or Plate due to a Passing Train or other Moving Object for Signalling or other Purposes.
Year: 1885

page_text: or Plate due to a Passing Train or other Moving Object for
Signalling or other Purposes.
I, CHARLES DENTON ABEL, of No 28 Southampton Buildings, Chancery Lane
in the County of Middlesex, Consulting Engineer and Patent Agent, do hereby
declare the nature of my invention for "HYDRAULIC APPARATUS FOR UTILISING
THE DEFLECTION OF. A RAIL, BAR, OR PLATE DUE TO A PASSING TRAIN OR OTHER
MOVING OBJECT FOR SIGNALLING OR OTHER PURPOSES to be as follows:-
33
According to the present invention the slight deflection of a rail, bar, or plate
due to a passing weight such as a railway train etc. is caused to act upon a confined
body of liquid in such manner as to impart a considerably increased motion to a
portion of such liquid, such increased motion being available either for establishing
an electrical contact for signalling or indicating or imparting motion to a piston
operating some mechanical device for signalling or other purposes. The liquid is
for this purpose enclosed in a broad shallow vessel from which branches a tube of
small diameter that rises vertically to a certain height.
According to one arrangement the liquid is confined beneath a flexible diaphragm
or piston in the chamber, from which diaphragm or piston a stem passes upward
through the top of the chamber and is in contact with the surface of the rail, the
slight motion of which it is desired to impart in an increased inanner to the liquid
in the tube, so that such motion of the rail in depressing the diaphragm to a slight
extent will cause a portion of the liquid confined beneath the same to be forced up
the tube, the motion of the liquid in the tube being increased in proportion to the
ratio between the sectional areas of the liquid in the chamber and in the tube.
When the liquid employed is required to establish an electrical contact it consists
preferably of mercury and there is situated within the upper end of the tube the
insulated contact rod or wire of an electrical circuit the mercury being in electrical
connection either with earth or with another contact of the circuit so that on the
mercury rising in the tube it will close the circuit and actuate the signal. Or, the
mercury being insulated in the chamber and tube, there may be two or more

page_text: contacts of an electrical circuit in the upper end of the tube, which are connected
by the rising mercury so as to close the circuit or circuits. Or when a non con-
ducting liquid is employed, a small piston electrically connected to the body of the
vessel by a wire, is placed in the top of the tube, which piston, in being pressed
upward by the rising liquid, is caused either to close an electrical circuit or to
actuate a mechanical signal, or other mechanical device; in the latter case the
electrical connection between the piston and the body is not required.
The tube is by preference surrounded by a chamber communicating with the
interior of the tube by a side hole in the latter, so that any liquid overflowing the
top of the tube will fall into the chamber and pass thence back into the tube and
main vessel, when the pressure on the diaphragm is relaxed. Or the upper end of
the tube may be formed with an enlargement or cup for this purpose. The liquid
is by preference maintained at a higher level in the tube and surrounding chamber
than in the main vessel in order by the pressure of the head of liquid thus produced
to keep the stem of the diaphragm always pressed against the surface of the rail
or other object. Instead of the stem of the diaphragm being made to pass through
the top of the vessel, the top of the latter may be entirely closed and be made
sufficiently flexible to be depressed by the rail or other object and so actuate the
stem of the diaphragm; or in this case the top of the vessel may itself serve as the
flexible diaphragm acting on the liquid.
The apparatus is by preference connected to the rail, bar or plate by means of
arms projecting a certain distance on each side thereof and provided with claws by
which they are secured to the bottom of the rail &c, so that the flexure of the rail
between the said points of attachment due to a passing weight, will operate in the
above described manner upon the apparatus.
Instead of placing the apparatus directly in contact with the rail, it may be in
contact with the underside of its sleeper or support, so that the flexure of the latter
will operate the apparatus, and in order to obtain an increased amount of motion
for the diaphragm, the rail or its support may be made to act upon a lever or
combination of levers which in their turn act upon the diaphragm.
1
11 1
e
1007

page_text: Signalling or other Purposes.
I, CHARLES DENTON ABEL, of No 28 Southampton Buildings, Chancery Lane
in the County of Middlesex, Consulting Engineer and Patent Agent, 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:
According to this invention the slight deflection of a rail due to a passing train
acts on a flexible diaphragm covering a large area of mercury contained in a vessel,
so as to force a portion of the mercury up a tube sufficiently far to make contact
with an electric wire fixed therein, as will be understood on reference to the
accompanying drawings.
Fig. 1 is a side view of part of a rail between two sleepers shewing how the
mercury vessel A is attached thereto, Fig. 2 is a transverse section through the rail,
mercury vessel, and contact tube. The other figures shew modifications herein-
after referred to. The mercury vessel A is carried on, or preferably forms part of,
a bent bar or girder B which is attached to the rail by its two ends b b situated as
far apart as the space between two sleepers will allow. The surface of the
mercury in the vessel A. is covered by a flexible diaphragm C on which rests a
disc c and a plug D free to slide vertically in the cover of the vessel and bearing
against the lower side of the rail. From the bottom of the vessel A a passage
extends to a vertical tube E which stands up within a vessel F and has extending
into its upper part an electrical conducting wire G. Usually the mercury in E is
considerably below the wire G, but when the wheel of a train passes over the rail,
the slight deflection of the rail between the two points of attachment b b by
depressing the diaphragm C over a large area of mercury causes a considerable
rise of the mercurial column in the tube E so that it makes contact with the
wire G. Instead of the disc c and plug D interposed between the diaphragm and
the rail, the diaphragm itself may, as shewn in Fig. 2ª, be circularly corrugated
with a central protuberance bearing against the rail. By suspending the vessel A.
from the rail itself, the action of the apparatus is not affected by any subsidence
or change of position of the rail. As, after the descent of the mercury in the
tube E, some drops of it might remain held between the wire G and the tube,
thereby giving conduction, the upper part of the tube E is made of, or lined with
non-conducting material such as glass or ebonite. At the bottom of the vessel F
there is a small lateral hole f leading into the tube E to allow of the return of such
portion of the mercury as may be caused to overflow at the top of the tube E.
In order to prolong the duration of contact, a spring valve H may be inserted in
the tube E as shewn in Fig. 3. The valve H rises to allow a considerable quantity
of mercury to pass it upwards, but closes against its return. Contact is there-
fore maintained during a great part of the time occupied in the back flow of
the mercury through a small hole in the valve. Instead of placing the valve as

page_text: described in the tube E, it may be in another part of the passage, as shewn in
Fig. 4, and the upper part of the tube E may be expanded into a cup, so as to
hold a quantity of mercury that has to flow back through a small hole K leading
from the passage into the diaphragm vessel. Instead of one contact wire there
may be several, as shewn in Fig. 5, protruding into a tube and into a cup
surrounding its upper end.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim in respect of "Hydraulic apparatus for utilising the deflection of a rail
bar or plate due to a passing train or other moving object for signalling or other
purposes
is:
"
1. The combination of a vessel, containing a large area of mercury covered by
a flexible diaphragm pressed on by the rail, with a small vertical tube in which
is fixed a conducting wire, so that a slight depression of the diaphragm causes a
considerable rise of mercury in the tube, to make contact with the wire, substan-
tially as herein described.
2. Mounting the mercury vessel between two points attaching it to the rail;
so that the action of the apparatus is due only to deflection of the rail between
these points, without being affected by subsidence or change of position of the
rail itself.
ABEL & IMRAY,
Agents for the Applicant.