IMPROVEMENTS IN ROTARY AND RECIPROCATING ENGINES
Year: 1857

page_text: LETTERS PATENT to Thomas Ivory, of Edinburgh, Advocate, for the
Invention of "IMPROVEMENTS IN ROTARY AND RECIPROCATING ENGINES,"
Sealed the 26th January 1858, and dated the 30th July 1857.
PROVISIONAL SPECIFICATION left by the said Thomas Ivory at the
Office of the Commissioners of Patents, with his Petition, on the
30th July 1857.
I, THOMAS IVORY, of Edinburgh, Advocate, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN ROTARY AND RECIPROCATING ENGINES,"
to be as follows:-
My Invention consists in producing the rotary or the reciprocating motion
of the engine by the use of steam or other fluid or aeriform body, in such
a manner as to cause a recoil or reaction of one or more revolving or recipro-
cating bent arms through which the fluid issues, and which are open at their
outer extremity, except in so far as they are closed by the outer ring or abuttal
herein-after mentioned.
For this purpose the steam or fluid is admitted at the centre of motion of
the arms by a central pipe or axis and allowed to impinge at the outer end of
each arm against a fixed ring or rigid abuttal opposite and close to the orifice
of the arm, thereby causing a recoil on each arm in the same direction of revo
lution around the centre, and thus producing rotary motion.
The steam or fluid after impinging upon the abuttal is free to escape at tho

page_text: extremity of the arm through an orifice in that side thereof which is nearest
the centre; and in order to reverse the rotary motion, or to produce a recipro-
cating motion, there is to each of the above arms a corresponding arm in the
same semicircle, extending from the central steam pipe or axis to the circum-
ference of the outer ring or abuttal on opposite sides of the centre to those
above described, whereby the steam or other fluid is made to impinge against
the part of the ring or abuttal directly opposite to that acted upon by the other
corresponding arm, so as to produce a rotary or reciprocating motion of these
arms around or about the centre in the opposite direction to that above
described. For this purpose a four-way cock or valve for transferring the
passage of the steam from one set of arms to the other is adapted and applied
to the central pipe or axis, which, for the reversal of the rotary motion, is
worked by hand, but for producing the reciprocating motion is worked by self-
acting mechanism; or, if preferred, the same effect may be produced by means
of a cock or valve at or near the outer extremity of the arms to be worked in
the same manner.
My Invention is not confined to the above described mode of producing the
rotary or the reciprocating motion, but the same may be produced by a recoil
action caused by the impinging of the steam or fluid against abuttals fixed
between two plates or flanges forming a kind of chamber or partial inclosure,
within which the steam or fluid is partially confined as it issues from orifices in
he arms as they successively enter the said chamber or partial inclosure, the
arms in this case being closed at their outer extremity.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Ivory in the Great Seal Patent Office on the
30th January 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
IVORY, of Edinburgh, Advocate, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of July, in the year of our.Lord One
thousand eight hundred and fifty-seven, in the twenty-first year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the
said Thomas Ivory, Her special license that I, the said Thomas Ivory, my
executors, administrators, and assigns, or such others as I, the said Thomas
Ivory, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during

page_text: the term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
ROTARY AND RECIPROCATING ENGINES," upon the condition (amongst others) that
I, the said Thomas Ivory, by an instrument in writing under my hand and seal,
should particularly describe and ascertain the nature of the said Invention.
and in what manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Thomas Ivory, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Drawings hereunto annexed, and to the
letters and figures marked thereon (that is to say):-
My Invention of "Improvements in Rotary and Reciprocating Engines"
consists in producing the rotary or the reciprocating motion of the engine by
the use of steam or water, or other fluid or aeriform body, in such a manner
as to cause a recoil or reaction of one or more revolving or riciprocating bent
arms, through which the fluid issues, and which are open at the outer extremity.
except in so far as they are closed by the outer ring or abuttal herein-after
mentioned.
For this purpose the steam or fluid is admitted at the centre of motion of
the arms by a central pipe or axis, or at any other part of the arms, and
allowed to impinge at the outer end of each arm against a fixed ring or rigid
abuttal opposite and close to the orifice of the arm, thereby causing a recoil
on each arm in the same direction of revolution around the centre, and thus
producing rotary motion.
The steam or fluid after impinging upon the abuttal is free to escape at the
extremity of the arm through an orifice in that side thereof which is nearest
the centre; and in order to reverse the rotary motion, or to produce a recipro-
cating motion, there is to each of the above arms a corresponding arm in the
same semicircle, extending from the central steam pipe or axis to the circum-
ference of the outer ring or abuttal on opposite sides of the centre to those
above described, whereby the steam or other fluid is made to impinge against
the part of the ring or abuttal directly opposite to that acted upon by the other
corresponding arm, so as to produce a rotary or reciprocating motion of these
arms around or about the centre, in the opposite direction to that above
described. For this purpose a four-way cock or valve or other means for
transferring the passage of the steam from one set of arms to the other is

