Year: 1886

page_text: Date of Application, 2nd Sept., 1886.
Complete Left, 29th Oct., 1886.
Complete Accepted, 18th Feb., 1887
I, HERBERT BOYD, Doctor of Medicine, native of St. John, New Brunswick,
Dominion of Canada, now residing temporarily at 3 Arthur Villas, Hythe in the
County of Kent, England, do hereby declare the nature of this invention to be as
follows:-
My invention consists of a new and improved rotary Engine with perfect control of
the expansion.
My Engine contains two metal cylinders, the larger outer one being fixed, the
smaller inner one to revolve eccentrically within the outer one.
The outer cylinder (called for distinction the casing) being turned smooth inside,
is round with the exception of a slot or groove along the side nearest to the inner
cylinder. In this space packing is placed which is kept tight against the inner
cylinder by means of screws passing through the casing at the centre line of the
groove. The inner cylinder, turned on the outside, is placed so that one side of it
would touch the casing along its whole length inside, were it not for the groove over
which it is placed.
The inner cylinder revolves truly on its own centre, and is divided interiorly by a
partition extending along its own, length. On the opposite side of the inner cylinder
and close to the opposite sides of the partition two slots are cut in the inner cylinder
corresponding in length with the length of "the casing." In these slots two wings or
flaps work up and down. The proportion of the inner cylinder to the casing is such
that these wings can shut inside the inner cylinder, leaving a small space when shut,
between the inside of the wall of the inner cylinder and the bottom of the wing, the top
of the wing being level with the outside of the inner cylinder. When extended these
wings will reach from the inner cylinder to the casing, when these are farthest
separated, enough of the wing remains inside the inner cylinder to keep it (the wing)
steady.

page_text: The ends of the casing are closed by covers through which the inner cylinder passes.
The wings fit in the slots allowing of motion in and out only, the back of each wing
bears on the partition. The edges of the wings are made steam tight against the
inside of the covers of the casings by means of packing, and guides which extend
partially over the face of the wings. These guides are fixed inside the inner cylinder
at each end of the slots.
Through the wings from the bottom to near the top, a hole extends for the passage
of steam or other fluids.
The wings will be forced out against the casing, by the pressure under them, but to
prevent any chance of sticking, they are also moved by a lever, from one end of which
a pin passes under the flap, and at the other end of which a pin passing out through
the wall of the inner cylinder and packing boxes is actuated by a eccentric outside the
end of the casing.
The inner cylinder is closed at one end, and also at the other with the exception of
two holes on each side of the partition, near the inside circumference of the wall of
the inner cylinder, for the admission of steam etc. Over the end of the inner cylinder
and over these holes a slide fits which can be moved up and down to allow the steam
to pass into the interior of the inner cylinder (on one side of the partition at a time)
for as much of the revolution as is required.
The slide is arranged so that when open to its fullest extent steam or other fluid is
admitted through one hole, until the corresponding flap is protruded from the inner
cylinder through the slot to its fullest extent. This slide valve extends over nearly
half the end of the inner cylinder. The remainder of the end has a similar slide over
it but it is immoveable.
The outside pressure keeps these slides tight against the end of the inner cylinder.
The slide when open remains in the position in which it is placed and does not move
at each stroke of the engine like the slide valve of an ordinary steam cylinder engine,
the different ports are opened and shut by the inner cylinder revolving, an effective
expansion of the steam is thus obtained, and is under complete control, being actuated
by the movement of the cylinder.
The end of the inner cylinder carrying the valves is flanged, and presses (with the
intervention of a friction disc) on bearings on the cover of the casing.
The end of the inner cylinder away from the valve passes through a packing box in
the cover of the casing, and has in it two slots cut, outside the packing box, corre-
sponding in position to the slots for the wings. These are the exhaust parts and are
covered part of the way round by a fixed conical bearing (the inner cylinder being
made conical at this point to receive the bearing). This bearing is cut away partially
on one side so that an exhaust port opens and discharges steam through this cut
away portion, when about one-sixth of a revolution beyond the point at which the
wing is at its greatest extension and continues to discharge until the part of the
revolution at which the wing has completely closed into its cavity.
The pins to work the levers pass through stuffing boxes in the sides of the shaft
beyond this bearing, and here run inside a fixed eccentric. The inner cylinder then
becomes solid throughout and is supported on bearings beyond which is a driving
pulley or other gearing for transmission of the force.
The action of the engine is this :-The steam or other fluid passes through one of
the ports in the end of the inner cylinder (the part of the revolution which it does
so, being regulated by the slide valve), to its interior, then partly forcing the wing out
through its slot, at the same time it passes up through the interior of the wings and
escapes near the top, on the side opposite to that in the direction of which the inner
cylinder is revolving, and filling the space between the inner cylinder and the casing,
and the wing, forces the wing and with it the inner cylinder to revolve. After the
wing has passed over the centre by about one-sixth of the circumference of the casing
the exhaust opens and the steam escapes either into the air or into other cylinders as
in compound engines.
The slide to admit the steam may be moved by a lever or by a screw.

