IMPROVEMENTS IN THE CONSTRUCTION OF STEAM ENGINES, FOR THE PURPOSE OF CONVERTING THE RECIPROCATING MOTION INTO A ROTARY MOTION, AND FOR OPERATING THE SLIDE VALVES
Year: 1856

page_text: LETTERS PATENT to Alfred Vincent Newton, of the Office for Patents,
66, Chancery Lane, in the County of Middlesex, Mechanical Draughts-
man, or the Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF STEAM
ENGINES, FOR THE PURPOSE OF CONVERTING THE RECIPROCATING MOTION INTO A
ROTARY MOTION, AND FOR OPERATING THE SLIDE VALVES."-A communication.
PROVISIONAL SPECIFICATION left by the said Alfred Vincent Newton
at the Office of the Commissioners of Patents, with his Petition, on the
18th February 1856.
I, ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane,
in the County. of Middlesex, Mechanical Draughtsman, do hereby declare
the nature of the said Invention for IMPROVEMENTS IN THE CONSTRUCTION OF
STEAM ENGINES, FOR THE PURPOSE OF CONVERTING THE RECIPROCATING MOTION INTO
A ROTARY MOTION, AND FOR OPERATING THE SLIDE VALVES, to be as follows:-
This Invention relates to the employment of driving curves, formed of a
cylinder with screw-like projections erected upon it, or grooves cut into it, in
combination with a piston rod, for the purpose of converting a reciprocating
into a continuous rotary motion.
To render this class of mechanism more efficient, the Inventor has discovered
that the angle of the driving curves with the line of the axis of their rotation
should be made to approximate more nearly to a right angle, and that the
action of the piston rod should be applied indirectly to the surface of the
guide curves, through the medium of wheels placed upon the piston rod or.
cross head, and that these wheels should be made of a considerable diameter,
so as to apply the action of the piston rod on the curves out of the line of th

page_text: piston rod. By increasing the diameter of these wheels the driving curves
could be brought almost to a right angle with the line of the piston rod,
without any material loss by friction, or in consequence of the angle at which
the force of the steam was applied to the driving curves by the piston rod.
By this system of construction it is found that the diameter of the driving
curves may be increased to a very great extent without increasing necessarily
the length of the axis or drum of the curves, and the shock of the piston rod
in passing the dead points, or points where the curves meet may be diminished
almost indefinitely. A capacity will be afforded for the employment of steam
cylinders of large diameter and short stroke, and greater compactness and
greater uniformity of motion can be obtained than has been done heretofore.
or
.1
In constructing engines in accordance with this Invention, it will be found
advantageous to employ two cylinders, furnished with pistons, and piston rods
and wheels, working into opposite sides of the driving curves. The axis of
the driving curves is to be placed a little above the plane of the piston rod, so
that the wheels shall not work on the surface of the driving curves at points
diametrically opposite, in order that the wheel on one side may be just past
the one point of meeting or intersection of the driving curves on its side,
while the other wheel is passing the other point of intersection of the curves,
and thus an additional preventive against shock is secured. A series of two
more driving curves may be arranged on parallel axes and cylinders and
pistons adapted to them, so as to run conveniently. The valve gear in this
engine consists of a vertical disc of small diameter, placed upon the pro-
longation of the main shaft, and hinged by a vertical pin passing through the
'shaft in such a manner that the disc can be rocked upon its pivot. This
disé revolves with and upon the main shaft, and when brought to an
inclined position, it operates as an excentric or cam upon the rods of the slide
valves, and causes the driving curves to be propelled in a given direction.
When the disc is inclined in an opposite direction, it will in like manner cause
the driving curves to be propelled in an opposite direction.
SPECIFICATION in pursuance of the conditions of the Letters; Patent, filed
by the said Alfred Vincent Newton in the Great Seal Patent Office on
the 16th August 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME; I; ALFRED
VINCENT NEWTON; of the Office for Patents, 66; Chancery Lane, in the County
of Middlesex, Mechanical Draughtsman, send: greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighteenth day of February, in the year of our
Lord One thousand eight hundred and fifty-six, in the nineteenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Alfred Vincent Newton, Her special license that 1, the said Alfred
Vincent Newton, my executors, administrators, and assigns, or such others
as I, the said Alfred Vincent Newton, my executors, administrators, and 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 THE CONSTRUCTION OF STEAM ENGINES, FOR THE PURPOSE
OF CONVERTING THE RECIPROCATING MOTION INTO A ROTARY MOTION, AND FOR
OPERATING THE SLIDE VALVES," being a communication from abroad, upon the
condition (amongst others) that I, the said Alfred Vincent Newton, 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 Alfred Vincent Newton, do hereby declare
the nature of the 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 Drawings hereunto annexed, and to the
letters and figures marked thereon (that is to say):-
Prior to the discovery of the present improvements, attempts were made by:
the inventor thereof and others to employ driving curves, formed of a cylinder
with screw-like projections erected upon it, or grooves cut into it, in com-
bination with a piston rod, for the purpose of converting a reciprocating into
a continuous rotary motion, but none of these proved practically available,
their failure being attributable to an erroneous method or system of construc-
tion and adaptation of the screw-like projections, and of the application of the
piston rod thereto. The idea in such constructions appears to have been that
the angle of elevation or rise of the thread of the screw from a plane at right
angles to the axis of the driving shaft was of little or no importance as to the
result, or that it was necessary or important to make the angle of the driving
curves with the line of the axis of the driving curves very small, in order to
prevent the piston rod acting at or nearly at right angles to the surface of
these curves. Accordingly the piston rod was made to act directly against the
:

