Improved Method of Jointing Rail Lengths of Railways and Tramways.
Year: 1898

page_text: Date of Application, 5th Apr., 1898-Accepted, 7th May, 1898
COMPLETE SPECIFICATION.
Improved Method of Jointing Rail Lengths of Railways and
Tramways.
I, HERMAN WAHL FALK, of The Falk Manufacturing Company, of Milwaukee,
Wisconsin, United States of America, Manufacturer, 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 :-
This invention relates to that method of jointing the rail-lengths of railways and
tramways in which the ends of the rails to be joined are placed closely end to end
within a mould, into which molten cast iron is then run so as to form a coupling sleeve
which is practically weld-jointed to the ends of the rails.
This method of jointing is subject to two difficulties; on the one hand the
unavoidable heating of the rail-ends on casting the sleeve thereon and the consequent
expansion thereof produces deformations of the rails which are injurious to the traffic
of the line, and secondly the changes of temperature to which the rails are subjected
produce compressional and tensional strains which also act injuriously on the
line.
The present invention relates to a method of operating whereby the said
disadvantages of the above described method of jointing are obviated. In forming a
continuous line of rail by welding the abutting rail ends together, any detrimental
deformation due to compressional strains produced by the expansion of the rail in
hot weather can be obviated if the rail be firmly supported at points sufficiently
near together, so that it cannot bulge laterally between the supports.
On the other hand, the detrimental effects due to tensional strains, which may
result in the tearing apart of the welded joints, cannot be readily guarded
against.
The present invention has for its object, firstly, to effect the weld-jointing of the
rails in such a manner that tensional strains do either not occur at all, or only to a
very slight extent, and secondly, to prevent any deformation of the abutting rail
ends by their heating and expansion when casting the jointing sleeve round
them.
The deformation of the rail ends is due to the fact that on casting the sleeve
round them, they become heated to the degree at which the metal becomes soft, and
as the expansion due to such heating cannot take place entirely in the outward
direction from the joint, it follows that the soft abutting ends, in being forced
together, are bulged upwards. By this action the length of the line of rail becomes
shortened to an extent corresponding to the amount of bulging or setting-up of the
joint, so that on the cooling and contraction of the rail considerable tensional strains
are set up therein.
It is therefore a main object of the present invention to prevent such bulging
or setting up of the abutting rail-ends, and this is effected by the employment
of means whereby a considerable downward pressure is exerted upon the rail heads
at the joint, so as to prevent their rising.
The rail heads being left exposed to the air during the process of casting the
jointing sleeve, they do not become softened like the other parts, and consequently
.מ

page_text: if held against such rising, as described, they will withstand the tendency to set
up the joint and the consequent shortening of the rail, so that the occurrence of
tensional strains will be prevented by this means.
The accompanying drawing shews by way of example one arrangement for carrying
out this part of the invention.
Figure 1 shews a side view of a rail joint with the pressure device applied thereto.
Figure 2 shews a cross section.
The device consists of a strong stirrup or bridge-shaped bar D D¹ D2, of which
the parts D1 D2, are formed with claws, d d, adapted to fit under the bottom
flanges of the rail ends A A. At the middle of the bar is a threaded hole through
which is screwed a strong screw spindle E having at its lower end a plate E¹ the
underside of which is formed to fit closely upon the surfaces of the two abutting
rail heads, at the joint, so that on screwing down the screw E, a considerable"
downward pressure is exercised upon the two rail ends, which effectually prevents
them from rising as above described when the cast iron is being poured in the mould B
for forming the coupling sleeve F.
The mould B is preferably made in two halves B1 B2 for facility of removal. The
holes are the usual holes for the fish bolts, through which the cast iron runs in
casting; but these holes are not essentially necessary.
But other precautions are necessary besides those above described for preventing
the occurrence of tensional strains in the rail. If only a single such joint were made
in a line of rail, leaving the length of rail on one or both sides free to shift by
expansion, then the contiguous rail lengths would be shifted longitudinally to a
corresponding extent by the expansion of the heated joint, so that on then proceeding
to make consecutively a number of other joints along the line, a considerable total
expansion and elongation of the line of rail would be produced, and this, on the
cooling of the rails, would produce considerable tensional strains resulting in
ruptures.
This action is prevented according to the present invention by the following method
of proceeding.
A number of rail lengths are laid closely end to end, and a considerable number of
the joints are prepared simultaneously for the casting operation. The number of
joints thus prepared will vary considerably according to circumstances; thus if the
rails are so secured to the permanent way as to offer considerable frictional resistance
to longitudinal shifting, or if the line is being made in an uphill direction, so that
the action of gravity would operate against such shifting, comparatively few joints
need be simultaneously prepared.
Before the casting of these joints is proceeded with, iron or steel wedges are
driven into any crevices that may exist between some of the joints owing to imperfect
fit, and the clamping devices DE are then fitted upon all the joints which it is
considered necessary to prepare simultaneously, such for instance as ten or fifteen;
the casting moulds are then fitted on, and the cast iron is run in, either simultaneously
or as rapidly as possible one after the other. The clamps DE are left in position
until the joints have cooled down to such an extent that the compressional strains
have either entirely disappeared or have at least been so reduced that no upward
bulging at the joints can be caused thereby. The clamps are then removed, and
any projecting ends of the wedges driven in the joints are cut off.
A line of rail thus prepared will not be injuriously affected by either hot or cold
weather.
As the making of the joints proceeds in the above described manner, it is advisable
to progressively prepare other joints in advance of the last one where the casting is
being effected, as otherwise the same effects of expansion and shifting of the rail
lengths as above described would take place. For this purpose the clamps are
removed from those cast joints in the rear that have cooled sufficiently, and are fitted
on to the said joints in advance.
The before mentioned driving in of the wedges at the prepared joints is necessary

page_text: because otherwise the open joints on each side of the place of casting would be closed
up by expansion, and tensional strains would result.
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 :-
A method of jointing rail lengths by casting metal round the abutting ends thereof,
which consists in first placing a number of rail lengths closely end to end, then driving
wedges into any crevices between the abutting rail ends, then applying clamps or
equivalent devices simultaneously to a number of the rail joints so as to exercise a
downward pressure upon the heads, and then fitting casting moulds round the said
joints and running molten metal into them, the clamps being left upon the joints until
these have cooled down sufficiently to prevent bulging or setting up, substantially as
and for the purposes described.
ABEL & IMRAY,
Agents for the Applicant.