IMPROVEMENTS IN VALVE SEATS FOR STEAM ENGINES
Year: 1878

page_text: LETTERS PATENT to Herbert John Haddan, of the Firm of Herbert and
Company, Solicitors of Patents, of 67, Strand, in the City of Westminster,
Civil Engineer, for the Invention of "IMPROVEMENTS IN VALVE SEATS FOR
STEAM ENGINES." A communication from abroad by Henry Watkeys, of
Syracuse, State of New York, United States of America.
Sealed the 2nd May 1879, and dated the 28th November 1878.
PROVISIONAL SPECIFICATION left by the said Herbert John Haddan at the
Office of the Commissioners of Patents on the 28th November 1878.
HERBERT JOHN HADDAN, of the Firm of Herbert and Company, Solicitors of
Patents, of 67, Strand, in the City of Westminster, Civil Engineer. "IMPROVE-
MENTS IN VALVE SEATS FOR STEAM ENGINES." A communication from abroad by
Henry Watkeys, of Syracuse, State of New York, United States of America..
The Invention consists of a plate or diaphragm provided with the requisite
steam induction and eduction ports, and mounted loose upon the cylinder and
confined in its position by either lugs, studs, shoulders, or other equivalent staying
devices, rigidly connected with either the cylinder or the steam chest, the whole so
constructed and arranged that the valve seat may be both attached to and removed
from the cylinder without the necessity of loosening the said stays from the parts
which contain them. The Invention also consists in the combination with a valve
seat mounted loose upon the cylinder face, and confined thereon in the manner
aforesaid of set screws, keys, or other devices arranged to adjust and tighten the
valves at their position on the cylinder.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Herbert John Haddan in the Great Seal Patent Office on the 20th
May 1879.
HERBERT JOHN HADDAN, of the Firm of Herbert and Company, Solicitors of
Patents, of 67, Strand, in the City of Westminster, Civil Engineer. "IMPROVE-
MENTS IN VALVE SEATS FOR STEAM ENGINES." A communication from abroad by
Henry Watkeys, of Syracuse, State of New York, United States of America.
The Invention relates more particularly to the cylinder face or seat for recipro-
cating or so-called slide-valves of steam engines. The object of the Invention
being to provide the cylinder with a face or valve seat which shall be more readily
attached to or detached from the cylinder, and thus capable of being refaced or
repaired with great facility and at a materially reduced expense, and when worn
out, readily replaced by a new one. The Invention consists essentially of a plate or
diaphragm provided with the requisite steam inlet and outlet ports, and mounted
loose upon the cylinder and confined in its position by either lugs, studs, shoulders,
or other equivalent staying-devices rigidly connected with either the cylinder or
the steam chest, the whole so constructed and arranged that the valveseat may be
both attached to and removed from the cylinder without the necessity of loosening
the said stays from the parts which contain them. The Invention also consists in
the combination with a valveseat mounted loose upon the cylinder face and confined
thereon in the manner aforesaid, of set screws, keys, or other devices arranged to
adjust and tighten the valveseat in its position on the cylinder, all as hereinafter
more fully described. The Invention admits of many variations and modifications
in the details of construction, and depends to some extent on the construction,
dimensions, and arrangement of the steam chest, and in some respects on the
relative position of the steam inlet and outlet ports. The accompanying Drawing
illustrates a few of the principal constructions of the Invention, adapted to meet the
most common exigencies, Figures 1, 3, and 11 being plan views of three forms of
the insertion as applied to the cylinder, Figure 2, a longitudinal section taken on
line x, x, in Figure 1, "with the steam chest detached, Figure 4, a longitudinal
section through y-y, in Figure 3, Figure 5, a longitudinal section through z, z, in
Figure 3, and Figures 6, 7, 8, and 9 are irometrical views of four different forms of
the valve seat, those shown in Figures 6, and 7 being adapted for the fastening
device illustrated in Figures 1 and 3. Figure 10 is a longitudinal section of a steam
chest provided with the valve seat illustrated in Figure 8, Figure 11 is a plan of a
.steam chest, illustrating the means of securing upon the cylinder face the valve
seat shown in Figure 9, and Figures 12 and 13 are sectional views illustrating
further modifications in the details of the Invention. A represents the cylinder,
and B the steam chest of a reciprocating steam-engine. The top of the cylinder is
usually cast with a saddle C, of sufficient height to contain the steam inlet a and
steam outlet a', the former leading into the cylinder from the steam chest mounted
on the top of the saddle C. The top surface of the said saddle is provided with a
raised face or valve seat originally cast thereon, and planed to form a true bearing
for the valve. The subsequent refacing of the valve seat, which is frequently
required in consequence of the wear produced by the friction of the valves, has on
account of the inconvenience of access to the valve seat, heretofore generally been
effected by means of cold chisels and files, and therefore proved very expensive both
as regards the time required and files consumed by the operation. After the
original seat had thus been reduced to its minimum height, a so-called false seat has
heretofore been rigidly attached to the cylinder face by countersunk bolts passing
through the said seat, and into the metal of the cylinder or saddle aforesaid. The
false seat being likewise subjected to the aforesaid destructive effects of repeated
refacing and requiring frequent renewal, the bolting of same to the cylinder face
has been found a very objectionable mode of fastening, inasmuch as the bolts were

