Improvements in Rotary Motive Power Engines.
Year: 1892

page_text: Date of Application, 28th Oct., 1892
Complete Specification Left, 28th Aug., 1893-Accepted, 28th Oct., 1893
PROVISIONAL SPECIFICATION.
Improvements in Rotary Motive Power Engines.
I, ARTHUR BOYD, of. 26, Newstead Road, Middlesbrough-on-Tees, in the
County of York, Engineer, do hereby declare the nature of this invention to be
as follows:-
This invention relates to rotary motive power engines of the type which derive
their efficiency from a differential piston resistance, and consists of improvements
upon my previous invention the nature of which is described in my Provisional
Specification Number 2820 of 1892, except in respect of the driving cylinder and
its pistons, the particular and novel arrangement of which constitutes the essential
feature of this invention.
"
The object in view is to substitute for rectangular or wing pistons which sweep
round an axis in edgewise contact with a cylindrical surface and which are con-
sidered more difficult to keep steam tight than ordinary pistons, circular pistons
having a linear movement in their cylinders as in ordinary reciprocating engines,
in which a reliable steam tight fit between piston and cylinder is readily obtainable
by various well known devices.
The general construction of my improved rotary engine apart from the cylinder
and pistons is in both principle and detail analogous to the rotary engine described
in my Provisional Specification No. 2820 of 1892, that is to say that the main
shaft of the engine is compounded of two separate parts rotating in the same
direction and about the same axis with different motions, one shaft which is the
driving shaft of the engine having a uniform rotary motion and the other shaft,
which for distinction I term the resistance shaft, having a variable motion. These
two shafts are connected together by a system of links and levers and their
accessory parts or by some equivalent mechanism by which the uniform rotary
motion of the driving shaft is converted into the variable motion of the resistance
shaft, or rice-versa according to which way the engine is running.
The particular arrangement of the cylinder and pistons which constitute this
invention consist as follows:-The cylindrical body which I will term the main
shaft cylinder is mounted on and axially secured to the driving shaft so that both
rotate together which gives the heavier moving parts of the engine a uniform
angular velocity. This cylinder furnished at opposite parts with two piston
cylinders extending therefrom in opposite and parallel directions, and at right
angles to the same diameter from the extreme points of which they extend in the
form of tangential projections to the main shaft cylinder. These cylindrical
projections are the driving cylinders of the engine and are furnished with pistons
and cylinder covers against which the steam does its work in driving the engine.
The pistons are coupled together by a cross lever attached at its opposite ends to
the piston connecting rods. The cross lever is secured at mid length to the
resistance shaft which extends into the main shaft cylinder in line with the main
shaft. The length of the piston cylinders, the positions and stroke of the pistons
and the movements of the connecting rods and cross lever are all adjusted so that
each piston and its cylinder cover are closed together at the starting point of each
revolution of the main shaft, and are forced apart as the steam is giving out work,
and are brought together again as the steam exhausts, which result is due to the
pistons partaking of the variable angular velocity of the resistance shaft, whilst
the cylinder covers partake of the uniform angular velocity of the main shaft.
The mechanical advantage by which greater resistance is offered to the stean
by the pistons for part of a revolution and by the cylinder covers for the
remainder of the revolution and so on through each complete revolution of the
engine is derived from the system of links and levers with their accessory parts

page_text: by which the two shafts are coupled together, and which do not constitute a part
of this invention.
Engines constructed on the above described plan are reversible when the driving
cylinders are placed with their linear centre lines set far enough apart from the
centre of the main shaft so that the cylinder covers have leverage or moment.
The work being done either by the cylinder covers or the pistons and depending
upon the external gearing in its relation to the steam and exhaust ports in the
cylinder and fixed framing. When the driving cylinders are placed diametrically
opposite in line the cylinder covers will have no leverage or moment and cannot
drive anything round in either direction. The engine in such cases can be reversed
by detaching the piston connecting rods from the cross lever and re-attaching
thereto in the reverse position or by other means.