page_text: surface of the driving curves, and the drum or cylinder was made long, and
the driving curves were arranged at a small angle with each other and with
the line of the piston rod. This was probably done upon the supposition that
the more acute the angle of the screw with the line of the axis, the more
power would be developed by the action of the piston rod upon it, and the
less would be the friction of the end of the piston rod upon the surface of the
.screw-like projection. When the driving curves were thus placed at a low or
acute angle with the line of their axis and of the piston rod, it followed, that
the drum or axle, which supported the driving curves was necessarily made of
considerable length, and required a corresponding length of stroke in the
engine. Moreover, at the points where the two driving curves meet, the angle
being acute, the piston rod acting therein caused a great shock and loss of
power. This arrangement of parts was objectionable, therefore, on account
of the friction of the piston rod against the surface of the driving curves, the
shock when the piston rod passed the points where the driving curves meet,
the great length of stroke required, and the limited space allowed for the steam
cylinders.
After numerous experiments, the inventor of the novel arrangement of
machinery, shewn in the accompanying Drawings, has discovered that the
angle of the driving curves L, L', (Fig. 4,) with the line of the axis S, S', of
the curves should be made to approximate more nearly to a right angle, and
that the action of the piston rod should be applied indirectly to the surface of
the guide curves, through the medium of wheels placed upon the piston rod
or cross head, and that these wheels should be made of a considerable diameter,
so as to apply the action of the piston rod on the curves out of the line of the
piston rod. By increasing the diameter of these wheels, the driving curves
could be brought almost to a right angle with the line of the piston rod, with-
out any material loss by friction, or in consequence of the angle at which the
force of the steam was applied to the driving curves by the piston rod. By
this system of construction it is found that the diameter of the driving curves
may be increased to a very great extent without increasing necessarily the
length of the axle or drum of the curves, and the shock of the piston rod, in
passing the dead points, or points where the curves meet, may be diminished
almost indefinitely. A capacity will be afforded for the employment of steam
cylinders of large diameter and short stroke, and greater compactness and
greater uniformity of motion can be obtained than has been done heretofore.
To enable others skilled in the art to construct and use the improved system
of constructing and arranging driving curves in combination with steam engines,
I proceed to describe the same fully, reference being had to the annexed
"

page_text: Drawings, in which Fig. 1, Sheet I., is an end view of an engine containing the
improvement, as seen from the back; Fig. 2 is a side view of the same; Fig. 3
is an end view, as seen from the front; Fig. 4 is a top view of the same; Fig. 5
is a modification of the engine; and Figures 6, Sheet II., represent Diagrams,
herein-after explained. F, D, G, H, (Fig. 4,) represents the bed plate of the
improved engine. On this bed plate are placed two ordinary steam cylinders
I and K, worked by slide valves in valve chests N and N¹; S, S', is the main
or driving shaft, to which two curves L, L, L", L, and M, M', M", M",
are keyed.
By these keys also the effect due to any wear of the driving curves may be
overcome. P, P, P", P, are the piston rods, with cross heads at P¹, and P!",
which cross heads slide upon a pair of ordinary guides at Q and Q. To each
of these cross heads Q and Q' an iron wheel O or a wheel O¹ is attached, so
as to turn freely on its bearings; this wheel should have a diameter about
one-half the diameter of the driving screw or curves. The effect of
attaching to the cross head wheels O, O', of such a diameter is, that the
point of application of the power to the circumference of these wheels
is removed out of the line of the piston rod, and as the piston rod moves
backward and forward, the wheels O and O¹ roll freely upon the surface
of the driving curves. By thus increasing the diameter of the cross head
wheels O and O', the angles which the surfaces of the screws or driving
curves make with the line of the axis of the driving curves may be increased
to almost a right angle, without that great loss of power and increase of
friction which would otherwise result. In Figures 2 and 4 the diameter of
the driving curves is three times the length of the stroke of the piston, and the
angle, which the surface of the driving curves makes with the line of the axis,.
is about seventy-eight degrees, or only about twelve degrees short of a right
angle. This has been proved to work well. It has also been found that the
diameter of the driving curves may be increased until it is twelve times the
length of the stroke, in which case the angle of the surface of the driving
curves with the line of their axis is about eighty-eight and a half degrees, or
one and a half degrees short of a right angle. By increasing the diameter of
the driving curves between these limits and the angle of the driving curves
also, the shock of the piston rod, when working against the points of inter-
section of the driving curves, is very greatly lessened, and an enlarged capacity
for steam cylinders is obtained; while at the same time, the corresponding
increase in the diameter of the cross head wheels O, O', obviates the objection
which would otherwise arise from the approximation of the driving curves
to a right angle with the line of the piston rod.

