IMPROVEMENTS IN THE CONSTRUCTION AND MODE OF FASTENING RAILWAY FISH PLATES AND CHAIRS
Year: 1869

page_text: PROVISIONAL SPECIFICATION left by Robert Chapman at the Office
of the Commissioners of Patents, with his Petition, on the 8th
October 1869.
I, ROBERT CHAPMAN, of Shrewsbury, in the County of Salop, Civil
Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE CONSTRUCTION AND MODE OF FASTENING RAILWAY FISH
PLATES AND CHAIRS," to be as follows :-
The first part of my Invention consists of an improved method of
constructing railway fish plates and chairs so that the two are combined,
and the object of this combination is to enable a sleeper and chair to be
placed under the junction of two rails at the same time that the rails
are secured together by fish plates bolted to them. I construct the
combined fish plates and chairs as follows:-The chairs are made in two
parts, one for the inside and the other for the outside of the rails.
Each half of the chair and a fish plate form one piece.
Figure A. is a section, and Figure B. is an elevation (the latter shewing
one half only of the chair with a fish plate combined). The same
numbers indicate the corresponding parts in each Figure. 1, 1, is the
sleeper; 2, 2, the fang bolts fastening the chairs to it; 3 is the outer,

page_text: and 4 is the inner half of the chair and fish plate combined; 5, 5, are
those parts of the combination which act as fish plates; 6, 6, the bolts
which secure them to the rails; 7, 7, the rails. Wooden keys are not
used, the rails being secured to the chairs by the bolts which pass through
the fish plates.
The second part of my Invention consists in a mode of preventing
the fish plate bolts from working loose, which is applicable to fish
plates forming parts of chairs as above described, and also to ordinary
fish plates. The nature of this part of my Invention is shewn in
Figures A. and B. The fish plate bolt when in its place is prevented
from turning round by the projection 8, Figure B., which fits into a slot
in the fish plate, or by any other convenient known method. The
nuts 9, 9, have their angles on the side next to the fish plate cut off to
a sufficient depth, so that the ends of a piece of iron 10, 10, which is
fitted in tight between the sides of the nuts and a rim or projection 11, 11,
on the fish plate may when bent down be forced between that part of
the angle of the nut which is left and the face of the fish plate. One
of the sides of the nuts when screwed up must be brought parallel to
the rim on the fish plate. The piece of iron fitting tightly between the
rim and the nuts prevents the latter from turning round, and the ends
of the piece of iron being bent down between one of the angles of the
nuts and the fish plate as above described they are prevented from being
shaken out of their places.
The third part of my Invention consists of a method of preventing
the wooden keys of chairs from working loose. To do this I use a nail
formed as shewn in Figure C; this is driven through a hole made in
the outer cheek of the chair into the wooden key up to the shoulder 1,
which is made larger than the hole. The nail can be easily withdrawn
by a claw acting on the head of the nail 2, and as the shoulder 1
prevents the head 2 from coming close up to the cheek of the chair the
head can be readily seized by a claw; the nail should be chisel pointed,
the chisel cutting across the grain of the key so as not to split it.