page_text: liable to either become so permanently fixed in their hold as to cause them to
break by the attempt at their removal or work loose, and by their contact with
the valve cause breakage of either the valve seat, valve yoke or other parts con-
nected therewith. Furthermore the bolt holes have a tendency to weaken the
valve seat, and the difference of expansion of the latter with that of the cylinder
caused the valveseat to mark and raise off the cylinder face between the bolts, and
thus produce leakage of steam through the exhaust port. It is therefore the object
of this Invention to reduce to a minimum the expense of refacing the valve seat
and to obviate the dangerous effects last mentioned, and for the attainment of this
object I employ the following device:-In the accompanying Drawing D represents
my improved valve seat, which I mount loose on the cylinder and confine in its
position by means best adapted for the existing construction and arrangement of
the steam chest and its appurtenances, though invariably in such a manner, as to
admit of the ready attachment to and removal from the cylinder. When the
position of the steam ports admit of it, I construct the valve seat of the form
shown either in Figure 6 or in Figure 7 of the Drawing, and secure it upon the
cylinder face by means of flanged ribs r, 1, either cast on or otherwise permanently
fixed to the cylinder face and engaging with flange s on the base of the valve seat.
In this case the steam chest is removed, and the seat inserted sideways into its
position and tightened by a key c driven between the engaging parts. Large
valve seats I provide with additional bracing, by forming at the sides of the steam
chest shoulders which bear upon the valve seat as indicated by dotted lines in
Figure 1.
In steam chests having the steam inlet through the end of the cylinder
face, I prefer to fasten the said seat by lugs L, cast on the inside corners of the
steam chest and abutting against the ends of the valve seat, and having a flangè
engaging the top of flanges on same. To compensate for any variations which
may occur in the size of the interchanged valve seat, and to properly tighten the
same in its positions, I arrange between one end of the valveseat and the adjacent
end of the steam chest a set screw e, as fully shown in Figures 3 and 5 of the
Drawing. To prevent this set screw in case of its working loose, from becoming
displaced and interfering with the working of the valve or causing other injury,
I fit the ends of the set screw in sockets u and v respectively in the steam chest and
valve seat of sufficient depth to retain the set screw. The said set screw may also
be employed in connection with the ribs r before described. If the steam chest is
too short, or the stean ports in too close proximity to the valve seat to admit of the
flange s on the latter, I construct the valve seat of the form shown either in Figure 8
or 9, that illustrated in Figure 8 being formed with lugs m extending from the
two ends, and abutting against the ends of the steam chest as fully shown in
Figure 10 of the Drawing, thus preventing all horizontal displacement. The
lifting of the seat by back pressure incident to the reversing of the engine is
prevented by studs n, projecting either from the steam chest cover as shown, or
from the sides or ends of the steam chest, and having their inner end fitted into
countersinks in the sides or ends of the valve seat. In case the valve seat is so
large as to require a stay at its central or main port, I provide the seat with a
flange or shoulder o on its two ends, as shewn in Figure 9, and form in the sides of
the steam chest corresponding recesses to receive the said flange. The scat being
first mounted on the cylinder and the chest then placed in position, thus effectually
preventing both vertical and horizontal displacement. To guard against all
horizontal play which may be occasioned by variations in the dimensions of the
engaging parts, I provide the said seat on one end with lugs m¹ of sufficient length
to abut against one end of the chest, and on the opposite end with short lugs m²,
having an eye or socket in which rests the end of a set screw w operating against
the adjacent end of the steam chest. In Figure 12, the valve seat is provided at
the base of all its vertical sides with a flange analogous to that shown in Figure 7
of the Drawing, and is confined in its position by the steam chest mounted on said
flange and bolted to the cylinder in the usual manner. In Figure 13, both the
valveseat and steain cliest are provided on their contiguous sides with lugs a, a,

page_text: bevelled on such an angle as to produce a downward wedge on the valve seat,
which is inserted from the top of the steam chest, and then, by means of set screws
d, forced longitudinally towards the opposite end of the steam chest until wedged
tight by the engaging lugs a, a. By both constructions shown in Figures 10 and
13, the valve seat can be placed in position without removing the steam chest, a
feature which is very desirable for large engines, such as marine engines, and for
those baving the steam pipe connected with the steam chest. It will be observed
that either of the described constructions admits of a ready attachment and detach-
ment of the valve seat, which feature is the essential part of this Invention, as by
that means the worn or injured seat can be removed from the cylinder, and placed
on the planer to reface it, and by keeping on hand duplicates of the seat, the
injured seat can immediately be replaced by a new one, and thus frequently save
expensive delays and stoppage of the use of the engine. The function of the over-
lapping part of all the described lugs and shoulders bearing down upon the valve
seat, is to prevent its lifting off from the cylinder face by the back pressure
occasioned at times by the reversing of the engine while in motion. Practical tests
of the Invention have proved that usually, when the engine is in motion, the
pressure of steam in the steam chest acting on the valve and valve seat is sufficient
to hold the valveseat steam tight upon the cylinder face. It has also been found
that by my improvements the valve seat is maintained uniformly and perfectly on
the cylinder face under various degrees of expansion. CLAIMS.-1. A valveseat
mounted loose on the cylinder and confined in its position by either studs, lugs,
shoulders, or other stays rigidly connected either with the cylinder or with the
steam chest, all so constructed and arranged that the valve seat may be readily
attached to and detached from the cylinder without, loosening the said stays from
the parts which contain them, substantially as specified. 2. In combination with a
valve seat mounted loose on the cylinder and confined in its position in the manner
described, set screws, keys or wedges arranged to adjust and tighten the seat in its
position, substantially as set forth.
In witness whereof, I, the said Herbert John Haddan, have hereunto set my
hand and seal, this Nineteenth day of May, A.D. 1879.
H. J. HADDAN. (L.S.)