CERTAIN IMPROVEMENTS IN STEAM ENGINES
Year: 1853

page_text: LETTERS PATENT to William McNaught, of Rochdale, in the
County of Lancaster, Engineer, for the Invention of "CERTAIN
IMPROVEMENTS IN STEAM ENGINES."
Sealed the 24th June 1853, and dated the 24th March 1853.
PROVISIONAL SPECIFICATION left by the said William McNaught
at the Office of the Commissioners of Patents, with his Petition,
on the 24th March 1853.
I, WILLIAM MCNAUGHT, of Rochdale, in the County of Lancaster,
Engineer, do hereby declare the nature of the said Invention of
"CERTAIN IMPROVEMENTS IN STEAM ENGINES" to be as follows:--
My Invention applies to that class of steam engines wherein the
steam is worked expansively by being "cut off" at any desired portion
of the stroke.
The precise period of the stroke at which the steam is "cut off" is
variable, and is regulated by the action of the "governor." Upon a
shaft (which receives its motion direct from the crank shaft of the
engine) are keyed a series of cams, each a little in advance of the other.

page_text: Those cams act upon two bowls mounted in a sliding frame, which is
connected to the "cut off valve "by means of levers and links. These
bowls are connected to the "governor" in such a manner that as the
balls of the same expand or collapse, the bowls are slidden into gear
with one or other of the cams, so as to "cut off"" the steam at an
earlier or later period of the stroke, according as the speed of the
engine varies. My improvement consists principally of a certain novel
arrangement of apparatus for "shifting" or sliding the bowls into gear
with the different cams as required.
To each of the links of the governor a double inclined plane (having
a notched surface) is connected by means of links and levers. These
inclined planes are opposed to certain chisel-formed points, which are
capable of sliding in the moving frame which carries the bowls.
These points are connected to the bowls by racks and pinions in such a
manner that as the points are caused to recede by coming into contact
with the notches on the inclined planes, the bowls are moved opposite
to the various cams as required. The precise period of "cutting off"
the steam being regulated by the action of the governor raising or
depressing the inclined planes. The same apparatus may (if preferred)
be caused to slide the cams instead of the bowls; or it may be applied
in cases where a single cam is employed, in order to set the cam either
sooner or later (by means of a spiral or helical slot) as the speed of the
engine increases or decreases.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William M'Naught, in the Great Seal Patent 2
Office, on the 24th September 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
WILLIAM MONAUGHT, of Rochdale, in the County of Lancaster, Engi-
ncer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her 3
Letters Patent, bearing date the Twenty-fourth day of March, in the
year of our Lord One thousand eight hundred and fifty-three, in the
sixteenth year of Her Reign, did, for Herself, Her heirs and succes-

page_text: sors, give and grant unto me, the said William McNaught, Her
especial licence that I, the said William M°Naught, my executors,
administrators, and assigns, or such others as I, the said William
McNaught, 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 Inven-
tion for "CERTAIN IMPROVEMENTS IN STEAM ENGINES," upon the condition
(amongst others) that I, the said William McNaught, by an instru-
ment 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William MºNaught, 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 and accompanying drawings (that is to
say):
My Invention of certain improvements in steam engines applies to
that class of steam engines wherein the steam is worked expansively by
being "cut off" at any desired portion of the stroke of the piston.
The precise period of the stroke at which the steam is cut off is variable,
and is regulated by the expanding or collapsing of the arms of the
"governor." Upon a shaft, which receives its motion by means of
spur or bevil wheels direct from the crank shaft of the steam engine, a
series of cams are keyed or otherwise secured, each a little in advance of
the other. These cams act upon two bowls mounted in a sliding frame
or "headstock," which is connected to the "cut off" valve by means
of levers and links. These said bowls are connected to the " governor'
in such a manner that as the balls of the same expand or collapse, the
bowls are thereby slidden into gear with one or other of the cams, so
as to cut off the steam at an earlier or later period of the stroke,
according as the speed of the engine varies.

