IMPROVEMENTS IN AND RELATING TO VALVES AND PORTS AND THEIR PASSAGES, AND VALVE GEAR FOR STEAM AND OTHER ENGINES
Year: 1881

page_text: LETTERS PATENT to Jeffrey Snelling, of 32, Gilbert Road, Kennington
Road, Lambeth, in the County of Surrey, Engineer, for an Invention of
"IMPROVEMENTS IN AND RELATING TO VALVES AND PORTS AND THEIR
PASSAGES, AND VALVE GEAR FOR STEAM AND OTHER ENGINES."
COMPLETE SPECIFICATION filed by the said Jeffrey Snelling at the Office
of the Commissioners of Patents on the 24th March 1881.
JEFFREY SNELLING, of 32, Gilbert Road, Kennington Road, Lambeth, in the
County of Surrey, Engineer. "IMPROVEMENTS IN AND RELATING TO VALVES
AND PORTS AND THEIR PASSAGES, AND VALVE GEAR FOR STEAM AND OTHER
ENGINES."
The object of my Invention is to simplify the construction and working of the
valves and valve gear of steam and other engines and of the parts immediately
connected therewith; and that my Invention may be understood I have hereunto
attached a Sheet of Drawings marked with letters and figures of reference corre-
sponding with those in the following explanation :-
Figure 1 is a sectional elevation through the upper half of a steam cylinder
provided with a valve and ports and passages according to my Invention.
Figure 2 is a plan of valve as at Figure 1.
Figure 3 is a section through A, B, Figure 1.
Figure 4 is a section through A, B, Figure 6.
Figure 5 is another arrangement of my Invention.
Figure 6 is a plan of valve as at Figure 5.
Figure 7 is a further arrangement of my Invention.
Figure 8 is an elevation of the cylinder and parts of an horizontal steam engine
provided with a valve and gear constructed according to my Invention.
Figure 9 is a plan of Figure 8.
Figure 10 is an enlarged view of cam lever as at Figures 8 and 9.
Figure 11 is a plan of Figure 10.
'
Figure 12 is a front elevation of the cylinder and parts of an inverted cylinder
engine showing another arrangement of my Invention.
Figure 13 is an end elevation of Figure 12.

page_text: Upon reference to Figures 1 to 3 of the Drawings it will be seen that my
Invention consists of a balanced valve A working within a casing B and having
reciprocating movement imparted to it by the valve rod C, which receives motion
from the cam lever I, Figures 8 and 9, or other rod. F is the induction port of the
valve A; E, E', are the steam ports of the cylinder valve face; D is the steam
inlet branch; G, G¹, are the exhaust outlet branches of the valve casing B; H, H³,
are the spiral springs of the valve rings I, I'; the flange rings I, I', are in the back
of the valve A.
Upon reference to Figures 1 to 3 of the Drawings, it will be seen that tho
valve A has passages through it, which allows the steam when entering the steam
inlet branch D to pass up through the valve and press upwards against the valve
case cover, thus balancing the pressure inside the valve and permitting it to slide
easily upon its seat. To prevent the steam escaping from the valve I fit one or
more flange rings, which, with grooves turned in them to receive spring rings,
allows the flange rings to work steam tight in the back of the valve. The spiral
springs H between the top and the bottom of the valve keep the valve faces in
position.
Upon reference to Figures 1 and 2, it will be seen that the valve A is shown on
the centre or at stop; to start the engine it is necessary that the port F of the
valve A should be moved to cover the port E or the port E¹ of the cylinder J, the
movement being imparted to the valve A through the valve rod C; as the port of
the valve A cover the ports E and E, so will be the direction of the steam and the
direction of action of the engine, the exhaust steam escaping outside the valve A
and thence through the exhaust outlet branches G, G', of the valve casing B.
It will be seen that Figure 3 is a section through the line A, B, Figure 2,
showing steam inlet branch D, the exhaust outlet branches being shown in
Figure 2.
It will be seen upon reference to Figures 4, 5, and 6, that the steam passages
are cast in the valve A instead of on the cylinder valve face, as at Figure 1, the
steam inlet to the valve A being the same as in Figure 1; when the port K or
the port K¹ of the valve A cover the port E or the port E¹ of the cylinder J, so
will be the direction of the steam and the direction of action of the engine.
In the arrangement shown at Figure 7, it will be seen that there are two
valves A and A¹ working within the valve casing B, the movement being imparted
to the valves A and A¹ through the valve rod C; as the port F of the valve A, or
F of the valve A¹, cover the ports. E and E¹ of the cylinder J, so will be the
direction of the steam and the direction of action of the engine.
This balanced valve, it will be understood, is applicable not only for steam and
other engines, but for steam pumps, steam hammers, and kindred uses.
In the arrangement at Figures 8 and 9 I have shown the cylinder, guide bars,
and governor of an horizontal engine provided with a valve and valve gear
according to my Invention.
A is the valve; B, the valve casing; C, the valve rod; D is the steam inlet
branch, and G, G, the exhaust outlet branches of the cylinder J; J¹ is the piston ;
Q, the piston rod; J, the cylinder; P is the crosshead pin; I is the cam lever
working upon the pivot O; V is the slotted lever fixed to the cam lever I; the
rod K connects the lever V to the valve rod C; the lever N and rod L of the
governor M support the end of the rod K in the slot lever V. It will be seen that
the friction roller upon the crosshead pin P is at the centre of its stroke, if the
crosshead is moved to the end of its stroke; the friction roller upon the crosshead
pin P coming in contact with the point at R will depress the cam lever I and
impart movement to the valve rod C. When the friction roller reaches the point S
it will give the valve A the required amount of lead. The crosshead will now
have reached end of its stroke; upon the return stroke the friction roller upon the
crosshead pin P in its contact with the cam T causes a further depression of the
cam lever I, and gives the valve full opening. When the friction roller reaches
the point U of the cam lever I it will lift the cam lever I, and the valve A will

