IMPROVEMENTS IN PRESSURE GAUuges
Year: 1873

page_text: LETTERS PÅTENT to George Alonzo Everett, of the City, County, and -
State of New York, in the United States of America, but at present
of 35, Southampton Buildings, in the County of Middlesex, for the
Invention of "IMPROVEMENTS IN PRESSURE GAUuges."
PROVISIONAL SPECIFICATION left by the said George Alonzo Everett
at the Office of the Commissioners of Patents, with his Petition,
on the 30th September 1873.
I, GEORGE ALONZO EVERETT, of the City, County, and State of New
York, in the United States of America, but at present of 35, South-
ampton Buildings, in the County of Middlesex, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN PRESSURE Gauges,"
to be as follows:-
The Invention has for its object improvements in pressure gauges
whereby in addition to the ordinary indication of the actual pressure the
gauge is made to indicate the number of times a given pressure has

page_text: been exceeded in the working of the boiler or machine to which the
gauge is fixed, as also the extent to which such pressure has been
exceeded. For this purpose I mount on the axis of the ordinary hand
or pointer another hand or pointer which is operated by the first men-
tioned hand or pointer in such manner as to carry it to the highest point
to which the pressure has reached, and there leave it as a permanent
record.
In addition to the above mentioned hands or pointers I also employ
other hands or pointers acting in combination with suitable dials to
indicate the number of times the pressure has exceeded a certain fixed ]
point, and the amount within certain limits by which such pressure has
been exceeded. These last mentioned hands or pointers may be
mounted upon the same stud or axis, and may point to dials struck from
the same centre, or they may be each mounted upon a separate stud.or
axis, and point to dials struck from different centres.
.
1
The mode in which I prefer however to arrange and operate these last
mentioned hands or pointers is as follows: -On the toothed segment
gearing with and giving motion to the pinion on the axis of the ordinary
hand or pointer is a stud or projection in which is or are mounted a
screw or screws, which is or are capable of being readily adjusted 2
therein to suit the maximum pressure to which it is desired to work the
boiler or machine to which the gauge is fixed. This screw (when only
one is employed) bears against a lever on which is mounted a number
of clicks or drivers corresponding to the number of hands or pointers
employed. Each of these clicks or drivers operates in connection with 2
a ratchet wheel to give motion thereto whenever the pressure has
exceeded a fixed point. Thus one of such ratchet wheels may be moved
a tooth forward every time the desired maximum pressure has been
exceeded to the extent of one pound, another of such ratchet wheels
may be moved a tooth forward every time the desired maximum pressure 3
has been exceeded by two pounds, and so on for every ratchet wheel
employed.
On the axes of these several ratchet wheels are fixed hands or pointers
which by pointing to different dials are caused to indicate the number
of times the pressure has exceeded a fixed point to the extent of one, 3
two or more pounds, according to the arrangement and numbian of diele

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Alonzo Everett in the Great Seal Patent
Office on the 30th March 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE -
ALONZO EVERETT, of the City, County, and State of New York, in the
United States of America, but at present of 35, Southampton Buildings,
in the County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirtieth day of September, in the
year of our Lord One thousand eight hundred and seventy-three, in
the thirty-seventh year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said George Alonzo Everett, Her
special license that I, the said George Alonzo Everett, my executors,
administrators, and assigns, or such others as I, the said George Alonzo
Everett, 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 PRESSURE GAUGES," upon the condition (amongst others)
that I, the said George Alonzo Everett, my executors or adminis-
trators, 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 the Great Seal Patent
Office within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE, that I, the said George Alonzo Everett, do hereby
declare the nature of the said Invention and in what manner the

