Improvements in Prismatic Piston Valves.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in Prismatic Piston Valves.
I, JAMES JENNINGS CAMPBELL, of No. 67, Warwick Road, Earls Court, in the
County of Middlesex, Engineer, do hereby declare the nature of this invention
to be as follows:-
-
My invention relates to prismatic piston valves of the type described in the
Specification of my Patent dated 26th May 1896 No. 11438.
According to my present invention I
valve in such
that it is
manner
The parts
or
construct a prismatic piston
divided longitudinally into several
sections.
parts or
sections are pressed apart by springs
of the chamber or
which
casing in
against the corresponding faces
the valve works or against the faces of a liner which is mounted in the
chamber. If there be a liner it is conveniently made outwardly of cylindrical
form to facilitate fitting into the casing, but this is not essential. The sections
of the valve are secured to or mounted on the valve rod, (which passes through
their centre) between two large washers or other suitable devices; and arrangement
is made for jamming them between these washers from the outside of the chamber
or casing, making practically a solid valve. When it is desired to take up any
wear that may have occurred, it is only necessary to slack the fastening which
jams the valve sections together, thus freeing the said sections and allowing
the springs to set them up to the faces of the liner or chamber. On again tighten-
ing the washers the valve becomes practically solid as before. This operation
may be performed as ofien as is considered advisable.
1004
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.
Improvements in ITISMATIC
1, JAMES JENNINGS CAMPBELL, formerly of No. 67, Warwick Road, Earls Court,
in the County of Middlesex, but now of No. 155, Fenchurch Street, in the City
of London, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement:-
My invention relates to prismatic piston valves of the type described in the
Specification of my Patent dated 26th May 1896 No. 11438.
According
to
my present invention
I construct
a prismatic piston

page_text: valve in
such manner that it is divided longitudinally into several
parts or sections. The parts or sections. are pressed apart by springs
against the corresponding faces of the chamber or casing in which
the valve works or against the faces of a 'liner which is mounted in the
chamber. 'If there be a liner it is conveniently made outwardly of cylindrical
form to facilitate fitting into the casing, but this is not essential. The sections
of the valve are secured to or mounted on the valve rod (which passes through
their centre) between two large washers or other suitable devices; and arrangement
is made for jamming them between these washers from the outside of the chamber
or casing, making practically a solid valve. When it is desired to take up any
wear that may have occurred, it is only necessary to slacken the fastening which
jams the valve sections together, thus freeing the said sections and allowing
the springs to set them up to the faces of the liner or chamber. On again tighten-
ing the washers the valve becomes practically solid as before. This operation
may be performed as often as is considered advisable.
=
In order that my invention may be more easily understood I will proceed to
describe the same with reference to the accompanying drawings of which
Figure 1 is a longitudinal section of a single ported prismatic piston valve
chamber and liner.
'
Figure 2 is a similar view but at right angles to the section shown in Figure 1
and shewing also the valve within the chamber.
Figure 3 is a cross section and
Figure 4 is a section on the line GH Figure 3.
Figure 5 is a longitudinal view of a double ported valve partly in section and
Figure 6 is an end view partly in section.
centre)
Referring to Figures 2 and 3 it will be observed that the prismatic piston
valve is divided longitudinally into three parts A¹ A3 and A³. These parts or
sections are pressed apart by springs H mounted in recesses B B B³ in bosses
therein (see also Figure 4) against the corresponding faces of the chamber or
casing in which the valve works or as shewn against the faces of a liner C which
is mounted in the casing D. If there be a liner it is as shown made outwardly
of cylindrical form to facilitate fitting into the casing but this is
not essential. The sections A¹ A and A³ are secured to or mounted
on the valve rod E (which passes through their common
between two large washers E¹ and E2 Figure 1. The washer E¹
is practically a fixture on the valve rod while the washer E is conveniently
provided with a long neck or sleeve E³ capable of sliding on the rod and this
sleeve is turned to permit of its passing through the stuffing box F. By means
of nuts E E or other equivalent device on the rod the valve sections A' A² and A³
can from the outside of the chamber be jammed tight between the washers E' E
thus forming a practically solid valve working steam tight in the liner C. When
it is desired to take up any wear that may have occurred, it is only necessary
to slacken the nuts EE which jam the valve sections together, thus freeing the
said sections and allowing the springs B 1 and B3 to set them up to the faces
of the liner or chamber. It is apparent that instead of their being only one spring
between each two sections, there may be two or more in order to ensure a better
fit between the valve sections and the walls of the casing or the liner C. On
again tightening the nuts E E and consequently jamming the valve sections A¹
A and A³ betweens the washers E¹ and E, the valve becomes practically solid
as before and this operation may be performed as often as is considered advisable.
If desired the bar A+ (see Figure 3) in each valve section and the bars C¹ in the
liner C may be dispensed with. Instead of the nuts E E5 a cotter or other suitable
fastening device may be employed.
Figures 5 and 6 represent a double ported hexagon piston valve constructed
according to my invention the lower left hand part of Figure 5 being a section
on the line a b Figure 6 and the lower right hand part of Figure 5 being a section
on the line c d Figure 6.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
1. A prismatic or polygonal hollow piston valve formed with ports and made
in sections normally jammed between two washers or shoulders on the valve rod
and provided with springs for forcing the sections apart when the sections are
released for the purpose of taking up the wear substantially as set forth.
2. The constructions of valves substantially as described and shewn on the
drawing whereby facility is given for taking up the wear without opening the
valve chest.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.