A New or Improved Rotary Engine.
Year: 1896

page_text: Date of Application, 1st June, 1898
Complete Specification Left, 1st Mar., 1897-Accepted, 15th May, 1897
A New or Improved Rotary Engine.
I WILLIAM JOSEPH PITT, of No. 9, Avenue Road, Weymouth, in the County
of Dorset, Captain, do hereby declare the nature of this invention to be as
follows:-
This invention relates to a new or improved rotary engine which may be worked
by steam, hydraulic, or other power. The construction is exceptionally simple and
the working parts being reduced to a minimum, there is no liability of the engine
getting out of order and constantly requiring repair. Any power desired may be
one of the
obtained with engines of this construction and economy in working
chief advantages obtained therewith.
The steam exhausting from one cylinder to the other may be utilized several
times over, and the engine is instantly reversed by simply changing the direction
of the flow of the steam, water, or other fluid, employed as motive force.
In accordance with this invention the engine may be either simple or compound,
one, two, or more cylinders being employed as best adapted for particular
circumstances. The main shaft is carried through the cylinder or cylinders which
latter I make of a particular construction as will hereinafter be explained. The
portion or portions of said shaft within the cylinder or cylinders I make with a
slot therethrough in which works an oblong or square metal slide and upon this
slide as it protrudes from the shaft the steam water or other power acts and causes
said shaft to revolve and actuate the machinery or the like to be driven.
In cross section the cylinder has parallel sides (for a given distance) terminating
in semicircular ends. The shaft is eccentrically situated within the cylinder in
such manner that one part of its periphery touches or nearly touches the inner side
of one of the semicircular parts of the cylinder, the slide beforementioned then
protruding from the opposite side of the shaft bears upon the inner surface of the
opposite semicircular part of the cylinder. Steam or other pressure being
admitted through inlet port acts upon the protruding portion of the slide aforesaid
and gives a rotary motion to the shaft. The inner walls of the cylinder serve as a
guide to the slide and in the revolution of the shaft cause the slide to protrude
alternately from each side of the shaft in such manner that the inlet and exhaust
ports are each in turn opened and operated. To reverse the engine the steam,
water, or the like, is simply admitted through the exhaust port and the inlet port
becomes the exhaust.
The relative diameters of the shaft and cylinder are such that the requisite area
of the protruding or operative part of the slide is obtained according to the power
required to be given off by the engine.
connect my shafting with suitable couplings to permit of free working of the
parts and to allow for the expansion and contraction of the metals. This may be
done by dispensing with the bolts to fasten thein together and forming one flanged
end of the shaft with a square or other suitably shaped recess therein and the
flanged end of the other portion of shalting to be coupled with a correspondingly
shaped projecting portion to fit loosely within the recess.
To allow the engine to run loose, as for trials, without working the machinery or
the like usually to be driven therewith, I have suitable clutch gearing for
connecting and disconnecting, or throwing into or out of gear.
HUGHES, SON & Co.,
38, Chancery Lane, W.C., Agents for the Applicant.

page_text: I WILLIAM JOSEPH PITT, of No. 9, Avenue Road, Weymouth, in the County
of Dorset, Captain, 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:-
This invention relates to a new or improved rotary engine which may be worked
by steam, hydraulic, or other power. The construction is exceptionally simple and
the working parts being reduced to a minimum, there is no liability of the engine
getting out of order and constantly requiring repair. Any power desired may be
obtained with engines of this construction and economy in working is one of the
chief advantages obtained therewith.
The steam exhausting from one cylinder to the other may be utilized several
times over, and the engine is instantly reversed by simply changing the direction of
the flow of the steam, water, or other fluid, employed as motive force.
In accordance with this invention the engine may be either simple or compound,
one, two, or more, cylinders being employed as best adapted for particular
circumstances. The main shaft is carried through the cylinder or cylinders, which
latter I make of a particular construction as will hereinafter be explained. The
portion or portions of said shaft within the cylinder or cylinders I make with a
slot therethrough in which works an oblong or square metal slide and upon this
slide as it protrudes from the shaft the steam, water or other power acts and causes
said shaft to revolve and actuate the machinery or the like to be driven.
