IMPROVEMENTS IN VALVES OR APPARATUS FOR REDUCING OR REGULATING PRESSURE
Year: 1878

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for the Invention of "IMPROVEMENTS IN
VALVES OR APPARATUS FOR REDUCING OR REGULATING PRESSURE. A com-
munication from abroad by C. Louis Strube, of Backan, near Magdeburg,
in the Empire of Germany
Sealed the 21st May 1878, and dated the 5th February 1878.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents on the 5th February 1878.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN VALVES OR APPARATUS FOR REDUCING OR
REGULATING PRESSURE." A communication from abroad by C. Louis Strube, of
Backan, near Magdeburg, in the Empire of Germany.
This Invention relates to valves intended chiefly for reducing and regulating the
high tension of steam in order to employ it in digesters, heating apparatus, and the
like, but which are also adapted for gas and liquids.
According to one mode of carrying out this Invention, the reducing valve consists
chiefly of a body closed above by a plate, and a circular membrane of a cup valve
and a weighted lever.
The valve seat is screwed on to the inner end of the outlet branch, which is bent
upwards. The contact surface between the valve and its seat is formed by a conical
plane.
A plate loaded by a weight, which is movable on a lever, is closely fastened to
the valve.
As above indicated a flexible undulated membrane, made of any suitable material,
is spread over the unoccupied circular space between the plate and the circular
cover.
The space above the membrane and beneath the projecting edges of the plate and
cover is filled by a number of metallic sectors or small bars, which form together an
obtuse cone tapered to above, or to beneath, or form a plain plate, according to the
[Price 6d1

page_text: position of the plate. These small bars are placed loosely one against another,
covering well the whole membrane, but permitting without difficulty the motions
of the plate.
The bars operate after the manner of single armed levers, movable at the edge of
the cover, and, taking up the pressure of the membrane, transfer it to the plate.
This arrangement admits of the material of which the membranes are composed
being greatly varied, and the application of a caoutchouc sheet, protected by water
of condensation, is rendered unnecessary.
The membrane if made of any metal should be thin, and consequently flexible.
The whole pressure exercised on the plate, both directly by the steam & by
means of the small bars, is always equal to the pressure which the same steam
would exercise on a circle of a determined diameter. By the solution of a simple
integral the proportions existing between the said diameter and the outer and inner
diameters of the compound circle will be found.
In the apparatus the dimensions are so chosen that the total pressure exercised on
the plate is equal to that pressure with which the live (not reduced) steam presses
down the valve, that is to say, that the valve is wholly relieved of the pressure of
the entering steam. Consequently the valve remains only under the pressure of the
reduced steam and the weighted lever.
If in the outlet pipe and in the inner space of the valve there exists exactly that
pressure which corresponds to the weight on the lever, then the valve can be in
equilibrium in every position. By a small increase of the reduced pressure the
valve closes; by lessening the pressure the valve opens in proportion.
According to another mode of carrying out this Invention the apparatus is con-
structed generally, as herein-before described, but the valve and body are modified
in the following manner, viz. -The valve consists of a plain plate, with its border
or edge bent upwards, of the valve rod, and of several radial wings, which serve as
guides in the valve seat inserted from beneath.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the 24th
July 1878.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN VALVES OR APPARATUS FOR REDUCING OR
REGULATING PRESSURE." A communication from abroad by C. Louis Strube, of
Backan, near Magdeburg, in the Empire of Germany.
The said Invention relates to valves intended chiefly for reducing and regulating
the high tension of steam in order to employ it in digesters and heating apparatus,
but which are also adapted for gas and liquids.
The two Figures on the accompanying Sheet of Drawings illustrate respectively
two modifications of apparatus constructed according to the said Invention.
The reducing valve shewn in Figure 1 consists chiefly of a body A closed above
by the plate B, and the diaphragm c of a cup valve F, and a weighted lever G ; D is
the inlet, and E the outlet passage for the steam.
The valve seat H is screwed on to the upwardly bent inner end of the outlet
branch E; the contact surface between the valve F and its seat H is formed by
the conical plane i.
The plate B which is loaded with a weight G¹ movable on the lever G is closely
secured to the valve F.
As above indicated a flexible corrugated diaphragm c made of any suitable
material is spread over the unoccupied circular space between the plate B and the
circular cover K..
The space above the diaphragm and beneath the projecting edges of the plate B
and cover K is filled by a number of metallic segments of a ring or small bars m,
which form together either an obtuse cone, the apex of which is above, or below, or
form a plane ring, according as the plate B is in its elevated, depressed, or inter-
mediate position. These small bars are placed loosely side by side, covering the
whole diaphragm, but admitting of the free motions of the plate B.
The bars operate after the manner of single armed levers, movable at the edge of
the cover K, and taking up the pressure of the diaphragm transfer it to the plate B.
This arrangement admits of the material of which the diaphragms are composed
being greatly varied, and the application of a caoutchouc sheet, protected by water
of condensation, is rendered unnecessary.
The diaphragm if made of metal should be thin, and consequently flexible.
The whole pressure exercised on the plate B, both directly by the steam and by
means of the small bars, is always equal, though the pressure which the same steam
would exercised on a circle of a determined diameter. By the solution of a simple
integral the proportion existing between the said diameter and the outer and inner
diameters of the compound circle will be found.
In the apparatus the dimensions are so chosen that the total pressure exercised
on the plate B is equal to the pressure with which the live (not reduced) steam
presses down the valve, that is to say, that the valve is wholly relieved of the
pressure of the entering steam. Consequently the valve remains only under the
pressure of the reduced steam and the weighted lever.
If there exists in the outlet pipe and in the inner space of the valve exactly that
pressure which corresponds to the weight of the lever, then the valve can be in
equilibrium in every position. By a small increase of the reduced pressure the valve
closes; by lessening the pressure the valve opens in proportion. By means of this
arrangement the necessity for the use of a double seated valve is obviated.
The reducing valve shewn in Figure 2 differs only in the construction of the
valve proper and the body from the apparatus herein-before described.
The valve F consists of a disc, with its border or edge bent upwards of the valve
rod and of several radial wings, which serve as guides in the valve seat H, inserted

page_text: from beneath, as will be well understood from an inspection of the Drawing without
further explanation.
This apparatus operates in a similar manner to the apparatus herein-before
described with reference to Figure 1.
Having now described and particularly ascertained the nature of the said
Invention and the manner in which the same is or may be used or carried into
effect, I will observe in conclusion that what I consider to be novel and original,
and therefore claim as the Invention secured to me by the herein-before in part
recited Letters Patent is,-
1st. The employment of segments or small bars, covering the diaphragm, and
taking up the pressure exercised on the latter, this arrangement admitting of the
use of a very thin and flexible diaphragm of any suitable material, substantially as
herein-before described.
2nd. The application of any suitable single seated valve on which the live (not
reduced) steam exercises the same pressure as on the diaphragm, and effecting thus
the opening and closing of the valve only by the reduced steam, whereby the
necessity for the use of a double-seated valve is obviated, substantially as herein-
before described.
In witness whereof, I, the said John Henry Johnson, have to this my
Specification set my hand and seal, this Twenty-fourth day of July, One
thousand eight hundred and seventy-eight.
J. HENRY JOHNSON. (L.S.)