Iм- PROVEMENTS IN MOTIVE-POWER ENGINES, WHICH IMPROVEMENTS ALSO IN PART APPLICABLE AS BRAKES AND DYNAMOMETERS
Year: 1870

page_text: LETTERS PATENT to Thomas Ivory, of Edinburgh, in the County of
Mid Lothian, North Britain, Advocate, for the Invention of "Iм-
PROVEMENTS IN MOTIVE-POWER ENGINES, WHICH IMPROVEMENTS ARE ALSO IN
Sealed the 14th February 1871, and dated the 18th August 1870.
PROVISIONAL SPECIFICATION left by the said Thomas Ivory at the
Office of the Commissioners of Patents, with his Petition, on the
18th August 1870.
I, THOMAS IVORY, of Edinburgh, in the County of Mid Lothian, North
Britain, Advocate, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN MOTIVE-POWER ENGINES, WHICH IMPROVEMENTS ARE ALSO IN
PART APPLICABLE AS BRAKES AND DYNAMOMETERS," to be as follows, that is to
say:―
The improvements constituting this Invention relate to that class of
motive-power engines usually designated "rotary engines," but part
of the said improvements apply to a similar order of machines when
used otherwise than as prime movers, for example, when used as
exhausting or forcing pumps, as blowers, as liquid meters, or as dynamo-

page_text: meters or brakes, and these may be actuated either by steam, compressed
air, gas, or by water or other liquids.
The first improvement relates to that class of rotary engines in which
a cylinder revolving eccentrically within a non-circular close case forms
an abutment for the motive fluid by being in contact with it at one
portion of its circumference, and consists in the use of a single slider
instead of the two or more hitherto used. The revolving cylinder is
provided with a single slider passing diametrically through it as herein-
after described, and the case is constructed of a form to a small extent
deviating from the circular, and in such a way that both ends of the
slider are at all times in contact or nearly in contact with it. The
internal revolving cylinder or drum is placed so much eccentrically
with its surrounding case that a portion of its circumferential surface
is always practically in contact with the internal surface of the drum
or casing, thus constituting the abutment or stop from which the
motive fluid reacts, in the manner herein-after set forth. The revolving
drum is kept in place within the case by means of ends or covers, and
diametrically through the said drum an opening is made to receive the
said slider, which is so made that where it projects from the revolving
cylinder it fills or nearly fills the space between the said ends or
covers.
The second improvement consists in forming a more efficient abutment
or stop than that which results from the mere tangential contact of the
surface of the drum and case as herein-before described, by making a
portion of the curve of the internal case of a radius equal to that of
the revolving drum, under which arrangement the circumference of the
said revolving drum projects into or beyond the curve of the case, so
that the two curves intersect each other.
The third improvement consists in diminishing the friction of the
sliders by providing them with an antifriction roller at each end, and
also carrying them on rollers situated within the revolving drum, so as
to ensure its sliding action being effected with a minimum of friction.
The ports or openings for admitting and exhausting the motive agent
are situated on either side of the abutment or stop.
And the fourth improvement consists in so arranging the ports or
openings that they extend from where the revolving cylinder ceases to
be in contact with the external case to or nearly to that part of the
case at which in the course of revolution the portions of the slider which