page_text: adapted and applied to the central pipe or axis, which for the reversal of the
rotary motion is worked by hand, but for producing the reciprocating motion
is worked by self-acting mechanism; or, if preferred, the same effect may be
produced by means of a cock or valve at or near the outer extremity of the
arms to be worked in the same manner.
5
A distinguishing feature of this mode of producing rotary motion is, that it
is an application of the steelyard principle to rotary engines, so that the greater
the diameter of the circle described by the arms, the less steam is expended
for the same work done.
Such being the nature of my Invention, I will proceed to describe several 1
modes of carrying it into effect, showing how the principle of recoil or reaction
obtained by means of a fixed outer ring concentric with revolving arms may be
applied to the production of rotary motion in steam or other engines.
DESCRIPTION OF DIAGRAMS.
Fig. 1 represents the two arms A, B, of an engine, arranged so as to be 1
capable of being made to revolve round the centre C, at which the steam is
supplied for working the arms; D is the orifice or outlet for the escape of the
steam, by which the balance of the pressure within the arm is disturbed. In
the Figure this is represented so that the area of the orifice may be one-fourth
that of the arm or tube in the cross section; E is the fixed ring or rigid 2
abuttal which is intended to be supported on any suitable framework, to give
it the required stability. It will be seen that the arms A and B reach all but
in contact with the interior of the ring or abuttal E, so that the only outlet
for the steam from the arms into the atmosphere is through the orifice D.
Now, on steam being admitted into the arms A and B at the centre C, it 2
will exert an equal expansive force or pressure upon every square inch of the
arms, and if the orifice D were closed, there would be no rotary motion of the
arms produced, because the pressure upon the area of the orifice D balances
that on the area a, b, at the extremity of the short limb of the arm; but on
this balance of pressure being disturbed by the steam being allowed to escape 3
at the orifice or outlet D, the pressure continuing on the area a, b, the arms
will be made to revolve around their centre of motion by means of the effective
pressure-left on that area and in the direction opposite to that portion of the
outer ring E, against which the steam for the time impinges. By this means
a continuous rotary motion of the arms A and B will be kept up while steam 3
is supplied to them, which motion may be transmitted in the ordinary manner
to machinery required to be driven by the engine. The arms A and B may
be varied as to their form, length, and area, and generally in any other way,

page_text: so long as the principle of recoil produced by means of a fixed outer ring is
preserved, and there may be adapted and applied to the ring or abuttal E and
to the arms A and B, modes of contracting the orifice and of delaying the exit
of the steam, as herein-after described, or otherwise.
Fig. 2 represents a mode of contracting the orifice by applying to the interior
of the ring or abuttal a projection d, which is made to pass into a recess
within the ring or abuttal, so as to enable the end of the revolving arm to pass
it, and immediately afterwards to spring out so as to contract the orifice, as
shewn; or there may be a spring valve on the end of the arm, capable of
yielding to a blow of the fixed projection d. In this case there is provided a
tail to the arm by which the escape of the steam is retarded. This tail is open
to the outer ring and at the orifice d*, but closed in every other direction.
Fig. 3 represents a tail or continuation of the arm in which the steam may
expand and escape more gradually than as in Fig. 1; by this means the expen-
diture of steam may be economized. This tail may be considerably increased
in length, and may be used either open or closed towards the outer ring, and
being applied to each arm and made to revolve on opposite sides of the
centre of motion, will form a balance and serve to equalize the motion of the
arms.
In Fig. 4 is represented an arrangement at the inner end of the arm to
direct the passage of the steam against the area a, b, as nearly as possible
at right angles, so as to increase the effect of the pressure of steam on that area.
In Fig. 5 is represented a mode of admitting the steam near the outer end
of the revolving arm, the arm being closed at the part shewn by a dotted line,
and the recoil obtained in the same way as above described, but upon the area
represented by the dotted line, and the back part of the arm merely acting as
a lever from that point to its centre of motion. This application of the prin-
ciple of my Invention might be found useful in some cases wherein it would be
required to have a wheel of large diameter, or to move a heavy weight, as for
instance, a turntable.
Fig. 6 shews the combination of the second pair of revolving arms A*, B*,
with the arms A, B, for the purpose of reversing the motion of the engine, or
of producing a reciprocating instead of a rotary motion. It will be seen, that
for reversing the engine, the passages for admitting steam at the centre must
be opened, so as to cause it to escape from the arms A, B, instead of from
the arms A, B; and this may be done by means of a hand lever connected
with a four-way cock, or otherwise arranged, so as to enable the orifices D
to be opened and D* closed, or vice versa, or arranged so as to enable the
admission orifices F at the centre to be opened and F* closed, or vice versa.

