Improvements in Pressure Reducing Valves.
Year: 1891

page_text: Date of Application, 9th June, 1891-Accepted, 1st Aug., 1891
COMPLETE SPECIFICATION.
Improvements in Pressure Reducing Valves.
I, GUSTAV KRAISS of 8 Weissenburgstrasse, Stuttgart, in the Empire of
Germany, Manufacturer, 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:—
This invention relates to pressure reducing valves and has for its purpose to
obviate various inconveniences attached to similar devices hitherto known.
Almost all constructions of pressure reducing valves are apt to become so far
untight after short use that a rather strong pressure on the diaphragm plate is
required for effecting a complete closing of the valves. Consequently a considerable
reduction of pressure is rendered difficult or frequently even impossible. Moreover
most of the valve arrangements hitherto known have the disadvantage that the
mechanism effecting the opening or closing works too slowly owing to unsuitable
and complicated disposition of the parts, that is to say great differences of pressure
are required for causing the opening or closing whereby a continuous inequality of
the reduced pressure ensues. In most cases the untight closing is caused by the
displacing of the sliding valve being effected by an inclined surface acting direct on
the said valve or sliding up and down at the end surface thercof. As the valve
plug must slide with facility in its box, the latter is always made a little larger and
in working, it is more and more widened by the continuous opening and closing of
the valve plug. The to-and-fro movement of the inclined surface at the valve end
presses the valve at one end to the one lower side of the valve box and at
the closing end to the other upper side. The consequence is a slight sliding
to-and-fro movement of the valve plug at the valve seat, which movement, though
slight, is sufficient to soon effect unti rhtness. A further drawback causing the
slow working of the valve and thereby an irregular reduction pressure results from
the circumstance that the slide piece, which is slanted on one side and opens and
closes the valve plug by its inclined surface when sliding up and down—cannot move
during sliding, in the direction of the valve motion, and thereby causes a strong
friction, which must be overcome prior to a valve motion taking place.
Referring to the accompanying drawing
Fig. 1 is a vertical section and
Fig. 2 a horizontal section of the improved arrangement, in which the said
inconveniences are intended to be removed by providing the sliding piece a in its
middle part a' with a hard steel wedge b.so lodged therein as to slide in the direction
of movement of the valve plug.and acting with an inclined surface through a long
pressing rod d on valve plug e while it can be regulated by screw c which presses
upon the slightly bevelled opposite surface of the wedge and receives the valve
reaction pressure. The axis of screw c and that of valve e lie in one straight line
so that a direct receiving of pressure takes place. Thereby the guide pivots a a of
the slide piece, which slide in the bottom B of the valve and in the manometer
screw o may be made very thin. The wedge is made hollow on the surface acting
against the pressing rod d in order to give greater working surface for the latter.
Owing to this arrangement the friction of wedge bat screw c and rod d is very
slight and the action of the valve is simultaneous with the slightest alterations of
pressure. By the application of a spindle d which is rounded off on the surface
lying towards the valve plug e in the same manner as the latter, the pressure
produced by the wedge is transmitted only to the centre of this rounded surface of
the plug, that is to say the valve is always pressed in its axis against the valve
seat. The valve seat which has a conic shape the same as the valve, is made
from copper or caoutchouc and is held fast by means of screw g, which on its own

page_text: part is protected from getting loose by screw
high pressure reservoir.
and connected by nut i with the
The slide piece a is secured by means of plate p-and screwn to the diaphragm M
and the degree of reduction of pressure is produced by the known regulating
device C. is the discharge cock for the reduction pressure and the safety
valve.
All parts can be easily replaced; and, the wear and tear of the sliding) parts
is very slight..
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :
In pressure reduction valves the opening and closing of the valve plug by means
of a steel wedge so lodged in a slide piece a as to slide in the direction of
the movement of the valve plug and acting with its one, more slanted surface against
a long pressing rod d thereby displacing the valve plug precisely in its axis, while
the reaction pressure is transmitted by the slightly slanted surface of the wedge to
a set screw c the axis of which coincides with that of the valve plug substantially
as and for the purpose set forth.
Dated this 9th day of June 1801
GUSTAV KRAISS.
By Huelser & Co.,
Temple Chambers, London, his Agents.