page_text: project beyond the cylinder are equal to one another, and the portion
of the slider situated at any time between the revolving drum and the
case constitutes the area on which the motive agent acts.
The fifth improvement consists in working engines of the construction
herein-before set forth as compound engines, that is, as combined high
and low pressure engines. Under one arrangement the revolving drums
may be upon one driving shaft; under another they may be upon
independent shafts, which may be placed at any angle with each other,
so as to actuate driving shafts situated at any angle.
At the parts
where the driving shafts pass through the covers or ends of the case
stuffing boxes are provided, and the bearing portions of the shafts may
be made to revolve against rollers. When arranging the compound
engines herein-before referred to, to revolve in either a right or left
.hand direction, they are connected together by a pair of four-way cocks,
so that the actuating fluid may be directed to either side of the sliders
as may be desired, but other reversing arrangements may be adopted.
The four last-mentioned improvements are not confined to engines
which have one slider, but apply to all engines otherwise of a similar
construction with more than one slider.
The sixth improvement consists in an arrangement whereby engines
constructed with a revolving drum and slider as herein-before described
may also be actuated by the pressure of the wind. In this case in lieu
of using a close case to enclose the drum and slider, these are contained
in an open guide framework, so that the wind may have free access to
the projecting part of the slider, and in such engines it is preferred to
use two or more sliders.
Under the seventh improvement by arranging a passage governed by
a cock or valve to connect the spaces on the opposite sides of the
abutment and providing no other means of escape for the fluid employed,
the said apparatus herein-before described as forming a steam or water
engine or force pump constitutes when entirely or almost entirely filled
with water or oil or other liquid or fluid a dynamometer or brake, the
number of revolutions. in a given time with any given passage area
being dependent upon and giving the means of measuring the amount
of the force by which the revolving shaft is actuated.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Ivory in the Great Seal Patent Office on
the 17th February 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
IVORY, of Edinburgh, in the County of Mid Lothian, North Britain,
Advocate, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the 18th day of August, in the year of
our Lord One thousand eight hundred and seventy, in the 34th 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, or
assigns, should at any time agree with, and no others, from time to
time and at all times thereafter during 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 MOTIVE-POWER ENGINES,
WHICH IMPROVEMENTS ARE ALSO IN PART APPLICABLE AS BRAKES AND DYNAMO-
METERS," 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
performed, to be particularly described and ascertained in and by. the
following statement, reference being had to the accompanying Drawings,
and to the letters and figures marked thereon, that is to say :-
The improvements constituting this Invention relate to that class of
motive-power engines usually designated "rotary engines," but part of
the said improvements apply to a similar order of machines when used
otherwise than as prime movers; for example, when used as exhausting
or forcing pumps, as blowers, as liquid meters, or as dynamometers or
brakes, and these may be actuated either by steam, compressed air, gas,
or by water or other liquids.

page_text: The first improvement relates to that class of rotary engines in which
a cylinder revolving eccentrically within a non-circular close case forms
an abutment for the motive fluid by being in contact with it at one
portion of its circumference, and consists in the use of a single slider,
instead of the two or more hitherto used. The revolving cylinder is
provided with a single slider passing diametrically through it as herein-
after described, and the case is constructed of a form to a small extent
deviating from the circular, and in such a way that both ends of the slider
are at all times in contact or nearly in contact with it. The internal
revolving cylinder or drum is placed so much eccentrically with its
surrounding case that a portion of its circumferential surface is always
practically in contact with the internal surface of the drum or casing,
thus constituting the abutment or stop from which the motive fluid
reacts in the manner herein-after set forth. The revolving drum is kept
in place within the case by means of ends or covers, and diametrically
through the said drum an opening is made to receive the said slider,
which is so made that where it projects from the revolving cylinder it
fills or nearly fills the space between the said end or covers.
The second improvement consists in forming a more effecient abutment
or stop than that which results from the mere tangential contact of the
surface of the drum and case, as herein-before described, by making a
portion. of the curve of the internal case of a radius equal to that of the
revolving drum, under which arrangement the circumference of the said
revolving drum projects into or beyond the curve of the case, so that the
two curves intersect each other.
The third improvement consists in diminishing the friction of the
sliders when the engines are driven by water or air or used as pumps by
providing them with an antifriction roller at each end, but where steam
is used it is found in practice that packing strips are more efficient than
the rollers, yet it is to be understood that packing strips may be used in
all the apparatii comprised under this Invention. The ports or openings
for admitting and exhausting the motive agent are situated on either
side of the abutment or stop.
And the fourth improvement consists in so arranging the ports or
openings that they extend from where the revolving cylinder ceases to
be in contact with the external case to or nearly to that part of the case
at which in the course of revolution the portions of the slider which
project beyond the cylinder at each side are equal to one another, and the
.

