IMPROVE- MENTS IN VALVES APPLICABLE ESPECIALLY TO THE AIR PUMPS OF STEAM ENGINES
Year: 1885

page_text: "
I, JOHN LIST of 32 Shooters Hill Road, Blackheath in the County of Kent,
Mechanical Engineer do hereby declare the nature of my invention for IMPROVE-
MENTS IN VALVES APPLICABLE ESPECIALLY TO THE AIR PUMPS OF STEAM ENGINES
to be as follows:-
"
This invention bas for its object improvements in valves applicable especially to
the air pumps of steam engines.
For this purpose I make the valve of a thin disc of sheet metal fitting over a
circular grid that forms the valve face. I also as heretofore fix the lift of this disc
by a guard or plate held in place by a central stud or bolt.
.
In place however of as usual making the body of the stud or bolt the central
guide for the disc in its up and down motion, I make ribs or guides on the lower
side of the guard which ribs are equally spaced around the stud and form between
its outer surface and the edge of the central circular hole in the disc vertical
channels which lead up through the plate or guard.
The result of the above arrangement is that when the disc begins to lift passages
are opened for fluid not only outwards from the periphery of the disc but also
centrally through the above described channels around the stud.
In this way the valve or disc will rise and fall with little wear on the guides or
ribs and will afford a large area of outlet with a limited lift.
CARPMAEL & Co.,
Agents for the Applicant.

page_text: Improvements in Valves, Applicable Especially to the Air Pumps
of Steam Engines.
I JOHN LIST of 32 Shooters Hill Road Blackheath in the County of Kent
Mechanical Engineer, do hereby declare the nature of my invention for IMPROVE-
MENTS IN VALVES APPLICABLE ESPECIALLY TO THE AIR PUMPS OF STEAM ENGINES,
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
My improvements consist in applying to light sheet metal lifting valves which
open and close by the pressure of the fluid, certain particular forms of centre
opening which present passages for flow not only outwards from the periphery, but
also centrally upwards through the guard or plate regulating the lift. I also use
such forms of centre opening with valves consisting of discs of wood, vulcanized
indiarubber, vulcanized fibre, or other suitable non metallic substance, the thickness
of the valve varying with the material used.
In other modifications I use certain special forms of light flanged sheet metal
valves with a view to securing greater rigidity and freedom from change of form
consequent on the continual beating of the valves on the grids and guards.
In order that my invention may be better understood I append a sheet of
drawings to which reference is made.
In these drawings the same figures are used to indicate the same parts where
repeated.
Fig. 1. is a section of one form of valve and guard. The valve 14 consists of a
thin disc of rolled sheet metal, preferably brass or Muntz metal, but it may for
some purposes be made of wrot, or cast iron, or steel, cast brass or other alloy, or
of wood vulcanized rubber or other rigid non-metallic substance.
The guard 11 which may be of cast iron brass or other alloy is held in place as
usual by a bolt or stud 10 to the valve face or grid 12.
This guard has formed upon its under surface wings or guides 16 upon which
the valve 14 slides up and down.
When the valve lifts, the guides 16 form passages 17 upwards through the
guard, thus forming a double opening valve.
Fig. 2. shows a half plan of the guard and half section of the guides.
Fig. 3. shows another modification, in which the valve 14 consists of a disc of rolled
sheet metal dished by spinning stamping or pressing to the form shown. The object
being to obtain a larger wearing surface for the valve on the guides together with
greater rigidity. The wings or guides 16 are in this case formed on the grid 12,
and the central passages 17 are formed between the inner flange of the valve 14,
and the outer surface of a boss on the grid into which the stud 10 is screwed.
These passages are of a curved form to direct the flow upwards without shock.
Fig. 4. shows a half plan of the guard 11, and of the guides 16.
Fig. 5. sbows in section a modification in which the guides 16 are formed on the
stud or bolt 10. The valve being of the same form as in Fig. 1.
Fig. 6 shows in section a modification in which another form of dished valve 14
is used. In this case the lower edges of the flanges form parts of the bearing

page_text: surfaces on the grating 12. The central passages are in this case formed entirely
in the guard 11.
Fig. 7. shows a modification in which the guides 16 are formed separate from
the guard 11 and are held in place on the stud 10 by the guard 11 and the nut on
the top. The valve in this case is of the same form as in Figs. 1 and 5.
Fig. 8 shows a modification of guard in which the centre stud is dispensed with,
and three smaller studs 13 are adapted and spaced round the periphery of the
guard. The valve 14 is in this case of the same form as in Figs. 1, 5 and 7. This
form of guard admits of large centre passages and is of a strong form.
Fig. 9. shows a half plan of the guard 11.
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
1. The particular forms of centre openings in guards of pump valves to form
double opening valves, constructed substantially as described in this specification
and illustrated by the accompanying drawings.
2. The application of guards having such forms of centre opening to valves of
light sheet metal, or to thicker valves of cast forged or rolled metal, or of wood,
vulcanized indiarubber vulcanized fibre or other rigid non-metallic substance.
3. The particular forms of dished or flanged valves illustrated by Figs. 3 and 6
whether used in combination with the particular form of guard there shown or in
combination with any other form of guard or central guiding piece.
Dated this twenty-first day of January 1886