Improvements in Electrical Time Switches for Signalling.
Year: 1893

page_text: Date of Application, 20th June, 1893
Complete Specification Left, 14th Mar., 1894-Accepted, 14th Apr., 1894
PROVISIONAL SPECIFICATION.
Improvements in Electrical Time Switches for Signalling.
I, EDWARD TYER, of Ashwin Street, Dalston, in the County of London, Electrical
Engineer, do hereby declare the nature of this invention to be as follows:-
Special signals are often electrically transmitted from one station to another, as
for instance ou a railway, by various numbers of strokes on a bell or gong, each
number of strokes signifying a particular signal.
The operator to whom the signals are addressed, may, without waiting to hear
the whole number of strokes intended to be given, make some electrical connection
which, being inconsistent with the intended special signal, may involve serious
danger.
My invention relates to means of preventing any such electrical connection from
being made until a certain time has elapsed after the greatest number of strokes
required for any special signal may have been given. For this purpose, in the
conducting line forming part of any circuit that can be closed in obedience to a
signal, I introduce a time switch which is of the following description. An electro-
magnet when excited by the signalling current or by a current transmitted by a
relay operated by the signalling current, attracts its armature.
To this armature I attach a partitioned vessel containing mercury. When the
armature is attracted, this vessel is canted at each stroke of the bell or gong, but,
as there is only a small hole through the partition, the mercury has not time to flow
from the one compartment to the other. When the last stroke of the bell or gong
has been given, the signalman at the distant station, by holding down his trans-
mitting key, keeps the vessel in a canted position so that the mercury flows into
the other compartment, and rises therein to meet a conductor projecting into the
compartment. The circuit is thus closed for the special sigual.
In order to avoid the repeated canting of the mercury vessel during the
transmission of ordinary signals, I connect a spring contact to the time switch,
which keeps it out of circuit until the signalman, by depressing a button when the
special signal is required, permits that signal to be received. In a modified
form of time switch, the armature, instead of acting on a mercury vessel, is retarded
by being connected by gearing to a flyer, so that contact is not made by it until
sufficient time has elapsed after all the signalling strokes have been made.
Dated this 20th day of June 1893.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Electrical Time Switches for Signalling.
I, EDWARD TYER, of Ashwin Street, Dalston, in the County of London,
Electrical 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 :-
Special signals are often electrically transmitted from one station to another, as
for instance on a railway, by various numbers of strokes on a bell or gong, each
number of strokes signifying a particular signal.
The operator to whom the signals are addressed, may, without waiting to hear
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page_text: the whole number of strokes intended to be given, make some electrical connection
which, being inconsistent with the intended special signal, may involve serious
danger.
My invention relates to means of preventing any such electrical connection from
being made until a certain time has elapsed after the greatest number of strokes
required for any special signal may have been given. For this purpose, according
to one arrangement shewn in plan by Fig. 1 of the accompanying drawings, and in
end view partly in section by Fig. 2, in the conducting line A A forming part of
any circuit that can be closed in obedience to a signal, I introduce a time switch
which is of the following description.
An electromagnet B B when excited by the signalling current or by a current
transmitted by a relay operated by the signalling current, attracts its armature CC.
To this arinature attach a partitioned vessel D containing mercury. When he
armature C is attracted, this vessel is canted at each stroke of the bell or gong,
but as there is only a small hole through the partition, the mercury has not time to
flow from the one compartment to the other.
When the last stroke of the bell or gong has been given, the signalman at the
distant station, by holding down his transmitting key, keeps the vessel in the canted
position indicated by the dotted lines D' so that the mercury flows into the other
compartment and rises therein to meet a conductor E projecting into the compart-
ment while at the same time another conductor F is in contact with a spring G
forming part of the circuit A A. The circuit A A is thus closed for the special
signal.
In order to avoid the repeated canting of the mercury vessel during the
transmission of ordinary signals, I connect a spring contact H to the time switch,
which keeps it out of circuit until the signalman, by pressing in a button K, when
the special signal is required, makes contact at h for the switch. In a modified
form of time switch shewn in plan by Fig. 3 and in side elevation by Fig. 4 the
armature, instead of acting on a mercury vessel, is retarded by being connected by
gearing to a flyer so that contact is not made by it until sufficient time has elapsed
after all the signalling strokes have been made.
As shewn in Figs. 3 and 4 X is the line wire, Y the wire to bell and earth,
A A are the conductors for the special signal, B B is the electromagnet and C its
armature, the lever of which, extended upwards, bears with a roller against a
lever L to which it is also attached by a spring. The lever L is connected through
multiplying gear M to a flyer N, by which the movement of the lever Lis
rendered comparatively slow, and consequently the contact for the special signal
is not made until sufficient time has elapsed for completion of the whole number of
signalling strokes.
As in the construction first described, the time switch is kept out of circuit by
a contact spring H which completes the line circuit at contact until the
operator, by pressing a button K breaks the line contact at ', and then the
armature lever C moved by the electromagnet acts on H so as to make contact at h
for the special signal.
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. An electrical time switch, substantially as described with reference to
Figs. 1 and 2 of the accompanying drawings.
2. The modified time switch substantially as described with reference to
Figs. 3 and 4.
1
L 1004
ABEL & IMRAY,
Agents for the Applicant.