CERTAIN NEW AND USEFUL IMPROVEMENTS IN STEAM ENGINE VALVES
Year: 1862

page_text: LETTERS PATENT to George Tomlinson Bousfield, of Loughborough Park,
Brixton, in the County of Surrey, for the Invention of "CERTAIN NEW AND
USEFUL IMPROVEMENTS IN STEAM ENGINE VALVES."-A communication from
abroad by John Baird, residing at the City of New York, United States
of America.
COMPLETE SPECIFICATION filed by the said George Tomlinson Bousfield
at the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 21st June 1862, pursuant to the 9th Section of
the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, BE IT
KNOWN that I, GEORGE TOMLINSON BOUSFIELD, of Loughborough Park,
Brixton, in the County of Surrey, do hereby declare. the nature of the
Invention for "CERTAIN NEW AND USEFUL IMPROVEMENTS IN STEAM ENGINE
VALVES," communicated to me from abroad by John Baird, a person resident
at the City of New York, United States of America, and in what manner the
same is to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say:
This Invention consists in certain new and useful improvements in steam
engine valves, and the following, taken in connection with the Drawings, is a
full, clear, and exact description thereof.

page_text: ;
In the Drawings, Figure First is a longitudinal vertical section through the
valve chest, valve, and face plate; Figure Second is a top view or plan of the
valve seat, shewing the ports and equalizing recesses or pockets therein;
Figure Third is a plan of the valve; Figure Fourth is a longitudinal vertical
section through the valve on the line A, B, of Figure Third; Figure Fifth is a
vertical cross section through the same on the line C, D, of Figure Third;
Figure Sixth is a plan of that side of the face plate nearest the valve; Figure
Seventh is a vertical section through the face plate on the line E, F, of Figure
Sixth and Figure Eighth is a side elevation of the same; Figure Ninth is an
end view, partly in elevation and partly in section, of the parts shewn in Figure
First; Figure Tenth contains a plan and an elevation of the adjusting keys;
and Figure Eleventh is an elevation of a spring or part of a spring.
This Invention relates solely to that class of valves which and close
open
their ports by sliding over them, and the object of the Invention is twofold,
first, to relieve the valve from pressure, so that it may be moved over its seat
with a comparatively small expenditure of power; and, second, to prevent a
rocking or tilting motion of the valve, such rocking being due to the fact
of unequal pressure upon the ends of the valves alternately greater at one
end than the other, and resulting in the valve grinding itself out of a plane
surface, thus making it leaky. These objects have been essayed before in
many different ways, the end to be accomplished is not new, the manner in
which it is accomplished is believed to be new; and, as subsidiary to these objects,
the Invention consists in a useful combination of a valve of a certain con-
struction with a face place so constructed that a cut-off slide can be worked
with ease and efficiency upon the face plate.
The Invention is described, by reference to the Drawings in which it is
embodied, in a certain form, and in referring to the Drawings, for the sake of
shortening the description, the valve will be considered as if lying on the upper
side of a horizontal cylinder, the Invention being applicable however to valves
'placed on any side of a cylinder either oscillating or fixed in any given
position.
In the Drawings the two steam ports leading from the valve seat to the
cylinder are shewn at a, a', the valve' seat at b, b, the exhaust aperture at c,
the valve chest at d, d, and the entrance for steam from the boiler at e. In
addition to the ports there are two equalizing recesses or pockets f, f¹, formed
in the face of the valve seat. The valve chest may be of any usual or proper
construction; it is preferred to make it with longitudinal grooves or recesses in
its sides, and with either one or both ends removeable. Upon the valve seat
slides the valve g, g. This valve has thrée apertures through it at h, h', and j,

page_text: and may be strengthened by rods or ribs k, k. The valve has two faces,
parallel to each other; one face rests upon the valve seat, and the other face;
slides in close contact (steam-tight) with the under side of a face plate l, l. This
face plate has cut through it two passages m, m', and has on its lower side
two equalizing recesses n, n', and a large recess o. This latter recess, like the
one o¹ in the top of the valve seat, is cut so as to avoid a large rubbing surface
when the valve moves, and to facilitate the planing, scraping, and grinding of
the valve seat and. lower side of the face plate. The valve is, according to
the plan, to slide with one side in contact with the valve seat, and the other in
contact with the surface of the face plate; the valve must therefore have
parallel faces and there must be proper means for adjusting and securing the
working face of the face plate in contact with the valve. Many plans will
answer for this purpose; a simple one is to let the sides and ends of the face
plate rest upon set screws, and then to insert other screws through the top
of the valve chest bearing upon the upper side of the face plate. Various
kinds of wedges and keys will also serve to hold it in place, but the
preferred plan is shewn in the Drawings, and it consists in recessing
the sides of the steam chest, as at p, p, Figure Ninth, and then, making.
the face plate so wide as to enter these recesses. The lower sides of
these recesses are planed fair and parallel with the valve seat, and on
them rest two long tapering keys q, q, planed or made plane surfaces on the
top and bottom, but with those surfaces inclined to each other. The edges
of the face plate which enter the recesses have their lower sides planed at
the same inclination to the valve seat that the upper sides of the keys.have,.
and this inclined part of the face plate (see s, s, Figures 6, 7, and 8), rests.
upon the upper surface of the keys. The lower side of the face plate
is therefore supported parallel with the valve seat, and by moving the keys
endwise the face plate may be adjusted to and from the valve seat, so as to
embrace closely between them different, thicknesses of valve, or the same valve,
when new and when worn by use. In order to adjust the keys, screws are
cut upon their ends, which project through the ends of the valve chests, and
screw nuts upon them permit the keys to be adjusted and held as required.
When the valve chest lies on top of a cylinder, the steam will hold the face
plate down upon the keys; but it is best, in all cases, to hold the face plate
down either by keys like those that held it up, or by set screws, or by springs,
as at t, t, t, forced. in between shoulders on the chest and the top of the faco
plate. As a measure of precaution, to prevent the steam from springing the
face plate, it is supported along its centre by screw bolts, as at w, w.
In practice the valve is to be laid in its seat; the face plate is then to be

