Year: 1887

page_text: We, JAMES MAC EWAN Ross of Ravensleigh, Dowanhill, Glasgow, and JAMES
MCDOWALL, 21 Greenhead Street, in the City of Glasgow, Engineers, do hereby
declare the nature of this invention to be as follows:-
Our invention relates to improvements in rotary engines and pumps the improved
engine under various modifications being adapted to be operated by steam, air or
other fluid under pressure or by the explosion of a combustible mixture such as gas
and air and being applicable as a pump when driven from a motor.
EL
The engine consists of a cylindrical casing with closed ends and through whose
axis passes a central shaft having in it ports for the admission and exhaust of steam
or other actuating fluid and having fitted eccentrically upon it within the casing
cylindrical or conical boss through which the inlet an exhaust ports are carried to
the interior of the casing. Concentrically with this boss is a cylindrical casing fitted
within the main casing and between it and the boss are fitted a series of segmental
pistons filling up to a greater or less extent what forms the steam space within the
inner casing. The pisions are held in fixed and equidistant angular positions relatively
with the axis of the main casing to which they are connected by bolts passing through
or into radial slots formed in them or in the casing but as their distance from said
axis varies according to their position around the eccentric boss their distance apart
also varies, those pistons bearing on the portion of the boss having the least
eccentricity being close together and those on the opposite side of the boss being
farthest apart.
When the pistons travel around the eccentric boss their velocity is
therefore highest at the point of greatest eccentricity and the ports are formed to
admit the steam between each pair of pistons as they pass the point of least eccentricity
and to exhaust when they pass the line of greatest eccentrity of the boss, the steam
being however cut off at any desired point, and expanding while the piston in front of
it is impelled forward at a greater relative velocity than that following it and the
intervening space becoming greater until the line of greatest eccentricity is reached and
the exhaust of the steam between that pair of pistons takes place. Each succeeding
piston is acted on in like manner and a continuous motion of rotation is thus imparted to
the outer casing which is connected by the bolts to the pistons the inner casing being
free to rotate with it and accommodating itself, by sliding within the main casing to the
sliding movement of the pistons relatively with the axis of the casing. The central shaft

page_text: is in this case held stationary while the main casing which may form a fly wheel or be
provided with gearing teeth revolves upon it, but if the casing be fixed rotation may
he imparted to the shaft in the opposite direction. The speed and power attained
depends on the degree of eccentricity of the toss around which the pistons move as
well as on the area presented for the pressure of steam, and by varying the degree of
eccentricity of the boss the speed and power of the engine may be increased or
diminished while at work. This may be done automatically or by hand by turning
the shaft to bring the eccentric boss more or less nearly concentric with the axis of
the casing.
In lieu of the eccentric a crank and cylindrical or conical distance piece may be
used and the steam instead of being admitted through the central shaft may pass
through ports in the casing.
When employed as a gas engine the casing is by preference divided into two
compartments by a central web and a sèries of pistons is fitted in each compartment
one series being employed to draw in and compress the charges of air and gas which
are admitted through suitable ports and, exploded between the pairs of pistons in the
ajoining compartment.
Dated thi
107
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow,
Agents.

