IMPROVED EXPANSION OR CUT-OFF GEAR POR STEAM ENGINES
Year: 1858

page_text: LETTERS PATENT to William Edward Newton, of the Office for Patents,
66, Chancery Lane, in the County of Middlesex, Civil Engineer, for the
Invention of "IMPROVED EXPANSION OR CUT-OFF GEAR POR STEAM ENGINES."
-A communication..
Sealed the 29th April 1859, and dated the 29th November 1858.
PROVISIONAL SPECIFICATION left by the said William Edward Newton
at the Office of the Commissioners of Patents, with his Petition, on the
29th November 1858.
I, WILLIAM EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane,
5 in the County of Middlesex, Civil Engineer, do hereby declare the nature of
the said Invention for "IMPROVED EXPANSION OR CUT-OFF GEAR FOR STEAM
ENGINES," to be as follows:-
This Invention consists in a combination of vibrating arms, vibrating links,
rods, and lifters, whereby the "cut-off" valve is opened, and subsequently
tripped by a continuation of the same inherent movement by which the
opening is effected. It further consists in certain devices operating in combi-
nation with the said lifting and tripping apparatus, for the purpose of rendering
the trip motion variable to cut off the steam at different points within the first
half of the stroke of the engine.
The principal features of novelty are, 1st, the combination of two rock
shafts with their arms connected by rods to vibrating arms, in combination
with which there are lifters applied in such a manner as to operate upon a
tappet or tappets on the valve stem, or its equivalent, for the purpose of lifting
the valve, and subsequently tripping it by the continued and inherent motion
of the lifters.

page_text: 2nd, in combination with the above specified lifting and tripping mechanism,
there are pendulous levers provided with toggle links and a sliding piece
connected with a governor or other means of adjusting the same to vary
the positions of the centres of motion of the vibrating arms of the first-
mentioned combination, for the purpose of varying the point of cutting off the
steam
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Edward Newton in the Great Seal Patent Office on
the 28th May 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane, in the County
of Middlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of November, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-second year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Edward Newton, Her special license that I, the said William
Edward Newton, my executors, administrators, and assigns, or such others as I,
the said William Edward 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 night
make, use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for "Im-
PROVED EXPANSION OR CUT-OFF GEAR FOR STEAM ENGINES," being a communication
from abroad, upon the condition (amongst others) that I, the said William
Edward 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 imme
diately after the date of the said Letters Patent...
NOW KNOW YE, that I, the said William Edward 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:):—
This Invention, as communicated to me by my foreign correspondent,

page_text: consists in a certain combination of vibrating arms, vibrating links, rods, and
lifters, whereby the "cut-off" valve is opened, and subsequently tripped by a
continuation of the same movement, by which the opening is effected. It
further consists in certain devices operating in combination with the lifting.
and tripping apparatus, for the purpose of rendering the trip motion variable
to cut off the steam at different points within the first half of the stroke of the
engine.
The Invention is illustrated in the accompanying Drawings, in which Fig. 1
is an elevation, partly in section, of a "cut off" and its operating gear, exhi-
biting also the application of a governor to regulate the engine by the action
of the cut off. Fig. 2 is an elevation also partly in section, taken in a plane-
at right angles to the plane of Fig 1; Fig. 3 is a side view, exhibiting only
the operating gear which is shewn in a different position to that represented.
in Fig. 1. Similar letters of reference indicate corresponding parts in all the
Figures.
A is a hollow casting or box, in which is the seat for the cut-off valve B,
which may be of the balanced, puppet, piston, slide, or any other kind. This
box has a flanch at the bottom by which it is to be attached to the steam chest
of an engine, and an opening in one side furnished with a flanch with which
to connect the steam pipe. In the cover D of this box. A there is a stuffing
box, through which passes the upright stem C of the valve; this stem passes
up through a guide in the centre of a horizontal plate E, supported some
distance above the box A by pillars V, V, erected upon the box. In case of
the valve being of the piston kind like that represented, or otherwise of such
character that it does not stop in closing like, a puppet valve, an elastic
cushion is provided in or above the plate E, and a crosshead or collar 9 on
the upper part of the valve stem, which collar is placed above the cushion, for
the purpose of arresting the valve in its descent when closed. H, H, are rock
shafts arranged horizontally and parallel with each other on opposite sides of
and at equal distances from the valve stem in bearings attached to or supported.
by the pillars V, V; these rock shafts are furnished with arms I, I, connected.
at equal distances from their respective rock shafts by a link J of such length.
as to keep them always parallel; and the link has attached to a wrist pin K
which is intended to, connect with an ordinary excentric gear, or with other
suitable means of imparting motion. from the crank shaft to the rock shafts.
Each rock shaft H carries a pair of arms N, N; which are connected by a pair
of parallel rods L, L, with one of two links O, O, of a length corresponding
with said arms; the links O, O, are pivoted to two pendulous rods R, R,
attached to the plate E; these rods are connected by links S, S, with a slide T,

