IMPROVEMENTS IN THE CONSTRUCTION OF DRIVING WHEELS FOR ROAD LOCOMOTIVE ENGINES
Year: 1878

page_text: LETTERS PATENT to David Greig, of the Steam Plough Works, Leeds, in the
County of York, for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION
OF DRIVING WHEELS FOR ROAD LOCOMOTIVE ENGINES."
PROVISIONAL SPECIFICATION left by the said David Greig at the Office
of the Commissioners of Patents on the 4th June 1878.
DAVID GREIG, of the Steam Plough Works, Leeds, in the County of York.
"IMPROVEMENTS IN THE CONSTRUCTION OF DRIVING WHEELS FOR ROAD LOCO-
MOTIVE ENGINES."
Hitherto the power of the engine has been transmitted to the driving or pro-
pelling wheels of road locomotives by intermediate friction gear, or by connecting
the hob or the spokes of the road wheel by a pin to a spur or gear wheel keyed on
to the main axle of the wheels, or otherwise by a ring of gear bolted or rivetted to
the spokes of the road wheels, in all cases transinitting the power through the
spokes to the rim of wheels.
My improvement consists in forming in one casting the spur or gear wheel with
arms or projections of such form that it may be bolted or rivetted direct on to the
Tiron or angle iron ring which forms the periphery of the road driving wheels;
thus all intermediate pieces are avoided, and the hob and spokes being relieved of
the driving strain may be made much lighter than is usual, and wheels of larger
diameter may be employed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said David Greig in the Great Seal Patent Office on the 3rd December
1878.
DAVID GREIG, of the Steam Plough Works, Leeds, in the County of York.
"IMPROVEMENTS IN THE CONSTRUCTION OF DRIVING WHEELS FOR ROAD LOCO-
MOTIVE ENGINES."
This Invention has for its object improvements in the construction of driving
wheels for road locomotive engines.
I form in one casting the spur or gear wheel with arms or projections of such
form that it may be bolted or rivetted direct on to the T iron or angle iron ring
which forms the periphery of the road driving wheels; thus all intermediate pieces
are avoided, and the hob and spokes being relieved of the driving strain may be
made much lighter than is usual, and wheels of larger diameter may be employed.
Figure 1 is a side elevation, and Figure 2 is a transverse section of the driving
wheel of a road locomotive.
a is the spur or gear wheel; b, b, the tyres; c, shoes, or wearing plates rivetted to
the tyres; d, the spokes; e, the hob or wheel middle.
The tyres b, b, of the wheel are made of two tee irons; the ring of gear a is of
cast steel, and by preference I make this gear internal, as the Drawing indicates,
but this is not essential, as external gear may also be used if necessary. The inside
tee iron to which the ring of gear is attached is accurately bored on the inside edge
where the gear fits in. The gear ring is also turned to fit the tee iron tightly at
the bearings opposite the feet. The ring of gear is driven into the place provided
for it. Feet a, a, are cast on to the ring of gear, and through these feet and the
tee iron ring are holes drilled for turned bolts. These holes after being drilled are
rbymered out to a standard size. The turned bolts are driven tightly in and
secured by nuts, thus making the ring of gear and the tyre of the wheel equivalent
to a solid piece.
I claim the construction of driving wheels for road locomotives as herein described,
and illustrated by the annexed Drawings.
In witness whereof, I, the said David Greig, have hereunto set my hand
and seal, this Second day of December, in the year of our Lord One
thousand eight hundred and seventy-eight.
ADRIA
DAVID GREIG. (L.B.)