CERTAIN IMPROVEMENTS IN STEAM ENGINES
Year: 1856

page_text: LETTERS PATENT to William Mac Naught, of Manchester, in the County
of Lancaster, Engineer, for the Invention of." CERTAIN IMPROVEMENTS IN
STEAM ENGINES."
Scaled the 23rd June 1857, and dated the 24th December 1856.
PROVISIONAL SPECIFICATION left by the said William Mac Naught at
the Office of the Commissioners of Patents, with his Petition, on the.
24th December 1856.
I, WILLIAM MAC NAUGHT, of Manchester, in the County of Lancaster,
Engineer, do hereby declare the nature of the said Invention for "CERTAIN
IMPROVEMENTS IN STEAM ENGINES," to be as follows:-
My Invention consists in a novel arrangement of apparatus for regulating
the trayerse of the slide valves of steam engines by the action of the governor,
so as to cut off and admit the steam according to the requirements of the
engine.
I effect this by causing the eccentric rod pin of the valve lever to traverse
or slide in the valve lever by means of a slide and screw, actuated by ratchets'
or catch boxes, the governor throwing either side in gear, so as to cause the
eccentric pin to move outwards or inwards, and thus alter the traverse of the'
valve as the engine requires less or more steam; and the motion of these
catch boxes or ratchets is given or induced by the vibratory action of the valve
shaft..

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Mac Naught in the Great Seal Patent Office on
the 23rd June 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
MAC NAUGHT, of Manchester, in the County of Lancaster, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of December, in the year of our
Lord One thousand eight hundred and fifty-six, in the twentieth year of Iler
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Mac Naught, Her especial license that I, the said William Mac
Naught, my executors, administrators, and assigns, or such others as I, the said
William Mac, Naught, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at all times there-
after 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 "CERTAIN.
IMPROVEMENTS IN STEAM ENGINES," upon the conditions, amongst others, that
I, the said William Mac Naught, 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 William Mac Naught, 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):-
0.66
My Invention consists in a novel arrangement of apparatus for regulating
the traverse of the slide valves of steam engines by the action of the
governor," so as to cut off and admit the steam according to the requirements
of the engine. I effect this by causing the excentric rod pin of the valve lever
to traverse or slide in the valve lever by means of a slide and screw, "actuated
by ratchet or catch boxes, the governor throwing either side in gear, so as to
cause the excentric pin to move outwards or inwards, and thus alter the
traverse of the valve as the engines requires less or more steam; and the's
motion of these catch boxes or ratchets is given or induced by the vibratory
action of the valve shaft.
In order that the Invention may be better understood, and explained more

page_text: fully, I have hereunto annexed a Sheet of Drawings, having similar letters of
reference marked upon corresponding parts of the machinery throughout all
the Figures shewn.
Fig. 1 is a vertical section of the lever and part of the valve shaft, and
Fig. 2 is an end view of the same; Fig. 3 is a side elevation, shewing the
governor gear and the slide valve lever, and Fig. 4 is a transverse section of
the same; Fig. 5 is a detached view of the back of the wheel e, showing tho
reverse ratchets; and Fig. 6 shews the application of the valve and apparatus
to a steam engine (on the compound principle). The excentric rod lever a is
fitted with a slide b, to which slide is attached the excentric rod pin. This
slide is moved by the screw c; in this case the screw passes through the
valve shaft, to which are attached the bevel wheels d and e, and the pulleys
f and g, for actuating the screw by means of the governor; the other end of
the screw c has fixed to it the hand-wheel h, for adjusting the traverse of the
valves by hand, if required. On the back of tho wheel e are two ratchets, tho
teeth of the one catching in an opposite direction to the teeth of the other.
This wheel is slipped on loose to the projecting part of the valve shaft, the
inner catch box i being fitted with a catch ring, corresponding to the inner
catch teeth on the back of the wheel e; this catch ring is fitted with notches
or slides k, and pressed forward into its position by means of springs, so as to
allow it to slip back clear of the teeth when required. The outer catch box is
fitted in a similar manner, but the teeth of the catch ring catching in the
opposite direction, and with the pulley fcast or fixed to it, is then slipped loose
on the pap of the inner catch box; and on this pap is fixed or keyed a pulley
g, the same size as the pulley f. A friction strap is fitted to each pulley and
attached to the lever 1, which is connected to and regulated by the governor.
These friction straps are crossed in opposite directions, so that when the lever !
is depressed by the governor one of the straps will hold the pulley g fast; when
raised it will hold the other pulley fast, and when equidistant between tho
extremes of the governor's travel will leave both pulleys at liberty. The action
being thus, when the engine is working at a determined speed the governor
lever will be in a position so as to leave both pulleys f, g, at liberty, and
the wheels d, e, must remain at rest, as the catches (having no fulcrum to
act upon) will merely vibrate with the action of the valve shaft. If the engine
works at too great a speed the governor lever l will be depressed, and one of
tho pulleys with its catch will be brought to rest; the vibratory action of the
valve shaft will then cause the wheel (e) to revolve on its axis, turning the
wheel (d) and screw (e), thus causing the sliding part (6), to which is attached
the excentric pin, to move further from the centre of the valve shaft, and

