close

Вход

Забыли?

вход по аккаунту

?

код для вставки
Sept. 24, 1946.
'
I
R. E; DAVIS
SELECTIVE
'
SIGNALING SYSTEMv
~ 2,408,299
'
Filed NOV. 18, 1944
6S,5taiotnw, '.Bridg:
'Paul
Ring
2Sta wn mMlar'tpy
4Sta ion
-.Hv't_1/mTip
g
INVENTOI'Z
BY
' ,\
’
t
‘
ATTORNEY
Patented Sept. 24, 1946
\ 2,408,299
UNITED STATES PATENT OFFICE
I
2,408,299
_'
'
v ‘ SELECTIVE SIGNALING SYSTEMT
I
_
Rowland'Fenner Davis, Tuckahoe, N..Y., assignor
to American Telephone and Telegraph Com-
pany, a corporation. of New York.
.
Application November. 18, 1944, Serial No. 564,127
I 4 Claims. ' (Cl. 179-46) 7
1
2
.
-
Y
The connections, of- the; gas-?lled tubesare such
that the ringers are oppositely poled. Bridged
This invention relatesto selective systems and
more particularly to arrangements for causing
the selective operation of electro-responsive de
vices such, for example, as telephone ringers on.
a multieparty telephone line.
across the line are shown the signal responsive
means of stations 5 and 6. Each of these includes
a ringer such as the‘ ringers I6‘ and 18. These
ringers are‘ bridged across the line by means of
the gas-‘?lled tubes l5 and I‘! in such a manner
One of the systems utilized in the past to ac‘
complish selective signaling on multi-party tele
phone lines has utilized two stations connected
that; they are oppositely poled. At the central
o?i'ce would be provided a plurality of switches
between the tip side of the line and ground and
such as S1, S2,‘ ‘S3, S4, S5 and S6 for selectively
twov stations connected- between the ring side of
signaling the respectivestations 1,2, 3, 4, 5‘ and 6._
the line and ground. The stations connected to
V To‘ signal station I I,Y switch S1 would be oper
the’ tip side of the line would‘ be oppositely poled
ated. This would apply negative pulsating cur
and one would operate when» negative pulsating
rent to the tip side of the line; This negative
current was applied to the ‘tip and the other‘ would
operate when positive pulsating? current was ap-' 15 pulsating-current, in a manner well-known in the
art, would: cause-the gas-?lled- tube ‘I to break
plied to the tip. In like manner the two stations
down and operate the ringer 8. Thenegative
connected to the ring; side of the line would be
‘pulsating
current applied to the tip side ‘of ‘the
oppositely poled and one would" operate when neg
line, however, would not operate the ringer H], as
ative pulsating current was applied to the ring
and the other would operate when positive pulsaté 20' the arrangements at station 2 are oppositely poled
with respect to those of station I. 'In arrange
ing current was applied‘to the ring; Such a sys-v
ments used. in the‘ past, the operation of the
tem provides means for selectively signaling'four
switch S1 would apply ground to the ring side
stations. The arrangements‘ of th'e‘in'ventionpro
of the’, line duringv the ringing period to avoid
videmeans whereby additional stationsv may be
added to such asystemandthese additional sta 25 excessive noise on other cablev pairs due to cross
induction. However, in accordance with the ar
tions may also‘be selectively signaled without-in
rangements' o-fthis invention the switch S1 will‘
terference to or from the'previously mentioned
stations. In one embodiment of the invention
connect to theringiside of the lineone or more
antieresonant circuits such as l9 and 20. The
stations’ across the linezandl providing meansvv at‘ 30 anti-resonant circuit 25 would present a high im
pedance'at, for example; 20 cycles, which might
the central o?ice for preventing: the signaling
'
the pulsating current applied
currents normally used for operating the- original , be the frequency of
this is accomplished by. bridging oppositely poled‘;
to‘ the tip side of the line. ' The introduction of
four stations from affecting th'ebridged: stations.
Also the bridged stations are so connectedthat
the signaling currents 1 applied‘ to selectively ' 0p
this impedance by the anti-resonant circuit 20
35
erate them willnot affect‘ the original four sta
tions. Other. objects and featuresof theinven
would prevent the operation of the tubes and
ringers at stations 5. and 6. Because of the un
symmetrical wave shape of the pulsating current
appliedto the tip of the. line, it might be desirable
'tion will appear more fully. from the’ detailed
to provide an additional; anti-resonant circuit
The invention may be more fully understood 40 such as l9 to introduce sufficient impedance to,
description thereof hereinafter given.
