IMPROVEMENTS IN THE CONSTRUCTION OF CAST IRON OR STEEL TOOTHED WHEELS
Year: 1880

page_text: LETTERS PATENT to John Andrew Vickers and Ebenezer Banton Burr, both
of Upper Thames Street, in the City of London, for an Invention of
"IMPROVEMENTS IN THE CONSTRUCTION OF CAST IRON OR STEEL TOOTHED
WHEELS."
PROVISIONAL SPECIFICATION left by the said John Andrew Vickers and
Ebenezer Banton Burr at the Office of the Commissioners of Patents on the
2nd November 1880.
JOHN ANDREW VICKERS and EBENEZER BANTON BURR, both of Upper Thames
Street, in the City of London. IMPROVEMENTS IN THE CONSTRUCTION OF CAST
IRON OR STEEL TOOTHED WHEELS."
The object of our Invention is to provide cast iron or cast steel toothed or gear
wheels for communicating or transmitting motion, and so made that they can be
fixed upon or removed from a shaft without moving or disturbing the same or any
other wheels which may be on the said shaft.
Heretofore in order to secure this object cast iron toothed wheels have been
made in halves, the division being effected through the centre of the boss, through
the longitudinal axis of two of the spokes radiating therefrom, and through the
rim at the end of such spokes. These two halves are bolted together along the
spokes so divided. It is found, however, in practice that the teeth of wheels so
made are very liable to break, for the reason that there is constantly considerable
strain upon the joint, because the work is practically always upon one or the other
of the two halves, as the half which is not in gear with the adjacent wheel
participates only to a slight degree in the total amount of strain to which the
entire wheel is subjected. The consequence is that there is a continual strain
along the joint, which soon causes the bolts and nuts to become loose, and when
this happens the teeth do not gear accurately with those of the wheel with which
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page_text: they are in connection, and the result is that one or more of the teeth aro broken,
and the wheel is consequently useless.
According to our said Invention we provide a cast iron or a cast steel toothed
wheel, which possesses all the advantages of a wheel made in parts, but is free
from the disadvantages above mentioned.
We carry our Invention into practice as follows, that is to say:-Wo make the
wheel in two parts, but instead of effecting the division as above described, wo
cast the wheel in such a manner that one part comprises a small segment of the
rim, together with one spoke and a part of the boss, and the other part comprises
the remaining parts of the complete wheel. The said segment is of such a length
that the gap or opening left in the rim when tho segment is removed will be
sufficient to allow the shaft to pass through the said gap. On the boss portion of
the smaller of the two parts of the wheel I provide four flanges which project
outward, two being on one side and two on the other side of the wheel. There are
also four corresponding flanges on the boss-portion of the larger of the two parts
of the wheel. These last named flanges fit outside the first named flanges, and all
are bolted together, the bolts passing through holes made for the purpose in all of
the flanges, and being secured by nuts. It will thus be seen that the two parts
of the complete wheel are secured together at the boss-portion thereof at four
points. A similar arrangement is provided at the rim, that is to say, the rim
portion of the smaller of the two parts of the wheel has four flanges projecting
outward from the web, two at each side thereof. The rim of the larger portion
of the two parts of the wheel is also furnished with four corresponding flanges at
the ends thereof, adjacent to the gap in such a manner that the flanges on the
smaller portion when the latter is inserted coincide therowith, and the eight flanges
are bolted together. When casting the wheel in such parts as above described, we
insert in the sand a thin piece of metal at each point where there is to be a
division, and when the wheel is fitted up corresponding plates or pieces are inserted
at the same points to take up the spaces.
We sometimes modify our Invention as follows, that is to say:-We divide the
boss portion across the centre at right angles to the axis thereof, and provide
flanges on the boss portion of both of the two parts of the wheel on each side of
the latter. When the two parts are fitted together the flanges coincide and arc
united by bolts and nuts at four points, two being upon one side of the wheel, and
two upon the other side thereof. The bolts in this caso pass through the flanges
in a direction at right angles to the axis of the wheel. In the boss-portion of
the larger-part an aperture is provided on two sides, into which apertures fit
corresponding ribs or projections on the boss-portion of the smaller part. The
boss-portions must be made of considerable thickness. At the rim portion flanges
are provided, which extend downward and inward from the rim, thore being two
flanges on the rim of the larger part, and two on the rim of the smaller part of the
wheel. These flanges are bolted together by means of two bolts below the rim.
Our said Invention may be applied with advantage to wheels the teeth of which
are made of wood and the remainder of cast iron or steel, as well as to wheels made
wholly of cast iron or cast stecl.