page_text: portion of the slider situated at any time between the revolving drum
and the case constitutes the area on which the motive agent acts.
The fifth improvement consists in working engines of the construction
herein-before set forth as compound engines, that is, as combined high
and low pressure engines. Under one arrangement the revolving drums
may be upon one driving shaft; under another they may be upon inde-
pendent shafts, which may be placed at any angle with each other, so as
to actuate driving shafts situated at any angle. At the parts where the
driving shafts pass through the covers or ends of the case stuffing boxes are
provided, and the bearing portions of the shafts may be made to revolve
against rollers. When arranging the compound engines herein-before
referred to, to revolve in either a right or left hand direction, they may be
connected together by a pair of four-way cocks, so that the actuating
fluid may be directed to either side of the sliders as may be desired, but
other reversing arrangements may be adopted.
The four last-mentioned improvements are not confined to engines
which have one slider, but apply to all engines otherwise of a similar
construction with more than one slider.
The sixth improvement consists in an arrangement whereby engines
constructed with a revolving drum and sliders as herein-before described
may also be actuated by the pressure of the wind. In this case in lieu of
using a close case to enclose the drum and slider, these are contained in
an open guide framework, so that the wind may have free access to the
projecting part of the slider, and in such engines it is preferred to use two
or more sliders.
Under the seventh improvement by arranging a passage governed by a
cock or valve to connect the spaces on the opposite sides of the abutment,
and providing no other means of escape for the fluid employed, the said
apparatus herein-before described as forming a steam or water engine or
force pump constitutes when entirely or almost entirely filled with water
or oils or other liquid or fluid a dynamometer or brake, the number of
revolutions in a given time with any given passage area being dependent
upon and giving the means of measuring the amount of the force by
which the revolving shaft is actuated.
And in order that my said Invention may be properly understood
I now proceed more particularly to set forth the system, mode, or
manner in or under which the same is or may be used or practically
carried into effect, that is to say :-

page_text: Upon Sheet 1 of the Drawings hereunto appended Figure 1 is a longi-
tudinal section, Figure 2 a transverse section on the line A, B, Figure 1,
and Figure 3 is a plan showing one modification of my improved
motive-power engine, whilst Figures 4 and 5 are respectively detached
views of that part of the mechanism herein-after described as the
slider G. In the Figures of this first modification as well as in those
of the succeeding modifications it is to be understood that the same
letters of reference mark the same or corresponding parts upon the
different Figures in which they occur.
The engine shewn at Figures 1 to 5, Sheet 1, consists of a revolving
drum or cylinder A situated within a casing B, and the position of the
said drum or cylinder A is such that a short segment of its circum-
ference is permanently in contact with a corresponding segment in the
circumference of the casing B, extending upon either side of the vertical
plane of the axis to the points marked a and b, as shewn at Figure 2,
whereby a steam-tight abutment is established, and the curved figure
of the casing is of such a nature that its true developement is established
by making the distance between any number of points opposite to
each other equal, the said distances being measured upon lines which
intersect and pass through the centre of the revolving drum or cylinder
A, this will be clearly understood by reference to the diagram Figure 9,
(Sheet 1), whereon the whole curve is clearly delineated, and from
which it will be observed that the curve is by preference symmetrical
on either side of the abutment. The casing B is provided with brackets
C on its under side, whereby it is bolted or otherwise secured to the
sole or bed plate D. To each end of the casing B covers E, E, are
fixed by screwed studs and nuts having stuffing boxes c, c, formed
upon them through which the engine shaft F passes and is in part-
supported thereby. At one side of the casing B an admission pipe d
is situated as shewn, passing downwards, and communicating with a
corresponding pipe & formed upon the sole or bed plate D, whilst upon
the opposite side an exhaust pipe e is placed, also passing downwards or
communicating with a corresponding pipe e¹ situated on the sole or
bed plate D. In a plane passing through the axis of the revolving
drum or cylinder A a slider G is passed and is moveable therein, the
length of the said slider G being equal, as shewn at Figure 2, to the
diameters of the casing B through the centre of the revolving cylinder,
and its breadth corresponding to the distance between the internal

