IMPROVE- MENTS IN PRESSURE OR STEAM GAUGES
Year: 1868

page_text: LETTERS PATENT to Thomas Bache Salter, of West Bromwich, in the
County of Stafford, Manufacturer, and John Silvester, of West
Bromwich, aforesaid, Manufacturer, for the Invention of "IMPROVE-
MENTS IN PRESSURE OR STEAM GAUGES."
Sealed the 15th June 1869, and dated the 18th December 1868.
PROVISIONAL SPECIFICATION left by the said Thomas Bache Salter
and John Silvester at the Office of the Commissioners of Patents,
with their Petition, on the 18th December 1868.
We, THOMAS BACHE SALTER, of West Bromwich, in the County of
Stafford, Manufacturer, and JOHN SILVESTER, of West Bromwich, afore-
said, Manufacturer, do hereby declare the nature of the said Invention
for "INPROVEMENTS IN PRESSURE OR STEAM GAUGES," to be as follows:-
Our Invention relates to pressure or steam gauges in which the
pressure is measured by the deflection of a plain or corrugated plate
of metal forming part of a box or chamber in connection with the steam,
or liquid, or gas, the pressure of which is to be measured.
Our Invention also relates to pressure or steam gauges in which the
pressure is measured by the deflection of a flat tube bent into a circular

page_text: or nearly circular figure, the flattening or opening out of the tube
measuring the pressure within it.
Gauges of the kind described are also employed for measuring the
difference of the pressure acting upon their exterior and interior. In
order to multiply the motion of the corrugated or plain plate, or the b
curved tube, a quadrant rack gearing with a pin on the axis of the
index finger is usually employed.
Our Invention consists in employing the arrangements herein-after
described for transmitting the motion to the index finger and multi-
plying it.
1
In ganges of the first-described kind, we fix the axis on which the
index finger turns to the back of the case. Another axis is fixed to the
back of the case on which an arm or lever turns in a plane parallel-to-
that in which-the-index finger works. On the underside-of the-bush-
of-the-index finger is a slot in the direction of a radius from the centre 1
of a bush. A pin on the end of the arm or lever described engages.
in the said slot, and a slight motion in the said arm or lever causes the
pin on its end to act on the bush of the index finger and move it
through a considerable_angle.-A-rod-bearing at one end against the
corrugated or other plate deflected by the pressure, and at its other end
against the said arm or lever, transmits motion from the former to the
latter. By this arrangement the motion of the said plate is transmitted
to and largely multiplicd in the index finger.
In-gauges in which the pressure deflects a flat tube, we fix the axis
on which the index finger turns on one end of the tube, and we fix the
pin which engages in the slot in the bush of the index finger on the
other end of the tube. Or we fix the axis of the index finger to the
case of the instrument and the said pin to one end of the tube.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Bache Salter and John Silvester in the 30
Great Scal Patent Office on the 15th June 1869.

page_text: facturer, and JOHN SILVESTER,, of West Bromwich, aforesaid, Manu-
facturer, send. greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by Hor
Letters Patent, bearing date the Eighteenth day of December, 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 succes-
sors, give and' grant unto us, the said Thomas Bache Salter and
John Silvester, Her special licence that we, the said Thomas Bache
Salter and John Silvester, our executors, administrators, and assigns,
or such others as wc, the said Thomas Bache Salter and John
Silvester, our 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, usc, 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 OR STEAM GAUGES," upon the condition
(amongst others) that we, the said Thomas Bache Salter and
John Silvester, our executors or administrators, by an instrument
in writing under our or their hands and seals, or under the handl
and seal of one of us. or them; 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, thic said Thomas Bachic Salter, on behalf
of myself and the said John Silvester, 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 thereof, that is to say :-
Our Invention relates to pressure or steam gauges in which the
pressure is measured by the deflection of a plain or corrugated plate of
metal forming part of a box or chamber in connection with the steam,
or liquid, or gas, the pressure of which is to be measured..
Our Invention also relates to pressure or steam gauges in which the
pressure is measured by the deflection of a flat tube bent into a circular
or nearly circular figure, the flattening or opening out of the tube
measuring the pressure within it.

page_text: Gauges of the kinds described are also employed for measuring the
difference of the pressure acting upon their exterior and interior. In
order to multiply the motion of the corrugated or plain plate, or the
curved tube, a quadrant rack gearing with a pinion on the axis of the
index finger is usually employed.
Our Invention consists in employing the arrangements herein-after
described for transmitting the motion to the index finger and multi-
plying it.
5
In gauges of the first-described kind we fix the axis on which the
index finger turns to the back of the case. Another axis is fixed to the 1
back of the case on which an arm or lever turns in a plane parallel to
that in which the index finger works. On the under side of the bush
of the index finger is a slot in the direction of a radius from the centre-
of the bush. A pin-on-the-end-of-the arm or lever described-engages
in the said slot,-and-a-slight motion in the said arm or lever causes the 1
pin on its end to act on the bush of the index finger and move it
through a considerable angle. A rod bearing at one end against the
corrugated or other plate deflected by the pressure, and at its other end
against the said arm or lever, transmits-motion-from the former to the
-latter. By this arrangement the motion of the said plate is transmitted 2
to and largely multiplied in the index finger.
In gauges in which the pressure deflects a flat tube we fix the axis
on which the index finger turns on one end of the tube, and we fix the
pin which engages in the slot in the bush of the index finger on the
other end of the tube. Or we fix the axis of the index finger to the case 2
of the instrument, and the said pin to one end of the tube.
Having explained the nature of our Invention we will proceed to
describe, with reference to the accompanying Drawings, the manner in
which the same is to be performed.
Figure 1 represents a front elevation of a steam or other gauge in 3
which the pressure is measured by the deflection of a plain or corrugated
plate of metal, the mechanism for transmitting the motion of the
deflected plate to the index finger and multiplying it being constructed
and arranged according to our Invention; Figure 2 represents the said
gauge with the dial plate and index finger removed; Figure 3 is a 3
vertical section of a portion of Figure 1; Figures 4, 5, and 6 are parts of
the same. The same letters of reference are employed to indicate the
same parts in Figures 1, 2, 3, 4, 5, and 6.

