Im- PROVEMENTS IN CUT-OFF VALVE GEAR FOR STEAM ENGINES
Year: 1870

page_text: LETTERS PATENT to David Hunter Brandon, Engineer, residing
No. 5, Quai Napoleon, Rouen, France, for the Invention of “Im-
PROVEMENTS IN CUT-OFF VALVE GEAR FOR STEAM ENGINES." -A com-
munication from Daniel Frank Mosman, of Chelsea, Suffolk County,
Massachusetts. United States of America.
Sealed the 29th November 1870, and dated the 20th September 1870.
COMPLETE SPECIFICATION filed by the said David Hunter Brandon at
the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 20th September 1870, pursuant to the 9th
Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
HUNTER BRANDON, Engineer, residing No. 5, Quai Napoleon, Rouen,
France, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
CUT-OFF VALVE GEAR FOR STEAM ENGINES," and have petitioned Her Majesty
to grant unto me, my executors, administrators, and assigns, Her Royal

page_text: Letters Patent for the same, and have made solemn Declaration that
the same has been communicated to me by Daniel Frank Mosman, of
Chelsea, Suffolk County, Massachusetts, United States of America.
NOW KNOW YE, that I, the said David Hunter Brandon, do hereby
declare that the following Complete Specification, under my hand and
seal, fully describes and ascertains the nature of the said Invention, and
in what manner the same is to be performed, in and by the following
statement, reference being had to the Drawing hereunto annexed, and
to the letters and figures marked thereon (that is to say): -
In this Invention I prefer to make use of a balanced poppet valve for
the cut-off valve, the cut-off valve being arranged independently of the
valve or valves which control the entrance and exhaust of the steam,
and serving only to regulate the periods during which steam or other
motive fluid is supplied to the valve or valves by which the motor is
allowed to pass, and to act upon a piston first on one and then on the
other side. To move this valve I make use of a rocker shaft carrying
rocker arms, the rocker shaft being made to partially rotate by con-
nection with any suitable reciprocator actuated by the engine. To the
rocker arms which are on opposite sides of the rocker shaft I pivot
pawls which alternately act upon a slide, which is so connected with the
stem of the cut-off valve that it may be moved by the pawls, the extent
of motion given to the slide being determined by the position of notched
radius bars, which are so arranged that their location is determined by
the degree of momentum given to an oscillating weight or weights
driven by connection more or less direct with the engine, so that when 2
the engine moves at more than its normal rate of speed the momentum
of the oscillating weight and distance moved by it are increased, and
when the engine falls below its normal rate of speed the momentum and
distance of movement of the oscillating weight are diminished. On the
slide which moves the cut-off valve are pivoted lifters, which have 3
projections, which in their movement come into contact with the
notched radius bars, and as the latter are changed in position by the
varied momentum imparted by the oscillating weight, said projections
come more or less quickly into contact with the said notched radius
arms, which causes the lifters carried by the slide to lift the pawls 3
carried by the rocker arms more or less quickly, and thus varies the
time during which the pawls remain in such contact with the slide as
to move it.

page_text: Having thus in general terms described the construction and operation
of my improved automatic cut-off regulating gearing, I will now describe
it more minutely and in detail, referring to the accompanying Drawing,
in which Fig. 1 exhibits said gearing in side elevation, the same being
also shewn in end elevation in Fig. 2.
The cut-off valve is shewn in dotted lines in its chest or casing a, of
which the nozzle 6 is the entrance, and nozzle c* is the exit passage for
the steam, the dotted arrows showing the direction of the steam current
which is discharged into the chest containing the main or shifting valve,
which is not shewn, as it may be of any of the known varieties worked
in any known way. In the chest a are two diaphragms in which the
valve seats are made, the entrance passage from nozzle b being bifurcated,
so as to conduct the steam to the end spaces left in the chest a, from
which spaces when the valve is forced away from its seats the steam
passes into the central space and out through the nozzle c to the main
or shifting valves of the engine. As the valve spindle d passes out of
chest a at one end only the steam exerts its pressure on the area of the
spindle to keep the valve closed upon its seat, and if desired the area of
the two parts of the valve may be proportioned so as to increase or
diminish this tendency, it being my intent to balance the valve nearly,
but to leave a preponderance of pressure on one side sufficient only to
close the valve promptly as soon as it is released from the opening
pawls, and so also that in case of breakage of any of the connections
the cut-off valve will act as a safety shut-off valve. On the top of the
chest and bolted thereto is a cover e, by removal of which the valve can
be got at conveniently. Two standards fare connected with this cover,
and serve to sustain in suitable bearings the rocker shaft g, and the
slide h, for the oscillating governing weight or weights. The slide i is.
guided between the uprights, and has at one end a roll j, which runs on
the cover e, the other end of the slide embraces the valve rod d, and is
connected thereunto, so that it has a slight range of motion without
moving the valve, and so that when moved beyond said range it will
operate on the valve spindle to open the valve. At the rear of slide i
and on each side thereof rise standards k, which carry a roll I, and on
shaft g are fixed two rocker arms m and n. To the arm m is pivotted
the pawl o, and to the arm n is pivotted the pawl p, said pawls acting.
alternately by the rocking movements imparted to shaft g against
roll to move it and the slide i. On the slide i are pivotted lifters q