page_text: reduce the traverse of the valve to the required amount for the work the
engine has to perform. If more work is required of or added to the engine
the reverse action takes place, increasing the traverse of the valve, thus
admitting more steam until the engine attains its proper speed, when the
governor lever (7) will leave both pulleys at liberty, and the traverse of the
valve remain stationary.
:
Figures (7 and 8) represent another method of accomplishing the same
object; but the action in this case is instantaneous.
In Figure 7 the excentric pin slides in the slot of the lover (a), and to this
pin is attached the rod (m) and levers (n) and (0); fixed on an axis or shaft.
On the lever (o) is attached the lever (p) with chisel points, and connected to
the governor by the rod (9). On the valve lever (a) is a segment with
graduated catches, and the lever (o) slides in the friction frames (r), the action
of this apparatus being as follows: When the engine is working at its proper
speed the lever (p) is in a position to escape the catches on either side of the
segment; if the engine works at too great a speed, one end of the lever p
is raised and is brought into contact with the catches of the segment; the
action of the valve shaft then pushes the lever (o) in the direction of the arrow;
driving the eccentric pin farther from the valve shaft, and decreasing the
traverse of the valve until the engine again attains its proper speed. The
pointed lever (p) then escapes both sides of the notched segment, and if
the engine works too slow the reverse action takes place.
Figure 8 is another variation of apparatus, shewn in Fig. 7. In this caso
the segment is secured upon a lever, so as to act as a balance weight if
required, and a straight simple lever (o) is obtained for actuating the eccentric
pin. The actuating lever (o) can be held by friction in any convenient manner,
and in both cases they can be moved by hand when required by the handle (s)
in Figure 7, and the handle (t) in Figure 8.
In Figure 8 is shewn a slide valve attached to the lever, with part of the
cylinder steam passages.
Although it is here described that when the engine works at too great
a speed the governor lever (l) is to be depressed, the mechanism herein
described may also be arranged that the reverse action attains the same object.
Figures 9 and 10 represent, respectively, a side view and plan of another
method of altering the traverse of the valve by the combined action of the
governor and the valve shaft. The arrangement of the valve lever is as
described in the first method, having a slide (6), to which slide is attached the
excentric rod pin. The slide (b) is moved by the screw (c); on its outer end'
is.fixed the toothed wheel (v). In a proper position is fixed the frame (w), ·

page_text: moving on a centre (y), and attached to the governor, so as to be moved
to either side as the engine works slow or quick. On the frame (w) is fitted
two catches (x), which spring back and allow themselves to escape when the
wheel (v) passes in one direction, moving it round when passing in the opposite
direction. The action is similar to that already described. When the engine
works at its proper speed both catches are out of action. When the engine
works too slow, the governor, by pushing the frame (w) to one side, throws one
of the catches (a) into geer with the wheel (v), and screws the eccentric pin
nearer its axis, thus increasing the traverse of the valve and admitting more
steam. If the engine works too quickly the reverse action takes place. Part
of the screw spindle can be made plain, so as to throw the nut out in a given
position, and have springs to throw it in gear when required.
Although in the foregoing descriptions the traverse of the valve is described
as being altered by the action of the governor, or by hand, by baving wheel (h)
or handles (s), (t), it will be evident that the alteration of the traverse of the
valve can also be effected by actuating by hand the levers or rods, described, as
the governor lever travels.
Having now described the nature of my said Invention, together with the
method of performing the same, I wish it to be distinctly understood that
I claim the novel and peculiar arrangement and construction of the mechanism
or apparatus for regulating the traverse of the slido valves of steam engines by
means of the vibratory action of the valve shaft, regulated by the governor
according to the requirements of the engine, and the several modifications or
variations of the mechanism for effecting the same principle thereof, as hercin-
before described, set forth, and fully exhibited in the Drawings annexed.
In witness whereof, I, the said William Mac Naught, havo hereunto set
my hand and seal, this Twentieth day of June, in the year of our
Lord One thousand eight hundred and fifty-seven.
W MCNAUGHT. (L.S.)