IMPROVEMENTS IN GAUGES OR APPARATUS FOR ASCERTAINING PRESSURE
Year: 1868

page_text: LETTERS PATENT to Henry James Hogg King, of Glasgow, in the
County of Lanark, North Britain, Engineer, for the Invention of
Sealed the 25th May 1869, and dated the 28th November 1868.
PROVISIONAL SPECIFICATION left by the said Henry James Hogg
King at the Office of the Commissioners of Patents, with his
Petition, on the 28th November 1868.
I, HENRY JAMES HOGG KING, of Glasgow, in the County of Lanark,
North Britain, Engineer, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN GAUGES OR APPARATUS FOR ASCERTAINING PRESSURE,"
to be as follows, that is to say:-
This Invention relates to improvements applicable to some of the
guages or apparatus for ascertaining pressure described in the Speci-
fication of certain Letters Patent granted to the present applicant,
John Auchinvole and Alexander Patrick, and dated 16th May 1868,
(No. 1606).

page_text: The present improvements, or some of them, are also applicable to
other kinds of pressure gauges in which a spring or combination of
springs is employed for indicating the pressure, including gauges like
the Bourdon gauge, in which the pressure acting within or without an
elastic vessel indicates the pressure by the change of form it produces.
The present Invention has for its objects increased.
accuracy and
reliability, and a part of it consists principally in providing for checking
the gauges at any time by originally marking a secondary or checking
scale on the dial in addition to the ordinary scale, and by fitting a hook
or ring in connection with the indicating mechanism, on which hook or
ring a predetermined weight may be hung. The parts may be arranged
so that the added weight will act either with or against the pressure,
and the checking scale is marked in accordance with the difference the
weight produces in the indications when the gauge is in order; then if
the elastic element of the gauge or the indicating mechanism gets out
of order, and the weight be applied, the indications by the checking scale
will not agree with those by the ordinary scale without the weight;
whereas if the two indications do agree upon trial the gauge may be
relied upon as being as accurate as when first made.
In one modification of gauge embodying the improvements the fluid,
the pressure of which is to be indicated, is admitted into the upper end
of a tube of a vulcanised rubber having its upper end attached to a fixed
part of the apparatus, whilst the other end is attached to a movable
piece. A helically coiled steel springs surrounds and encloses the rubber
tube, and has its opposite ends secured to the fixed and movable parts
respectively. The pressure acts by extending the tube and spring down-
wards, and a ring or hook is formed on or fixed to the movable picce at
the bottom so that the checking weight may be applied to increase. the
effect of the pressure. The action of the movable piece may be com-
municated to the index by means of a rack and pinion, or of any of the
various arrangements in use for such a purpose.
A second part of the Invention consists in providing for checking
pressure gauges of the kinds herein-before referred to by means of
weights which when applied should move the index to zero (or other
suitable point), the said weights being selected to correspond with the
pressure acting in the gauge. It is preferred to apply such checking
weights through a lever or levers, so that small weights may be used,

page_text: and the weight may be made to correspond with the pressure by being
shifted along the lever.
A third part of the Invention relates to the mercurial pressure gauge
described in the Specification of the earlier Patent herein-before referred
to, and consists in making the glass tube in separate U-shaped pieces
fixed or cemented into a metal head piece formed with suitable internal
communications, and in bending downwards the end of the tube at
which the pressure acts, such downward bend being made to dip into an
enlargement or vessel which will receive and retain matters deposited
from the steam pipe and so prevent their entering the gauge tube.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry James Hogg King in the Great Seal Patent
Office on the 27th May 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
JAMES HOGG KING, of Glasgow, in the County of Lanark, North Britain,
Engineér, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of November, in the
year of our Lord One thousand eight hundred and sixty-eight, in the
thirty-second year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Henry James Hogg King, Her
special licence that I, the said Henry James Hogg King, my executors,
administrators, and assigns, or such others as I, the said Henry James
Hogg King, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN GAUGES OR APPARATUS FOR ASCERTAINING PRESSURE,"
upon the condition (amongst others) that I, the said Henry James
Hogg King, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed in

page_text: the Great Seal Patent Office within six calendar months next and imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Henry James Hogg King, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement in writing, reference being had to the accom-
panying Drawings, that is to say:-
My said Invention relates to improvements applicable to some of the
gauges or apparatus for ascertaining pressure, described in the Specifica-
tion of certain Letters Patent granted to me, to John Auchinvole and
to Alexander Patrick, and dated Sixteenth May, One thousand eight
hundred and sixty-eight (No. 1606).
My present improvements, or some of them, are also applicable to other
kinds of pressure gauges in which a spring or combination of springs is
employed for indicating the pressure, including gauges like the Bourdon
gauge in which the pressure acting within or without an elastic vessel
indicates the pressure by the change of form it produces.
My present Invention has for its objects increased accuracy and
reliability, and a part of it consists principally in providing for checking
the gauges at any time by originally marking a secondary or checking
scale on the dial in addition to the ordinary scale, and by fitting a hook or
ring in connection with the indicating mechanism, on which hook or
ring a predetermined weight may be hung. The parts may be arranged
so that the added weight will act either with or against the pressure,
and the checking scale is marked in accordance with the difference the
weight produces in the indications when the gauge is in order; then if
the elastic element of the gauge, or the indicating mechanism gets out
of order and the weight be applied the indications by the checking scale
will not agree with those by the ordinary scale without the weight;
whereas if the two indications do agree upon trial the gauge may be
relied upon as being as accurate as when first made.
And in order that my said Invention and the manner of performing
the same may be properly understood I have hereunto appended a Sheet
of explanatory Drawings to be herein-after referred to and representing
examples of pressure gauges made with my improvements.
One modification of my improved gauge is shown in Figure 1, 2, and 3,
which are respectively a front view and two vertical sections at right

page_text: angles to each other. The fluid, the pressure of which is to be indicated,
is admitted by an inlet pipe 1 into the upper end of a tube 2 of vulcanised
rubber having its upper end attached to the inlet pipe, and thereby to a
fixed part of the apparatus, whilst the other end is attached to a movable
piece 3; a helically coiled steel spring 4 surrounds and encloses the
rubber tube 2, and has its opposite ends secured to the fixed and movable
parts 1, 3, respectively. The pressure acts by extending the tube 2 and
spring 4 downwards, and a ring (or hook) 5 is fixed to the movable piece 3
at the bottom so that the checking weight may be applied to increase
the effect of the pressure. The action of the movable piece 3 may be
communicated to the index 6 by a rack 7 fixed on the movable piece
and gearing with the pinion 8 on the axle of the index 6, or instead of
this any of the various arrangements in use for such a purpose may be
adopted.
Figure 4 is a front elevation of a pressure gauge in which the pressure
acts within a coiled Bourdon tube 9, and Figure 5 represents the same
gauge with the dial removed. In order to provide for the application of
the checking weight 10 a lever arm 11 is formed or fixed on the toothed
sector 12 by which the movement of the gauge tube 9 is communicated
to the index 6, and to the end of this lever arm there is jointed a hooked
link 13 which projects down through the side of the case; a hook 14 is
fixed to the other side to hang the weight on when not applied in
checking.
A second part of my Invention consists in providing for checking.
pressure gauges of the kinds herein-before described or referred to by
means of weights, which when applied should move the index to zero
(or other suitable point), the said weights being selected to correspond
with the pressure acting in the gauge. Thus in the gauge shown in
Figure 5, in which a weight applied to the lever 11 acts against the
internal pressure, if a weight is applied corresponding to the pressure
indicated it will move the index 6 to zero of the ordinary scale when
the gauge is in accurate working order, but to some other point when
anything is wrong with it. I prefer to apply such checking weights
through a lever or levers, so that small weights may be used, and the
weight may be made to correspond with the pressure indicated by being
shifted along the lever, the lever having a scale marked on it for that
purpose.
my Invention walatos to the compound
merounial

page_text: pressure gauge, described in the Specification of the earlier Patent herein-
before referred to, and consists in making the glass tube in separate
U-shaped pieces fixed or cemented into a metal head piece formed with
suitable internal communications, and in bending downwards the end of
the tube 15 at which the pressure acts, as shown in Figure 6, such down-
ward bend 16 being made to dip into an enlargement or vessel 17 which
will receive and retain matters deposited from the steam pipe, and so
prevent their entering the gauge tube 15.
Having thus particularly described my said Invention, and the
manner in which the same is to be performed, I have to state that I do
not restrict myself to the precise details herein described or delineated;
but that what I believe to be novel and original, and claim as the
Invention secured to me by the herein-before in part recited Letters
Patent is,-
The making of pressure gauges with secondary or checking scales, and
so that checking weights can be applied, substantially as herein-before
described.
And the making of compound mercurial and other pressure gauges
with improved details, substantially such as are herein-before described.
In witness whereof, I, the said Henry James Hogg King, have
hereunto set my hand and seal, this Twenty-sixth day of May, in
the year of our Lord One thousand eight hundred and sixty-nine.
Witness,
BRISTOW HUNT,
Patent Agent and Solicitor,
1, Serle Street, Lincoln's Inn.
H. J. H. KING. (L.S.).