page_text: surfaces of the cylinder covers E, E. At each end of the slider Ga
groove is formed, into which a packing strip g is placed, and is kept
continually pressed outward against the internal surface of the casing B
by means of a low spring h which is attached as shewn to the slider G,
the special construction of which is more particularly shewn at Figures
4 and 5, Sheet 1. The engine shaft F has a journal i at each end,
which rests in a bearing k supported in brackets H secured to the sole
or bed plate D, and upon one end of the said engine shaft E a fly wheel
I is fixed, which may be employed also as a driving pulley. But the
fly wheel may be dispensed with and mechanism driven by gearing or by
a clutch or other coupling.
Having now particularly described the details of one modification of
my improved motive-power engine, its action will be more clearly under-
stood as follows:-
The steam from the boiler on being admitted into the pipe d¹ issues
therefrom and upwards through the passage d to the interior of the
cylinder or casing B in the direction indicated by the arrows, Figure 2,
and acting with its full pressure against the end g¹ of the slider.G forces
it round, and thereby causes the engine shaft F to revolve, and the steam
is prevented from passing from the admission side to the exhaust side of
the slider until the end g¹ of the slider G has been carried round into the
position which the end g² shewn at Figure 2 occupies, in which position
it has reached the upper edge of the opening leading to the exhaust
passage e, and the steam which has effected the portion of the revolution
referred to escapes into the said exhaust pipe e, when the end g² of the
slider a being now in the position of g¹, Figure 2, is in turn subjected to
the pressure of the steam issuing from the admission pipe d, and is in
like manner forced round; by this means a continuous revolution of the
rotary parts of the engine is maintained, the ends g¹ and g² of the slider
being alternately brought into a position to be subjected to the pressure.
of the steam. At the one side of the revolving drum or cylinder A the
steam-tight abutment extending from a to b, as herein-before specified,
practically prevents any leakage of steam between the admission and
exhaust ports, and it is to be understood that although not shewn upon
the Drawings, yet to ensure that the part may be constantly maintained
in a state practically steam; tight when the surfaces have become worn
by their continuous friction, a packing strip may be provided similar to
those marked g in the ends of the slider G and be inserted into the metal

page_text: of the casing B at the centre of the abutment, and to be kept continually
pressed inwards against the periphery of the revolving drum or cylinder
A by means of a spring or springs or other elastic cushion situated
beneath it, or the pressure of the steam may be brought to act upon it
through one or more ducts or passages leading from the admission pipe d.
It is still further to be understood that to ensure greater economy in
working, and although not shewn upon the annexed Drawings (these said
Drawings only shewing the engine in its most simple form), a cut-off
valve may
be placed in the admission passage and arranged to be actuated
by means of an eccentric or cam fixed upon the engine shaft, or a
governor may be used to regulate the cut-off.
Figure 6, Sheet 1, of the Drawings is a longitudinal section, Figure 7
a transverse section upon the line A, B, Figure 6, and Figure 8 a plan
shewing a second modification of my improved motive-power engine
arranged as a compound or high and low pressure rotary steam engine.
As the formation and construction of the principal parts of this the second
modification of my improved rotary steam engine is in most respects
similar to the first modification already specified it is necessary only that
I should further specify those parts wherein it differs therefrom. The
revolving piston or cylinder A is of sufficient length to extend the entire
distance between the outer extremities of the high pressure cylinder B
and the lower pressure cylinder B₁ between the said cylinders B and B¹;
a metallic ring or disc C is situated and secured to each through the
flanges a, the said ring or disc. C is bored out so as to allow the revolving
piston or cylinder A to pass through it and into the surface of the said
revolving piston or cylinder A; at the part where it bears in the ring or
disc C clastic metallic packing rings bare inscrted to prevent leakage of
steam between the interiors of the cylinders B and B¹. When it is desired
to set the engine in motion the steam from the boiler is admitted into the
pipe c, thence it passes upwards in the direction indicated by the arrows,
and enters the high-pressure cylinder B, where it acts with its full-pressure
against the slider G, causing the piston or cylinder A to revolve in the
direction indicated by the arrows and in the manner specified with
reference to the first modification. The exhaust steam on issuing from the
high-pressure cylinder B through the port d passes through the pipe d',
more particularly shewn at Figure 8, so as to enter the low-pressure
cylinder B at the same side as that at which it was admitted into the
high-pressure cylinder B, and consequently the sliders of the said cylinders
B and B are caused to revolve in the same direction, as will be clearly