page_text: then cut off the steam. When the friction roller reaches the position shown at R¹
the cam lever I will be depressed, and eduction commences and continues until the .
cam lever I is in an horizontal position. The governor M. being connected to the end
of the rod K, which works with a block in the slot lever V, causes the travel of
the valve A to be lengthened or shortened, according to the load upon the engine.
The maximum and minimum amount of travel is limited by the governor M. When
applied to a locomotive or any other reversing engine the rod K is connected to the
hand gear by the usual means.
It will be seen upon reference to Figures 10 and 11 that the cam lever is an
enlarged view of the cam lever I' in Figures 8 and 9. The letter R is the point of
contact for the eduction to commence; S gives the valve the required amount of
lead; T gives the valve full opening; U is the cut-off point for the valve; the
position of the cut-off point U in the cam lever varies according to the part of the
stroke that the cut-off is required.
Upon reference to Figures 12 and 13, it will be seen that my improvements are
arranged for an inverted cylinder engine. The cam lever I in this arrangement
works upon the pivot O in a vertical position. The rod L supports the end of the
rod K by a block in the link V; the lever Y being keyed upon the reversing shaft Z
holds the rod L in position. The levers W and W on the shaft X give movement to
the valve rod C through the rod K from the link V; Q is the piston rod; J is the
cylinder; B, the valve casing. When the end of the rod K is at the centre of its
travel in the link V, then the engine at stop; if it is put in position, as shown in
Figure 13, then the valve will have its full amount of travel. The nearer the rod K
is brought to the centre of the link V, so will the travel of the valve be curtailed
in proportion, and the steam used expansively. To reverse the action of the engine
it is necessary to shift the rod K to the bottom of the link V.
Having thus stated the nature of my Invention and described the mode of
performing the same, I wish to remark that I do not limit myself to the exact
details given, as in some cases the same may be varied according to the peculiar
purposes for which my improvements may be required; but that what I claim and
desire to be secured to me by the hereinbefore in part recited Letters Patent is,―
First. The construction and arrangement of valve and ports and their passages
for steam and other engines, as herein described and as shown at Figures 1 to 3 of
the accompanying Drawings, or any modification thereof.
Second. The construction and arrangement of valve and ports and their passages
for steam and other engines, as herein described and as shown at Figures 4, 5,
and 6 of the accompanying Drawings, or any modification thereof.
Third. The construction and arrangement of valve and ports and their passages
for steam and other engines, as herein described and as shown at Figure 7 of the
accompanying Drawings, or any modification thereof.
Fourth. The construction and arrangement of valve gear for working the valves
for steam and other engines, as herein described and as shown at Figures 8 to 11 of
the accompanying Drawings, or any modification thereof.
Fifth. The construction and arrangement of valve gear for working the valves
for steam and other engines, as herein described and as shown at Figures 12 and 13
of the accompanying Drawings, or any modification thereof.
In witness whereof, I, the said Jeffrey Snelling, have hereunto set my hand
and seal, this Twenty fourth day of March, in the year of our Lord One
thousand eight hundred and eighty-one.
JEFFREY SNELLING. (L.S.)