IMPROVEMENTS IN STEAM ENGINES."
Year: 1880

page_text: LETTERS PATENT to David Joy, of No. 32, Anerly Park, Anerly, Surrey,
Engineer, for an Invention of "IMPROVEMENTS IN STEAM ENGINES."
PROVISIONAL SPECIFICATION left by the said David Joy at the Office of
the Commissioners of Patents on the 20th August 1880.
DAVID JOY, of No. 32, Anerly Park, Anerly, Surrey, Engineer. "IMPROVE-
MENTS IN STEAM ENGINES."
My Invention relates to further improvements on Letters Patent granted to me,
dated Sth March 1879, No. 929, and consists,-
Firstly. In various modifications of the valve motion described; thus instead of
taking the motion to work the slide valves from the connecting rod within the
centres, I may take this motion from a point outside the centres, or from a
continuation of the connecting rod either at the crank or crosshead end, and either
in the line or out of the line of the centres, the attachments of the levers and links
transferring the motion to the valve being altered in conformity with the altered
action so given.
Also, instead of correcting the arc of the lever working the valve by a parallel
motion attached to the connecting rod, as described in the above mentioned Letters
Patent, I correct this by equalizing the vibration of the lever centre in the slot link
by the attachment of an extra lever.
Secondly. Modifying the gear so as to adapt it oscillating engines by taking
motion for the slide valve from the piston rod end, or from a suitable bracket
attached to it, and arranging the rest of the gear accordingly.
Thirdly. In correcting the errors arising in locomotive and other engines
where the crank axle centre has a moveable bearing by supporting the centro
of the quadrant link or lever substituting it in a frame or bracket, one end of
which is fixed to the axle box or to the crank shaft, and the other to the frame of
the engines.
Fourthly. In an improved form of slide valve specially suitable for my improved
gear by which two or more openings are made into the port at the same time, or
it may be arranged to make one opening for the lead, the others following on the
turn of the crank. By this means a more sudden admission and cut off are

page_text: obtained. The valve is similar to the ordinary D valve, but has an opening or
openings completely through it at the part forming "lap," and these are covered
on the back by a plate, which may also be the balancing plate; in this plate
openings are formed to correspond with those in the valve, so that when the lip
of the valve opens for lead these openings in the plate also open. They also open
by over running the valve face at the opposite end, and by connecting them
together over the back of the valve, four ports may be made to open simultaneously,
or they may be arranged to follow each other, or they may be made to open only
at one end by making them over run the valve face or the upper plate only at
one end.
Or instead of carrying the ports through the valve and using the back plate
with ports, I only unite the aforesaid ports together across the valve, and by
prolonging the valve face at one end allow the port only at the opposite end to
open. These openings can be multiplied if desirable as far as the practical limits
will allow.
And I treat the exhaust ports in a somewhat similar manner by forming small
ports in the valve face, and carrying them round the back of the exhaust chamber
of the valve into which they open; and in this chamber I support a plate which
(similarly to the plate on the back of the valve) covers these openings, only
allowing them to open at the same time as the ordinary exhaust port.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said David Joy in the Great Seal Patent Office on the 18th February
1881.
DAVID JOY, of 32, Anerley Park, Anerley, Surrey, Engineer.
IN STEAM ENGINES."
"IMPROVEMENTS
My Invention relates to further improvements on Letters Patent granted to mo
dated 8th March 1879, No. 929, and consists,—
Firstly. In various modifications of the valve motion described; thus, instead of
taking the motion to work the slide valves from the connecting rod within the
centres, I may take this motion from a point outside the centres, or from a
continuation of the connecting rod either at the crank or crosshead end, and either
in the line or out of the line of the centres, the attachments of the levers and links
transferring the motion to the valve being altered in conformity with the altered
action so given. Also instead of correcting the arc of the lever working the valve
by a parallel motion attached to the connecting rod, as described in the above
mentioned Letters Patent, I correct this by equalizing the vibration of the lever
centre in slot link by the attachment of an extra lever.