page_text: seen by reference to the diagram Figure 10, Sheet 1. The sliders G and G¹
of the high and low pressure cylinders B and B' respectively are set at an
angle to each other, the reason for which is obvious, namely, that the
steam issuing from the high-pressure cylinder B may be brought into
action against the slider of the low-pressure cylinder B' at the earliest
possible point of its revolution, that is to say, that when the steam begins
to issue from the high-pressure cylinder B the slider G¹ of the low-
pressure cylinder B' has advanced beyond the abutment a shorter distance
than the corresponding end of the high-pressure slider G, as shewn at
Figure 10, to expose it to the action of the steam issuing into the said
cylinder B¹ through the pipe d', and the steam and exhaust ports of the
low-pressure engine are entirely closed when its slider is in the position
shewn at Figure 10.
Upon Sheet 2 of the hereunto annexed Drawings, Figure 1 is a longi-
tudinal section, Figure 2 is a transverse section upon the linc A, B,
Figure 1, and Figure 3 an end elevation shewing a third modification
of my Invention as specially arranged and adapted for use as a rotary
pump for water or other fluids or for air or gases. Under this modifi-
cation the revolving cylinder A is similar to that already described with
reference to the foregoing modifications, whilst the casing B is also
similar thereto in configuration and construction. The pump spindle C
is supported in bearings a formed in the covers 6 at one end; one of
the bearings a has a cap c formed upon it which conceals the end of the
spindle C, and prevents dirt or other foreign substances from getting in
and cutting or abrading the bearings a or the spindle C when the
latter is revolving, whilst at the opposite end the spindle C is carried
outwards and supported at its extremity by an outer bearing & formed
in the bracket D, which is secured to and projects upwards from the
sole or bed plate E. Upon the spindle C fast and loose pullies F and
G¹ respectively are situated, provided for the purpose of transmitting a
rotary motion to the said spindle C, which is effected by means of a
belt or band passing round the fast pulley F and actuated by an adjacent
driving pulley, whilst by shifting the belt from the fast pulley F to
the loose pulley G¹ the rotation of the spindle C and consequent action of
the pump is stopped. When the pump is put in motion the exhaustive
action of the slider G in the interior of the casing B occasioned by the
rapid rotation of the spindle C and cylinder A creates a partial vacuum,
into which the liquid or gas as the case may be is drawn through the

