IMPROVEMENTS IN THE CONSTRUCTION OF RAILWAY for CHAIRS, AND " KEYS .. F I T T PROVISIONAL SP
Year: 1883

page_text: LETTERS PATENT to James Knapton Thompson of Leeds in the County of
York Civil Engineer and George Richard Race of Leeds aforesaid Gentleman
an Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF RAILWAY
for
CHAIRS, AND
"
KEYS
.. F I
T
T
PROVISIONAL SPECIFICATION left by the said James Knapton Thompson
and George Richard Race at the Office of the Commissioners of Patents on
the 23rd July 1883.
,
1.
JAMES KNAPTON THOMPSON of "Leeds in the County of York Civil Engineer
and GEORGE RICHARD RACE of Leeds aforesaid Gentleman IMPROVEMENTS IN
THE CONSTRUCTION OF RAILWAY CHAIRS AND KEYS
.1 f 344
0.
E"
The special feature of this chair is that it provides for the most secure and
effectual grip of the wooden keys or wedges' which are driven in between the
rails and the chair to wedge up and hold the rails of permanent way in exact
position.
The shape and construction of the chair is such that when the wedge is driven
into place it cannot fall or slip out again in the direction in which it was driven
but on the contrary is by the weight and force of passing trains' driven further
forward and as it is of wedge or taper shape being half an inch thinner at the
point than at the driving end or such other similar section as may be found most
suitable it is obvious that the key must remain a tight fit till it has been forced
through the whole length of the chair.
When the chair is in position, the face which touches the inside of the rail is
smooth and of such a form that it accurately fits the particular section of rail in
use flush with the web and round the bottom bulb; and on the other side, i.e. the
outside of the rails or permanent way the chair is made 1 more or less wider at
the end where the key, or wedge enters than at the other or in other words has a
wedge shape opening the narrower end being placed in the direction in which the
trains run. The face and seat of this side of the chair is serrated or has a number
of vertical barbs similar in shape to saw teeth the full depth of the chair and at
such an angle or position that they firmly grip and permanently, retain the key or
wooden wedge until it has passed over the last projection or tooth in the chair.
Whenever the key, requires to be tightened it is. simply necessary to drive it,
forward until it has passed over one tooth thus giving a fresh hold or biting place.
in new wood
Б

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Knapton Thompson and George Richard Race in the
Patent Office on the 23rd January 1884.
JAMES KNAPTON THOMPSON of Leeds in the County of York Civil Engineer and
GEORGE RICHARD RACE of Leeds aforesaid Gentleman "IMPROVEMENTS IN THE
CONSTRUCTION OF RAILWAY CHAIRS AND KEYS"
The special feature of this chair is that it provides for the most secure and
effectual grip of the wooden keys or wedges which are driven in between the
rails and the chair to wedge up and hold the rails of permanent way in exact
position.
'
The shape and construction of the chair is such that when the wedge is driven
into place it cannot fall or slip out again in the direction in which it was driven
.but on the contrary is by the weight and force of passing trains driven further
forward and as it is of wedge or taper shape being half an inch thinner at the
point than at the driving end or of such other similar section as may be found
most suitable it is obvious that the key must remain a tight fit till it has been
forced through the whole length of the chair.
When the chair is in position, the jaw or face which touches one side of the
rail and which may be either the inside or the outside jaw as may be found most
advantageous under special circumstances is smooth and of such a form that it
accurately fits the particular section of rail in use flush with the web and round
the bottom bulb; and on the other side of the rail or permanent way the jaw is
made" more or less, wider at the end where the key or wedge enters than at the
opposite end or in other words has a wedge shape opening the narrower end being
placed, in the direction in which the trains run. The face and seat of the jaw. on
this side of the chair is serrated or has a number of vertical barbs similar in.shape
to saw teeth the full depth of the chair and at such an angle or position, that, they
firmly grip and permanently retain the key or wooden wedge until it has passed
over the last projection or tooth in the jaw of the chair. Whenever the key
requires to be tightened it is simply necessary to drive it forward until it has
passed over one tooth thus giving a fresh hold or biting place in new wood for
every tooth..
In order that our said Invention may be most fully understood and readily
carried into effect we will proceed to describe the drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS
14
"
Figure 1 shews in perspective' a railway chair constructed in accordance with
our invention. Figure 2 is an horizontal section of the same; the section is taken
through the jaws of the chair, the web of the rail and the wooden key. Figure 3
is a vertical section.
'
The jaw of the chair against which the key bears is grooved vertically from top
to bottom of the surface which comes into contact with the key. The grooves are
so formed as to leave projecting teeth. These teeth are of ratchet like form that
is to say they are inclined on one side to permit the key to be driven freely and
on the other side the faces of the teeth are at right angles to the direction' in which
the key is inserted..
"
1
The jaw of the chair is inclined at a considerable angle to the web of the rail
and the wooden key is tapered to a corresponding form.
In consequence of this shape being given to the chair and key, the key when it
is inserted requires to be driven but a short distance forward in order to tighten it

page_text: upon the web of the rail. The teeth in the jaw of the chair when the key is
driven penetrate to some extent into the wood and hold the key so that it cannot
return, for any backward motion is directly opposed by the right angle faces of
the teeth.
The keys should be driven in the direction in which the trains usually pass
along the line of rails and then the traffic on the line will tend to carry them
forward and tighten them upon the rails. The chairs are made right and left to
admit of this being the case on both sides of the line:
Having thus described the nature of our said Invention and the manner of
performing the same we would have it understood that we claim railway chairs
with inclined jaws having vertical saw like teeth engaging with tapered wooden
keys substantially as described.
In witness whereof we the said James Knapton Thompson and George Richard
Race have hereunto set our hands and seals this Eighteenth day of January in the
year of our Lord One thousand eight hundred and eighty four.
TACT
TATA DONT
MITAMONT
4
JAMES KNAPTON. THOMPSON (L.S.)
GEORGE RICHARD RACE
(L.S.)