Apparatus for Making Electrical Contact by Passage of a Railway Train.
Year: 1894

page_text: Date of Application, 7th Aug., 1894
Complete Specification Left, 10th Apr., 1895-Accepted, 18th May, 1895
PROVISIONAL SPECIFICATION.
Apparatus for Making Electrical Contact by Passage of a Railway
Train.
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:--
The trigger or treadle, which is sometimes employed for making electric contact
when a train passes over it, is objectionable because contact may be made by it
accidentally or intentionally without the passage of a train, and also because it
becomes rapidly worn and damaged, being acted on by all the wheels that pass
over it.
My invention relates to the construction of trigger apparatus arranged to
operate in conjunction with a railway sigual or set of points in such a manner that
no contact can be made by it unless the signal or points be in a certain position,
and that, when a contact is made by the passage of a train, depressing the
trigger, the depression and the contact are maintained until the position of the
signal or points is altered. For this purpose, I pivot the trigger by the side of
the rail, preferably inside the rail so as to be operated on by the flange of the
wheel and I provide an arm connected to the signal pull or point rod, which arm
normally forms a stop to the tail of the trigger preventing the trigger from being
depressed. When, however the signal pull or point rod is moved in the one
direction this stop is withdrawn, and the trigger can then be depressed by passage
of a train. A rod connected to the tail of the trigger passes through packing
which has sufficient frictional hold on the rod to retain the trigger in its depressed
position and thus to keep it clear of the successive wheels of the train and to
maintain the contact made by its depression. But when the signal pull or point
rod is moved back, the arm connected to it acting on an incline on the tail of the
trigger, raises the trigger again, breaking the contact and retaining the trigger
in its raised position. The trigger is in the form of a blade sloped at each end and
of sufficient elasticity to yield to the passage of a wheel even when its tail is
stopped but without in that case making contact. The contact may be made by
metallic springs, mercury or otherwise.
Dated this 7th day of Anoush 1804
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Apparatus for Making Electrical Contact by Passage of a Railway
Train.
1, 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 :-
The trigger or treadle, which is sometimes employed for making electric contact

page_text: when a train passes over it, is objectionable because contact may be made by it
accidentally or intentionally without the passage of a train, and also because it
becomes rapidly worn and damaged, being acted on by all the wheels that pass
over it.
My invention relates to the construction of trigger or treadle contact apparatus,
arranged to operate in conjunction with a railway signal or set of points, in such a
manner that no contact can be made by it unless the signal or points be in a
certain position, and that, when a contact is made by the passage of a train
depressing the trigger, the depression and the contact are maintained until the
position of the signal or points is altered. For this purpose I arrange the contact
apparatus as I shall describe referring to the accompanying drawings. Fig. 1 is a
side view and Fig. 2 is a plan.
Inside the one rail A on a sleeper I fix a base plate B having a pair of
brackets C which form bearings for a rocking shaft S. On this shaft are fixed the
treadle E, which is an elastic blade, and a lever arm G which, being widened at H,
is sufficiently heavy to overbalance the blade E and keep its end up against a stop
pin F. In brackets D is mounted a rocking shaft M which extends beyond the
rail A to some convenient position where it has fixed on it a lever J connected
by a pull or rod to a signal or point motor. On each side of the lever arm G
is fixed a spring K between which G is pressed, and to G is linked a mercury
contact box L. In the position of the parts shewn a pin n on the arm N forms a
stop to the wide part H of the lever G, and consequently when the flange of the
wheels of a passing train pass over the blade E, they merely bend it down. But
when the lever J is moved in accord with the signal or point motor so as to throw
the arm N over to the position indicated in dotted lines removing the stop pin n
from the high part of H; in this condition of the parts the blade A is depressed
by passage of a train, and the arm G is raised canting the mercury box L and so
making contact.
The parts are held in this condition by the frictional pressure of the springs K
on G, the contact at L being thus maintained and the blade E held in its depressed
position so as not to be moved again by the successive wheels.
When the point or signal motor moves the lever J back to its former position
thereby moving the arm N to the right, its pin n moving along the slope of H
depresses Hand G and raises E thus breaking the contact at L and restoring the
parts to the condition ready to be operated by a succeeding train.
Obviously instead of a mercury box L canted by the movement of G, other
forms of contacts may be operated by that movement, and instead of employing
the frictional pressure of the springs K to hold G in its raised position, the friction
might be obtained by other means, such, for instance as by a rod connected to G
and passing through a stuffing box more or less tightly packed.
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 :-
Apparatus for making electrical contact by passage of a railway train,
constructed and operating substantially as described with reference to the
accompanying drawings.
D101
J
די
1000
ABEL & IMRAY,
Agents for the Applicant.