IMPROVEMENTS IN RAILWAY WHEELS
Year: 1877

page_text: LETTERS PATENT to Dugald Drummond, of Cowlairs, vid Glasgow, County
of Lanark, for the Invention of "IMPROVEMENTS IN RAILWAY WHEELS."
Sealed the 22nd March 1878, and dated the 17th December 1877.
PROVISIONAL SPECIFICATION left by the said Dugald Drummond at the
Office of the Commissioners of Patents on the 17th December 1877.
DUGALD DRUMMOND, of Cowlairs, via Glasgow, County of Lanark.
MENTS IN RAILWAY WHEELS"
"IMPROVE-
This Invention has for its object improvements in railway wheels, and applies
especially to the class of wheels in which the body or part between the boss and the
tyre is of wood, being built up of seginents fitted closely together.
Where brakes are applied in connection with such wheels, and where they act
unequally on the two wheels fixed upon the same axle, there is a twisting action
tending to twist the boss of the wheel within the wooden segments. To resist this
twisting action the side rings or plates and bolts are found insufficient.
For the purpose of increasing the resistance to this twisting action I form the
parts eccentric the one to the other, that is to say, I form the boss of the wheel, at
the part where the timber segments abut upon it eccentric to the axle and the tyre,
and again I form the boss at the parts where the two side plates embrace and fit
around it, eccentric not only to the axle and tyre and to the part upon which the
segments abut, but also eccentric the one to the other
The side plates are flanged inwards at the periphery, and the flanges fit into
grooves turned in the sides of the tyres, and they are retained in place by lips on
the tyres, which are closed over when the side plates are in position Bolts are
passed through the timber, and the side plates close up to the tyre and the boss.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Dugald Drummond in the Great Seal Patent Office on the 15th
June 1878.
DUGALD DRUMMOND, of Cowlairs, vid Glasgow, County of Lanark. "IMPROVE-
MENTS IN RAILWAY WHEELS."
This Invention has for its object improvements in railway wheels, and applies
especially to the class of wheels in which the body or part between the boss and the
tyre is of wood, being built up of segments fitted closely together.
Where brakes are applied in connection with such wheels, and where they act
unequally on the two wheels fixed upon the same axle, there is a twisting action
tending to twist the boss of the wheel within the wooden segments. To resist this
twisting action the side rings or plates and bolts are found insufficient.
For the purpose of increasing the resistance to this twisting action I form the
parts eccentric the one to the other, that is to say, I form the boss of the wheel, at
the part where the timber segments abut upon it, eccentric to the axle and the tyre,
and again I form the boss at the parts where the two side plates embrace and fit
around it, eccentric not only to the axle and tyre and to the part upon which the
segments abut, but also eccentric the one to the other
The side plates are flanged inwards at the periphery, and the flanges fit into
grooves turned in the sides of the tyres, and they are retained in place by lips on
the tyres, which are closed over when the side plates are in position. Bolts are
passed through the timber and the side plates, close up to the tyre and the boss.
Figure 1 of the Drawings hereunto annexed shews a side clevation of a wheel
constructed as above described; Figuro 2, a side elevation on a larger scale of the
central boss of this wheel; and Figure 3, a section taken through the centre of the
wheel.
A is the central boss; B, the tyre; C, the wooden blocks interposed between the
boss and tyre; D and E, the side plates.
The boss, where the wooden blocks abut upon it, is struck from a centro at F
(see Figure 2), eccentric to the axle. The part of the boss which is embraced by:
the side plate D is struck from a centre at G, and the part embraced by the side
plate E is struck from a centre at H; these three points are equidistant from the
centre of the axle, and are also equidistant from one another. The side plates are
flanged inwards at their periphery, and the flanges enter grooves in the sides of the
tyre. The plates are held together by bolts I and K, and also at their periphery by :
lips L at the edges of the grooves in the tyre, being closed over them, as shewn in
the Drawing. The closing in of the lips can be done cold after the wheel has been
put together; thus in the event of a tyre breaking, the flanged plates on either side
of the wheel render it impossible for the tyre to fly off.
A modification of the wheel is shewn at Figures 4 and 5. In this modification in
place of a portion of the central boss entering between the side plates, as in the
wheel shewn at Figures 1, 2, and 3, flanges from the boss come on the outer side of
these plates. One of the flanges is formed by a ring which embraces an eccentric
portion of the boss struck from a centre at F (see Figure 5). The side plates D
and E embrace eccentrics on the inner face of the flanges, and these eccentrics are
struck from the points G and H. The parts are held together by the bolts I, and
also at the periphery of the side plates by the bolts K, as in the wheel shewn at
Figures 1, 2, and 3.
The boss of the wheel, where the wooden blocks C abut upon it, is shewn
to be concentric with the axle, and the side plates alone are relied on to prevent 5
twisting.
Another modification is shewn at Figures 6 and 7. In this case the side plates
D and E come outside instead of inside the flanges on the boss. The boss, where
the wooden blocks C abut upon it, is concentric with the axle. The inner side

page_text: plate embraces an eccentric on the boss struck from a centre at F, and the
outer side plate an eccentric struck from a centre at G, and these points are
on opposite sides of the centre of the axle.
Having thus described the nature of my Invention, and the manner of performing
the same, I would have it understood that I do not confine myself to the precise
details above given, but that I claim,-
First. The manufacture of railway wheels, substantially as herein-before
described.
Second. Forming the parts of which the body of a wheel is built up eccen-
tric to one another to prevent them from twisting or turning one on the other.
In witness whereof, I, the said Dugald Drummond, have hereunto set my
hand and seal, this Fourteenth day of June, in the year of our Lord
One thousand eight hundred and soventy-eight.
D DRUMMOND.
(L.S.)