page_text: suction pipe H, as more particularly shewn at Figure 2. The said liquid
or gas is drawn around in the direction indicated by the arrows by the
action of the end g' of the slider G, until the said end g¹ has arrived at the
position of y, Figure 2, where the liquid or gas is discharged through the
pipe I, whilst the end g² is now in that position originally indicated
by g' and is following up and repeating the action herein-before set
forth, which each of the ends of the slider continues to effect in
alternate succession.
Figure 4, Sheet 2, is a longitudinal section of another arrangement of
my Invention, being in this instance constructed for use as a combined
rotary engine and rotary pump, and as under this modification the
construction of the casing B of the engine is similar to that already
specified with reference to the high-pressure cylinder included in the
second modification and illustrated at Figures 6, 7, and 8, Sheet 1 of
the Drawings, whilst in like manner the casing B' of the pump corre-
sponds with that specified with reference to the third modification and
illustrated at Figures 1, 2, and 3, Sheet 2 of the Drawings, it is there-
fore unnecessary to repeat the description of these parts, but those parts
of the arrangement which specially belong to Figure 4 consists of the
revolving cylinders A and A', which are each fixed upon the same shaft or
spindle C and situated within their respective casings Band B'. Between
the cover a¹ of the pump casing B' and the cover a of the engine casing B
a packing D of wood or other non-conducting substance is inserted for
the purpose of preventing the water or other fluid which the pump is
employed in lifting from cooling down, and condensing the steam
operating in the steam cylinder A. On the upper side of the said
packing Da duct or channel is placed, which as it proceeds downwards
is separated into two smaller ducts or channels c and d leading respec-
tively to the bearings e and f, which are provided for the purpose of
conducting oil or other lubricant thereto. When it is desired to set
the apparatus in motion the steam is admitted into the casing A through
the admission pipe c', shewn in dotted lines at Figure 4, Sheet 2, and
is allowed to escape therefrom through the exhaust pipe d', whilst the
water to be lifted is drawn through the suction pipe H into the interior
of the casing B, and is finally discharged through the pipe I, also shown
in dotted lines Figure 4, Sheet 2.
Figure 5, Sheet 2, is a vertical section, and Figure 6, Sheet 2, a plan
shewing my improved motive-power engine arranged for being driven
somewhat after the manner of a turbine.

page_text: Under this modification there is no material departure in the construc-
tion of any of the principal parts from those which are the leading
features of the foregoing modifications. The revolving drum or cylinder
A is fixed to a shaft or spindle A', which is arranged vertically and is
supported at its lower end by a footstep bearing a attached to the bottom
cover C of the casing B, whilst the upper end of the shaft A¹ is supported
by a bearing b formed in a bracket D secured at both sides to beams E
and F, which are secured in their respective positions. The top side or
mouth of the casing B is closed by the cover E', provided with a stuffing
box c of the ordinary form and through which the shaft or spindle A
passes. At one side of the casing B an admission pipe G' is situated,
whilst at the opposite side a discharge pipe H is fixed. The whole
apparatus is supported by means of the bottom cover C.being carried out
on both sides in the form of a sole plate, as more particularly shewn at
Figure 6. When the water is admitted through the admission pipe G₁
it passes to the interior of the casing B, exerting against the slider Ga
pressure due to the height of the column of water situated above it; this
forces round the slider G, and thereby effects the rotation of the spindle
A'; when a certain part of a revolution has been attained the water
escapes through the discharge pipe H in the manner already described
with reference to the preceding modifications.
Figure 7, Sheet 2, is a transverse section, and Figure 8 a horizontal
section shewing a sixth modification of my improved motive-power
engines as adapted for being driven by the pressure of the wind. Under
this modification the revolving cylinder A is fixed upon a shaft B and is
supported between two end frames C and D. Through the revolving
cylinder A, intersecting its centre and at right angles to each other, two
sliders E and F are passed, which under this modification act as the sails
of an ordinary windmill to catch the wind, as herein-after more par-
ticularly specified. Upon the end frames C and D non-circular rings a
are situated, which act as guides for the ends of the sliders or sails.
Referring now more particularly to Figure 7, it will be seen that it is the
parts of the sliders or sails E and F which are projecting upwards, that
is, above the horizontal plane of the axis of the apparatus which present
their surfaces to the wind, which acting against them causes the apparatus
to revolve in a manner similar to what has been already described with
reference to steam and hydraulic engines, so that the opposite ends of
each slider or sail E or F are alternately exposed to the pressure of the
wind, and thereby a continuous rotary motion is imparted to the cylinder

