IMPROVEMENTS IN CENTRIFUGAL MACHINES FOR THROWING AIR AND OTHER FLUIDS, AND COMMUNICATING MOTIVE POWER THEREBY
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by Thomas Webster Rammell at
the Office of the Commissioners of Patents, with his Petition, on
the 15th October 1875.
I, THOMAS WEBSTER RAMMELL, of No. 4, Westminster Chambers,
Westminster, in the County of Middlesex, Civil Engineer, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN CENTRIFUGAL
MACHINES FOR THROWING AIR AND OTHER FLUIDS, AND COMMUNICATING MOTIVE
POWER THEREBY," to be as follows:-
In applying centrifugal machines to the ventilation of mines and
other purposes it is desirable that they should be adapted to throw to
the best advantage the varying quantities of air required to be dealt
with, and which as a rule in the first-mentioned case increase from time
to time as the workings are extended. To effect this object I make the
vents of machines intended to throw a maximum quantity of air when
fully employed in such manner that they may be partially opened or
closed in proportion to the work to be done when employed to throw a
less quantity. By this arrangement the resistances from the vanes
beating against the external atmosphere (are reduced or avoided.

page_text: Another of my improvements consists in so arranging the inlets and
the central parts of large machines and connecting the shaft with the
engine employed, that a third bearing (always productive of incon-
venience and of increased friction) may be dispensed with; and I do
this by placing the engines as near as may be to the machine, and
forming spaces by divisions within the inlet pieces for the crank and
connecting rods.
It is found that much inconvenience is occasioned by the heating of
the bearings of machines driven at high velocities, and another of my
improvements consist in a particular arrangement of friction rollers
for the shafts or spindles of such machines calculated to lessen this
evil.
I arrange the friction rollers in two sets one on either side the shaft,
and both are contained in a box or casting. The rollers turn upon fixed
axles, and the axle of each set is supported both by the ends of the box,
and at intermediate points by divisions across it. By this arrangement
a length of bearing surface is obtained from the rollers almost equal to
that of the neck of the shaft.
With machines driven at high velocity there is considerable leakage
through the space between the fixed and the moving parts, and another
of my improvements consists in a new method of forming this joint; I
form this joint by inserting in the parts of the case around the mouth-
pieces rings of soft metal or of other soft material, within which if the
contact between the fixed and moving parts be too close, the mouth-
pieces may wear themselves channels.
Another of my improvements consists in the general arrangement
of the parts of small machines intended for high velocities and
pressures.
The general arrangement of the parts of small machines intended for
bigh velocities and pressures, consists in the casting of the case of the
machine in two parts divided horizontally, the lower part being the
larger of the two, and containing the entrances and the supports for the
bearings complete.