IMPROVEMENTS IN THE CONSTRUCTION OF PRESSURE GAUGES
Year: 1860

page_text: LETTERS PATENT to Alfred Vincent Newton, of the Office for Patents,
66, Chancery Lane, in the County of Middlesex, Mechanical Draughts-
man, for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF
PRESSURE GAUGES."-A communication from abroad by T. Wilson Lane,
of Meredith, New Hampshire, United States of America.
Sealed the 29th June 1860, and dated the 5th April 1860.
PROVISIONAL SPECIFICATION left by the said Alfred Vincent Newton
at the Office of the Commissioners of Patents, with his Petition, on
the 5th April 1860.
I, ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery
Lane, in the County of Middlesex, Mechanical Draughtsman, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE CON-
STRUCTION OF PRESSURE GAUGES," to be as follows:-
This Invention relates to certain improvements in the construction of the
Bourdon pressure gauge, the object being to remedy certain defects which have
detracted from its merits under certain circumstances. Thus, for example,
water accumulating therein has on exposure to a low temperature, frozen and
burst the gauge; again, when applied to locomotive engines, they receive a
tremulous motion, and give uncertain indications through the tremulous move-
ment of the index hand. To remove these objections the pipes through which
the pressure within the boiler is transmitted to the gauge is joined with the indi-
cating tube at a point between the two ends of the tube, and the ends are bent
upwards upon opposite sides of a vertical line passing through the junction
with the pipe, whereby the tube will discharge all water condensed in it down
the supply pipe, and it will be rendered less sensitive to the effects of the

page_text: vertical shocks to which the locomotive is subjected. The length of tube
least affected by these shocks is nearly a complete circle, to which, at a point
midway between its ends, the pipe from the boiler is joined, the two ends of
the tube approaching each other at the top, where they are connected with
the lever which transmits their motion to the index hand. By this con-
struction the horizontal vibrations of the tube are also materially lessened.
To prevent the transmission of the horizontal vibrations and to diminish as
far as practicable their influence upon the index hand, the two portions of
the indicating tube are bent symmetrically, or nearly so, upon opposite sides
of a vertical line passing through the junction of the tube with the pipe from
the boiler, and the two extremities of the tube are connected with the lever
which transmits their motion to the index hand in such a manner that the
sidewise motion or vibration of one extremity of the tube shall counteract the
side motion of the other extremity. The lever is pivoted to the case, and
is connected with the two branches of tube at opposite sides of the pivot.
But a more efficient mode of transmitting the motion of the indicating tube
to the index hand is to connect the lever to the branches of the tube in such
a manner that the points of attachment to the lever shall form the fulcrà
round which the lever turns. The lever through which the contracting and
expanding motion of the tube is transmitted to the index hand is pivoted to
one of the branches of the tube; the extremity of this lever is pivoted to an
arm which connects it to the other branch of the tube. Jointed to the lower
end of the lever is a straight rack, which engages with a pinion upon the
arbor of the index hand. When the gauge is thus constructed, upon the
occurrence of a shock in a horizontal direction both branches of the tube
will move equally or very nearly so in the same direction, carrying with them
the upper end of the lever, which not being pivoted to the case or other rigid
part of the gauge, simply turns on the pin which connects it with the rack
without influencing the index hand. The rack is prevented from being raised
by any sudden jar and disengaged from the teeth of the pinion by a stop screw
placed above it.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of April, in the year of our Lord 1860,
in the twenty-third year of Her reign, did, for Herself, Her heirs and succes-
sors, give and grant unto me, the said Alfred Vincent Newton, Her special
licence that I, the said Alfred Vincent Newton, my executors, administrators,
and assigns, or such others as I, the said Alfred Vincent Newton, my exe-
cutors, 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 of "IMPROVEMENTS IN THE CONSTRUCTION OF
PRESSURE GAUGES," a communication to him from abroad by T. Wilson Lane,
of Meredith, New Hampshire, United States of America, upon the condi-
tion (amongst others) that I, the said Alfred Vincent Newton, by an instru-
ment in writing under my hand and seal, 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 the Great Seal Patent
Office within six calender months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said Alfred Vincent Newton, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Drawings hereunto annexed,
and to the letters and figures marked thereon (that is to say) :-
Fig. 1 is a view of my improved gauge, the dial plate being removed, to
show the interior of the gauge; Fig. 2 a similar view of the Bourdon
gauge as heretofore constructed; Fig. 3 the dial plate; Figs. 4, 5, 6, and 7
will be referred to hereafter.
This Invention relates to certain improvements in the construction of the
Bourdon pressure gauge, the object being to remedy certain defects which
have detracted from its merit under certain circumstances. Thus, for example,
water accumulated therein has, on exposure to a low temperature, frozen and
burst the gauge; again, when applied to locomotive engines, they receive a
tremulous motion, and give uncertain indications through the tremulous'
movement of the index hand. To remove these objections the pipe through
which the pressure within the boiler is transmitted to the gauge is joined
with the indicating tube at a point between the two ends of the tube, and
the ends are bent upwards upon opposite sides of a vertical line passing
through the junction with the pipe, whereby the tube will discharge all the

