AN IMPROVEMENT IN SLIDE VALVES FOR LESSENING THE FRICTION BETWEEN SUCH VALVES AND THEIR SEATS
Year: 1884

page_text: I, JAMES WALL O'TOOLE, of Cork, Ireland, Mechanical Engineer, do hereby
declare the nature of the said invention for "AN IMPROVEMENT IN SLIDE VALVES
FOR LESSENING THE FRICTION BETWEEN SUCH VALVES AND THEIR SEATS" to be
as follows:
"
This Invention has reference to improved means for lessening..the friction
between a slide valve and its seat, resulting from the pressure of steam or other
fluids.
In carrying out my said Invention I form two or more chambers, of, convenient
size. and form, in suitable parts of the slide valve, and into these chambers I cause
steam or other fluid to flow from the steam. chest through perforations or apertures
formed on the upper side of the slide valve. Between the said chambers and the
valve face perforations or apertures are also formed of an area to be determined by
calculation according to the dimensions of the slide, valve and other conditions, the
object being to cause the steam to flow from the aforesaid, chambers through these
last described perforations or apertures in just sufficient volume to strike; or
impinge against, the valve seat without at the same time escaping from the said
chambers. By this means a certain buoyancy will be imparted to the slide valve
which will exhibit a tendency to float or slide, with little or no friction on its seat.
4: Thated this Wighteenth day of January 1884.

page_text: I, JAMES WALL O'TOOLE, of Cork, Ireland, Mechanical Engineer, do hereby
declare the nature of my invention for AN IMPROVEMENT IN SLIDE VALVES FOR
LESSENING THE FRICTION BETWEEN SUCH VALVES AND THEIR SEATS, and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
This invention has reference to improved means for lessening the friction
between a slide-valve and its seat, resulting from the pressure of steam or other
fluids.
In carrying out my said invention I form two or more chambers of convenient
size and form in suitable parts of the slide-valve, and into these chambers I cause
steam or other fluid to flow through perforations or apertures formed on the upper
side of the slide-valve. Between the said chambers and the valve face perforations
or apertures are also formed, of an area to be determined by calculation, according
to the dimensions of the slide-valve and other conditions, the object being to
cause the steam to flow from the aforesaid chambers through these last-described
perforations or apertures in just sufficient volume to strike or impinge against the
valve-seat without at the same time escaping from the said chambers. By this
means a certain buoyancy will be imparted to the slide-valve which will exhibit a
tendency to float or slide, with little or no friction on its seat..,
. ".
In order that my said invention may be more readily understood and carried
into practice, I will describe the accompanying drawings:-Fig. 1 represents
section of slide-valve and seat, spindle and stuffing-box, and gland; also connexion
between spindle and valve, in elevation; fig 2 is a plan of fig 1; fig 3 is a section
on line x. x. fig 2; fig 4 is a plan of face of valve showing perforations.
.
.
+
Similar letters refer to similar parts in the several views:-C represents a branch
pipe by which steam or other fluid under pressure may be conducted into the
gland.D which is closed' at the end and forms a reservoir for the steam or other
fluid. From D the steam passes through the core E, formed by preference in the
valve-spindle G, and from this core into the nipple H which is screwed into the
spindle G and connects the hollow bent rod J to the nipple K. This nipple is
screwed into the valve as shown by the dotted lines. The nipples H and K with
the bent hollow rod J serve to connect the core E with the core L shown on fig 3
by dotted lines, and also connects the upper side of the chambers M with the core E.
The perforations or apertures in face of valve are shown on figs 3 and 4 at c c c,
and communicate with the chambers as already stated. According to my invention
it will be obvious that if steam or other fluid be caused to flow into these chambers
under pressure at least equal to that in the chest in which the valve is working,
and if the perforations or apertures formed in face of the valve have an area of,
say, from to of a square inch, and one perforation of said area for each
square inch contained in the slide-valve face (that is to say, if the area of slide-
100 square inches, 100 perforations will suffice), the steam or other fluid
flowing from the chambers through these perforations will strike or impinge
against the valve seat with sufficient force to lessen the friction between the valve
and its seat, while at the same time the steam will not escape from the chambers.
valve =

page_text: Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is :-
The use and application of slide-valves, in the construction of which chambers
and perforations or apertures are introduced, in the manner and for the
purpose substantially as described and set forth.
J. K. FAHIE & SON,
Agents for Applicant,
10, Leinster St., Dublin.
HOOT
TO CON TATSU DAR