page_text: is to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say :—
-
The Invention has for its object improvements in pressure gauges
whereby in addition to the ordinary indication of the actual pressure the
gauge is made to indicate the number of times a given pressure has
been exceeded in the working of the boiler or machine to which the
gauge is fixed, as also the extent to which such pressure has been
exceeded. For this purpose I mount on the axis of the ordinary hand
or pointer another hand or pointer which is operated by the first men-
tioned hand or pointer in such manner as to carry it to the highest point
to which the pressure has reached, and there leave it as a permanent
record.
In addition to the above mentioned hands or pointers I also employ
other hands or pointers acting in combination with suitable dials. to
indicate the number of times the pressuro has exceeded a certain fixed
point, and the amount within certain limits by which such pressure has
been exceeded. These last mentioned hands or pointers may be
mounted upon the same stud or axis, and may point to dials struck from
the same centre, or they may be each mounted upon a separate stud or
axis and point to dials struck from different centres.
The mode in which I prefer however to arrange and operate these last
mentioned hands or pointers is as follows:-On the toothed segment
gearing with and giving motion to the pinion on the axis of the ordinary
hand or pointer is a stud or projection in which is or are mounted a
screw or screws, which is or are capable of being readily adjusted
therein to suit the maximum pressure to which it is desired to work the
boiler or machine to which the gauge is fixed. This screw (when only
one is employed) bears against a lever on which is mounted a number
of clicks or drivers corresponding to the number of hands or pointers
employed. Each of these clicks or drivers operates in connection with
a ratchet wheel to give motion thereto whenever the pressure has
exceeded a fixed point. Thus one of such ratchet wheels may be moved
a tooth forward every time the desired maximum pressure has been
exceeded to the extent of one pound, another, of such ratchet wheels
may be moved a tooth forward overy time the desired maximum pressure
has been exceeded by two pounds, and so on for every ratchet wheel
amploved

page_text: On the axes of these several ratchet wheels arc fixed hands or pointers
which by pointing to different dials are caused to indicate the number of
times the pressure has exceeded a fixed point to the extent of one, two,
or more pounds, according to the arrangement and number of dials and
parts acting therewith employed.
Figure 1 is a face view; Figure 2 is an elevation with the face or dial
removed; Figure 3 is a transverse vertical section; and Figures 4, 5, 6, 7,
8, 9, and 10, are detail views of an ordinary "Davics' or diaphgram
pressure gauge having my improvements applied thereto.
"
a is the ordinary hand or pointer which indicates the actual pressure
by pointing to the dial of large figures on the face of the gauge, but in
order to record the highest pressure to which the gauge has at any timo
been worked I employ another hand or pointer b which is operated by a¨
stud or projection a' from the hand or pointer a (shown more clearly at
Figures 7 and 8) and is thereby caused to indicate the extreme pressure
to which the gauge has been worked by pointing to the dial of smaller
figures around the centre of the face. The hand or pointer b is formed
with an annular space U¹ around the centre 6%, which centre is connected
to the part 6 by a bar 6³ against which the stud a' carried by the hand
or pointer a acts to operate the hand or pointer b. The hand or pointer
b is mounted on a sleeve axis c surrounding the axis a² of the hand or
pointer a, and is held on such sleeve axis c by means of a spring c¹
which presses the centre part b² against the head c. The sleeve axis c
is screwed into a socket d' carried by the plate & and forms a fixed axis.
around which the hand or pointer 6 can work. Thus in the motion of
the hand or pointer a 'the stud a' will act upon the hand or pointer 6 to .
b

page_text: carry it to the highest point to which the gauge has worked and will
there leave it.
I also form on the face of the gauge another dial or dials e to which
the hands or pointers f,,, point to indicate the number of times, a
given pressure has been exceeded within certain limits and to what
extent.. Thus according to the arrangement shewn in the Drawings the
hand or pointer f which extends only to the inner edge of the dial e
is employed to indicate the number of times a given pressure has
been exceeded to the extent of 2 pounds; the hand or pointer f¹
which extends as far as the Figure 5 on the dial e is employed to
indicate the number of times a given pressure has been exceeded by 5
pounds, and the hand or pointer 2 which extends to the outer edge of
the dial e is employed to indicate the number of times a given pressure
has been exceeded by 10 pounds.
The mode in which motion is given to such hands or pointers f,f¹, f*,
is as follows:-Motion is given to the axis a² by the toothed segment
taking into the toothed pinion a, on the axis a³ as is well understood.
On the segment g is fixed a stud g' in which are mounted three screws
h, h¹, h², which are capable of adjustment therein. These screws h, h³, h³,
are respectively caused to operate levers i, j, k, on the lower ends of
which are mounted clicks or drivers ¹, j', k', and these clicks or drivers
in the motion of the levers i, j, k, are caused to give rotary motion to
the ratchet wheels l, m, n, to the extent of one tooth for every move-
ment of such levers beyond a given point. The levers i, j, k, arc acted
upon by springs o attached thereto, and to a fixed stud o¹ to bring them
back to their normal position. The ratchet wheels l, m, n, as shown
in the Drawings, are all mounted so as to move around the same centre.
The ratchet wheel has a solid axis ♬ on which the hand or pointer f³ is
mounted, the ratchet wheel m has a sleeve or tubular axis m³ which is
passed over the axis and has fixed thereon the hand or pointer f
whilst the ratchet wheel n has a sleeve or tubular axis ¹ which is passed
over the axis m¹ and has fixed thereto the hand or pointer f. pare
check pawls to prevent the accidental return of the ratchet wheels 7, m,
n, after being moved forward a tooth.
I would here remark that instead of making the dial e as hercin-
before shown and described to answer the purpose of three dials, threo
separate dials may be employed, in which case the three ratchet wheels

