Improvements in Telephonic Arrangements or Systems Especially Adapted for Intercommunication in Houses, Offices, and the like.
Year: 1887

page_text: Date of Application, 21st Sept., 1887
Complete Left, 21st June, 1888
Complete Accepted, 27th July, 1888
PROVISIONAL SPECIFICATION.
Improvements in Telephonic Arrangements or Systems Especially
Adapted for Intercommunication in Houses, Offices, and the
like.
I ALAN ARCHIBALD CAMPBELL-SWINTON of 75 Queen Victoria Street in the City
of London Engineer do hereby declare the nature of this Invention to be as
follows:-
The object of my Invention is to provide telephonic arrangements or systems
especially adapted for intercommunication in houses offices and the like the said
arrangements or systems being simple and giving great facility in use.
The arrange-
ments or systems are employed in connection with direct acting telephones wherein
the transmitters receivers or the single instruments that may serve for both receiving
and transmitting batteries, if any are used to actuate the telephones and line wire are
all in the same circuit and are such that a number of stations can communicate each
with either of the others no central station being required. At each station the
telephone instrument is fitted with an electric bell or signal and a switch preferably
automatic in its action for inserting either the telephone or the bell or signal in the
circuit. The two terminals of the instrument are separately connected to the two
insulated metallic faces of what is known as a "Jack Knife" contact maker one wire
is required for each station besides two additional ones these additional wires being
run through to all the stations. Earth connections can be substituted for one of these
wires. At each station there is a switch board containing contact springs in number
equal to the stations each spring being connected to one of the station wires. Opposite
these contact springs but not touching them are fixed at each station two contact bars
one bar being short and opposite one spring only the other being long and extending
opposite all the remaining springs. The springs and bars are so placed that when
the "Jack knife" at a station is inserted between them it connects one terminal of
the telephone instrument to one spring and the other terminal to one bar.
At each station the short bar is placed opposite a different spring so that every
station has the spring that is opposite the short bar connected to a separate wire. The
short bars at all the stations are connected together by means of one of the additional
wires and the long bars are all connected together by the other of the additional wires
and a battery perinanently connected between these two wires serves for the whole
system.
Under ordinary circumstances the "Jack knife" at each station is left inserted
between the short bar and the spring opposite to it, the automatic switch or the tele-

page_text: phone instrument being in such a position as to connect the call bell in circuit When
the person at any station wishes to call the person at any other station. he removes his
"Jack Knife" from its position and inserts it between the long bar and the spring
connected to the particular wire that is connected to the spring opposite the short
bar at the station which he wishes to call and as the "Jack knife" at this latter station
is in contact with this spring and connects it through the call bell or signal to the said
short bar, this completes the circuit through the battery and rings the bell or gives
the signal at the station called and on the automatic switches being moved at both
stations the telephone instruments are placed in circuit with the battery between them
and conversation can be carried on between the two stations so connected.
In like manner any one station-can call up and communicate with any other.
Instead of using "Jack knives" to push in and pull out as described above a
circular or other sliding switch arrangement may be employed.
According to this plan the "Jack knife" at each station may be replaced by an arm
formed of two insulated metal plates or strips this arm being pivoted so that it may
be turned round or moved so that the two strips may make contact with contact pieces
or springs corresponding to the contact springs and bars in the "Jack knife" arrange-
ment which pieces may be arranged in a circle round the point where the arm is
pivoted the connections being effected as before.
In order to make this switch automatically return to the normal position, vizt. the
position in which it should remain when not in use, the said switch may be provided
with a spring or weight tending always to make it return to this position and a catch
arrangement may be fitted to retain it in any other desired position the said catch
being so connected to a hook on which the Telephone is hung that the weight of the
latter when hung up will withdraw the catch and allow the switch under the action of
its spring or weight to return to its normal position.
If more convenient each station may have its own independent battery and one of
the additional wires can be dispensed with. The battery at each station is in this case
inserted in the circuit between one conducting face of the "Jack knife" and the
terminal of the telephone instrument and one continuous long contact bar may be
employed at each station instead of the two bars as above described. Bars springs and
"Jack knives are so arranged that when the stations are in communication with
one another the batteries are connected in series so that both send their current in the
same direction and this may be effected by inverting the position of either the "Jack
knife or the contact springs and bars at one station and so shaping the "Jack knife"
and the apperture for it that the "Jack knife " can be inserted only in the proper
"
manner.
"
A switch may be used instead of the contact springs bars and "Jack knife" as
hereinbefore described and this switch may be made automatic in its action as also
hereinbefore described.
In the several arrangements hereinbefore described the call bells may be omitted
and instead thereof the calling may be effected by sending an intermittent electric
current through the telephone instruments thus producing a rattling sound sufficiently
loud to call attention.
36
"
The intermittance in the current may be conveniently made by means of a vibrating
electro magnetic contact breaker or by means of a contact breaker actuated by hand
and this may be combined with the Jack Knives or other switches hereinbefore
mentioned so that the turning of the said switches or the act of inserting the said
"Jack knives" may make or break the circuits rapidly in the manner required.
2
I
1
1000
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields,
Agonts.