Secondly. Modifying the 'gear so as to adapt it to oscillating engines by taking
motion for the slide valve from the piston rod end, or from a suitable bracket
attached to it and arranging the rest of the gear accordingly.
Thirdly. In correcting the errors arising in locomotives and other engines where
the crank axle centre has a moveable bearing, by supporting the centre of the
quadrant link or lever substituting it in a frame or bracket, one end of which
is fixed to the axle box or to the crank shaft, and the other to the frame of the
engine.
Fourthly. In an improved form of slide valve, specially suitable for my improved
gear, by which two or more openings are made into the port at the same time, or it
may be arranged to make one opening for the lead, the others following on the
turn of the crank. By this means a more sudden admission and cut off are
obtained. The valve is similar to the ordinary D valve, but has an opening or
openings completely through it at the part forming "lap," and these are covered on
the back by a plate, which may also be the balancing plate; in this plate openings
are formed to correspond with those in the valve, so that when the lip of the valve
opens for lead these openings in the plate also open. They also open by over
running the valve face at the opposite end, and by connecting them together over
the back of the valve, four ports may be made to open simultaneously, or they may
be arranged to follow each other, or they may be made to open only at one end
by making them over run the valve face or the upper plate only at one end.
Or instead of carrying the ports through the valve and using the back plate
with ports, I only unite the aforesaid ports together across the valve, and by
prolonging the valve face at one end allow the port only at the opposite end to
open. These openings can be multiplied is desirable as far as the practical limits
will allow.
And I treat the exhaust ports in a somewhat similar manner by forming small
ports in the valve face, and carrying them round the back of the exhaust chamber
of the valve into which they open. And in this chamber I support a plate which
(similarly to the plate on the back of the valve) covers these openings, only allowing
them to open at the same time as the ordinary exhaust port.
And in order that my said Invention may be well understood I shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the accompanying Sheets of Drawings, like letters of reference indicating corre-
sponding parts in the respective Figures.

page_text: Figure 1, Sheet 1, is a modification of my valve gear (as described in my said
previous Letters Patent), only in this case, according to the first part of my
Invention, I take motion for the valve from a continuation d of the connecting rod
towards the cylinder end outside the centres. And, as in this case, all the
movements are reversed. I connect the valve spindle e to a point e¹ on the lever a
inside its fulcrum a'. And in case of want of room below the centre of connecting
rod in lieu of producing the lever c from c¹ to c², as shown, and connecting it with
the fixed nut c³, I may make the connection from c¹ to a point inside the crank
centre c³, as shewn by dotted lines. Figure 2, Sheet 1, is another modification of
the gear which consists in separating the two motions of the connecting rod
transferred to the valve by the lever a, and transferring them by distinct con-
nections. Here the lever action is transferred by the lever a, the end of which is
carried to and fro by the loose pin a² on the connecting rod through which it
slides, and the vibration of the centre a' in the quadrant block b is transferred
by the link g, thus avoiding the necessity for correcting the arc of the lever a, as
described in my said former Letters Patent.
Figure 3, Sheet 1, is another modification of the gear where the error of the arc
of the lever A is corrected by carrying its centre on one arm of a small bell crank
lever h, the centre of which slides in the quadrant block b while the other arm k is
attached to a radius link fixed to a point on the quadrant block, the are of the
link being set to be such as to correct at once the arc of the lever a and the arc of
the valve spindle link e, so allowing the employment of a straight slot in the quadrant
block. Or in lieu of placing the bell crank lever h as described and shown, it may
be placed at the valve spindle joint.
Figure 1, Sheet 2, shows the application of my gear to oscillating engines
according to the second part of my Invention, where the connecting rod being
absent I attach a bracket P to the crank end of the piston rod, from which I take
motion for actuating the lever which works the valve. All the other parts of the
gear may be the same as I have already described in my said previous Letters
Patent, the proportions being altered to suit the circumstances.