the second harmonic of. the pulsating current
from the following description, together withthe
accompanying drawing, in the ?gure of which is
shown a circuit;~ diagramillustrating a; preferred
which might be transmitted over the line, so that
this second harmonic would not operate the gas
?lled tubes l5 and If‘! of stations 5 and‘ 6. It is
pointed
out that as the circuits is and 20 are not
In the drawing is shown a-line L which might 45
embodiment of‘ the invention.
.
-
anti-resonant at'the higher noise frequencies they
e?ectively. ground the ring side of the line with
respect to these frequencies and hence prevent ex
be a multi-party telephone» line. , Connected to
tlie'line'L area pluralityofst‘ations suchas I‘, 2,‘
3, 4, 51a'nd'6. Only the signal responsive arrange
ces's'ivei noise on other cable pairs due to cross
ments of these‘ stations" are illustrated; Stations
I and 2' are connected to ‘the tip of line L and each 50 induction. vTo operate the signal responsive
means at station 2 the switch. S2 would be op
includes a ringer such asthe ringers» Biand H].
erated.
This .would apply positive-pulsating cur
These ringers areconnected-tc the tip side of the
rent to the tip side. of'the line and, in a manner
line by means of ‘the gas-?lled’ ‘tubes; T and‘ 9
well-known inthe art, would cause the gas-?lled
The connections of'these tubes are such-that-the
stations land 2-are oppositely poled. connected
between the ring side of the line and ground
would be the signal responsive arrangements of
55
tube, 9‘ to operate and‘ cause the ringer i0 too-p
erate,butit.would1have no, effect. on the gas-?lled
tube ‘l and ringer 8'. In.like manner, the opera
tion of the switch Sewould connect the anti- .
stations 3 and 4. These each include the ringers
resonant circuits 2| and 22 similar to 19 and 201
such as 12 and I4 connected to the ring side of
to
the ring side of the line, so that the positive
60
the line through the gas-?lled tubes II and I3.
2,408,299
3
pulsating current or harmonics thereof would not
operate the signal responsive apparatus at sta
tions 5 and B. In a similar manner the opera
tion of either the switch S3 or S4 would cause
the signal responsive’apparatus at station 3 or
station 4 to operate by applying either negative
pulsating current or positive pulsating current to
the ring side of the line. When switch S3 is
operated, the anti-resonant circuits 23 and 24
would be connected to the tip side of the line,
and when switch S4 is operated the anti-resonant
circuits 25 and 26 would be connected to the
tip side of the line to prevent the operation of
the signal responsive apparatus at stations 5 and.
6. To operate the signal responsive apparatus
at station 5, the switch S5 would be operated.
This would apply negative pulsating current out
over the tip side of the line and back over the
4
each other and operatively connected between
the other side of said, line and ground, certain of
said devices being oppositely poled with respect
to each other and operatively bridged across said
line, switching mechanism for connecting posi
tive or negative pulsating current between one
side of said line and ground to selectively oper
ate any of thesignal responsive devices con
nected to said side of the line, means connected
by said switching mechanism between the other
side' of the line and ground for presenting su?i
cient impedance to said pulsating current to pre
vent its operation of said devices bridged across
said 'line, and additional switching means for
connecting positive or negative pulsating current
across said line to selectively operate any of said
signal responsive devices bridged across said line.
3. A line having a plurality of signal responsive
devices connected thereto, two of said devices be
ring side of the line, and would cause the gas
?lled tube I5 to break down and operate the 20 ing oppositely poled with respect to each other
ringer IS. The gas-?lled tubes utilized have a
and connected between one side of said line and
de?nite break-down voltage as, for example, of
ground, another two of said devices being oppo
between 65 and 70 volts. The voltage connected
sitely poled with respect to each other and con
to both sides of the line by the operation of switch
nected between the other side of said line and
S5 is su?‘icient to operate the gas-?lled tube 15.
~ ground, another two of said devices being oppo
However, this Voltage will not operate the tubes 1
sitely poled with respect to each other and bridged
and 13 because they would be connected in series
