IMPROVEMENTS IN OR APPERTAINING TO THE VALVES OF AIR COMPRESSING ENGINES
Year: 1880

page_text: LETTERS PATENT to Samuel Griffiths, of Wrexham, in the County of Denbigh,
Engineer, for an Invention of "IMPROVEMENTS IN OR APPERTAINING TO THE
VALVES OF AIR COMPRESSING ENGINES."
"
PROVISIONAL SPECIFICATION left by the said Samuel Griffiths at the Office
of the Commissioners of Patents on the 12th June 1880.
SAMUEL GRIFFITHS, of Wrexham, in the County of Denbigh, Engineer.
"IMPROVEMENTS IN OR APPERTAINING TO THE VALVES OF AIR COMPRESSING
ENGINES."
This Invention relates to certain improvements in the valves of air compressing
engines, by which the rapid vibration of the valves against their seats called
chattering" during the passage of air through them is entirely prevented, thus
avoiding the noise and excessive wear in the seatings and faces of such valves.
The means whereby I accomplish these improvements are as follows:-
The inlet and outlet valves are of the mushroom type, and arranged in the usual
manner, either vertically or horizontally.
I lengthen the spindle of each valve in order to continue it through a small
stuffing box containing packing and a gland, which in the case of the inlet valves
are either attached to the valve seatings or upon an independent base, and in the
outlet are contained in or formed on the cover of the chamber surrounding the
valves. I cause the gland to press against the packing by a spiral or other
convenient form of spring, the tension of which, and consequently the pressure
against the packing surrounding the valve spindle, is controlled and regulated by
a thumb screw. The action of the above described arrangement is to restrain the
too free movement of the valve by the adjustable resistance applied to the valve
spindle passing through the packing of the stuffing box, the result being that the
chattering" and excessive wear are entirely prevented.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Samuel Griffiths in the Great Seal Patent Office on the 9th December
1880.
SAMUEL GRIFFITHS, of Wrexham, in the County of Denbigh, Engineer.
"IMPROVEMENTS IN OR APPERTAINING TO THE VALVES OF AIR COMPRESSING
ENGINES."
45
This Invention relates to certain improvements in the valves of air compressing
engines, by which the rapid vibration of the valves against their seats called
chattering" during the passage of air through them is entirely prevented, thus
avoiding the noise and excessive wear in the seatings and faces of such valves.
The means whereby I accomplish these improvements are as follows:-
The inlet and outlet valves are of the mushroom type, and arranged in the usual
manner, either vertically or horizontally. I lengthen the spindle of each valve in
order to continue it through a small stuffing box containing packing and a gland,
which in the case of the inlet valves are either attached to the valve seatings or
upon an independent base, and in the outlet are contained in or formed on the
cover of the chamber surrounding the valves. I cause the gland to press against
the packing by a spiral or other convenient form of spring, the tension of which,.
and consequently the pressure against the valve spindle, is controlled and regulated;
by a thumb screw. The action of the above described arrangement is to restrain
the too free movement of the valve by the adjustable resistance applied to the
valve spindle passing through the packing of the stuffing box, the result being
that the "chattering" and excessive wear are entirely prevented.
DESCRIPTION OF THE DRAWING.
Figure 1 represents a section an air outlet or delivery valve of an air compressing
engine, in which A is the valve; B, the seating; C, the spindle of the valve, which
is lengthed in order to continue it through the stuffing box D containing
packing E; F is the gland which is forced against this packing by screwing down
the thumb screw H against the spiral spring G. The packing in its turn is forced
against the valve spindle with a uniform pressure, which has the effect of restraining
the movement of the valve within certain limits. This restraining action when
applied as above described, and delicately adjusted by regulating the position of
the thumb screw H when the air compressing engine is at work, has the effect of
immediately stopping the "chattering" of the valves against the seat, and instead
of a succession of beats, which rapidly wear and in course of time break the valve,
it is found that but one lift of the valve is made to allow the air to pass through it
for each stroke of the engine, and upon the return of the piston as the inlet valves
open the valve closes gently without any blow being given.
The above describes the nature of my said Invention and the usual manner in
which I perform the same, and in which I claim the application of the means of
controlling the movement of inlet and outlet valves of air compressing engines, as
and for the ends and purposes substantially described above.
In witness whereof, I, the said Samuel Griffiths, have hereto set my hand and
seal, this Seventh day of December, in the year of our Lord 1880.
SAMITEL CRIFFITHS
(701