APPARATUS FOR CAUSING AN ELECTRICAL CIRCUIT TO BE CLOSED OR OPENED BY PASSAGE OF A RAILWAY TRAIN
Year: 1885

page_text: Opened by Passage of a Railway Train.
I, WILLIAM BUCK of No 31 Brondesbury Villas, Kilburn in the County
of Middlesex, Engineer do hereby declare the nature of my invention for
APPARATUS FOR CAUSING AN ELECTRICAL CIRCUIT TO BE CLOSED OR OPENED
BY PASSAGE OF A RAILWAY TRAIN to be as follows:-
"
"
My invention relates to apparatus arranged at some part of a railway line
in connection with the electrical conductors of a circuit in such a manner that
movement produced by the passage of a train over that part of the line shall close
or open the circuit. For this purpose, I attach to the rail by an elastic or jointed
bar a box containing mercury and having the conducting wires arranged relatively
to the level of the mercury in the box so that, when a wave of the mercury occurs
in consequence of the passage of a train, it makes or breaks the electrical connection
between the wires, in the one case the wave rising so as to cover the end of one of
the wires which is usually above it, and in the other case, the wave descending so
as to uncover the end of the wire which is usually immersed in it. In order that,
notwithstanding alteration in the level or attitude of the box, the mercury may
still retain a level suited to the position of the wires, I divide the box by a central
partition having a small hole through it, and whilst one of the wires is immersed
in the mercury so deeply that it can never be uncovered, the other wire terminates
at a point in the middle of the box just above or just below the level of the
mercury, according as it is desired to have contact made or broken by the wave.
In some cases instead of attaching the apparatus to the rail, I mount it beside
the rail with an arm projecting from it in such a position, that the wheels of a
passing train acting on this arm cause vibration of the mercury box so as to
produce waves of the mercury..
ABEL & IMRAY,
Agents for the Applicant.

page_text: Opened by Passage of a Railway Train.
I, WILLIAM BUCK, of N° 31 Brondesbury Villas, Kilburn in the County of
Middlesex, 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 :-
--
My invention relates to apparatus arranged at some part of a railway line in
connection with the electrical conductors of a circuit in such a manner that
movement produced by the passage of a train over that part of the line shall close
or open the circuit. For this purpose, I attach to the rail by an elastic or jointed
bar, a box containing mercury and having the conducting wires so arranged
relatively to the level of the mercury in the box that when a wave of the mercury
occurs in consequence of the passage of a train, it makes or breaks the electrical
connection between the wires, in the one case the wave rising so as to cover the
end of one of the wires which is usually above it, and in the other case, the wave
descending so as to uncover the end of the wire which is usually immersed in it.
In some cases, instead of attaching the apparatus to the rail, I mount it beside
the rail with an arm projecting from it in such a position that the wheels of a
passing train acting on this arm cause vibration of the mercury box so as to
produce waves of the mercury.
One form of apparatus according to my invention is shewn in front view in
Fig. 1 and in side view to a smaller scale in Fig. 2. Between two of the sleepers S
that support the rail R, a clamp A which is rigidly fixed to the rail is connected
by links B to the short arm of a lever C, the long upright arm of which carries a
box D containing mercury. This mercury is arranged, as will be presently
described, in such relation to wires E, F, that the electrical connection of these
wires is made or broken by the wave caused by the passage of a train along the
rail, the depression of the rail multiplied by the leverage of C giving to the box D
a longitudinal shake whereby the wave is generated. In a similar manner if, as
shewn in Fig. 3, the mercury box D be carried on a bent spring G, the longitudinal
shake imparted to the box D by the passage of a train will produce a wave of the
mercury in the box. Or, again, as shewn in side view in Fig. 4 and in plan Fig. 5,
the mercury box may be suspended by a bell crank lever H, the horizontal arm
of which has a pallet K that is depressed by the wheels of a passing train. There
may be other means of imparting to the mercury box the longitudinal shake for
producing the wave, it is most important however that the box and contact wires
should be so arranged as to provide against error arising from alteration in the
level or horizontality of the box itself. In order to provide effectually against
such errors, the contact is made or broken at the middle of the box as shewn in
Figs. 6 to 11 inclusive, so that, the capacity of the box being symmetrical on each
side of the contact wire, the accidental inclination of the box does not alter the
relation of the wire to the level surface of the mercury. Thus in Fig. 6, which is
a longitudinal section, and Fig. 7, which is a transverse section of the box D

page_text: containing mercury M, the one wire E near the bottom remains always immersed
in the mercury, the other wire F is situated in the middle of the box a little above
the level of the mercury when it is in repose, so that there is no electrical
connection of the two wires. When however the box receives a longitudinal
shake, the wave produced in the mercury makes contact with F and so for the
time electrically connects E and F. It is found that as shewn in Fig. 8, by
inserting in the box a partition L dividing it unequally, there is greater certainty
of the wave reaching the wire F when a moderate shake is given to the box. Or,
as shewn in Fig. 9, a wedge shaped obstruction N may be placed in the middle of
the box, causing the wave to mount over it. When the electrical connection of
the two wires has to be broken by the wave, the wire F as shewn in Figs. 10
and 11, is immersed a little in the mercury, either along a partition P as in Fig. 10
or without a partition as in Fig. 11. In that case contact is broken by the
uncovering of F when the hollow of the wave comes under it. In all these
arrangements of the mercury box, the wire F is placed in the middle, and
consequently the surface of the mercury in repose is always in the same position
relatively to the wire even when the box is not level but somewhat inclined either
way. Also when a partition is used as in Figs. 8, 9 and 10, there is a hole through
the lower part of the partition which allows the mercury always to take its repose
level, but which does not give so much passage as to affect the operation of the
wave in making or breaking contact.
Obviously when the wire E is intended to connect to earth, instead of
employing it as a conductor, the box D may itself be of conducting material. In
order more effectually to shake the box so as to produce a wave of the mercury,
the rail near where it is attached, may present a slight hollow or protuberance to
be acted on by the passing wheels.
As the making and breaking of electrical contact have been effected by the
movement of mercury in a tube or vessel relatively to conducting wires, I make no
general claim to that method of operating, nor do I claim generally the imparting
of such movements to mercury by the action of a passing train on a rail, but what
I claim is
Electrical contact apparatus wherein a vessel containing mercury extending
symmetrically on each side of a middle contact wire is mounted beside a rail in
such manner that the depression caused by a passing train magnified by the action
of a lever or spring on which the mercury vessel is mounted, gives longitudinal
movement to the vessel and thereby produces waves of the mercury, making or
breaking contact with the middle wire, substantially as herein described.
Dated this 30th day of December 1885.
ABEL & IMRAY,
Agents for the Applicant.