IMPROVEMENTS IN RAILWAYS
Year: 1879

page_text: PROVISIONAI, SPECIFICATION left by James Clark Bunten at the Office of
the Commissioners of Patents on the 14th March 1879.
JAMES CLARK BUNTEN, of Glasgow, in the County of Lanark, North Britain,
Machinist and Ironfounder. "IMPROVEMENTS IN RAILWAYS."
"
This Invention has for its object the construction of railways in an improved,
simple, durable, and economical manner, and entirely of metal.
In carrying out the Invention according to one modification transverse sleepers
of wrought iron or steel are employed, each sleeper being formed out of a long
rectangular plate of suitable size shaped by a stamping operation, so as to have a
trough-like form with a semicircular or curved or partly curved cross section, except
at the ends, which are made spherical or spheroidal with the corners of the original
plate projecting horizontally or nearly so. Combined with this sleeper, which is
placed with its convex side uppermost, there is for each rail a single-jaw chair
specially designed for rails of the double-headed or double-bulb or I section, but
capable of modification to suit rails of other sections. The single jaw of the chair
is on the inner side and engages with the bottom bulb of the rail, whilst a
movable jaw is provided for the outer side of the rail, and is shaped to bear on the
upper part of the bottom bulb, and also against the upper part of the web. The
movable jaw is formed with a horizontal or nearly horizontal palm of which the
outer edge or part of the underside bears against one or more projections formed
for it on the chair base. The outer edge of the palm and the projection or rib
against which it bears are by preference curved to allow the movable jaw to
adjust itself so as to bear evenly with its entire width against the rail. The
movable jaw is fixed by a screw bolt or cotter bolt passing through it and through
the chair and sleeper; and the chair is additionally kept in position on the sleeper
by one or more snugs or projections formed on its under side, and engaging in a
hole or holes made in the sleeper; or if found necessary the chair may be
additionally secured to the sleeper by a screw bolt or a cotter bolt. The underside
of the chair and the surface of the sleeper are by preference shaped relatively to
each other, so as not to be in contact at the part where the bolt passes until the
nut of the bolt is screwed or cottered up, so that the part of the sleeper may be
slightly sprung by the screwing or cottering action, and thus be made to exert an
elastic pressure on the bolt which will make the nut less liable to become loose.
A spring washer or other suitable known contrivance may also be used for
preventing the loosening of the nut; two screw or cotter bolts may be used for
fixing the movable jaw; no other fastening or key is required.

page_text: The chair may be modified by making the jaw cast on it of a form projecting
sufficiently to bear on the web of the rail or just under the upper bulb, and in this
case the movable jaw need not be made with the part bearing on the lower bulb of
the rail.
The improved chair hereinbefore described may be used with "bowl" or other
wrought-iron or steel sleepers differing from that herein before described.