page_text: My present Invention consists principally of a certain novel and
peculiar arrangement of mechanism or apparatus for connecting the
said bowls to the governor, and for "shifting" or sliding them into
gear with the different cams as required.
To cach of the links of the governor, which in this case are inde-
pendent of each other, a double inclined plane is connected by means
of suitable links and levers. These said inclined planes are notched
upon their surfaces, and opposed to certain chisel-formed or other
suitably formed points, which are capable of sliding in a small frame
attached to the moving "headstock" which carries the bowls. These
chisel-formed points are connected to their respective bowls by means
of racks and pinions in such a manner that as the points are caused to
recede by coming into contact with the notches upon the inclined
planes, the bowls are moved opposite to the various cams as required,
thus causing the steam to be cut off sooner or later. The precise
period of the stroke at which the steam is cut off being regulated by
the action of the governor raising or depressing the notched inclined
planes. I would here remark that by means of these notched inclines
the above-described cams may be made to shift successively opposite to
the bowls; or a single cam upon a helical groove may be moved in a
lateral direction by the same means, so as to effect an earlier or later
motion of the above-mentioned sliding frame. In the latter case,
instead of the bowls, a roller would be required with a grooved sur-
face, so as to hold tho cam from being shifted laterally by the action of
the helical groove whilst it is in contact with the roller.
The method of carrying my said improvements into practical effect
will be readily understood upon referring to the two sheets of drawings
hereto annexed, upon which figures and letters of reference are marked
corresponding with those in the following explanation thereof. In Sheet 1,
of the drawings my improved apparatus is drawn about half size, as
adapted for a steam engine of about twenty horses power, Fig. 1, being a
front elevation, and Fig. 2, a plan view of the same. In Sheet 2, of the
drawings, Fig. 1, is a front elevation, and Fig. 2, a plan view drawn to
a scale of about three inches to a foot, and representing more especially
the method of connecting the apparatus to the governor of the steam

page_text: engine. a, a, represents the crank shaft of the steam engine, which is
connected to the cam shaft b, b, by means of spur gearing; c, c, are the
cams; d, d, the bowls; and c, e, the sliding "headstock" which is
connected to the "cut off valve" by means of suitable levers and links
attached thereto at f, f. The bowls d, d, are loose upon their shafts,
and are capable of being slidden or moved into gear with any of the
cams c, c, as occasion may require. 9, g, g', g', are the double inclined
planes, which are mounted so as to be capable of sliding in a vertical
direction. h, h, h, h', are the chisel-formed points attached to
racks i, i, i, i, and mounted so as to be capable of sliding in a ver-
tical direction. Small spur pinions k, k', connect these racks together,
so that as one recedes the other advances, and vice versa. The pinions
k, k', are connected to other pinions 1, l', which are engaged with the
racks m, m', one of which is connected to each of the bowls d, d. It
will be observed that the inclined planes do not travel with the head-
stock, and only move in a vertical direction, whilst the chisel-points
both move with the headstock, and are capable of sliding in their bear-
ings in an horizontal direction. It will therefore be evident that as
the "headstock" is caused to traverse by the cams c, c, acting against
the bowls d, d, the chisel points h, h, h', h', will come into contact
with the notches upon the inclined planes g, g, g', g', and by means of
the racks and pinions before mentioned will slide the bowls d, d, oppo-
site to any of the cams c, c, according to which of the said notches is
presented to the action of the said chisel points. Each of the double
inclined planes g, g, g', g', is connected to one of the links n, n', of the
governor, so that they act perfectly independent of each other. The
inclined planes g. 9, 9', g', are connected by means of links o, o¹, to
levers p, p'.
These levers are connected to other levers q, q', by means of studs 1, 11.
The lever q, is attached to a shaft s¹, and the lever q, to a tubes,
which turns freely thereon. Upon the other end of the shaft s', a
lever t', is keyed, and upon the same end of the tubes, another lever t,
is keyed. The lever t, is connected by rods and tubes to the link u, of
the governor, and the lever t', is similarly connected to the link w,
of the governor. Thus it will be evident that the instant either of the

page_text: arms of the governor expand or collapse, a corresponding movement is
imparted to its respective inclined planes, which, by acting upon the
chisel points as aforesaid, will bring one of the bowls opposite to a fresh
cam, and thus alter the period of "cutting off" the steam in a corre-
sponding ratio. The relativo proportion between the movement of the
arms of the governor and that of the inclined planes can be altered and
adjusted, when desired, by changing the position of the pins or studs
,, which connect the levers p, p, and q, q'.
Having thus described the nature and object of my said Invention
of certain improvements in steam engines, together with the manner of
carrying the same into practical effect, I would remark, in conclusion,
that I claim as my Invention, firstly, the peculiar arrangement of
mechanism above described and shewn in the drawings for "shifting"
the bowls opposite to the different cams, consisting of the double
notched inclined planes and the chisel-formed or other suitable points
connected to the bowls by means of racks and pinions. Secondly, I
claim the connection of each arm of the governor separately to its own
notched inclines. And, thirdly, I claim the grooved roller or rollers
(where one cam only is used) for the purpose of preventing the cam
from sliding laterally whilst in action against the said rollers.
In witness whereof, I, the said William MeNaught, have hereunto
set my hand and seal, this Twenty-third day of September, Ono
thousand eight hundred and fifty-three.