In cross section the cylinder has parallel sides (for a given distance) terminating
in semi-circular ends. The shaft is eccentrically situated within the cylinder in
such manner that cue part of its periphery touches or nearly touches the inner side
of one of the semi-circular parts of the cylinder; the slide beforementioned theu
protruding from the opposite side of the shalt bears upon the inner surface of the
opposite semi-circular part of the cylinder. Steam or other pressure being
admitted through inlet port acts upon the protruding portion of the slide aforesaid
and gives a rotary motion to the shaft. The inner walls of the cylinder serve as a
guide to the slide aud in the revolutions of the shaft cause the slide to protrude
alternately from each side of the shaft in such manner that the inlet and exhaust
ports are each in turn opened and operated. To reverse the engine the steam,
water, or the like, is simply admitted through the exhaust port and the inlet port
becomes the exhaust.
The relative diameters of the shaft and cylinder are such that the requisite area
of the protruding or operative part of the slule is obtained according to the power
required to be given off by the engine.
I connect my shafting with suitable couplings to permit of free working of the
parts and to allow for the expansion and contraction of the metals. This may be
done by dispensing with the bolts to fasten them together and forming one flanged
end of the shaft with a square or other suitably shaped recess therein and the
flauged end of the other portion of shafting to be coupled with a correspondingly
shaped projecting portion to fit loosely within the recess.
To allow the engine to run loose, as for trials, without working the machinery
or the like usually to be driven therewith, 1 have suitable clutch gearing for
connecting and disconnecting, or throwing into or out of gear.
And in order that this my invention may be fully understood and readily carried
into effect will now describe same fully with reference to the accompanying
drawings and the letters of reference marked thereon, that is to say:
The invention is illustrated as being applied to a screw steam ship, but it will
be readily seen that the same, by obvious and simple modifications, is equally

page_text: applicable for a locomotive, an ordinary mill engine, or a pumping engine, the
advantages previously mentioned of simplicity of construction and economy in
working applying in each instance.
Fig. 1 of the accompanying drawings represents in longitudinal elevation partly
in section, the high pressure cylinder of a marine engine, with shafting passing
therethrough and slide in position in the shaft boss within the cylinder all in
accordance with this invention.
Fig. 1 is a perspective view of the slide aforesaid.
Fig. 2. shews the low pressure cylinder (partly in section) with a portion of the
shafting and the gearing in connection therewith.
Fig. 2 on a smaller scale is a section of the shaft boss, and Fig. 2B a plan of
same both shewing a convenient method of building same up.
Fig. 3 is a plan view of the high and low pressure cylinders, and
Fig. 4. is a cross section of one of the cylinders.
Figs. 5 and 6 are diagram views illustrating the positions of the slide at different
parts of the stroke.
Similar letters of reference indicate like parts throughout.
a, a, a, a³, are various lengths of shafting connected together by means of the
expansion clutches bbb. To permit of the engine being disconnected at will one
of the flanges, (see Fig. 2,) may be made capable of sliding upon feathers upon
the end of the shafting a and so be withdrawn from gearing with the opposite
flange upon end of the length of shafting a3 and thus permit the engine to run
loose when desired.
c is the high pressure cylinder and d the low pressure cylinder and through these
cylinders the shafting aforesaid passes; stuffing boxes e and glands are provided
so that all may be kept steam tight. Within each cylinder the shafting is formed
with a boss and through this boss works the slide h (shewn separately in
Fig. 1^).
i, i represent bearings for the shafting. k, k, k, are pulleys placed upon the end
of shafting from which by belts a dynamo for electric lighting, machinery, pumps,
and the like, may be worked when required.