page_text: Improvements in Rotary Engines and Pumps.
We, JAMES MCEWAN Ross of Ravensleigh, Dowanhill, Glasgow and JAMES
MCDOWALL 21 Greenhead Street in the City of Glasgow, Engineers, do hereby
declare the nature of this invention and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement :-
Our invention relates to improvements in rotary engines and pumps the improved
engine under various modifications being adapted to be operated by steam, air or
other fluid under pressure or by the explosion of a combustible mixture such as gas
and air, and being applicable as a pump when driven from a motor.
As represented in longitudinal vertical section at figure I and in sectional side
elevation at figure 2 of the accompanying drawings the engine under one modification
consists of a cylindrical casing A with closed ends A' and through whose axis passes
a central hollow shaft B carried upon bearing brackets X and having in it ports for
the admission and exhaust of steam or other actuating fluid the shaft being in the
present example divided by a central web to form admission and exhaust passages bb¹
and having fitted eccentrically upon it within the casing A a cylindrical or conical
boss C through which the inlet and exhaust ports c, e re carried to the interior of
the casing A. Concentrically with this boss is a cylindrical ring or casing D fitted
within the main easing A and between it and the hoss are fitted a series of segmental
pistons E E filling up to a greater or less extent what forms the steam space within
the inner casing or ring D. The pistons E E are held in fixed and equidistant
angular positions relatively with the axis of the main casing to which they are
connected by bolts F, F passing through or into radial slots formed in the
pistons or in the casing but as the distance of the pistons from said axis varies
according to their position around the eccentric boss C their distance apart also
varies, those pistons bearing on the portion of the boss having the least eccentricity
being close together and those on the opposite side of the boss being farthest
apart. When the pistons travel around the eccentric boss their velocity is therefore
highest at the point of greatest eccentricity and the ports c
are formed
to admit the steam between each pair of pistons as they pass the point of least
eccentricity and to exhaust when they pass the line of greatest eccentricity of the boss,
the steam being however cut off at any desired point and expanding while the piston
in front of it is impelled forward at a greater relative velocity than that following it,
and the intervening space becoming greater until the line of greatest eccentricity is
reached and the exhaust of the steam between that pair of pistons takes place. Each
succeeding piston is acted on in like manner and a continuous motion of rotation is
thus imparted to the outer casing A which is connected by the bolts F to the pistons E
the inner casing D being free to rotate with it and accommodating itself, by sliding
within the main casing, to the radial sliding movement of the pistons relatively with
the axis of the casing. The central shaft B is in this case held stationary whilst the
main casing A which may form a fly wheel G, or be provided with gearing teeth,

page_text: revolves upon it; but if the casing be fixed rotation may be imparted to the shaft in
the opposite direction. The speed and power attained depends on the degree of
eccentricity of the boss around which the pistons move, as well as on the area
presented for the pressure of steam, and by so fitting the parts that the degree of
eccentricity of the boss C may be varied the speed and power of the engine may be
increased or diminished while at work. This may be done automatically or by hand
by turning the shaft to bring the eccentric boss more or less nearly concentric with
the axis of the casing. In the example shown at figure 1 the automatic or hand
regulation is accomplished by means of the end of hollow shaft B forming a valve in
the bracket with suitable ports so that steam is cut off or admitted consequent on the
motion of the shaft B. The engine is reversed by turning the shaft B so that the
inlet becomes the exhaust port.
In lieu of the eccentric a crank H and cylindrical or conical disiance piece I may
be used as indicated in elevation and longitudinal section in figure 4 and the steam
instead of being admitted through the central boss or crank may pass through ports a
in the casing. In figure 3 the pistons E are shown as jointed or butted directly on to
the crank pin H without any distance piece.
In the example shown in vertical section at figure 5 the casing A is fitted to run
upon eccentric bearings formed on the brackets X whilst the pistons E work in a
separate casing D running on a cylindrical or conical piece on the shaft, B, which is
carried eccentrically through the bearings on the brackets X. In this example an
eccentric may be arranged on the shaft B in a manner similar to that shown in
figure 1 or a crank may be used as shown in figure 4. When employed as a gas
engine the casing is by preference divided into two compartments by a central web
and a series of pistons is fitted in each compartment one series being employed to
draw in and compress the charges of air and gas which are admitted through suitable
ports and exploded between the pairs of pistons in the adjoining compartment, or a
double series of pistons may be fitted in the same casing, one series being employed
to draw in and compress the charges which are exploded in the spaces between them
and the several pistons of the second series.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. A rotary engine or pump constructed and arranged to operate substantially as
hereinbefore described and in part shown in the accompanying drawings.
2. In a rotary engine or pump the combination of a shaft, an eccentric boss or
crank on said shaft, the shaft and boss having admission and exhaust passages, and a
series of segmental pistons within a ring or casing enclosed within an outer casing or
cylinder which is concentric with the shaft substantially as described.
3. In a rotary engine a series of segmental pistons arranged eccentrically to the
engine shaft and so as to move radially relatively to the said shaft the propelling fluid
being admitted between each pair of piston as or when they pass the point of leasi
eccentricity and exhausted as or when they pass the point of greatest eccentricity
substantially as set forth.
Dated this Perant, third dose of Documber 1887
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow,
Agents.