page_text: adjusted so as to be in contact with the upper surface of the valve, and held
there, and then the valve is to be moved, and, if necessary, both it and the
face plate turned up until the valve slides steam tight between its seat and the
face plate, and this latter must not be confounded with a packing; it is not
intended to rest upon or be supported by the valve, but it is to be held in its
place by appropriate supports, entirely independant of the valve. Through
the valve are drilled holes v, v, and by referring to Figure. 3rd, it will.
be perceived that one side of the openings h, h', is curved: By examining.
Figure First, the action of the valve can be most easily understood; both ports.
are closed when the valve is in the position there represented; but as
it moves from X towards Y, the opening h will come over the port a, and as
it uncovers this port steam will pass from the chest through. m, through h,.
and into the port a, that part of the valve at any time lying over the port
having the pressure thereon balanced, so long as the port a is in connection
with the pocket m by means of the holes v. Before the port. a is opened for
the entrance of steam, the port a¹ will, by the same motion, be uncovered by:
the valve, and exhaust will come out of that port into the aperture j, thence
into the cavity o¹, and so out through the exhaust aperture c. When the valve
gets fairly under the aperture m', the holes v make a connection between it
When
and the pocket f, and the steam pressure on the valve is balanced.
the piston is at balf-stroke (minus the lead), the valve comes to rest,
and commences to move from Y towards X, and steam continues to enter
through a, and exhaust to flow out of a', until those ports are covered by the
valve; at that time the holes v, v, connect the ports with the pockets n, n',
equallizing the pressure due to their area; and as the valve continues to move
towards X, port a¹ is opened, and steam flows through m¹, h', and a', into the
cylinder, while exhaust escapes from a through ; and o¹ into the aperture k.
When the valve comes under the opening m, the holes v connect it with the
equallizing recess f, and the steam pressure due. to the size of the aperture
is balanced. When the piston is again at half stroke, minus the lead,
the valve ceases to move, and again returns towards Y. If no separate cut-off
valve is used, or if such valve slides on or works in seats, making. a
tight partition across the chest' above the face plate, then the two ends w, x, of
the valve may be removed, and so, may all that part of the face plate ends
which is outside of the passages m, m¹; but when the cut-off valve or valves
slide on the upper side of the face plate, as at y, y, then the ends. both
of the valve and face plate are essential; for when the cut-off: valve covers
either of the passages m, m', and either port is still open for. steam, or
uncovered by the, valve, then one of the ends w, x, lying under the face

page_text: plate and on the valve seat, prevents steam from passing down at the
ends of the face plate, and so into the port; it will therefore be perceived
that a valve with apertures for the passage of steam through it, in combination
with a face plate with apertures through it, is an arrangement which renders
the application of a cut-off easy to a slide valve working between a seat and a
face plate. The curved sides of the apertures in the valves unclose the ports
for the admission of steam, and this curved edge opens but part of the width
of the port at a time, and thus lets the steam in gradually; but the apertures
may have straight sides as usual. Equalizing recesses or pockets are not new
devices; but in no case that is known of is the connection between the pocket
and the port made by apertures through the valve itself, as herein-before
described.
What is claimed as new is, first, a slide valve with parallel faces, in com-
bination with a valve seat and an adjustable face plate, supported and held in
place without any aid from the valve, the combination being substantially
such as is described, and the parts acting in combination substantially as
specified.
. Second, a face plate substantially such as is specified, with apertures through
it for the entrance of steam, in combination with a slide valve having also
through it apertures for the admission of steam, whereby a cut-off valve or
valves may be applied on that side of the face plate farthest from the valve,
the combinanation being substantially such as described.
Third, in combination with a slide valve and equalizing recesses or pockets,
substantially such as described, apertures through the valve itself, which at the
proper time make a connection substantially as specified between a passage
for steam or exhaust, and a recess or pocket for the purpose specified.
And lastly, the specific means herein described for adjusting and supporting
a face plate acting as herein specified, said means being keys with inclined
faces, which, by being slid endwise, adjust and support a face plate at
the required distance from a valve seat, substantially as herein-before set
forth.
In witness whereof, I, the said George Tomlinson Bousfield, have here-
unto set my hand and seal, this Twentieth day of June, in the year
of our Lord One thousand eight hundred and sixty-two.
GEO. T. BOUSFIELD. (L.S.).