page_text: water condensed in it down the supply pipe, and it will be rendered less
sensitive to the effects of the vertical shocks to which the locomotive is
subjected. The length of tube least affected by these shocks is nearly a
complete circle, to which, at a point midway between its ends, the pipe from
the boiler is joined, the two ends of the tube approaching each other at the
top, where they are connected with the lever which transmits their motion
to the index hand. By this construction the horizontal vibrations of the
tube are also materially lessened. To prevent the transmission of the hori-
zontal vibrations, and to diminish as far as practicable their influence
upon the index hand, two portions of the indicating tube are bent sym-
metrically, or nearly so, upon opposite sides of a vertical line passing through
the junction of the tube with the pipe from the boiler, and the two extremities
of the tube are connected with the lever which transmits their motion to the
index hand in such a manner that the sidewise motion or vibration of one
extremity of the tube shall counteract the side motion of the other extremity.
The lever is pivoted to the case, and is connected with the two branches of
the tube at opposite sides of the pivot. But a more effecient mode of trans-
mitting the motion of the indicating tube to the index hand is .to connect the
lever to the branches of the tube in such a manner that the points of attach-
ment to the lever shall form the fulera round which the lever turns. The
lever through which the contracting and expanding motion of the tube is
transmitted to the index hand is pivoted to one of the branches of the tube;
the extremity of this lever is pivoted to an arm which connects it to the other
branch of the tube. Jointed to the lower end of the lever is a straight rack,
which engages with a pinion upon the arbor of the index hand. When the
gauge is thus constructed, upon the occurrence of a shock in a horizontal
direction, both branches of the tube will move equally or very nearly so in the
same direction, carrying with them the upper end of the lever, which not being
pivoted to the case or other rigid part of the gauge simply turns on the
pin which connects it with the rack without influencing the index hand. The
rack is prevented from being raised by any sudden jar and disengaged from
the teeth of the pinion by a stop screw placed above it.
0
In Fig. 2 of the accompanying Drawings is represented a gauge of this
description of the usual construction, the bent tube A being attached at one
extremity to the pipe B, through which the pressure within the boiler is
transmitted to the interior of the tube. When thus constructed, if the bent
tube exceed a semicircle in length, a portion of the tube (as from e to fi
Fig. 2,) hangs down below the point e, so as to form a receptacle in which
water soon accumulates from the condensation of vapor within it. The water

page_text: thus collected is liable to freeze in winter, by which the indicating tube is often
burst or strained. To remedy this difficulty it is necessary so to combine
the bent tube with the pipe that any water that may condense within the tube
shall drain back into the pipe, but it is manifest that a tube attached to its
pipe, as represented in Fig. 2, will not thus drain itself in any position in
which it can be placed. To accomplish this end is the object of the first part
of my Invention, which consists in so combining the indicating tube with the
pipe through which the pressure within the boiler is transmitted to the gauge,
that the length of tube in any direction from its junction with the pipe
shall not exceed a semicircle, and in placing the tube in such a position that it
sball descend at every point towards its junction with and drain back into the
pipe. When used upon locomotives, the gauge represented in Fig. 2 is liable
to another serious objection, arising from the violent shocks and jarring to
which the engine is subjected as it passes over the road. These shocks are of
a two-fold character, 1st, those which are occasioned by obstacles encountered
by the tread of the wheels (as the end of rails, &c.), and which occur in
directions nearly vertical; 2nd, those which are occasioned by the swaying of
the engine from side to side, and by the striking of the flanges or fillets of the
wheels against the sides of the rails, and which occur in horizontal directions.
The first class of these disturbances communicate to the bent tube, when
arranged as in Fig. 2, a tremulous motion in a vertical direction, while. the
horizontal shocks to which the engine is exposed cause the tube to vibrate in
directions nearly horizontal. These vibrations of the indicating tube inipart.
a frivolous vibratory motion to the index hand through a considerable arc,
which renders it difficult, if not impossible, accurately to judge of the pressure
within the boiler; they also speedily wear away the teeth of the rack and
pinion by friction, the one upon the other. This frivolous vibration of the
index hand is considerably augmented by the water of condensation which is
allowed to collect and remain within the tube, and which materially increases.
its weight and momentum.
To diminish as far as possible the vertical vibrations of the tube, as well as
to do away [with their influence upon the index hand, is the object of the
2nd part of this Invention, which consists in joining the pipe through which
the pressure within the boiler is transmitted to the gauge with the indicating
tube at a point between the two ends of the tube, and bending the latter upon
opposite sides of a vertical line passing through its junction with the pipe,
whereby the tube is rendered less sensitive to the effects of the vertical shocks
to which the locomotive is subjected. The length of tube which I have
found to be least effected by these shocks is nearly a complete circle, to which,