Figure 2, Sheet 2, shows a slight variation of the above, where a weigh bar
shaft is used to transfer the motion to the two valves, instead of the levers s, s, as
in Figure 1.
Figure 4, Sheet 1, according to the third part of my Invention, shows the
application of my gear to locomotive and such engines as have their crank axles
subject to variations, here the centre 6 of the quadrant block b.is carried on a bar
or frame o, one end of which o' is attached to the axle box through the spring pin,
while the other end o² is attached to the frame of the engine at a distance from
the crank axle centre equal to the length of the connecting rod. The quadrant b
will thus have imparted to it a variation of position equal to that of the point c² on
the connecting rod, from which motion is taken to work the valve, and any error
arising from the variation of position of the axle is thus eliminated, this plan of
correction will equally apply if the motion for the valve be taken from an eccentric
on the crank shaft as from the connecting rod as described.
Figures 3 to 7, Sheet 2, show various modifications of a valve specially arranged
to suit this gear, further utilizing its advantages of the quick opening and closing
of the ports. Figure 3 is a valve substantially of the same general proportions as
to lap as the usual D valve employed for admitting steam to steam engines, with
the addition of a channel or port t passing round the back of it, as in the
"trick" valve, and opening through that part of the valve face which forms the
lap at t¹, t, into this port, other small ports u, u, u, u, pass through the back of
the valve and are covered by a plate w which is stationary, and in which are
corresponding small ports v, v, v, v, which uncover or open the ports u, u, u, u, at
the time that the valve by its movement on the valve face gives the usual opening
of the cylinder port for lead. All the small ports u, u, u, u, delivering into the
port t pass the steam into the main steam port x of the cylinder, the port t also
takes steam by over running the valve face at either end at y, y, and so again

page_text: augments the supply of steam. The exhaust is treated partially in the same
manner by the port z carried round the back of the exhaust chamber and opening
into the main exhaust by the small ports ¹, z¹, and so doubling the port exhaust
opening.
Figure 4 is an ordinary double port valve treated on my plan so far as the
admission of steam is concerned, the same letters having reference to all the parts
as in the valve already described.
Figure 5 is a single port valve treated on my plan but only as far as the release
is concerned.
Figures 6 and 7 are modifications of the plan when both the admission and the
release are treated similarly.
It is obvious with all these valves the usual balancing apparatus for relieving
the pressure of the steam on the back of the valve may be employed, as it is used
in cases where an extra expansion valve is used working on the back of the main
valve.
The supplementary ports passing through the back of the valve or opening by
over running, the valve face may be made to open with the usual main opening
into the port, or they may open after it, or all may open at one end and only at
part at the other, depending upon how it is wished to distribute the steam.
Having now described and particularly ascertained the nature of my Invention,
and the manner in which the same is or may be used or carried into effect, I would
observe in conclusion that I do not claim generally taking movement for the slide
valve of steam engines from the connecting rod, but what I consider novel and
original and therefore claim as my Invention is,―
1. The various modifications of the method of moving the slide valves of steam
and other engines (as already described in my said previous Letters Patent),
substantially as herein before described and illustrated by Figures 1, 2, and 3 of
Sheet 1, and Figures 1 and 2 of Sheet 2 of the accompanying Drawings.
2. The method of correcting the error communicated to valve motions of this
type (whether the motion be taken from the connecting rod or from an eceentric)
by the variation of the centre of the crank axle, substantially as hereinbefore
described and shown by Figure 4, Sheet 1 of the accompanying Drawings.
3. The arrangements of ports in a slide valve and the parts connected therewith,
by which the openings for the admission and release of the steam or other fluid are
multiplied, substantially as hereinbefore described and shown by Figures 3 to 7,
Sheet 2 of the accompanying Drawings.
In witness whereof, I, the said David Joy, have hereunto set my hand and
seal, this Twelfth day of February, in the year of our Lord One thousand
aight hundred and sights one
Witness,
E. T. HUGHES,
123, Chancery Lane,
W.C.
DAVID JOY. (L.S.)