Improvements in Steam Engines.
Year: 1888

page_text: COMPLETE SPECIFICATION.
Improvements in Steam Engines.
I, WILLIAM AUGUSTUS PITT of Glenbrook, in the County of Fairfield, State of
Connecticut, one of the United States of America, Gentleman, do hereby declare the
nature of my invention for "IMPROVEMENTS IN STEAM ENGINES," and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement :-
My invention has reference to improvements in the construction of steam engines;
and the object of my improvement is to obtain the fullest theoretical duty of the
steam; and this I attain by cutting off the steam at initial pressure, at a given point
in the cylinder, and by making up for all loss due to the expansion of the steam,
by means of a constantly increasing leverage from the commencement to the finish
of a given stroke of the piston.
This is effected by the use of cranks in connection with cylinders and intermediate
cranks, so arranged and connected together as to have alternate movements, so that
one shall exert its power from the minimum to the maximum, and the other from
the maximum to the minimum, whereby the full effective power of the steam is
maintained throughout the entire stroke of the engine.
In the accompanying drawings which clearly illustrate the novel features of my
improvement :-
Figure 1, is a side elevation of a steam engine, and
Figure 2, is a top plan view of the same.
Figure 3, is a side elevation of an engine showing a single crank connection.
Figure 4, is an end view of the same.
Figure 5, shows the cranks and connection applied to a steam cylinder and com-
pression or vacuum cylinder.
i

page_text: Referring to Figures 1, and 2, let a and a¹, represent two steam cylinders, of equal
dimensions arranged side by side, and b, 61, the respective piston rods which carry
the pistons of the same. el, are cross heads.
Suitably mounted in the bed or frame of the engine, (which is not shown in the
drawing) are two independent cross shafts g and g¹ set on the same plane. On the
shaft are set the two cranks d and f so that they are in a position at right angles
one to the other, and on the other shaft g' are similarly set the two cranks d¹ and f¹.
The cranks d and dare each connected with the respective steam cylinders a a¹ by
means of a pitman c¹, and oscillate in opposite directions, each moving one fourth of
a circle.
The other cranks fand f¹ which, like the cranks d and d¹, are mounted on inde-
pendent shafts, and are set at right angles to each other, are each connected, by
means of a pitman. 1, with another crank (h and ¹) which latter are set on the
common working shaft i.
The pistons in the cylinders a and a¹, have a continuous movement, in opposite
directions, but with varying speed, that in the cylinder a, at the commencement of
its stroke, starting with the full maximum power of steam and the maximum leverage,
working from such start with a continual diminish of power until it reaches the
end of its stroke, while the condition and operation of the power created by the
cylinder a¹ is directly the reverse, except as to the maximum power of the steam.
During the full stroke of the pistons in the cylinders a and a', the cranks & and d
cach make a one quarter revolution in an opposite direction, and the connected
cranks, on the work shaft, each make a one half revolution on each and every
stroke of the pistons, whereby one of the cranks on the work shaft i, and one on
each of the intermediate shafts g and g', are always off of the dead center. By this
means the full initial effect of the power of the steam, although used expansively, is
maintained throughout the entire stroke of the piston.
By reference to Figure 3, it will be seen that I accomplish the same result simply
by placing the steam cylinder a and crank shaft i at right angles, to each other, and
intercepting the same with a single crank d set on the shaft g, so that, in operation,
the said crank d will be alternately at right angles with the connected crank on the
shaft i, and with the cylinder a. This represents one half of a set of cylinders and
cranks, and accomplishes the same result attained by a pair of cranks set at right
angles, as in Figures 1 and 2.
Figure 5, shows the same principle of levers as illustrated in Figure 1, applied to
a steam cylinder and a compressing or air cylinder, in which instance, the cranks d¹
and are connected directly with the two cylinders, and in their operation effect a
ratioing and equalizing of power expended and created, whereby a like volume or
amount of one is secured for the other as may be required.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed I declare that what; I
claim is:
1. In an engine a combination of levers and cranks so arranged and connected with
the piston, that any travel may be effected on the one end by a constant greater or
lesser travel on the other end, as may be desired.
2. In an engine the combination of a leverage so arranged and connected with the
piston that the power and weight is constantly moved in and out from the fulcrum,
or center of power in any proportion to each other, the fulcrum being stationary, as
set forth.
3. The combination with two steam cylinders and their piston rods of a leverage
consisting of two pair of cranks set on independent shafts at right angles to cach
other and two cranks on a common shaft, the said cranks being arranged to move
with unequal speed, as set forth.
4. The combination in a steam engine of two cranks, set on independent shafts,

page_text: at right angles to each other, and connected with the steam cylinders and two other
cranks similarly set and connected with two shorter cranks on the work shaft, all
so arranged that the cranks on the work shaft will make a one half revolution,
and the other cranks a one quarter revolution on each stroke of the pistons, as
set forth.
5. The combination of an air cylinder and steam cylinder with two cranks, set
at right angles to each other, on an intermediate shaft placed at an unequal distance
between the said cylinders, and connected respectively with the steam and air piston
rods, as set forth.
Dated this 8th day of April 1888.
WILLIAM AUGUSTUS PITT.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.
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