page_text: at a point midway between its ends, the pipe from the boiler is joined, the
two ends of the tube approaching each other at the top, where they are con-
nected with the lever which transmits their motion to the index hand. But.
this arrangement may be slightly departed from without materially varying the
result; for instance, the extreme ends of the tube may be carried farther from
each other than is above indicated, or they may be brought nearer together,
and even be allowed slightly to pass each other, without greatly modifying the
result. As before stated, however, I have found the form and position of the
tube above indicated, and shown in Fig. 1, as best calculated to diminish
the effects of the vertical jars. upon the indicating tube and index hand. By
the above construction the horizontal vibrations of the tube are also materially
lessened.
To prevent the transmission of these horizontal vibrations, and to diminish,
as far as practicable, their influence upon the index hand, is the object of the
'3rd part of this Invention, which consists in bending the two portions of the
indicating tube symetrically, or nearly so, upon opposite sides of the vertical
line passing through the junction of the tube with the pipe from the boiler,
and connecting the two extremities of the tube with the lever which transmits
their motion to the index hand in such a manner that the sidewise motion or
vibration of one extremity of the tube shall counteract the side motion of the
other extremity, and prevent the horizontal vibration of the tube from being
transmitted to or otherwise influencing the motion or position of the index
hand. In Fig. 6 the lever i is pivoted to the case at 3, and is connected with
the two branches of tube at 4 and 5. It is obvious that, with a lever thus
pivoted, a single branch of the tube will produce as great a motion of the
lever and index hand as the two branches combined. And in order that
sufficient motion may be transmitted to the index hand, it is necessary that
the distance of the points of attachment 4 and 5 from the pivot 3 be quite
short; but the shorter the distance is, the greater will be the effect upon the
index hand of any jar of the indicating tube, and also the greater will be the
disturbing effect upon the hand produced by any wear of the pivots 3, 4,
and 5; on this account it is desirable that the distance between the points of
attachment of the tube with the transmitting lever and the pivot upon which
this lever turns be as great as practicable, and still afford the necessary range
of motion to the index band.
To accomplish this, and thus still farther to diminish the effect upon the
index hand of any vibrations to which the indicating tube may be exposed, as
<well as to render. the motion of the two branches of the indicating tube
available, is the object of the 4th part of this Invention, which consists in

page_text: hanging or pivoting the lever which transmits the motion of the indicating
tube to the index hand to one of the branches of the tube without pivot to
the case or other rigid part connected therewith, and connecting the other
end of the tube with the lever, in such a manner that the points of attachment
to the lever shall form the fulcra round which the lever turns.
To enable others skilled in the art to understand this Invention, I will
proceed to describe the manner in which I have carried it out.
In Fig. 1 of the accompanying Drawings is represented my improved
gauge, the dial plate (seen detached in Fig. 3), being removed to show the
parts within. The pipe through which the pressure is brought from the boiler
is attached to the indicating tube E, at T. For the purpose of carrying out
the first part of this Invention, the two branches, 1 and 2, of the indicating
tube are made of a length not exceeding a semicircle, while they are both so
placed as to descend at every point towards their junction with the pipe C,
that the water which may condense within the tube may drain back to the
pipe. It is obvious that, so far as mere drainage is concerned, the indicating
tube, in lieu of consisting of two branches, as in Fig. 1, may be much shorter,
even less than a semicircle, as represented at C³, in Fig. 4, or of two branches
arranged as in Fig. 5. On account of other considerations, however, which
will be explained in treating of the other branches of my Invention, the con-
struction shown in Fig. 1 is to be preferred.
To diminish as far as possible the vertical vibrations of the indicating tube
and to lessen their influence upon the index hand, which is the object of the
second part of my Invention, the pipe C is joined with the tube at a point T
between its two extremities, and the two branches, 1 and 2, are bent upon.
opposite sides of the vertical line X, X, passing through the point T, the
extremities of the tube being nearly over the points y, y, where the tube is rigidly.
supported. It is manifest that, so far as the vertical jars are concerned, the
tube, represented in Fig. 4, and consisting of a single branch C², if properly
connected with an index hand, would answer the purpose. But although it
might serve to carry out both the 1st and 2nd part of this Invention, it would
obviously still be exposed to the objections arising from the horizontal vibra-
tions; to remedy these the tube is formed of two branches, 1 and 2, which are
bent symetrically upon opposite sides of the vertical line X, X, that their.
motions in a horizontal direction may coincide as nearly as possible with each.
other. The lever i through which the contracting and expanding motion of
the tube is transmitted to the index hand is pivoted to one of the branches (1)
of the tube at s, the extremity of this lever being pivoted at r to a connecting,
arm g, the other end of which is pivoted at c to the branch (2) of the tube;.