page_text: The relation of the length of stroke, diameter the driving curves, and
the angle of the driving curves, with the line of their axis, are shewn by the
series of projections in Sheet II., in which a, a, a, a, a, a, &c, represent the
length of the axle or drum of the driving curves, which are made the same
throughout the series of Diagrams. a, b, a, b, represent a series of driving
curves projected, in which the diameter of the driving curves is equal to the
length of the stroke; and a', b', a, b, represent driving curves, whose diameter
is twice the length of the stroke; a, b, a, b, are driving curves, whose diameter
is three times the length of the stroke, and so on, to a¹¹, 6, a, b, in which
the diameter of driving curve is twelve times the length of the stroke. By
the use of a wheel on the end of the piston rod or cross head, whose diameter
is varied, as above described, engines having any of these proportions of
diameter of driving curve and length of stroke, and the consequent angle of
the driving curves to each other, and to their axis, can be beneficially used,
while hitherto there was no method or system of construction and adaptation
by which a diameter of driving curves could be successfully used, greater in
length than the length of the stroke, while, as above stated, by this improve-
ment, the diameter of the driving curves can, if desired, be made even twelve
or more times the length of the stroke, and with the advantage of diminishing
the shock at dead points, and affording a capacity for increased diameter of
steam cylinder. The proportion best adapted to ordinary use is found to be,
where the diameter of the driving curves is from three to six times the length
of the stroke; but all the above proportions are practical. In using the engine
thus arranged, it will be found advantageous to employ two cylinders, furnished
with pistons and piston rods and wheels, working into each side of the driving
curves. The axis S, S', of the driving curves is placed a little above the plane
of the rod, so that the wheels O and O shall not work on the surface of the
driving curves at points diametrically opposite, in order that the wheel O
may be just past the one point of meeting or intersection of the driving
curves on one side, while the wheel O' is passing the other point of intersection
of their curves, and thus an additional preventive against shock is secured.
A series of two or more driving curves may be arranged on parallel axles, and
cylinders and pistons adapted to themi, so as to run conveniently, as shown in
Fig. 5. The valve gear in this engine consists of a vertical disc T, T', of small
diameter, placed upon the prolongation of the main shaft S, S', and hinged
at t, by a vertical pin passing through the shaft, is such a manner that the
disc T, T, can be rocked upon the pivot t into the line T, T, or the line T", T".
This disc revolves with and upon the main shaft S, S', and when inclined upon
its pivot into the position T, T', it operates as an excentric or cam upon

page_text: corresponding projections on the rods U, U', of the slide valves, and causes
the driving curves to be propelled in one direction; but when it is inclined
into the position T", T", it causes the driving curves to be propelled in an
opposite direction. The disc T, T, can be conveniently rocked upon the pivot
at t, by a lever or other appliance; and I find it to be an excellent mode of
working the slide valves, and to afford great facility for reversing the motion
of the engine.
Having thus described the Invention of "Improvements in the Construction
of Steam Engines, for the Purpose of Converting the Reciprocating Motion
into a Rotary Motion, and for Operating the Slide Valves," as communicated
to me by my foreign correspondent, I wish it to be understood that under the
above in part recited Letters Patent, I claim,-
First, the employment of the driving curves, and the wheels on the piston
rod, arranged and combined in the manner above described, whereby driving
curves of a more obtuse angle and larger diameter than heretofore used may
be employed, without increasing the length of the stroke, and at the same
time a more efficient and uniform action may be obtained.
Second, arranging two pistons and steam cylinders on opposite sides of the
driving curves, in such a manner that the piston rods shall not operate simul-
taneously against the points of intersection of the driving curves.
Third, I claim the employment of a simple vertical disc, attached by a pivot
to and revolving with the main shaft, for regulating the valves and reversing
the action of the engine, as above described.
In witness whereof, I, the said Alfred Vincent Newton, have hereunto
set my hand and seal, the Fourteenth day of August, in the year of
our Lord One thousand eight hundred and fifty-six.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
A. V. NEWTON. (L.S.)