page_text: As I prefer the use of the compounding system, I should also prefer reverse motion
to be obtained by means or gearing and friction couplings.
In compounding I should use two sets of engines at high pressure cutting off at
about one-fourth or one-sixth the capacity of each space between the casing and the
inner cylinder, for each half-revolution.
From each of these ordinary cylinders I should connect two other engines, cutting
off by means of standing valves, like the exhaust in the primary engines, at about one-
fourth the capacity of the same space in each half revolution. Other arrangements
may be made to suit the work pressure.
S. S. BROMHEAD,
97, Newgate Street, E.C.,
Patent Agent.
An improved Rotary Engine.
I, HERBERT BOYD, M.D. attached to the 45th Sikh's of her Majesty's Indian Army,
represented in England by Mr. S. S. Bromhead of 97 Newgate Street, London, 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:
My improved rotary Engine has several advantages over those now in use.
It is characterised by simplicity of design and possesses few working parts, and it is
so contrived as to ensure perfect control over the expansion.
My Engine consists of a fixed metal Cylinder and a rotary cylindrical piston with
the necessary shaft and ports.
In the provisional specification, this "Cylinder" is described as the "Casing" and
the "Piston was referred to as the "Inner Cylinder."
""
The Cylinder is fixed, and the Piston revolves excentrically within the said Cylinder.
The Cylinder is turned smooth inside, and is circular with the exception of a groove
formed from end to end along the side nearest to the piston.
This groove is filled with packing which is kept tight against the Piston by set
screws passing through the Cylinder.
The ends of the Cylinder are closed by covers through which the Piston passes.
The Piston is turned on the outside and is so placed that one side of it would
touch the Cylinder along its whole length, but for the packed slot over which it is
placed.

page_text: The Piston revolves truly on its own centre, and its interior is intersected length-
ways by a fixed partition extending its whole length and thus dividing it into two
semi-cylindrical chambers.
On opposite sides of the Piston, and close to opposite sides of the partition two slots
are cut in the Piston of corresponding length to the Cylinder.
In these slots two gates or flaps work in and out.
The relative size of the Piston and Cylinder is such that when these gates are shut
inside the Piston, their outer edge is flush with the edge of the Piston while a small
space is left between the inner edge of the gate and the inside of the wall of the
Piston, and when extended the gate reaches to the Cylinder when it is farthest from
the Piston, but enough of it remains inside the Piston to ensure steadiness.
The gates fill up the slots so as to allow motion in and out only.
One side of each gate bears on the partition and their ends or edges are made steam
tight against the inside of the covers of the Cylinder by means of packing.
They are also steam tight against guides which are fixed at each end of the slots
inside the Piston and extend partly over the face of the gates.
The gates are hollow, having apertures to allow the steam or other fluid to pass
through from one end to the other.
The pressure behind them will force them out against the Cylinder, but to prevent
sticking, they are also each impelled outwards by a lever, from one end of which a
connecting rod passes out through the end of the Cylinder and is actuated by an
excentric outside.
The Piston is entirely closed at one end and nearly closed at the other end, the
exception being two holes, one on each side of the partition near the circumference
which are left as inlet ports for the admission of steam and the like.
Over the end of the Piston and over these ports are two Valve covers, one of which
is fixed, and the other can be so adjusted by means of a screwed bar or lever to which
it is attached, as to allow the steam to pass into the Piston, on one side of the partition
at a time, during the revolution of the Piston.
One of these Valve covers can be moved up and down, and they are both kept tight
against the ports, by the pressure of steam outside them.
Each inlet port when open admits the steam to its half of the Cylinder until the
corresponding gate is projected through its slot to its fullest extent.
The movable Valve cover when open remains in the position in which it is placed,
and does not move at each stroke of the Engine like an ordinary slide Valve.
The ports are alternately opened and shut by the revolution of the Piston.
An effective expansion of the Steam is thus obtained and is under complete control
by the action of the movable Valve cover.
When this is opened the steam enters the Piston projects the gate and starts the
Engine.
When it is closed or partly closed the steam is wholly or partly excluded.
The end of the Piston that is farthest from the inlet ports passes through a packing
box in the cover of the Cylinder, and has in it two slots cut outside the Cylinder
corresponding in position to the slots for the gates.
These are the exhaust ports, and are covered part of the way round by a conical
bearing, the Piston being made conical at this part to fit the bearing.
This conical bearing is cut away partially on one side so that an exhaust port opens
and discharges steam through this cut away portion, when about one-sixth of a revolu-
tion beyond the point at which the gate is at its greatest extension and continues to
discharge until the part of the revolution at which the gate has completely closed into
its cavity.
The pins to work the levers pass through stuffing boxes in the sides of the shaft
beyond this bearing and here run inside a fixed excentric.
The Piston then merges into a solid shaft and is supported on bearings, beyond
which is a driving pulley or other gearing for the transmission of the force.
The action of the Engine takes place thus ;-The steam or other fluid passes through