The above description applies to a simple engine, but it is obvious that the
arrangement of pistons working in cylindrical projections to a main shaft cylinder
are readily adapted to a compound engine, as more pistons and piston cylinders
can be employed suitably placed, with their relative steam capacities properly
proportioned to the conditions of a compound engine.
Dated this 27th day of October 1909
G. J. CLARKSON,
Stockton-on-Tees, Agent for the Applicant.
.
COMPLETE SPECIFICATION.
Improvements in Rotary Motive Power Engines.
I, ARTHUR BOYD, late of 26, Newstead Road, and now of 32, Borough
Road West, Middlesbrough-on-Tees, in the County of York, Engineer, 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 rotary motive power engines of the type which derive
their efficiency from a differential piston resistance and consists in improvements or
modifications upon my previous invention as described in the Specification of the
Letters Patent granted to me, bearing date February the 13th, 1892 and
numbered 2820 from which the said improvements or modifications differ mainly
in respect of the driving cylinders and pistons the particular and novel arrangement
of which constitutes the essential feature of this invention.
The object in view is to substitute for rectangular or wing pistons (which sweep
round an axis in edgewise contact with a cylindrical surface and which are con-
sidered more difficult to keep steam tight than ordinary pistons) circular pistons
having a linear movement in their cylinders as in ordinary reciprocating engines
and in which a reliable steamtight fit is consequently readily obtainable by various
well known devices.
The general construction of my improved rotary engine apart from the cylinders
and pistons and their accessory parts is in both principle and detail analogous or
similar to the rotary engine described and illustrated in the Specification of my
Letters Patent No. 2820 of 1892 that is to say that the main shaft of the engine
is compounded of separate shafts having a uniform angular velocity and rotating
in the same direction and about the same axis in combination with another shaft
which for distinction I term the piston or resistance shaft which has a variable
angular velocity. These two shafts are connected together by a system of links
and levers and their accessory parts as illustrated in the drawings hereto annexed
or by some equivalent mechanism by which the uniform rotary motion of the main
shaft is converted into the variable motion of the piston or resistance shaft or
vice versa according to which way the engine is running.
And in order that the particular arrangement of the cylinders and pistons which
constitute this invention may be clearly understood and the invention readily carried

page_text: into effect I will now proceed to describe the same with reference to the accom-
panying drawings in which I illustrate my invention as applied to both a simple
and a compound single acting engine.
As illustrating a simple single acting engine,
Figure 1 represents a longitudinal sectional view thercof and Figure 2 is a
transverse sectional view taken on line a x of Figure 1, but with the pistons shown
at a different part of the stroke, (the main shaft being 90° further round).
Figure 3 is a repetition of Figure 2 except that the piston rods are shown
furnished with tail rods and guides and the pistons are set at full stroke.
Figure 4 is a longitudinal sectional view of the engine in the compound form
corresponding to which Figure 5 is a transverse sectional view taken on line y y of
Figure 4, and is intended to show an arrangement of links and levers by which the
uniform motion of the main shaft is converted into a variable motion of the piston
or resistance shaft of a convenient design for placing between the high and low
pressure cylinders in cases where it is required to make the engine drive from
both ends.
Figures 6 and 7 are transverse views of a centrifugal gear which is specially
adapted for steadying this type of engine.
In the figures a al is the main shaft the rotary motion of which is to be utilized.
In this case the part a of the main shaft is made hollow for the reception of the
piston or resistance shaft b to one end of which the pistons el e' with their accessory
moving parts within the cylindrical body care attached in the manner shown.
The cylindrical body c is mounted on and axially secured to the driving shaft a a²
so that both rotate together, which gives the heavier moving parts of the engine
a uniform angular velocity the combined weight of the cylindrical body c and
crank disc serving as a flywheel. A convenient form of mounting the cylinders c¹²
and the main shaft a a' with their accessory moving parts is shown in the drawings
and consists of a cylindrical casing 9 with cover g erected on a bedplate / and
forming a chamber in which the cylinders c¹ c³ revolve. The standards with
the several parts mounted thereon are in all respects combined, arranged and
intended to operate in the manner described and illustrated in the Specification of
my Letters Patent No. 2820 of 1892 and although forming part of my improved
engine as illustrated in Figure 1 by which the lead and cut off of the steam is
regulated and controlled and the engine reversed do not in themselves constitute a
feature of my present invention and require no further or separate description in
connection therewith.
