IMPROVEMENTS IN THE PERMANENT WAY OF RAILWAYS
Year: 1873

page_text: PROVISIONAL SPECIFICATION left by William Alexander Lyttle at the
Office of the Commissioners of Patents, with his Petition, on the
15th March 1873.
I, WILLIAM ALEXANDER LYTTLE, of the Grove, Hammersmith, in
the County of Middlesex, Engineer, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN THE PERMANENT WAY OF
RAILWAYS," to be as follows:-
With the view of dispensing with the oak or other hard wood key or
wedge now used for the purpose of fastening double headed rails in their
chairs I employ an iron key of somewhat similar shape, and I impart
to it by the following arrangement the same adjustability of fit between
the jaw of the chair and the rail as is now obtained through the
compressibility of the perishable and therefore insecure wooden wedge.
When this iron key is to be used with chairs of the ordinary construction
both the key and the inner surface of the jaw of the chair against which
it is to rest are tapered so as to cause the key to press evenly against
the side of the rail, and when this key is driven home a vertical key is
driven downward between the side of the iron wedge key and the jaw of

page_text: the chair through a keyway provided for that purpose at the proper part
of the surfaces of the wedge key and jaw. The part of this keyway
provided in the side of the wedge key is an inclined plane formed at
such an angle to the inner side of the jaw of the chair that when the
vertical key is driven home it shall, through its reaction against the
inclined plane, tend to force the wedge key further and more tightly
home. This inclined plane should also be made with an inclination
vertically so as to cause it to fit evenly to the angle of taper given to
the vertical key. If the passage or keyway is carried through the chair
to the surface of the sleeper the vertical key can be driven home as a
spike into the sleeper and so render it more secure. This vertical key
may also be provided with a slightly conical body terminating in a
"wood screw
"thread which can be worked home into the sleeper. Onc
or more of these vertical keys can be used with cach wedge key, as may
be found needful for security, and when the same arrangement is adopted
with oak or hard wood wedge keys, such as are now in use, the locking
action of the vertical key imparts greater security against the loosening
and escape of the wooden key.
This arrangement of wedge key can also be employed in the case of
chairs constructed of the peculiar form specified under my Letters
Patent, dated Fifteenth day of January of the present year and entitled
Improvements in the Permanent Way of Railways, but in the case of
that form of chair the wedge key should not be tapered so as to jam
itself sideways between the inside of the chair jaw and side of the
rail, but vertically between the lip or inside overhanging flange of that
jaw and the inside of the shoulder of the lower flange of the rail. By
this means the rail can be kept securely jammed down against the
surface of the sleeper, and the vertical key
the wedge key against the side of the rail.
this kind is used in connexion with chairs
top of the sleepers and underlying the rail, the latter can be prevented
from pressing upon and so being injured by the metal of the chair
indenting its lower face, if the iron wedge key on the one side and the
opposite jaw of the chair on the other side are made to bear evenly
against the inner faces or shoulders of the upper flange of the double
headed rail, the part of the chair underneath the rail must be at such
a depth that the rail when wedged and keyed home shall bear solely
downward on the jaw and wedge key. Under this arrangement a light
or keys will suffice to force
When an iron wedge key of
resting as at present on the

page_text: rail of T iron can be used, the top of the T being presented to the
wheels and the bottom being ribbed or flanged to such a depth as will
merely suffice to prevent the rail from leaping upward out of the chair.
If the jaws of the chair and the wedge key are made of sufficient length
in the direction of the rail about eight inches to one foot; in the case of
chairs to be used at the joints of rails fish plates bolted as at present will
be unnecessary because the long wedge key and the opposite jaw of the
chair, both bearing firmly home against the rail, will have precisely the
same effect. Another advantage of this mode of jointing the rails will
consist in the perfect levelness of the joined ends.