page_text: that is fitted to work up and down the valve stem C, and is to be connected
by two rods U, U, with a governor G, or with any apparatus that is capable
of moving it up and down the valve stem. Between each pair of parallel
rods L is fitted a lifter M, and these lifters are attached at their lower ends
respectively to the arms N, by means of the same pin a which connects the
rods in pairs: At-their upper-ends-these-lifters are furnished with a toe m,
which projects from between the rods towards the valve stem C, for the
purpose of lifting the stem by their action upon a double tappet P secured to
said stem. To the lifters springs Q, Q, are applied for throwing them towards
the valve stem, and they have stops n, n, attached to their backs for the
purpose of limiting the action of the springs by coming in contact with the
backs of the rods. The upper faces of the toes m, m, are in the form of arcs
described from the centres a, a, and the lower face of the tappet P is formed
to correspond, and the faces of said toes, which are towards the stem C and
the outer faces of the tappet P, are bevelled, as shewn in Figures 1 and 3.
The operation of this cut-off gear is as follows:-Steam being admitted to
the engine, and the wrist pin K being connected with the excentric or other
driving gear, motion will be imparted to the two rock shafts H, H, by the link
J and arms I, I, and the rock shafts will vibrate the two arms N in opposite
directions (one ascending while the other descends), thereby causing the rods
L, L, (under the guidance of the links O, O,) to receive a combined vertical
and horizontal motion, the links 0, 0, during this movement vibrating on the
pius C, C, which connect them with the rods R, R, in a corresponding manner
to their respective arms N, N. In the above-described motion of the rods L, L,
their ascent brings the toes of their lifters M, M, into contact with the tappet
P on the valve stem, and causes the valve to be lifted to admit steam to the
steam chest of the engine till the toe which is in operation on the tappet is, by
its horizontal movement, caused to pass the extremity of the tappet, or in
common phrase to "trip" it. The valve is then instantly closed, either by its
own weight, the pressure of steam, the action of springs d, d, applied to
operate on its stem, or by weights properly applied. The lines described by
the arms N, N, links O, O, and rods L, L, being the same-in-their return
or descending as in their ascending motions, the toes of the lifters M, M, are
brought into contact with the sides of the tappet P, but the springs Q, Q,
allow them to yield till they have passed the extremities of the tappet, when
the springs react and return them to a position to lift the tappet when they
ascend again.
Fig. 1 represents the valve close:l, and the toes m, m, in the position for
either to commence lifting according to the direction in which the arms I, I,

