IMPROVEMENTS IN MOTIVE-POWER ENGINES, PUMPS, AND METERS
Year: 1871

page_text: PROVISIONAL SPECIFICATION left by Algernon Guthrie and James
Stevenson at the Office of the Commissioners of Patents, with their
Petition, on the 27th February 1871.
We, ALGERNON GUTHRIE and JAMES STEVENSON, of Gravesend, in
the County of Kent, do hereby declare the nature of our Invention for
"IMPROVEMENTS IN MOTIVE-POWER ENGINES, PUMPS, AND METERS," to be as
follows:-
This Invention has for its object the simplification of the construction,
combined with the regularity of action and more universal applica-
bility to the purposes for which they are usually applied, of motive
power engines, pumps, and meters. The construction of the apparatus
according to our Invention is as follows:-Several cylinders are arranged
radially on a circular disc, having their outer ends closed and their inner
ends open, and having passages also arranged radially leading from
their outer ends towards the centre of the disc. The disc is fastened on an
axle or spindle, and the said axle or spindle is carried in a bearing or
bearings, the bearing next the disc being placed in contact with the
disc and having an outlet and an inlet port or passage formed in it.
This bearing may be made in two parts, the part in which the inlet

page_text: and outlet passages are formed being separated from the other portion,
so that it can slide on the shaft and be kept in contact with the face of
the disc by springs or other suitable mechanical incans, the moveable
part being prevented from turning on the shaft. by suitable stops. The
surfaces of the bearing and disc which are in contact may be either
cylindrical, conical, or flat, the ports in the bearing being so propor-
tioned that as the disc revolves they present themselves alternately to
the passages formed in it during a greater or less part of its revolution.
In line with the shaft of the disc there is a second shaft having a
crank formed on or attached to it, and so arranged that the centre of
the crank pin is in or near the plane of the axes of the cylinders; this
second shaft is carried in a bearing or block, and is either firmly
fastened in the bearing or is movable through a certain are which may
be either of a fixed or a variable length, but whilst the resistance is
constant the crank remains in one position or nearly so. The second
shaft may have a similar disc in one or more pieces or with doors, or
man-holes with ports or passages formed in it similar to the first disc,
and communicating with the outer ends of the cylinders in a similar
manner, and the bearing or block in which it is fixed may have an inlet
and an outlet port formed in it in a similar manner to the bearing of
the first shaft. The second disc is, whether a plain disc or having ports
formed in it, firmly attached to the cylinder, but is free to turn on
the crank shaft in either direction, thus acting as a support for the
overhanging weight of the first disc and cylinders, and preventing
any leakage from the cylinders escaping into the atmosphere; it also
enables the connecting rods of the pistons to be readily got at. The
cylinders are each fitted with pistons or buckets or some with pistons
and others with buckets, and to each piston or bucket a connecting rod
is jointed, the inner ends of the connecting rods being jointed also ou
the crank pin or to a circular wheel or boss on the crank pin, in which
latter case one of the connecting rods is firmly fastened to the said
wheel or boss on the crank pin, and the arrangement of the connecting
rods and boss becomes similar to that adopted in a paddle wheel with
Chathoring Goats

page_text: near the outer end of their respective cylinders, and the outlets commence
to open when they are nearest to the inner ends, so that as the inlets
are opened the disc is forced to revolve by the angular action of the
connecting rods on the crank pin.
When the apparatus is used as a pump the revolution of the disc
causes the pistons to recede from the closed cuds of their respective
cylinders and draw or allow the fluid or medium acted upon to fill the
cylinders during half a revolution of the disc, and during the other
half, the outlet being open, the fluid or medium escapes or is in its
turn forced out of each cylinder. By this arrangement a very regular
action is produced whether our said apparatus is used as a motive
power engine, pump, or meter. When used as a meter we prefer to
enclose the whole apparatus in a water-tight case and to carry the
inlet into the case and the outlet through the side of the case so that
there may be but slight difference of pressure between the opposite sides
of the pistons and inlet and outlet ports, thereby reducing the risk of
leakage to a minimum.
In arranging the contrivance as a meter the cylinders are made of a
known capacity and the water or liquor to be measured flows into and
completely fills each cylinder in turn and is discharged through the
discharge pipe which passes through the side of the outer case. A
suitable counter to indicate or record the number of revolutions and
consequently the quantity of water passed through the apparatus may
bc attached to the outer case and worked by the shaft to which the
revolving disc is attached. We prefer to place the counter outside
of the outer case and carry the axle of the revolving disc through a
stuffing box at its side.
When used as a steam engine, the steam can be worked expansively to
almost any extent by making the inlet port in the bearing of suitable
length, and the degree of expansion may be increased at will by turning
the crank round by a lever or by other suitable mechanical means ; this
increases the " lead," and closes the inlets at an earlier point of the
stroke of the piston. By causing the crank to move through a longer
arc the "lead" becomes so great that the action is reversed, and
what was the "cut off" becomes the "lead" and vice versa, the "lead"
becomes the "cut off," the engine running in the opposite direction.
The same end can be accomplished and in large engines we prefer to
-

page_text: do so, by the introduction of an intermediate plate or valve between
the surface of the disc and bearing with suitable ports formed in it,
and arranged so as to change the inlet and outlet ports to their correct
positions.
The outlet, when the apparatus according to our Invention is used
and working as a steam engine, may be in direct communication with
the condenser, the atmosphere, or with a second engine of the same
construction working on the condensing principle; in the latter case,
very great ranges of expansion can be effected and very regular motion
obtained.
When used as a combined engine and pump we arrange the passages
for the motivo power in one disc, and the passages for the pumps in
the other disc.
We also sometimes arrange the steam inlets, when our apparatus is
used as a steam engine, in one disc, and the exhaust in the other disc.