page_text: l, m, n, would be each mounted on a separate axis coincident with the
centre of its respective dial, and the screws h, h¹, h³, and levers i, j, k,
would cach be adapted in form and position to operate its respective
ratchet wheel as will be well understood.
The glass cover g of the gauge is as shown screwed on, but in order to
prevent the possibility of any one tampering with the gauge the cover q.
may be locked thereto by any suitable and secure lock, I prefer however
to do so by the means shown in the Drawings at Figures 4, 5, and 6,
which represent an application of the glass seal lock thereto. r is a
sliding bolt having a space in which a glass seals can be placed, and t
is a spring having a stud (not shown) fixed thereto. Thus when in the
position shown in Figure 5, with the glass seal therein the bolt" cannot
be retracted until the glass seals is broken; but when such seal is broken
an instrument can be inserted in the hole ¹ to push back the spring t
and thereby release the stud carried thereby from the sliding bolt r,
when such sliding bolt can be. retracted by means of the stud, to the
position shown at Figure 4, in which position of the sliding bolt » the
face of the gauge can be readily unscrewed, and in this position of the
sliding bolt the hole in the sliding bolt r comes opposite the hole u in
the case of the gauge, thereby enabling a key or instrument to be
inserted through such holes into the interior of the gauge when required
to adjust the screws h, h³, h³; but when the parts are in the position
shown at Figure 5, the hole is covered and protected by the sliding
bolt and glass seal a.

page_text: the back of the caso; as shown at Figure 12, or it may be otherwise
supported.
Another mode in which the ratchet wheels l, m, n, may be operated is
as follows:-On the axis a² of the hand or pointer a underneath the face
or dial plate I fix a segmental wheel corresponding to the dial of large
figures and marked with similar numerals, but in the reverso direction
to that of the numerals on the dial of large figures. On this segmental
wheel I fix a clamp which is capable of being adjusted in position
according to the limit to which it is desired that the pressure shall be
worked. This clamp is provided with one or more spring clicks or 1
drivers according to the number of ratchet wheels l, m, n, employed.
Thus, whenever the pressure has exceeded the maximum to which it is
desired the gauge shall be worked, the clicks or drivers carried by the
clamp will act upon the ratchet wheels l, m, n, in a similar manner
to that described with the arrangements before described.
I have not thought it necessary to give a Drawing of the last
described arrangement as aided by the description above given such
will be readily understood by a competent mechanic.
I would further remark that according to my Invention a greater
number of hands or pointers f may be employed than that herein shown a
and described, and instead of being caused to indicate up to only 60 or
100 times that a given pressure has been exceeded, they may be caused
to indicate any larger number desirable by simply having ratchet wheels
l, m, n, with the desired number of teeth, or by the employment of
multiplying gear in connection therewith, as will be well understood, or g
if desired a space may be left in the ratchet wheels without any
teeth so that when they have been onco completely rotated the clicks
or drivers shall work on the plain part of such wheels and give no
further action thereto.
Having thus described the nature of my said Invention, and the mode g
in which I carry the same into effect, I would have it understood that I
do not confine myself to the precise details herein shown and described
for operating the various additional hands or pointers, as such may be
varied without departing from the peculiar nature of my Invention;
but what I do claim is the employment in pressure gauges of additional 3
hands or pointers b, f, f', and fs, and dials corresponding therewith,

page_text: arranged and operated in manner and for the purpose substantially as
herein shown and described.
In witness whereof, I, the said George Alonzo Everett, have
hercunto set my hand and seal, this Twenty-sixth day of March,
in the year of our Lord One thousand eight hundred and seventy-
four.