page_text: are moved. Fig. 3 represents the valve lifted to its full opening by the left
hand toe, which is just about to escape.
The excentric or driver is intended to be so set that the stroke of the arms
N, N, and links O, O, will terminate as the crank of the engine is at half
stroke, and by varying the position of the centres of motion c, c, of the
links O, O, in planes corresponding or parallel with the planes of movement
of the links and the arms N, 'N, the toes m of the lifters may be made to
trip at any point in the stroke of the engine from the commencement to half
stroke, or may even be prevented tripping altogether if it should be desirable
at any time to run the engine under a full head of steam. It is to effect such
variation of position of the centres c, c, that the points of suspension are
arranged in pendulous rods R, R. When the rods R, R, occupy such a
position that the horizontal movement of the rods L, L, and lifters M, permits
the escape of the lifters from the tappet at the precise moment that their
upward movement terminates, the steam is cut off at half stroke, but if the
rods R, R, occupy a position which brings the points c, c, closer to the valve
stem, the lifters will not escape at all, but after lifting the valve stem will
gradually lower and close it, or if the rods occupy positions which bring the
points c, c, farther from the valve stem, the lifters will escape and permit the
tripping of the valve before their vertical movement terminates, and thus cut
off the steam at a point earlier than half stroke. The rods R, R, are adjusted
to vary the cut-off by moving the slide Ț up or down the valve stem, which
movement causes the links S, S, to act as a toggle upon the pendulous rods:
R, R, and thus draw them towards or force them from each other; the slide T
may be adjusted by hand gear to effect the cutting off permanently at such
point in the first half of every stroke of the engine as may be desired, and also.
to vary such point as may be desired, but it is represented as connected with
a governor, for the purpose of employing the cut-off as a regulator of the
speed of the engine, the connection being such that any increase of speed of
the engine will cause the rods R, R, to carry the centres of motion c, c, away
from the valve stem to make the valves trip earlier in the stroke, and vice
versa.
In case of the valve employed being of such kind or having such
arrange-
ment that the upward continuation of the stem C cannot be used in the
manner represented to lift the valve, a rod arranged like C relatively to the
operating gear may be employed, connected with the valves by arms, links,
bell cranks, levers, or other devices in a suitable manner to cause the
operating gear to control it in the manner described. The peculiar advantages
which characterise this cut-off gear are as follows:-First, by means of the

page_text: combined vertical and horizontal action of the lifting rods. L, L, and lifters M,
the lifters are caused alternately to connect with and disconnect from the
valves by the continuous reciprocating motion imparted to them without the
use of stops, cams, or other appendages commonly employed to effect their
tripping or disengagement. Second, owing to the rods L, L, remaining
throughout the whole lifting movement parallel, or at the same angle with the
rod or stem. C, the lines of the surfaces of contact of the lifters and tappet are
always in the same direction and coincide with each other, thus rendering.
them but little liable to wear. Third, as a governor attachment it renders the
governor capable of exerting great power to effect the variation of the cut-off,
while the power required to effect such variation is comparatively insignificant,
hence it allows the governor to retain the sensitiveness due to an almost;
unimpeded action.
Having now set forth the nature of the Invention of "Improved Expansion.
or Cut-off Gear for Steam Engines," as communicated to me from abroad,
and. explained the manner of carrying the same into effect, I wish it to
be understood that under the above in part recited Letters Patent, I
claim,
:
First, the combination of the two rock shafts H, H, their arms N, N, the
vibrating links 0, 0, the rods L, L, and the lifters M, M, the whole applied
substantially as described to operate upon a tappet or tappets on the valve.
stem E or its equivalent, for the purpose of lifting the valve, and subsequently
tripping it by the continued motion of the lifters.
Second, in combination with the above-specified lifting and tripping
mechanism, I claim the combination of the pendulous rods R, R, the toggle
links S, S, and the slide T, or their equivalents, connecting with a governor or
other means of adjusting the same to vary the positions of the centres of
motion c, c, substantially as described, for the purpose of varying the point
of cutting off the steam.
"
In witness whereof, I, the said William Edward Newton, have hereunto
set my hand and seal, the Twenty-eighth day of May, in the year of
our Lord One thousand eight hundred and fifty-nine.
W. E. NEWTON. (L.s.)