g
The cylindrical body c is furnished at opposite parts with two piston cylinders c¹ c³
extending therefrom in opposite and parallel directions and at right angles to the
same diameter from equidistant points of which they extend in the form of
tangential projections to the main body c that is to say that this is a simple
mechanically and pressure balanced arrangement for the purposes of my invention
but is open to modification as to the positions and number of piston cylinders used
to adapt it to meet special conditions.
These cylindrical projections care the driving cylinders of the engine and
are furnished with the pistons e¹³ and cylinder covers flf in the manner shown
and against which the steam does its work in driving the engine. The pistons e¹³
are coupled together by a cross lever d attached at its opposite ends to the piston
connecting rods d' d'. The cross lever d is secured at mid length to the piston
or resistance shaft which extends into the cylindrical body c in line and within
the driving shaft a a¹. The length of the stroke of the pistons and the movements
of the connecting rods and cross lever are all adjusted so that each piston and its
cylinder cover are close together at the starting point of each stroke, are forced
apart as the steam is giving out work and are brought together again as the steam
exhausts, which result is due to the pistons ele partaking of the variable angular
velocity of the piston or resistance shaft b, whilst the cylinder covers f¹ ƒ³ partake
of the uniform angular volocity of the main shaft a a¹.
The mechanical advantage of the pistons over the covers f¹ƒ³ when the engine

page_text: is driven by the pistons in one direction and the mechanical advantage of the cylinder.
covers over the pistons el e when the engine is being driven by the covers in
the reverse direction is derived from the system of links and levers in¹ m³ m³ and m
with their accessory parts by which the main shaft a¹ and shaft are coupled
together as shown in Figure 1, or by some modified or equivalent mechanism as
shown in Figures 4 and 5 and hereinafter described.
In order that the pistons may have an easy and well balanced action especially
at the high speeds at which engines constructed according to this invention are
intended to run and which speeds would if unprovided for tend to excessive friction
between piston and cylinder and excessive outward throw of the piston due to
centrifugal force, I prefer to provide deep pistons where only simple connecting rods
are used as shown in Figure 2 and to attach to the connecting rods balance
weights d d to counteract the tendency to excessive side pressure of the
pistons, or I substitute for this arrangement the tail rods d³ with or without
the upper tail rods ff as shown in Figure 3 in which case the pistons them-
selves are kept as light as practicable and the tail rods des by being bored
through their full length serve the purpose of plungers for pumping oil into their
connecting rod joints and acting as balance weights to check excessive outward
throw of the pistons at high velocities. The annular spaces & communicate by
a port in each valve and ot and through the flanges a of the main shaft, with
the inlet and outlet ports in the fixed casing, the exhaust ports being preferably
longer than the inlet ports.
Engines constructed on the above described plan are reversible when the driving
cylinders care placed with their linear centre lines set parallel to one another
equidistant from the centre line of the main shaft a a¹ as shown more particularly
in Figures 2 and 3 so that the cylinder covers have leverage or moment, the work
being done either by the cylinder covers or the pistons and depending upon the
position of the controlling shaft in its relation to the steain and exhaust ports
in the fixed framing. When the driving cylinders are placed diametrically
opposite or in line with a diameter of the main shaft the engine in such cases
is not practically reversible to do which involves detaching the piston connecting
rods from the cross lever and reattaching them thereto in the reverse position.
The above description refers to a simple single acting engine but it is obvious
that this arrangement of pistons working in cylinders projecting from a main
cylindrical body can be readily adapted to the compound principle. Referring to
Figure 4 which is intended to show a suitable form of compound engine as
constructed to embody this invention it will be observed that a smaller and larger
main cylindrical body each constructed precisely in the manner as hereinbefore
described with reference to Figures 1, 2 and 3 and axially secured to the same
main shaft al a a' are connected by a steam pipe by which the steam exhausted
from the high pressure cylinder of c is delivered into the low pressure cylinder
of c³.
