IMPROVE- MENTS IN CHAIR SUPPORTS FOR THE RAILS OF RAILWAYS
Year: 1866

page_text: PROVISIONAL SPECIFICATION left by Alfred Davy at the Office of
the Commissioners of Patents, with his Petition, on the 30th November
1866.
I, ALFRED DAVY, of Park Ironworks, Sheffield, in the County of York,
Engineer, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN CHAIR SUPPORTS FOR THE RAILS OF RAILWAYS," to be as follows:-
In the permanent way of railways it has been found that a certain amount
of elasticity is necessary in the bearing supports of the chairs and rails;
heretofore this for the most part has been obtained by the employment of
wooden sleepers, which in themselves are elastic, and being light in weight
derive a further amount of elasticity from the ground on which they rest;
this latter is objectionable to the permanence of the way, as the sleepers
ultimately begin to rock or become loose in their beds, and require constant
attention and occasional packing up. Where stone sleepers have been
employed the necessary elasticity has been attempted to be obtained by the
introduction of wood or some slightly elastic material between the chairs and
the sleepers, or even between the rails and chairs or their other immediate
supports; this system, however, is objectionable, as the elasticity so obtained
affects the bolts or connections between the rails and sleepers, tends to loosen
their hold, and is therefore highly objectionable.
Now my Invention relates to a chair support which, while being entirely of
metal, has in itself all the elasticity required, Lut which at the same time

page_text: provides for a rigid connection with a stone sleeper, or other hard, heavy, and
enduring support, which connection will not be affected by the elasticity of the
chair, the chair being composed of a stiff and rigid part, which forms the
surface in immediate contact with the stone or it may be cast-iron sleeper,
and an elastic part which forms the part in immediate contact with the rail;
the whole being, by preference, of one and the same piece of metal; moreover
the elasticity is utilized also for the purpose of holding the rail in the chair,
while at the same time the greater the weight placed on the rail the tighter
it will be gripped in the chair.
In the Drawing annexed I have represented a chair in illustration of my
Invention; it may be made in various other forms, but I have found a chair
of this form to answer all requirements.
Figure 1 represents a side view of this chair, and section of the rail held
therein; and Figure 2, a side view of the rail, and end view of chair; this
chair is made of a bar of metal of sufficient breadth for the breadth of chair
required; it is doubled at a, and bent in the form shown in Figure 1 (or it
may be in other suitable form, according to the rail to be held and otherwise),
and the ends welded together at b, thus the stretcher piece A is a rigid part,
while
part B, B¹, B, (B, B, forming the cheeks of the chair) is elastic. For
a rail such as shown a key D is necessary, which may be a solid piece of iron;
à rail being placed in this chair and wedged up by the key D will be gripped
by an elastic pressure, and any weight placed on the rail will receive an elastic
support from the part B, B', B, of the chair, which is capable of depression,"
until the under part B' below the rail comes in contact with the stretcher
part A. The elasticity is of course graduated, so that such contact would not
occur except under excessive and extraordinary weights. The ends a, b, are
furnished with bolt holes or other means of fastening to the heavy rigid
sleepers, which I prefer to use; these fastenings not having any tendency to
displacement by reason of the elastic action of the chair will tend to remain
permanently fixed, at least will have no cause of disturbance in consequence
of the elastic support derived from the chair. Some forms of rails may be
conveniently fixed in these chairs without wedges or keys, where the mid-rib
of the rail is nearly as broad as the bottom part, as in that case it is simply
necessary to spring the chair open and drop the rail into its place; I prefer
to make these chairs of spring steel, which I harden and temper as may be
required to afford the necessary elasticity, but iron or other metal sufficiently
hardened and elastic may be used for the purpose; for instance, wrought iron,
case hardened or partially converted into steel, may be used, and either
tempered or not, as may be required, the object being to produce a chair in

page_text: one piece of metal, a certain extent of which is elastic while the other remains
rigid, as and for the purpose described.
Instead of fixing these improved chairs on sleepers of stone or iron, as
before-mentioned, they may be fixed on sleepers of wood or other material.
Instead of making the chair absolutely in one and the same piece of metal it
might be made in two pieces to answer the purposes required, but I prefer it
as above described; for instance, the base or rigid part A may be made of one
piece thickened at each end so as to form abutments for the feet or ends of
the spring part B, B', B. The abutments should be undercut, and the ends
of the spring part fitted thereto; in addition to the hold so obtained (the one
part of the other) bolt holes may be made through both parts, these in
part B, B', B, should be in flat parts bearing on A, and beyond the limits of
the spring action; the bolts passing through said parts may simply secure the
two together, or may be utilized to secure the chair to the sleeper. Instead
of both ends of part B, B', B, resting against abutments on part A the metal
may be doubled as before and the one foot or end rest against an abutment,
as described, and rivetted or bolted through the end of A, besides being
undercut as described.
The chair may be further modified by bending the bar to a suitable form,
and as represented in the Drawing, but with the ends terminating at the
lower edges of the rail, where a gutter piece may be applied to embrace the
two ends, and so connect and keep them together; in all cases elasticity is to
exist only in the upper part of the chair.