page_text: the lower end of the lever i is pivoted at v to the rack m, which engages with
a pinion upon the arbor of the index hand P. When thus constructed and
connected, it will be observed that upon the occurrence of a shock in a hori-.
zontal direction both branches of the tube move equally, or very nearly so, in
the same direction, carrying with them the upper end of the lever i, which, not
being pivoted to the case or other rigid part of the gauge, simply turns round
the point without influencing the rack m or the index hand. This loose
joint v between the lever i and the rack m is also important for the purpose
of preventing the motion of the joint s from causing the rack to bind upon the
pinion n, or to disengage itself therefrom. Where the lever i is pivoted to
the case, as in Fig. 6, the forces with which the two branches of the tube are
thrown in one direction by a horizontal shock are brought to bear upon the
pivot 3 in opposite directions, by which they mutually counteract each other,
and no effect is produced upon the index hand.
. In the gauge represented in Fig. 6, the first, second, and third parts of this
Invention are carried out, but this construction is liable to the objections
which it is the object of the fourth part of this Invention to remove.
1st, it
will be difficult to adjust the points of attachment, 4 and 5, so as not to cause
the pivot 3 to bind in its bearings; 2nd, the jarring of the indicating tube,
whether in a vertical or horizontal direction, brings great strain and wear
upon the pivot 3, whereby it or its bearings are soon worn; 3rd, the effect
upon the index hand of the looseness of parts thus produced, as well as of the
jarring of the tube, is greatly increased by the shortness of the distance
between the pivot 3 and the points 4 and 5. I do not therefore propose to
adopt this construction, but to employ that represented in Fig. 1, in which the
lever is hung upon one of the branches of the indicating tube, as before
described, in lieu of being rigidly pivoted to the case; by means of this con-
struction I am enabled to avail myself of the aggregate motion of the branches,
1 and 2, of the tube, while the short arm of the lever i may be made of
double the length which it would be necessary to have if this lever were
pivoted to the case, the point r serving as fulcrum for the motion imparted to
the lever by the branch 1 of the tube, and the point s as fulcrum for the
motion imparted to it by the branch 2. The aggregate motion of the two
branches of the tube is thus made available, and I am therefore enabled, as
before stated, to double the length of the short arm of this lever, and thereby
greatly diminish the vibration of the index hand when the indicating tube is
subject to jars. The extremity of the lever i, to which is pivoted the arm g
(Fig. 1), is made in a separate piece t, which is fitted to the body of the lever i
by a screw, by which means the distance between the pivots and s may be

page_text: varied, and the tubes adjusted to the dial plates. The rack m is preventeil
from being raised by any sudden jar, and disengaged from the teeth of the
pinion n by a screw o (Figs. 1 and 7).
Having now set forth the nature of this Invention, and explained the
manner of carrying the same into effect, I wish it to be understood that
under the above recited Letters Patent, I claim so combining the indi-
cating tube with the pipe through which the pressure within the boiler is
transmitted to the gauge, that the length of tube in either direction from
its junction with the pipe shall not exceed a semicircle, and placing the tube
in such a position that it shall descend at every point towards its junction with
and drain back into the pipe.
2nd, I claim joining the pipe from the boiler with the indicating tube at a
point between its two ends, and bending the latter, as set forth, so that the
ends of the tube shall be nearly over the points where its two branches are
rigidly supported, whereby the tube is rendered less sensitive to the vertical
shocks to which it is subjected.
3rd, I claim bending the two portions of the indicating tube symetrically, or
nearly so, upon opposite sides of a vertical line as described, and connecting
the two extremities of the tube with the lever i, as set forth, for the purpose
of preventing the horizontal vibrations of the tube from being transmitted to
the index hand.
4th, I claim pivoting the lever i to the indicating tube without attachment
to the case, for the purpose specified.
5th, I claim pivoting the lever i to the rack m, as set forth, for the purpose
specified.
In witness whereof, I, the said Alfred Vincent Newton, have hereunto
set my hand and seal, this Second day of October, in the year of our
Lord One thousand eight hundred and sixty.
30 Witness,
J. W. MOFFATT,
66, Chancery Lane.
A. V. NEWTON. (L.S.)