page_text: a is the case of the gauge, and b is the box or chamber in which the
plain or corrugated plate is situated, the deflection of which is to be
measured by the instrument; c is an axis fixed on the back of the case a,
on which said axis the index finger & turns. The index finger dis
represented separately in Figure 4. e is a nearly horizontal arm or lever
turning on the axis or centre f fixed to the back of the case. The said
arm or lever e moves in a plane parallel to that in which the index
finger & moves. The lever e is shown separately and in connection
with the index finger d in Figure 5. g is a vertical rod, which bears at
bottom against the corrugated or plain plate in the box or chamber b,
and is connected at top with the lever e. The connection of the rod to
the lever is effected by means of the flat end e² of the said rod being
passed through a rectangular slot e³ in the lever, the parts being secured
together by a cross pin. The rod g is shown separately in Figure 6. By
means of a small coiled spring attached to the free end of the arm or
lever e the rod g is kept to its bearing on the plain or corrugated plate
in the box or chamber b. The said spring also effects the return
motion of the moving parts. A stop at i on the case a limits the rising
motion of the rod g. On the under side of the bush d of the index
finger d is a slot made in the direction of a radius from the centre of
the said bush, or a diameter of the said bush (see Figure 4), the said
slot crossing the hole in the bush, which receives the pin or axis co.
which the said index finger d turns. The free end of the lever e is
provided with a short pin e' which engages in the cross slot d³ in the
bush d, as represented in Figures 3 and 5. The pin e' when the parts
of the gauge are in their normal position is situated at one
cross slot that is near the periphery of the bush .
end of the
When the
rod g is lifted by the deflection of the plate in the box or chamber
the lever e is also lifted and turns on its centre f. As the lever e rises
its pin c' at the free end moves in the cross slot d³ in the bush d² towards
the centre of the said bush. The index finger d is thereby caused to
move on its axis c in a contrary direction to that in which the lever e
moves, and to traverse the graduated dial , and indicate thereon the
pressure of the steam, liquid, or gas on the plane or corrugated plate in
the box or chamber b..
By an examination of the Drawing it will be understood that a slight
2.1.

page_text: angle. On removing the pressure from the plain or corrugated plate-thic
parts of the gauge are returned to their normal positions by means of the
spring h.
Figure 7 represents a front clevation of a steam or other gauge in
which the pressure is measured by the deflection of a flat tube of a b
circular or nearly circular figure; Figure 8 represents the same with
the dial plate and index finger removed, and Figure 9 represents in plan
and front elevation the same without the case; Figure 10 represents an
under side of the index finger separately.
The action of the mechanism for transmitting and multiplying the 1
motion or deflection of the flat tube is essentially the same as that of the
gauge heroin first described. Z is the flat tube bent into a circular or
nearly circular figure, the ends &,, of the said tube being closed. The
said flat tube is in communication with the-steam-liquid or gas pipe m
of the gauge. On one end of the tube-l -is-an arm carrying a pin or 1
-axis-g-on which the index finger d turns, and on the other end of the
said tube is another arm n carrying a short pin which engages in the
cross slot d³ in the bush d' of the index finger d. The ends of the tube /
when they separate are guided by the pin or rod 8. One-end-of-the-pin s
works through.a.slot-in-the-plate on one end of the tube, and the other 2
end of the pin s is screwed into the plate at the opposite end of the
tube as represented. When steam, liquid, or gas is admitted into the flat
tube through the pipe m the two ends 1, 2, of the tube separate and
the tube is slightly opened out. The pin on one end of
thereby caused to work in the cross slot d³ in the bush
the index finger d and cause it to traverse the dial plate u and indicate
thercon the pressure of the steam, liquid, or gas within the tube l, as
herein-before particularly explained with reference to the first-described
gauge. On shutting off the steam, liquid, or gas from the tube m the
ends of the tube approach one another, and the parts of the gauge 3
resume the positions represented in the Drawing. Gauges provided with
mechanism of the kind described and represented may also be employed
for measuring the difference of the pressure acting upon their exterior
and interior, such, for example, as vacuum gauges.
the tube
is
and depress 2
Having now described the nature of our Invention, and the manner in 3
which the same is to be performed, we wish it to be understood that we
do not limit ourselves to the precise details hercin described and
illustrated, as the same may. be varied without departing from the nature

page_text: of our Invention; but we claim as our Invention the improvements in
pressure or steam gauges hercin-before described and illustrated in the
accompanying Drawings, that is to say, transmitting to an index finger
and multiplying the motion produced by the deflection or change of
figure of a plain or corrugated plate of metal or flat tube by means of a
slot on the under side of the bush of the index finger and a pin working
in the said slot, the motion of the deficcted plate or flat tube being
transmitted to the said pin by mechanism constructed and arranged
substantially as described and illustrated.
In witness whereof, I, the said Thomas Bache Salter, have here-
unto set my hand and seal, this Eleventh day of Junc, in the
year of our Lord One thousand eight hundred and sixty-nine.
Witness,
GEORGE SHAW.
THOMAS BACHE SALTER. (L.S.)