clock work or mechanical motor, substantially as hereinbefore described.
Fourth. In a switch board consisting of two sets of intersecting bars, the one set
communicating with the telephones of the circuit and the other set normally com-
municating with earth, I claim so arranging the parts that the bars of the one set,
which form the communication with earth, shall be capable of sliding, in order
that the communication with earth may be cut off or established simultaneously
with the act of connecting or disconnecting the bars of the two sets, substantially
as herein before described.
Fifth. In a switch board consisting of two sets of intersecting bars, the bars of
one set of which are capable of sliding, I claim the combination with the two sets
of intersecting bars of pins of a conical, inclined, or wedge shape for making the
contact between the bars of the two sets, substantially as and for the purposes
herein before described.
Sixth. In a switch board consisting of two sets of intersecting bars, the bars of
one set of which are capable of sliding and are connected with earth by means of
spring contact pieces, I claim the combination with the apparatus of-a combined
annunuator, drop, and circuit changer, so arranged that the act of notifying the
switch board operator shall place his telephone in circuit with the telephone at
the station from which the notification has been received, substantially as herein-
before described.
Seventh. In a switch board consisting of two sets of intersecting bars, the one
set communicating with the telephones of the circuit and the other set commu-
nicating with earth, I claim arranging the bars of the set communicating with the
telephones in pairs, and connecting each pair with a separate battery, so that any
two telephones may have a battery at a central station placed in their circuit,
substantially as hereinbefore described.
In witness whereof, I, the said George Lee Anders, have to this my Speci-
fication set my hand and seal, the Fifth day of January, One thousand
eight hundred and eighty two.
GEORGE LEE ANDERS. (L.S.)