IMPROVED CHAIRS OR SUPPORTS FOR DOUBLE-HEADED RAILS ON RAILWAYS
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by Daniel Biddle at the Office of the
Commissioners of Patents on the 12th November 1878.
DANIEL BIDDLE, of Kingston on Thames, in the County of Surrey, Surgeon.
"IMPROVED CHAIRS OR SUPPORTS FOR DOUBLE-HEADED RAILS ON RAILWAYS."
This Invention is intended to prevent by means superior to those hitherto
adopted that indentation of the lower head of double-headed rails which has caused
such rails, when turned, so rapidly to wear out. The support is applied to the
shoulders of the upper head, and to the sides of the narrow portion or web of the
rail, but to the edges only of the lower head. And the claim to novelty is set up
in respect of the methods (two in number) by which this is effected. The first
method is to be adopted where the traffic is heavy and the speed high; the second
method is to be adopted where the strain is lighter.
The first method consists in having a stout plate of iron to form the basis of the
chair, such plate being fastened by bolts to the sleeper. This plate is for the most part
flat, but is raised at the sides, and also has a groove in it directly underneath the
rail. This groove is shaped to receive half the lower head of the rail in such a
manner that the head shall be supported at its edges, but have a free space under
the greater portion. Between the rail and the raised edge of the plate on each side
of the rail lies firmly imbedded an iron block constructed so as to fit the hollow of
the rail, leaving however sufficient space for the flange of the wheels to pass easily,
and being gradually thinned down to a rounded edge, which corresponds with a
groove in the raised edge of the plate, such groove being placed laterally and facing
the rail.
These blocks, when the rail is in position, are more or less securely fastened to
the plate by bolts. The removal of one or both enables the rail to be changed or
turned readily. The rough hinge-action between the blocks and the raised edges
of the plate insures that the rail shall be firmly fixed on what is called the principle
of the Stanhope press.
The second method consists, like the first, in having an iron plate to form the
basis, but the shape of the plate is different. There is in it one broad groove having
overhanging edges. This groove is for the reception of a double chair, the halves of

page_text: which are identical in size and shape. Each half-chair consists of a single mass of
iron, comprising a horizontal portion, which fits into the groove afore-mentioned,
and two upright standards or "jaws," one on one side of the rail and one on the
other. These two standards are accurately fitted to the shoulders and sides of the
rail, and to the curved edges of the lower head, but leave the under surface free.
Instead of being placed opposite each other they are placed obliquely, and are far
enough apart to allow of the half-chair being adapted to the rail from beneath,
and then slid into position. The horizontal plates of the two half-chairs are so
shaped that the two lie partially side by side, and have a standard of each opposite
the similar standard of the other. This gives considerable stability to the structure
without the aid of any bolts, except those which fasten the basement-plate to the
sleeper. Indeed, in many instances sufficient stability would be afforded by one
half-chair, or by a single chair of larger dimensions, and if it were not for readiness
in changing the rail, such single chair might be bolted to the sleeper without need
of any intervening plate.