across said line, switching mechanism for con
with each other and the resulting voltage applied
necting positive or negative pulsating current be
thereto would be too low. In like manner, the
tween one side of said line and ground to selec
voltage applied-to both sides of the line would
tively operate either. of the signal responsive de
3,0
not operate the gas-?lled tubes 9 and l I, as they
vices connected to said side of the line, circuits
would be connected in series with each other and
anti-resonant at the frequency of the pulsat
I the resultant voltage would be too low to cause
ing current and harmonics thereof, and means
them to operate. In like manner, the operation of
controlled by said‘ switching means for connect
switch S6 would apply a positive pulsating cur
ing said anti-resonant circuits between the other
rent to both sides of the line of su?icient voltage
side of the line and ground to prevent the pulsat
to cause the tube I‘! to break down'and operate
ing
current‘ or harmonics thereof from operating
the ringer 18 at station 6. As this voltage would
said devices ‘bridged across said line.
be applied to tubes 1 and I 3 in series and to tubes
4. A line having a plurality of signal respon
5 and I I in series, the resultant voltage would not 40
‘ sive devices connected thereto, tWo of said devices
be suf?cient to break these tubes down.
being oppositely poled with respect to each other
While this invention has been disclosed as em
and operatively connected between one side of
bodied in certain speci?c forms which are deemed
said line and ground, another two of said devices
desirable, it is understood that it is capable of
being oppositely poled with respect to each other
embodiment in many and other widely varied
» and operatively connected'between the other side
form-s without departing from the spirit of the in
of said line and ground, another two of said de
vention as de?ned by the appended claims.
vices being oppositely poled with respect to each
What is claimed is:
other and operatively bridged across said line,
1. A line having a plurality of signal respon-i
sive devices connected thereto, certain of said 50 switching mechanism for connecting positive or
negative pulsating current between one side of
devices being oppositely poled with respect to each
said line and ground to selectively operate either
other and operatively connected between one side
of the signal responsive devices connected to said
of said line and ground, certain of said devices
side of the line, means connected by said switch
being oppositely poled with respect to each other
ing mechanism between the other side of the line
and operatively connected between the other side
and ground for presenting sui?cient impedance
of said line and ground, certain of said devices be
to said pulsating current to prevent its operation
ing oppositely poled with respect to each other
of said devices bridged across said line, and addi
and operatively bridged across said line, switch
tional switching means for connecting positive or
ing mechanism for connecting positive or nega
negative pulsating current across said line to se
tive pulsating current between one side of said
lectively operate either of said signal responsive
line and ground to selectively operate any of the
devices bridged across said line, each of said
signal responsive devices connected to said side
signal responsive devices including a gas-?lled
of the line and means connected by said switch
discharge tube and a ringer connected to said
ing mechanism between the other side of the line
line‘through its associated tube, the break-down
and ground for presenting sufficient impedance
to said pulsating current to prevent its operation ', voltage of each tube and the voltage of the pulsat
ing current utilized being such that the applica
of said devices bridged across said line.
tion to a single tube of the voltage of the pulsating
2. A line having a plurality of signal respon
current will cause it to operate but the application
sive devices connected thereto, certain of said
of the voltage of the pulsating current to two of
devices being oppositely poled with respect to
said tubes connected in series will not cause them
each other and operatively connected between
to operate. ,
'
one side of said line and ground, certain of said
ROWLAND FENNER DAVIS.
devices being oppositely poled with respect to
Документ
Категория
Без категории
Просмотров
0
Размер файла
405 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа