CERTAIN IMPROVEMENTS IN THE ARRANGEMENTS FOR WORKING THE SLIDE VALVE FOR THE INDUCTION AND EDUCTION OF FLUIDS
Year: 1852

page_text: LETTERS PATENT to Archibald Slate, of Woodside Iron Works,
near Dudley, in the County of Worcester, Civil Engineer, for the
Invention of "CERTAIN IMPROVEMENTS IN THE ARRANGEMENTS FOR
WORKING THE SLIDE VALVE FOR THE INDUCTION AND EDUCTION OF
FLUIDS."
Scaled the 20th April 1853, and dated the 17th December 1852.
PROVISIONAL SPECIFICATION left by the said Archibald Slate
at the Office of the Commissioners of Patents, with his Petition,
on the 17th December 1852.
I, ARCHIBALD SLATE, of Woodside Iron Works, near Dudley, in the
County of Worcester, Civil Engineer, do hereby declare the nature of
my said Invention of "CERTAIN IMPROVEMENTS IN THE ARRANGEMENTS FOR
WORKING THE SLIDE VALVE FOR THE INDUCTION AND EDUCTION OF FLUIDS"
to be as follows, reference being had to the Drawings annexed:-
Into the connecting link between the link motion and the slide I
insert a series of levers and slides, side and front elevations of which
arrangements are shewn in the Drawings, Figs. 1, and 2. I first fix
the lever A, upon the shaft or centre B; in a slot in this lever I place

page_text: two slides C, C; in the same frame D, I place two other levers E, E,
and F; I then correct the eccentric rod G, to the levers E, E, by the
joints H, and next connect the valve rod I, to the lever F, by the pin J,
which pin also passes through one pair of slides in the slot of the
lever A. I then pass the pin K., through levers e, e, and through the
second slide in the slot in the lever A, which completes the arrangement
of levers aud slides.
On motion being applied to the valve rod C, the levers e, e, through
the second slide in the slot, give motion to the lever A, and the
lever A, through the first slide in the slot gives motion to the lever f
and, at the same time, to the valve rod; the valve rod lever f, and the
first slide being connected together by the same pin.
All the motion being passed through the lever A, the result aimed at
is accomplished, namely, the causing the valve to travel quicker at the
ends of its stroke and slower in the middle than what is due to the
simple motion of the eccentric. This varying motion is attained by
causing the centres of action in the lever A, to change their position, so
that the throw of the eccentric running the same it acts upon the valve
with a longer leverage, and, consequently, a slower motion at the
middle of its stroke, and with a shorter leverage, and, consequently,
a quicker motion at the end of its stroke. The same results may be
attained by inserting a lever and slide into the link motion, as shewn
in Figure 3.
Supposing the valve to be at the end of its stroke, as shewn in
Fig. 3, and the motion to come from the leading eccentric D, and
the vibration of the link to take place on the centre C, of the sus-
pending rod B, the slide E, to. which are attached the valve rod E, and
the rocking lever G, in the course of the travel of the slide the
..distance between the centre of the eccentric rod D, and the centre of
the vibration C, is shortened as much as the versed sinc of the arc of
the vibration of the lever G, and this shortening reaching its maximum
in the middle of the stroke, it follows that the same results. are attained
as before described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Archibald Slate in the Great Seal Patent Office,
on the 15th June 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
ARCHIBALD SLATE, of Woodside Iron Works, near Dudley, in the
County of Worcester, Civil Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria,
by Her Royal Letters Patent, under the Great Seal of Great Britain
and Ireland, bearing date at Westminster, the Seventeenth day of
December, One thousand eight hundred and fifty-two, in the sixteenth
year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Archibald Slate, my executors,
administrators, and assigns, Her especial license, full power, sole
privilege, and authority that I, the said Archibald Slate, my executors,
administrators, and assigns, or such others as I, the said Archibald
Slate, my executors, administrators, or assigns, should at any time
agree with, and no others, from time to time and at all times during
the term of years therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, my Invention
of "IMPROVEMENTS IN THE ARRANGEMENTS FOR WORKING
THE SLIDE
VALVE FOR THE INDUCTION AND EDUCTION OF FLUIDS," in which said
Letters Patent is contained a proviso that I, the said Archibald Slate,
should cause a particular description of the nature of my said In-.
vention, and in what manner the same is to be performed, by an
instrument in writing under my hand and seal, to be inrolled in Her
Majesty's High Court of Chancery within six calendar months next
and immediately after the date of the said in part recited Letters
Patent, as in and by the same, reference being thereunto had, will more
fully appear.
NOW KNOW YE, that in compliance with the said proviso, I,
the said Archibald Slate, do hereby declare the nature of my, said.

page_text: Invention, and in what manner the same is to be performed,
to be particularly.described and ascertained in and by the following
statement thereof, reference being had to the Drawings. hereunto
annexed, and to the figures and letters marked thereon (that is
to say):
The nature of my Invention of improvements in the arrangements
for working the slidé valve for the induction and eduction of fluids
consists in making the valve move at a variable speed, and still retain
the perfect eccentric and link motion, if preferred, and I proceed to
lescribe the arrangements of levers and slides by which it is to be
accomplished. In the eccentric rod or connecting link I insert the
series of lovers and slides, as shewn partly in section and partly in
ulevation in the Drawings hereunto annexed.
Figure 1, shews, partly in section and partly in elevation, a front
view of one arrangement of such levers and slides; and Figure 2, shews,
partly in section and partly in elevation, a side view of the same
arrangement.
.
A portion of the eccentric rod is divided into three parts: in Figure
1, a, a, a; in Figure 2, a, a; and is also shewn in a reduced plan
and elevation in Figures 3, and 4. The centre division is joined
or works on to the centre pin B, in the double levers C, C, moving
on the centre d, and the two outside of the three divisions of the
eccentric rod are jointed on the centres e, e, on the double lever f, f.
which moves on its axis G, G; to the extremity of the lever e, e,
is jointed a link H, to the other end of which link is jointed the valve
rod I, and on the same end are slides J, J, which move in the double
lever f. f.
On motion being applied to the valve rod a, a, a, the levers c, c, and
f, f, are moved into the position shewn by the blue centre lines in
Figure 2, and as in the process of motion the angle of the two levers
increases, the centre i, of the valve rod is pulled up the grooves in the
double lever f, f, in which the slides J, J, move and increases in
the comparative velocity of its motion, in the same ratio as its distance
increases from the centre g, g, on which the double lever f, f, vibrates.

page_text: The relative variation of velocity in the movement on the valve may be
altered by the action of the screw handle K, shewn in Figures 1, and 2,
which alters the distance between the centres d, and g, and varies or
regulates the amount of expansion which may be desirable in the
cylinder.
.
Figures 5, 6, 7, and 8, show four similar views of another arrange-
ment of levers and slides by which a like effect may be produced.
The eccentric rod a, in this case is not divided, but is jointed on to
the centre B, in the double lever c, c, moving on the centre d; to-the
extremity of the lever c, c, is jointed by the pin e, the sliding frame if, f,
which moves in grooves in the double lever g, g, vibrating on its axis
H, H; and in the sliding frame f. f. is also jointed the valve rod i, by
the pin j.
On motion being applied to these arrangements the two levers c, c,
and g, 9, are caused to vibrate on their respective axis; the levers
c, c, and g. 9, are caused to move into the position shewn by the blue
centre lines in Figure 6, and the same results follow as described with
reference in Figures 1, 2, 3, and 4.
Figures 9, and 10, shew an arrangement of levers and slides by
which the same principle may be applied to a case in which the
eccentric acts upon what is technically known as a rocking or weiper
shaft, communicating motion to the valve. In Figures 9, and 10, is
the shaft b, b, the lever communicating motion to the valve c, c, the
sliding frame moving on the centre D, and sliding through the vibrating
centres e, e, and having the valve rod connected to it by the joints f, f,
moving on the centres g, g.
When motion is applied to the shaft similar results are obtained,
the levers taking the positions shewn by the blue lines in Figure 10.
Having now described the nature of my said Invention, and in what
manner the same is to be performed, I hereby declare that I claim the
arrangements herein-before described for causing the valve to move at
a variable speed, thereby affording a facility for cutting off the steam
more rapidly than can be done by an ordinary eccentric, and retaining
the steam in the cylinder, so as to allow it to give out the full extent

page_text: of its expansive power before the opening of the exhaust port allows it
to escape.
In witness whereof, I, the said Archibald Slate, have hereunto set
my hand and seal, this Ninth day of June, One thousand eight
hundred and fifty-three.
ARCHIBALD (L.S.) SLATE.
Taken and acknowledged by the said Archi-
bald Slate at N° 30, Waterloo Street,
Birmingham, in the County of Warwick, the
Ninth day of June, One thousand eight
hundred and fifty-three,
Before me,
W. JNO. BEALE,
A Master Extraordinary in Chancery.