IMPROVEMENTS IN MOTIVE-POWER ENGINES, PART OF WHICH IMPROVEMENTS ARE APPLICABLE TO THE ARRANGEMENT AND CONSTRUCTION OF PUMPS FOR RAISING AND FORCING LIQUIDS AND FLUIDS, AND OTHER SUBSTANCES GENERALLY
Year: 1867

page_text: PROVISIONAL SPECIFICATION left by Christopher Pottinger at the Office
of the Commissioners of Patents, with his Petition, on the 24th December
1867.
I, CHRISTOPHER POTTINGER, of Anstruther, in the County of Fife, North
Britain, Shipbuilder, do hereby declare the nature of the said Invention of
"IMPROVEMENTS IN MOTIVE-POWER ENGINES, PART OF WHICH IMPROVEMENTS ARE
APPLICABLE TO THE ARRANGEMENT AND CONSTRUCTION OF PUMPS FOR RAISING AND
FORCING LIQUIDS AND FLUIDS, AND OTHER SUBSTANCES GENERALLY," to be as
follows, that is to say:-
This Invention which relates in the first place to a novel arrangement of
motive-power engine of that class known as rotatory engines, consists of a
cylinder in which a revolving piston is placed, the part of the piston against
which the steam or other motive agent acts is packed so as to closely fit the
space of the cylinder in which it revolves. The cylinder is provided with ports
or passages in communication with both sides of the projecting part of the
revolving piston, on one side of which the motive agent for driving the engine
is admitted, and on the other or opposite side, and through the opposite
passage or passages, it escapes or exbausts. The passages are provided with
a valve or valves, which are opened and closed by the motion of the engine at
the proper time, and by means of the valve or valves the admission of the
motive agent may be cut off at the required moment, and the motive agent,
provided it be steam, compressed air, or other elastic fluid can thus be worked
expansively. The abutment from which the motive agent acts for producing

page_text: rotation of the piston is caused to slide laterally through an opening made in
one of the cylinder covers, it being drawn out to let the projecting part of the
piston pass it, and forced into its seat again as soon as the projection has
passed. The motion of the abutment is effected by means of a sheave or cam
guide keyed on the shaft of the engine, its periphery being formed with a
projecting or recessed, partly curved and partly concentric and circular guide,
the abutment being coupled to these guides by a suitable link, it is drawn out
and forced in at that part of the revolution where the projecting part of the
piston has to pass and has passed it. In place of forming the sliding abut-
ment in one piece as herein-before set forth it may be made in two pieces, one
working through each end or side of the cylinder, in this case two guide cams
or sheaves are required. By reversing the order of the admission and exhaust
ports, or by using separate pairs of admission and exhaust ports, the direction
of motion may be reversed. A construction of apparatus similar to that herein-
before described may be adopted for pumps, one passage or set of passages
being used for the admission of the liquid, fluid, or other substance to be
pumped, the other passage or set of passages for the escape or delivery.
In applying this pump to ships it is preferred to place it in any convenient
part of the ship so that the shaft may be connected by a rod or rope to a screw
propeller, the action of the ship in going forward draws the propeller behind
it, and thus assists the revolution and action of the pump. It is to be under-
stood that the engine and pump herein-before set forth are applicable in all
cases where such apparatus is at present used, and any number of cylinders
may be coupled together for the purpose of rendering the motion more
uniform.