page_text: COMPLETE SPECIFICATION.
Improvements in Telephonic Arrangements or Systems Especially
Adapted for Intercommunication in Houses, Offices, and the
like.
1, ALAN ARCHIBALD CAMPBELL-SWINTON of 75 Queen Victoria Street in the City
of 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:-
The object of my Invention is to provide telephonic arrangements or systems
especially adapted for intercommunication in houses, offices and the like the said
arrangements or systems being simple and giving great facility in use.
At each station the two
The arrangements or systems are employed in connection with direct acting
telephones, that is to say telephones wherein the transmitters and receivers (or the
single instruments that may serve for both receiving and transmitting) and line wire
are all in series with the batteries on the same circuit, and are such, that a number
of stations can communicate each with either of the others, no central station being
required. At each station, the telephone instrument may be fitted with an Electric
bell or Signal, and a switch, preferably automatic in its action for inserting either
the telephone or the bell or signal in the circuit. The arrangement at each station
may be as shewn at each of the stations 1 to 5 in Figure I of the accompanying
Drawings, where T, are transmitters, R, receivers, B, the bell or signal and S, the
automatic switch of ordinary or any convenient construction.
terminals of the instrument are separately connected to the two metallic faces j¹ j
(insulated from each other) of what is known as a
jack knife or plug contact
maker, which are shewn at J J. One wire is required for each station and also two
additional wires which latter are run through to all the stations. Earth connections
can be substituted for one of these wires. At each of the stations (of which 5 are
shewn in the drawing, but there may be any suitable number) there is a switch board
containing contact springs a³ a³ a³ a a³ in number equal to the stations, each such
spring being connected to one of the station wires as shewn. Opposite these contact
springs, but not touching them, are fixed at each station two contact bars, one contact
bar (1) being short and opposite one spring only, and the other bar (6) being long
and extending opposite all the remaining springs at each station. The springs (a to a³)
and bars 6 6 are so placed that when the "jack-knife" or plug J, at a station is
inserted between them it connects one terminal of the telephone instrument to one
spring and the other terminal to one bar. As shewn in Figure 1, the short bar bis
placed at each of the stations opposite a spring connected to a separate wire ¹ to ³,
and at each station the springs as to a are connected each to one of these wires -
to. The short bars b at all the stations are connected together by means of one of
the additional wires (that marked x,) and the long bars 62 are all connected together
by the other of the additional wires (that marked y,) and a battery C, Z, permanently

page_text: connected between these two wires, serves for the whole system. Under ordinary
circumstances, the "jack knife" or plug at each station is left inserted between the
short bar and the spring opposite to it, the automatic switch or the telephonic
instrument being in such a position that the call bell is in circuit. When the person
at any one of the stations wishes to call the person at any other of the stations, he
removes his "jack knife" or plug from its position between the bar 6¹ and its opposite
spring and inserts it between the long bar 62 and the spring connected to the particular
wire that is connected to the spring opposite the short bar at the station which he
wishes to call, and as the "jack knife' or plug at this latter station is in contact
with this spring and connects it through the call bell or signal to the said short bar,
this completes the circuit through the battery and rings the bell or gives the signal at
the station called and on the automatic switches being moved at both stations the
telephone instruments are placed in circuit through the battery and conversation can
be carried on between the two stations so connected.
In like manner, any one station can call up and communicate with any other-When
the battery employed is not powerful enough to ring the call bell through the
resistance of transmitting and receiving instruments, a short circuiting key or push
button K, (as shewn at station in Figure 1,) may be employed to cut out the said
transmitting and receiving instrument, when calling up.
In practice, the switch arrangement of contact springs and bars may be conveniently
arranged as shewn in back view in figure 7, and in cross-section in figure 7A
where a¹ to a are springs corresponding to the springs a¹ to as in Figure 1, and the
springs and are connected so as to correspond to the short and long bars & and 63
respectively in Figure 1. The several springs can conveniently be connected to
terminals t, to to, to which the outside wires are connected.
Figure 8 shews how the "jack knife " or plug J, may be conveniently constructed,
and being the two metallic contact pieces, insulated from one another, and
connected with the wires from the instrument, the whole being furnished with a handle
and made in a form convenient for inserting into the apertures between the contact
springs in the switch-board shewn in Figures 7 and 7^.
Instead of using "jack knives" or plugs to push in and pull out as described
above, a circular or other sliding switch arrangement may be employed, such as is
shewn in Figure 9.
"
According to this plan, the "jack knife" or plug at each station is replaced by arms
formed of insulated metal plates or strips, a and b, these arms being attached to a
central plate of insulating material, pivotted, so that it may be turned round or
moved, so that the two strips may make contact with contact pieces or springs corre-
sponding to the contact springs and bars in the "jack knife or plug arrangement,
these pieces being arranged in circles round the point where the arms are pivotted, the
connections being effected as shewn in the illustration in which the terminals are
marked similarly to those in figure 7, p and p which are as shewn always in
connection with the arms a and b being the terminals that have to be connected to the
telephone.
Or the arm b may be dispensed with as shewn in Figure 10, and its place be taken
by a spring which, when the switch is in the position shewn, is pushed by an
insulating pin d, into contact with a contact stop 61, and when the switch is in any
other position, the said spring is released and makes contact with another stop 62
the effect being similar to that obtained by the arrangements shewn in Figures 7
and 9.
In order to make these switches automatically return to the normal position, viz. ; the
position in which they should remain when not in use, the said switches may be
provided with a spring or weight, tending always to make them return to this position
and a catch arrangement may be fitted to retain the switch in any other desired position,
the said catch being so connected to a hook on which the telephone is hung that the
weight of the latter when hung up will withdraw the catch and allow the switch to
return to its normal position under the action of its spring or weight.

