APPARATUS FOR TESTING PRESSURE AND VACUUM GAUGES. IMPROVEMENTS IN
Year: 1882

page_text: 26
LETTERS PATENT to Willem Christiaan De Wit, of Amsterdam, in the
Kingdom of the Netherlands, for an invention of
APPARATUS FOR TESTING PRESSURE AND VACUUM GAUGES.
IMPROVEMENTS IN
A communication
from Carl Daniel Gäbler, of Hamburg, in the Empire of Germany.
PROVISIONAL SPECIFICATION left by the said Willem Christiaan De Wit
"
at the Office of the Commissioners of Patents on the 23rd February 1882.
WILLEM CHRISTIAAN DE WIT of Amsterdam in the Kingdom of the Netherlands.
"IMPROVEMENTS IN APPARATUS FOR TESTING PRESSURE AND VACUUM GAUGES.'
[A communication from Carl Daniel Gäbler, of Hamburg, in the Empire of
Germany.]
This Invention has for its object improvements in apparatus for testing pressure
and vacuum gauges.
For this purpose I form the testing apparatus of a cylinder fitted with a piston,
which can be moved to and fro along the cylinder by means of a screw spindle
made to screw through one end of the cylinder which is made solid. The other
end of the cylinder is by a passage put into communication with two nozzles one
situated at one end of the cylinder the other at the opposite end. A standard or
control gauge is by a screw coupling attached to one nozzle and the gauge to be
tested to the other nozzle. The cylinder and nozzles are filled with liquid.
By turning the screw spindle the piston can be forced against the water in the
cylinder and the pressure will then be communicated by the column of water to
both gauges simultaneously. To test for vacuum the screw spindle is turned in
the reverse direction. Preferably the apparatus is constructed in the following
manner.
The cylinder at one end is left open whilst the other end is closed with a solid
head through which the screw spindle is screwed. The end of the spindle inside
the cylinder is connected to the piston whilst on the outer end of the spindle is
a hand wheel by which it can be turned. The cylinder is inserted within another

page_text: cylinder of larger diameter. The solid head of the cylinder being made to screw
into one end of this larger cylindrical casing whilst the opposite end of the
cylindrical casing is closed by a screw plug-The cylindrical casing is formed with
feet at its ends by which it may be secured to a stand-it is also made with two
nozzles standing up from it-one at each end-to one of these nozzles a standard
or control gauge is connected by a screw coupling and to the other the gauge
which is to be tested.
Each nozzle is also provided with a cock by which the passage through it can be
closed. One nozzle may also be formed with a small tube branching out sidewise
from it-and the cock with which the nozzle is fitted is then made a three way
cock which can be turned so as either to open a passage between this small branch.
tube and the cylindrical casing or can close this passage and open the passage
through the nozzle. This three way cock and branch tube are provided to allow
of the cylinders being filled with liquid or emptied.
When the control gauge has been secured on to one nozzle and the gauge to be
tested secured on to the other nozzle the screw spindle is turned in a direction to
force the piston away from the solid end of the cylinder-the piston then bears with
considerable force against the column of water in the cylinder and acts both upon
the control gauge and the gauge to be tested-If a vacuum gauge is to be tested
the screw is as before stated turned in the opposite direction. The control gauge
is preferably made with two or more hands each worked by a totally separate
mechanism so that they are independent one from the other-in this way increased
security is obtained.
In place of the cylinder being surrounded by an outer cylindrical casing as above
described the end of the cylinder which in the arrangement just described is left
open may be closed by a screw plug and a small passage then made from it into a
tube or passage which connects the lower part of the two nozzles.
The action of the apparatus would be precisely the same.
By constructing testing apparatus in the manner above described it can be
made very portable and to pack into small space.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Willem Christiaan De Wit in the Great Seal Patent Office on the
22nd August 1882.
WILLEM CHRISTIAAN DE WIT of Amsterdam in the Kingdom of the Netherlands.
"IMPROVEMENTS IN APPARATUS FOR TESTING PRESSURE AND VACUUM GAUGES."
A communication from Carl Daniel Gübler of Hamburg in the Empire of
Germany.
This Invention has for its object improvements in apparatus for testing pressure
and vacuum gauges.
The
For this purpose the testing apparatus is formed of a cylinder fitted with a
piston which can be moved to and fro along the cylinder by means of a screw
spindle made to screw through one end of the cylinder which is made solid.
other end of the cylinder is by a passage put into communication with two nozzles
one situated at one end of the cylinder the other at the opposite end.
A standard
or control gauge is by a screw coupling attached to one nozzle and the gauge to be
tested to the other nozzle. The cylinder and nozzles are filled with liquid. By
turning the screw spindle the piston can be forced against the water in the cylinder
and the pressure will then be communicated by the column of water to both gauges
simultaneously.
To test for vacuum the screw spindle is turned in the reverse direction.
The Drawing annexed shews the way in which it is preferred to construct the
apparatus.
Figure 1 represents a longitudinal section and Figure 2 a cross section of the
apparatus. Figure 3 represents a longitudinal section of a modified construction
of the apparatus and Figures 4 and 5 are cross sections of this modified
construction.
A is the cylinder left open at one end whilst the other end is closed with a solid
head through which the screw spindle B is screwed. The end of the spindle B
inside the cylinder is connected to the piston C whilst on the outer end of the
spindle is a hand wheel by which it can be turned.
The
The cylinder is inserted within another cylinder D of larger diameter.
solid head of the cylinder being made to screw into one end of this larger
cylindrical casing whilst the opposite end of the cylindrical casing is closed by a
screw plug E. The cylindrical casing is formed with feet at its ends by which it
may be secured to a stand-it is also made with two nozzles F. G. standing up
from it one at each end-to one of these nozzles F. a standard or control gauge
is connected by a screw coupling and to the other G the gauge which is to be
tested. Each nozzle is also provided with a cock by which the passage through it
can be closed. One nozzle may also be formed with a small tube branching out
sidewise from it-and the cock with which the nozzle is fitted is then made a
three way cock which can be turned so as eitber to open a passage between this
small branch tube and the cylindrical casing or can close this passage and open
the passage through the nozzle. This three way cock and branch tubo are provided
to allow of the cylinder being filled with liquid or emptied.
When the apparatus has been filled with liquid and the control gauge and the
gauge to be tested secured on to the two nozzles the screw spindle is turned in a
direction to force the piston away from the solid end of the cylinder A. The
piston C then bears with considerable force against the column of water in the
cylinder and acts both upon the control gauge and the gauge to be tested. If a
vacuum gauge is to be tested the screw is as before stated turned in the opposite

page_text: direction. The control gauge is preferably made with two or more hands each
worked by a totally separate mechanism so that they are independent one from the
other in this way increased security is obtained.
In the modification shewn at Figures 3.4 and 5 the cylinder A in place of
being surrounded by an outer cylindrical casing D as above described has its end
closed by a screw plug H and a small passage is made from it into a
passage I which is as shewn in connection with the lower part of the two
nozzles F. G.
The action of the apparatus is precisely the same.
By constructing testing apparatus in the manner above described it can be made
very portable and to pack into small space.
Having thus described the nature of the Invention and the manner of performing
the same I would have it understood that I claim-
The construction of apparatus substantially as herein before described for testing
pressure and vacuum gauges.
In witness whereof I the said Willen Christiaan De Wit have hereunto set
my hand and seal this Fourteenth day of August in the year of our Lord
One thousand eight hundred and eighty two.