"
The system of links and levers m' m² m³ and m' as shown in Figure 1 could of
course be similarly combined and used with the engine in the compound form, but
in order to provide the requisite mechanism to convert the uniform rotary motion
of the main shaft a' a a' into the variable rotary motions of the piston or resistance
shaft b at an intermediate position between the high pressure and low pressure
cylinders as shown in Figure 4, I modify this system of links and levers in the
manner shown in section in Figure 4 and transversely in Figure 5 by mounting one
end of each link m' m² on the eccentric straps these straps taking the place of the
cross bar m³, the eccentrics m* m taking the place of the controlling shaft. These
eccentrics could be made moveable about the axis of the main shaft whereby the
engine would be linked up or reversed. I will now proceed to explain the
centrifugal gear which I have found to be suitable for counteracting the centrifugal
force of the pistons in their stroke. As this gear is only to be understood from
transverse views such as are shown in Figures 6 and 7, I have entirely omitted
it from the longitudinal views in Figures 1 and 4. This centrifugal gear which

page_text: is driven by the main shaft is free to act npon the piston or resistance shaft so
that the pistons may offer greater or less resistance to the steam without reference
to their own weight whereby the engine may work as well with the cylinder covers
driving, as when the pistons are driving, and if desired the gear may be carried
inside a fly-wheel shown in Figure 6 or in combination with the pistons of the
engine and their connections as shown in Figure 7.
Referring to Figure 6 the pins n' n² are fixed to the disc whilst the pins n³, n', n'
and n are joints for the links o¹, 03, 03 and o' and the cross lever o on the piston or
resistance shaft by which the weights q'q' are free to fall upon the said piston or
resistance shaft and are limited in action by the controlling gear of the engine.
The above explanation will also cover the modification of the centrifugal gear
as shown in Figure 7, which is intended to illustrate a way of attaching the said
gear to the piston connections instead of to a separate disc or flywheel of its own.
The whole of the resistance may be supplied in this way, the steam not being able
to overcome the centrifugal force of the gear the forces will all be constant in
the gear.
It will be seen that what are termed the main cylindrical bodies to which the
driving or working cylinders c c are attached as projections enclosing the pistons
and their connections, their cylindrical form is not an essential feature of my
invention but is to be taken as representing any convenient form of hollow vessel
capable of serving the purpose as hereinbefore described.
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 :-
Firstly. In rotary motive power engines, a combination of parts in which
a main shaft and piston or resistance shaft are coupled together to rotate in line, the
main body with the working cylinders attached thereto being axially secured to the
main shaft whilst the pistons are secured by a cross lever and connecting rods to
the piston or resistance shaft, the two shafts being connected end wise to a system
of links and levers or their equivalents by which the uniform angular velocity of
the main shaft is converted into the variable angular velocity of the piston or
resistance shaft when the engine is running ahead and the variable angular velocity
of the piston or so called resistance shaft is converted into the uniform angular
velocity of the main shaft when the engine is reversed, all arranged and operating
substantially as hereinbefore described with reference to the accompanying
drawings.
Secondly. The combination and arrangement of parts constituting the intermediate
gear by which the lead and cut off of the steam is regulated and controlled and the
uniform angular velocity of the main shaft converted into the variable angular
velocity of the piston or so called resistance shaft or vice versa substantially as
herein before described and illustrated in Figures 4 and 5.
Thirdly. In rotary motive power engines the use of the centrifugal gear
whether worked in combination with the piston connections or otherwise for
increasing or decreasing the effects of the centrifugal force of the pistons and their
connections whereby the engine will be free from shocks and the working joints
bear only in one direction during a complete revolution as illustrated by way of
example in Figures 6 and 7.
Fourthly. The combination of parts as a whole, constructed, arranged and
fitted together and constituting a single acting simple or compound rotary motive
power engine as the case may be as herein before described with reference to the
accompanying drawings.
.
G. J. CLARKSON,
Chartered Patent Agent,
Stockton-on-Tees, Agent for the Applicant.