CERTAIN IMPROVEMENTS IN ROTARY ENGINES
Year: 1840

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
MACKAY, of Mark Lane, in the City of London, Ship Broker, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Fifth day of May, in the third year of Her reign, did, for
Herself, Her heirs and successors, give and grant unto me, the said George
Mackay, Her especial license, full power, sole privilege and authority, that
I, the said George Mackay, my executors, administrators, and assigns, and
such others as I, the said George Mackay, my executors, administrators, or
assigns, should at any time agree with, and no others, from time to time
and at all times during the term of years therein mentioned, should and
lawfully might make, use, exercise, and vend, within England, Wales, and the
Town of Berwick-upon-Tweed, and in all Her Majesty's Colonies and Plan-
tations abroad, an Invention of "CERTAIN IMPROVEMENTS IN ROTARY ENGINES,"
being a communication from a certain Foreigner residing abroad; in which
said Letters Patent is contained a proviso obliging me, the said George
Mackay, by an instrument in writing under my hand and seal, particularly
to describe and ascertain the nature of the said Invention, and in what
manner the same is to be performed, and to cause the same to be inrolled
in Her Majesty's High Court of Chancery within six calendar months next
and immediately after the date of the said in part recited Letters Patent, as
in and by the same, reference being thereunto had, will more fully and at
large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
George Mackay, do hereby declare that the nature of the said Invention, and
the manner in which the same is to be performed, is particularly described
and ascertained in and by the following description thereof, reference being
had to the Drawing hereunto annexed, and to the letters and figures marked
thereon (that is to say):-
:-
My Invention of Certain Improvements in Rotary Engines consists in a
peculiar combination and arrangement of the parts whereby much compact-
ness of form is obtained and economy secured, and also in such an application
of the clastic force of the steam employed therein as to ensure the greatest
efficiency of action. This Invention is applicable in all cases where a motive
power is required, but is especially suited to circumstances wherein a saving
of space is an object.
I proceed now to describe more fully the nature of this Invention, referring
to the several Figures of the accompanying Drawing, in all which similar letters
indicate corresponding parts. Fig. 1 is a sectional elevation of the main work-
ing parts of the engine, the framework being removed in order the better to
shew the parts; Fig. 2 is a front view of the engine complete; and Fig. 3
is a side view of the same. A is the ordinary steam pipe, being fitted with a
cock B, by which the supply of steam to the engine is regulated. This cock
is opened and shut by a rod C working through a slot and between guides
in the bar D, which bar is jointed at one end to the lever E, (and having its
fulcrum at e, thus acts upon the valve F,) and has its reverse end connected
with the spring G, for the purpose of regulating its action upon the valve.
His a ratchet wheel suitably mounted, as shewn, on the axle of which the
spring G acts, and is thereby enabled to yield freely to the impulse of the bar
D. This ratchet wheel is furnished with a pall or click to prevent its turning
the opposite way to that required. I is a steam reservoir or receptacle
answering to the ordinary cylinder, but which is here represented in the form
of a quadrant. It is placed over the wheel N, so that the projections or
studs P, upon its periphery, may successively be presented to the action of the
steam admitted into the reservoir I. This wheel N (it will be seen on refe
rence to Fig. 2) has its shaft V properly mounted, and turning in plummer
blocks fixed on to the framework Q of the engine. J is a valve for keeping in
the steam until the projection or stud P, which is being propelled forward by
its elastic force, passes the mouth of the eduction passage L; this valve is
closed by a spring K the moment it has allowed the projection or stud P to
pass by it out of the reservoir I. T is a fly wheel for regulating the motions

page_text: of the engine. The operation of this engine is as follows:-On steam being
admitted to the reservoir or quadrant I, (the parts being in the position shewn
in Fig. 1,) its elastic force is exerted between the valve or shutter F and the
stud P. The former being unable to move in the direction in which it is
thereby urged, acts as an abutment for the steam, while the latter is driven
forward by its pressure, and, fitting exactly the space between the outer rim
of the wheel N and the internal periphery of the quadrant I, it receives on its
surface the full force of the steam until it reaches the mouth of the eduction
passage L, when, after allowing the steam to escape, it passes off through the
valve J, just previous to which time another projection or stud has entered
the quadrant through the valve F, to be acted on in a similar way. I would
here remark, it must be evident that, by applying the steam in the way
described, there is a considerable leverage obtained upon the shaft V, which
would be the medium for transmitting, in any convenient way, the power
the engine to any machinery required to be worked by it. I will now explain
the action of the valve F, as seen at Fig. 1. It is in full action, that is,
serving as an abutment for the steam, and is kept in its present position until
the inclined plane of the advancing projection or stud P, coming in contact with
it, forces it up into the recess X, the consequence of which is that the lever E
is thrown into nearly a horizontal position, carrying with it the bar D, which,
acting upon the rod C, shuts the cock as soon as the valve F begins to open.
The whole of this mechanism remains as described (and shewn by dots in the
Figure) until the stud P has passed from under the valve or shutter F, and
entered the steam reservoir I, when the spring G causes it to fly back against
the periphery of the wheel N, which motion also opens the cock B, and thus
admits a fresh supply of steam to act upon the stud P.
from
Having thus described my Invention of Certain Improvements in Rotary
Engines, I desire it to be understood that I do not mean or intend to confine
myself to the precise form or arrangement of mechanism shewn, as I am quite
conscious it is susceptible of considerable modification, but have exhibited that
set forth in these presents as a convenient mode of carrying out my Invention,
laying no claim, however, to any of the parts separately, but simply as they
are used in combination.
In witness whereof, I, the said George Mackay, have hereunto set my
hand and seal, this Fifth day of November, in the year of our Lord
One thousand eight hundred and forty.
GEORGE (L.S.) MACKAY.

page_text: AND BE IT REMEMBERED, that on the Fifth day of November, in
the fourth year of the reign of Her Majesty Queen Victoria, the said George
Mackay came before our said Lady the Queen in Her Chancery, and acknow-
ledged the Instrument aforesaid, and all and every thing therein contained and
specified, in form above written. And also the Instrument aforesaid was
stamped according to the tenor of the Statute made in the fifty-fifth year of
the reign of His late Majesty King George the Third.
Inrolled the Fifth day of November, One thousand eight hundred and
forty.