page_text: one of the ports in the end of the Piston, to its interior, the portion of the revolution
in which it does so being regulated by the movable valve cover.
Then it enters the gate and passes upwards through its slot, partly forcing the gate
out as it does so, and ascending through the interior of the gate, it escapes near the
top on the side opposite to that in the direction of which the Piston is revolving, and
filling the space between the Piston and the Cylinder, and the gate, it forces the gate
and with it the piston to revolve.
After the gate has passed over the centre of the Cylinder by about one-sixth of the
circumference, the exhaust opens and the steam escapes either into the air or into other
cylinders as in compound Engines.
As I prefer the use of the compounding system I should also prefer reverse motion
to be obtained by means of gearing and friction couplings.
In compounding I should use two sets of Engines at high pressure, cutting off at
about one-fourth or one-sixth the capacity of each space between the Cylinder and the
Piston at each revolution.
From each of these primary Cylinders and Pistons, I should connect two other
Engines, cutting off by means of standing valves, like the exhaust in the primary
Pistons, at about one-fourth the capacity of the same space, for each half revolution.
Other arrangements may be made to suit the working pressure required.
In the accompanying drawings,
Fig. 1. Shows a sectional elevation through centre of the Cylindrical piston and
exhaust bearings the ends of the Cylinder being shown by dotted lines.
Fig. 2. Shows a section through centre of the Engine showing Cylinder, Valve box,
and Piston with one of the gates extended.
Fig. 3. Shows a cross section of the Cylinder and Piston with the partition in the
Piston and one of the gates extended and the other closed.
Fig. 4. Shows the Valve box and Valve cover with valve half open, the end of the
Piston and inlet ports being shown in dotted lines.
Fig. 5. Shows a section through centre of exhaust ports.
A
Danates the Culindar

page_text: into 2 semi-cylinders, and fitted with the gates. C. C, and with the lever. G. actuated
by the excentric I; and with the inlet ports Y, and the exhaust ports. X, and the
exhaust bearing O, the whole forming a continuation of the driving shaft Q
substantially as herein explained and set forth.
2. In a rotary Engine the stationary Cylinder A fitted with a groove and packing W,
also with the heads or covers K and the rotary adjustable cut off or expansion valve D,
and stationary cover P, the valve box. L, the adjusting screw E, and the friction
discs. M, substantially as herein described and set forth.
3. In a rotary Engine, the combination of the whole or any of the following parts,
viz:-The fixed Cylinder. A, with the groove and packing W, the heads K and the
cut off valve D, the valve cover P, the valve box L, the adjusting screw E, the friction
discs M, and the rotary cylindrical Piston B, the gates C. C, and lever G, the
excentric I, the ports Y and X the exhaust bearing. O, with the shaft Q, substantially
as and for the purposes herein explained and set forth.
S. S. BROMHEAD,
97, Newgate Street, E.C.,
Patent Agent.