page_text: For producing a reciprocating motion the induction or eduction orifices will
be changed, so as to cause the steam to escape alternately from the arms A, B,
and the arms A*, B*, and this may be done by means of a tappet or a cam
acting upon a lever, or otherwise.
Fig. 7 represents the combination of the recoil principle with that of the
"Barker's mill." In this case the revolving arm is made deeper, so that one
part of it may be carried over the ring or abuttal, and the outer end of the
arm outside or beyond the abuttal, will be made to act on the "Barker's mill"
principle, while the inner portion thereof, or that within the ring or abuttal
will be made to act on the recoil principle above described. The portion of
the arm within the fixed ring may be made also to work on the "Barker's
mill" principle in combination with the recoil principle, by forming an orifice
as at De
Fig. 8 represents a mode of obtaining an increase of the recoil from the
abuttal E, by forming the end of the arm so as to allow a portion of the steam
to act on the abuttal, and cause a recoil on the end of the arm opposite to the
orifice.
Fig. 9 represents the outer end of the arm alone, with an enlarged area, the
inner portion being of smaller area, so that the steam may be supplied to the
outer end in a somewhat similar manner to the injection of water into
the cylinder of a hydraulic engine from the smaller pipe.
Fig. 10 represents a mode of applying the steam through the arm, so as to
produce the recoil from the outside of the fixed ring or abuttal. This may be
done by not allowing the steam to impinge upon the inner side of the fixed
ring, but carrying it over the same and bending the arm down, so as to enclose
the steam between the outer end of the arm and the outer surface of the ring,
the only orifice for the escape of the steam into the atmosphere being at G;
by this means the arms are made to revolve in the direction of the arrow.
Fig. 11 represents a combination of the impulse and recoil principles. The
steam being admitted at the pipe H or H*, external to the fixed ring or abuttal s
E, and passing through an opening in the said ring is made to act (the force
being applied substantially at right angles to the sine x, y, and the steam being
expended substantially at right angles to the versed sine,) on a series of vanes I,
of larger area than this opening, so that the steam may expand beyond the
mouth of the opening, and produce a recoil from the inner side of the fixed a
ring or abuttal E against the outer side of the vane I, in a line above the
centre of motion of the arms, which in this case are not hollow, for the passage
of steam, but serve for supports to the ring or wheel on which the vanes I are
carried. The vanes I are flanged, so as in combination with the inner surface

page_text: of the fixed ring to form a close chamber, such that the only orifice for the
escape of the steam into the atmosphere is at K. The rotary motion may be
thus obtained without the use of a projecting abuttal, but I prefer to use one
similar to that described above and represented in Fig. 2, and I prefer that it
be situated as indicated at L.
Having thus described the nature of my Invention, and in what manner the
same is to be performed, I would have it understood that I claim as of my
Invention the application of the recoil principle to the purpose of producing
the rotary or the reciprocating motion of steam or other engines, by means of
recoil against a fixed outer ring, concentric with revolving arms where the
expenditure of the steam or other fluid or aeriform body is at or near the
circumference, and the effective force is applied nearer the centre.
In witness whereof, I, the said Thomas Ivory, have hereunto set my
hand and seal the Twenty-sixth day of January, in the year of our Lord
One thousand eight hundred and fifty-eight.
Witness,
WILLIAM SPENCE,
50, Chancery Lane,
Patent Agent.
T. IVORY. (L.S.)