page_text: Figure 11 shews how this may be carried out w being the telephone hook drawn
up by the spring w² and resting when the telephone is on the hook upon a stop w³.
The lever of the hook has a tooth w engaging with one or other of the teeth in a
quadrant turning on a centre 2 and provided with a spring . When the telephone
is off the hook the tooth w engages with the tooth of the quadrant which is brought
opposite it when the switch is turned-When the telephone is put on the book the
tooth releases the quadrant and the switch is by the spring returned to its
normal position. Or an arrangement similar to that shewn in Figure 12 may be
employed the handle of the switch being made also the hook on which to hang the
telephone receiver and the arrangement being such that the hook is only in a proper
position to hang the receiver on it when it and the switch it operates are in the position
that is required as mentioned above.
If more convenient each station may have its own independent battery as shewn in
Figure 2 and one of the additional wires can be dispensed with as will be seen readily
by reference to the lower portion of Figure 2. The battery at each station is in this
case inserted into the circuit between one conducting face of the "jack knife" or plug
and one terminal of the telephonic instrument and one continuous long contact bar
may be employed at each station instead of the two bars as above described. Bars
springs and "jack knives are so arranged that when the stations are in communica-
tion with one another the batteries are connected in series so that both send their
current in the same direction and this may be effected by inverting the position of
either the "jack knife or plug or the contact springs and bars at one station and so
shaping the "jack knife or plug and the aperture for it that the " jack knife" or
plug can be inserted only in the proper manner.
22
"
For instance the apertures in the switch board may be made of the shape of a
segment of a circle and the jack knife being similarly shaped can only be inserted in
the position In this arrangement the batteries can be inserted either as shewn at
stations 1. 2 and 4 of the Figure or as shown at stations 3 and 5 and as above
mentioned a short circuiting keys k may be arranged as shown at stations 4 and 5
for the purpose of reducing the amount of battery power requisite to ring the bells.
When as can also be done with this arrangement the circular sliding forms of
switches are used it is necessary that these keys (k) should be used and the battery
power be so proportioned as not to ring the bells except when the keys are depressed.
If this were not done when a switch is turned round all the stations would be rung
up one after another but with the key and a proper amount of battery power this evil
is avoided.
-
The bells that are used in the several arrangements hereinbefore described need not
necessarily be of a form operated by the battery but may be of the magneto pattern
being operated by a small magneto electric generator of ordinary or any convenient
form Where magneto bells of this kind are used the arrangement of the connections
at each telephone instrument may be as shewn in Figures 3. 4 and 5 where B is the
Bell G the magneto generator and T and R the transmitter and receiver as before.
The automatic switch S may be employed either to connect generator and bell or
telephonic instruments as shewn in Figure 3 or merely to short circuit bell and
generator when speaking is going on as in Figure 5 or no automatic switch need be
used when the arrangement shewn in figure 4 may be employed.
In the several arrangements hereinbefore described the call bells may be omitted
and instead thereof the calling may be effected by sending an intermittent electric
current through the telephone instruments this producing a rattling sound sufficiently
loud to call attention.
The intermittance in the current may be conveniently made by means of a vibrating
electro magnetic contact breaker as is well known or by means of a contact breaker
actuated by hand as is well known and this may be combined with the "jack knives"
or plugs or other switches herein before mentioned so that the turning of the said
switches or the insertion of the said "jack knives" or plugs may make and break the
circuits rapidly in the manner required.

page_text: Having now described and particularly ascertained the nature of my said Inven-
tion and the manner in which the same is to be performed I declare that what I
claim is.
First. In telephone arrangements or systems the means whereby what I have termed
direct acting telephones at a number of different stations can be switched into direct
communication with one another the whole system being worked by one battery and
substantially as hereinbefore described with reference more particularly to Figure 1
of the accompanying drawings.
Second. In telephone arrangements or systems means whereby what I have termed
direct acting telephones at a number of different stations can be switched into direct
communication with one another these having a battery at each station substantially
as described with particular reference to Figure 2 of the accompanying drawings.
Third. In combination with the subject matter of either of the preceding claiming
clauses the several automatic or other switches substantially as hereinbefore described
and illustrated in the accompanying drawings.
Fourth. The combination with the telephone arrangements or systems as herein-
before claimed of the several arrangements of connections for the individual
stations substantially as hereinbefore described and illustrated. in the accompanying
Drawings.
Dated this 20th day of June 1888