page_text: machinery through the intervention of a belt or band passing over the
pulley G. Two sliders only are shewn, but it is preferred that three or
more should be employed, and the proportions should be such that the
revolving cylinder A should be rather more than two-thirds of the largest
diameter of the rings a.
Figure 9, Sheet 2, is an end elevation, whilst Figure 10 is a part plan
shewing my Invention arranged and adapted for use as a dynamometer
or brake. Under this modification the arrangement consists in the
attachment to an apparatus similar to a rotary engine as herein-before
specified a pipe A, which connects the ports B and C respectively on
the said pipe A, and between the steam ports B and C a through way
cock Dis placed. Upon the pipe A a tapped nozzle a is formed, through
which the fluid employed may be filled, in or into which a pressure
guage may be secured when desired, or a plug may be screwed therein
when a pressure guage is not desired. The action of this modification
will be easily understood as follows:-When it is desired to have the
apparatus in action the cock D is in the first instance in such a position
that the communication between the passages B and C is opened, the
apparatus is filled with water or oil or other liquid, and the shaft of
the apparatus is coupled to or otherwise arranged as to be capable of
being rotated by the movement of the machinery to which it is to be
applied to fulfill the functions of a brake or dynamometer. If for
the former, namely, to be employed as a brake when it is desired to
retard or stop the motion of the said machinery, the cock D is turned
into such a position that the communication between the passages B
and C is partially or totally closed and retards the force or stops the
motion of the driving power. When to be employed for the latter
purpose, namely, as a dynamometer, the number of revolutions or velocity
with which the apparatus is rotated in units of time is dependent upon
the passage area as reduced by the cock D in combination with the
amount of force applied to the shaft, and hence when the area of free
passage in the cock D is known the number of revolutions will give
the measure of the force applied. The amount of power expended in
producing any given number of revolutions in a given. time with a
known passage area may be at once ascertained by means of a table
constructed from actual experiments with varying weights attached to
a band wound round a barrel or wheel on the shaft of the dynamometer,

page_text: while the passage area remains the same, and with a varying passage
area while the weights remain the same.
Figure 11, Sheet 2, is a sectional view shewing another modification of
my Invention as arranged for a dynamometer or brake, or as a reversible
engine. In the passage A which communicates at both ends B and C
with the interior of the cylinder D two through-way cocks E and F
respectively are placed at opposite sides as shewn. When the apparatus
is to employed as a dynamometer or brake one of the cocks E or Fas
may be desired is turned into such a position as to form a through com-
munication with the passage A, whilst the other and opposite cock F
or E is partially or totally closed according as it is desired, and the
action of the apparatus will be similar to that already specified with
reference to Figures 9 and 10. It is to be understood that as a dynamo-
meter or brake the two cocks E and Fare not essential, for by employing
one cock situated in the passage A the apparatus may be made to
revolve in either direction, the fluid being allowed to flow through the
orifice of the cock from either sides. When the apparatus is employed
as a reversible engine an admission port is formed as shewn in dotted
lines at G, through which the steam or other motive agent is admitted,
and if the engine is to be driven in the direction indicated by the
arrows the cock E is turned into such a position as to open a clear
communication through the passage A into the interior of the cylinder
D through the port B, whilst the cock F is turned into such a position
as to close the communication between the passage A and the port
C, whilst opening a communication between the port C and the
passage through which the exhaust steam or other motive agent
employed issues, and when the engine is to be reversed the cocks E
and Fare each turned into opposite positions, whereby the admission
is established through the cock F, and the exhaust through the cock E
and passage H¹.
t
Having now described the nature of my said Invention, and the
system, mode, or manner in or under which the same is or may be used
or practically carried into effect, I desire to observe in conclusion that
I am aware engines have been heretofore constructed with several
sliders and also with one slider, and combined with pins and grooves
or other arrangements for adjusting its position passing through the
revolving cylinder, and to which I make no claim; what however I do
consider novel and original, and therefore claim as the Invention secured
to me by the herein-before in part recited Letters Patent is,-

page_text: First. The several arrangements of rotary engines and pumps wherein
a single slider is employed as herein-before described, or any mere modifi-
cation thereof.
Second. The arrangement and construction of windmill as herein-
before described.
Third. The arrangement or construction of dynamometer or brake as
herein-before described.
In witness whereof, I, the said Thomas Ivory, have hereunto set
my hand and seal, this Fourteenth day of February One thousand
eight hundred and seventy-one.
THOMAS IVORY. (L.S.)