page_text: and r, which respectively are located under pawls o and p, so that when
said lifters in moving with slide i come into contact with obstructions
their free ends rise and lift the pawls so that they are disengaged from
the roll 7, and then the slide i returns to its normal position when the
valve remains closed. The obstructions which cause the movements of
the lifters which result in the disengagement of the pawls from the roll
are the radius arms markeds and t, which are pivotted to the valve
chest cover e, the free ends of said arms s, t, being notched to receive
and resist progress of projections fixed on the lifters q, r. The higher
the arms s, t, are located when the projections from the lifters come into
contact therewith the longer will the pawls remain in contact with the
roll 7, resulting in an increased range of motion of the cut-off valve,
increasing the periods of time that the valve will remain open, and the
amount of steam supplied to the engine. The arms 8 and t are positively
raised to the greatest height each time the shaft g rocks, and are lowered
from that position by the degree of momentum given to the governing
weight, so that as the speed of the engine is accelerated the arms s and t
are lowered to an extent depending upon the momentum given to the
governor, which may lower said arms so that the lifters will force the
pawls out of gear with the slide so soon that the valve will not be
opened at all. On the weight shaft h are fixed cross arms which are
screw-threaded, and provided with adjusting nuts, so that weights u can
be fixed on said arms, and can be properly balanced and placed thereon,
the adjustment of the weights determining the rate of speed of the
engine. By moving the weights towards the centre of their motion the
rate of speed of the engine is increased and vice versa. To these
weights may be given oscillating movements by various means. In the
Drawing the following means are shown:-To the rocker arms m, n, is
bolted a piece V, which is connected to a wheel on shaft h, by two chains
oppositely attached thereunto, so that when the rocker shaft g is moved
the weights are oscillated in a corresponding direction, the weights
receiving a greater or less extent of movement proportional to the speed
at which shaft g is moved by the engine. Shaft h bears at its ends
rocker arms W, having wrist pins x, which operate in the slotted ends
of the jointed connections y, which are fixed to the notched radius
arms s, t, so that it will be seen how said arms are raised more or
less according to the extent of movements of the weights u.
The
movement when made so slowly as not to give momentum enough to the
oscillating weights to overcome the friction on shaft h, carries the

page_text: )
arms W slightly beyond a vertical position, the effect of which is to
raise the arms s, t, substantially to their highest position, where the
projections on the lifters do not come into contact with said arms so as
to cause the lifters to rise to detach the pawls from the slide i until the
piston has made very nearly its full stroke; but it will be seen that if
the motion of the engine becomes so quick as to give a momentum to
the oscillating weights then the arms W will pass the nearly vertical
position given them by the direct action of the chain connection, and in
so passing will lower the arms 8, t, more or less according to the amount
of momentum received by the oscillating weights, which will result in
releasing the pawls o, p, sooner, so that the valve will close and cut off
steam just in the proportion in which the arms 8, t, are lowered by the
momentum of the governor. To prevent the weights from rebounding
or recoiling from the position which they would obtain under the
greatest range of movements allowed them, I place on shaft h a wheel
in the periphery of which are made two holes diametrically opposite,
and I surround said wheel with a link, in which is a pin which falls into
one or the other of said holes and locks the shaft in position until
the shaft receives another rocking impulse from the engine, when
said link is raised so as to lift said pin out of the hole in which it is
engaged, said link being pivotted by a slotted hole to a stud fixed on
the top of the rocker arm m, so as to give to the link the desired move-
ments at the proper times.
.
This arrangement is shewn in sectional detail in Fig. 3, where said
wheel is marked a', the link b¹, the pin therein c¹, and the slotted hole
in the link by which it is connected to the stud on the rocker arm is
denoted by d. On the shaft g I fix an arm, generally slotted so as
to change the position of the connection which leads to any suitably
reciprocating part of the engine. In some situations it is desirable to
apply friction to the governing weight shaft h. For marine engines I
force a break shoe upon the shaft by means of the screw acting through
a spring, but for land engines I prefer to apply a weight to the break
through a lever. In either case the speed of the engine is increased
by increasing the pressure of the break, which prevents the oscillating
weights from moving so freely as to lower the arms s, t, so far as to
prevent the engine from taking steam. The spring e¹ is applied to the
slide i, so as to take up the lost motion allowed to the slide relatively
to the valve stem.

page_text: I claim a double-seated poppet valve balanced or nearly so, arranged
independently of the main or shifting steam valve of an engine, and
operative in connection with a governor as an automatic, regulating, or
cut off valve.
Also a vibrating governor arranged to impart in proportion to the
varied degrees of momentum which it receives from an engine varied
degrees of motion to a detaching mechanism arranged and operative to
release a cut-off valve from its mechanical connections.
Also the combination with a vibrating governor and cut-off valve stem
of the slide i, rocker shaft g, arms m, n, pawls o, p, lifters q, r, radius
arms 8, t, connections V, W, x, y, under an arrangement and operating
substantially as and for the purpose specified.
Also the spring e¹ in combination with the slide i, and valve rod d,
when so arranged as to permit relative motion between said slide and
rod substantially as and for the purpose set forth.
Also the combination with the vibrating governor and some part
positively moved by the engine of the locking and releasing devices com-
prised in the link b', wheel a', pin c¹, and notches d³, d, arranged and
operating substantially as and for the purpose specified.
In witness whereof, I, the said David Hunter Brandon, have
hereunto set my hand and seal, the Seventeenth day of Sep-
tember, in the year of our Lord One thousand eight hundred and
seventy.
Witness,
R. H. BRANDON,
5, Quai Napoléon,
Rouen.
D. H. BRANDON. (L.S.)
5, Quai Napoléon, Rouen.