To drive the engine ahead steam is admitted to the high pressure cylinder c
through pipe (see particularly Fig. 3) After performing its function therein the
steam exhausts through pipe m into the low pressure cylinder d from whence it
flows through piping n to the condenser. To reverse the engine the steam is
admitted to the high pressure cylinder c through pipe o when it exhausts through
piping p to the low pressure cylinder d and from thence flows to the condenser
through piping 9. Suitable cocks r, 1, 2, 3, control the ports of the cylinder in
such manner that when open for the admission of steam the exhaust pipe of that
port shall be closed; for instance (see Fig. 3) when the cock or valve r is open for
the admission of steam from pipe to the cylinder the pipe p is closed, and the
pipe o is closed by the opening of the cock to the pipe m. Similarly cock ris
open to pipe m and closed to pipe q, while cock is open to pipe n and closed to
pipe p. When the engines are reversed by admitting steam through pipe o to the
high pressure cylinder the cocks r², open and close the pipes in exactly the
opposite manner to that just described. The actuating handles or wheels of
the cocks or valves aforesaid may be connected or geared together in a suitable
manner to permit of their being all operated at once from one lever or wheel.
In Figs. 2 and 2B a convenient mauner of building up the boss of the shaft is
shewn. The length of shafting a' is formed in two portions each terminating in a
disc or flange g. Between these discs or flanges g the semi-cylindrical pieces s are
placed, openings s¹ being left for the passage of the slide h. See also Figs. 4, 5,
and 6.
The discs and connecting cylindrical portions are theu securely bolted together
as shewn.
The bosses on the shafting are eccentrically situated within the cylinders in such
manner that one part of the periphery of the boss touches or nearly touches the

page_text: inner side of one of the semicircular parts of the cylinder, see t Figs. 1, 2, 4, 5,
and 6. The slide h, as the boss and shafting revolve, protrudes from the boss
aforesaid and is acted upon by the steam as it enters the cylinder.
The inner walls of the cylinder serve as a guide to the slide h and to effect this
purpose I make the cylinder internally of somewhat an elliptical shape in cross
section as will be seen upon reference to the drawings. The relative diameters of
the shaft bosses and the cylinders are such that the requisite areas of the protruding
or operative parts of the slide are obtained according to the power required to be
given off by the engine.
A third cylinder (not shewn upon the drawings) may be affixed to the engine
with a shaft boss and slide therein to act as a pump for forcing water through the
condenser if desired, which will also serve to keep the heat from extending along
the tunnel. The shaft boss and slide in this cylinder would be caused to revolve
by the engine as above described and water being admitted through inlet would be
pumped out with great force through exhaust port and from thence be conducted to
the condenser as aforesaid or elsewhere as may be required, and another cylinder
with shaft boss and slide therein may be employed as an air pump if desired. The
operation of this engine is as follows:
Assuming the slide h to be in the position shewn in Fig. 4 within the high
pressure cylinder c steam when admitted through port u enters the cylinder in the
direction shewn by the arrows, strikes against the protruding portion of the slide h
and causes the shafting to revolve. In the revolution of the shaft boss within the
cylinder the inner walls of the cylinder c acting as guides to the ends of the slide /
cause said slide has it revolves to protrude alternately from each side of the shaft
boss so that the exhaust port v is open as required for the passage of the steam
carried upon that side of the slide h while live steam enters through port u and
acting upon its side of the slide h serves to keep the shaft revolving. See also
diagram Figures 5 and 6.
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. The new or improved rotary engine constructed, arranged and operating,
substantially as hereinbefore described and shewn.
2. In rotary engines the cylinder or cylinders constructed as hereinbefore
described and shewn, in combination with a shaft carried through said cylinder or
cylinders and provided within said cylinder or cylinders with a protruding slide
operated upon by steam, water, or other power, flowing through said cylinder or
cylinders in such manner that a rotary motion is given to the shaft, all substantially
as hereinbefore set forth and illustrated.
3. In rotary engines the shafting a a¹ a² a³ with expansion clutches bbb; the
cylinders c d with stuffing boxes e and glands and ports uv; the bosses g on
shafting; the slides working in the bosses g; the bearings i for shafting; the
steam pipes l, m, n, o, p, q; and the cocks or valves r, r', 72, 73, all combined,
constructed arranged and operating substantially as and for the purposes herein-
before described and shewn in the drawings.
Dated this 1st day of March 1897
HUGHES, SON & Co.,
38, Chancery Lane, W.C., Agents for the Applicant.