Improvements relating to Apparatus for Measuring Liquids.
Year: 1899

page_text: Date of Application, 1st Aug., 1899-Accepted, 2nd Sept., 1899
COMPLETE SPECIFICATION.
Improvements relating to Apparatus for Measuring Liquids.
I, MAX BIELER, of Stützerbach, Thüringen, in the Empire of Germany, Manu-
facturer, do hereby declare the nature of this invention and in what manner
the same is to be performed to be particularly described and ascertained in and
by the following statement:-
The present invention relates to an apparatus for measuring liquids, more
particularly as used for chemical purposes, or for selling by measure and similar
purposes.
The novelty of this apparatus consists in an arrangement which enables the
quantity of liquid exceeding the capacity of the measuring vessel to flow or be
forced back automatically to the reservoir or the like by air pressure when the
measure is again filled.
In the annexed drawings two forms of this invention are shown in section.
In the form of apparatus shown in Fig. 1, a bottle a is used as a reservoir with
two necks m and n and a so-called "pipette serves as a measuring vessel b, as
used in chemical laboratories.
"
In the form of apparatus shown in Fig. 2 the reservoir a is a receiver with
constant level of liquid, that is, a receiver closed on all sides, whose neck m is
arranged immediately above the bottom. A burette b serves in this case as a
measuring vessel.
In both forms there is arranged in the inlet of the measuring vessel b for
instance, a three-way-cock c. The inlet communicates with reservoir a by the
pipe f, the pipe i ending immediately above the bottom of the reservoir a.
The measuring vessel bends at the top in a short narrow tube d which is
surrounded by a bulb e. At the lower part of this bulb there enters a jointed
pipe gh whose other end, in the form shown in Fig. 1 passes into the air space
above the liquid, and in the form shown in Fig. 2 passes into the air space above
the constant level (in the neck m).
If the measuring vessel b is filled, the three-way-cock c or other valve replacing
the same is adjusted so that the measuring vessel communicates with the
pipe f,. The liquid then passes from the receiver a into the said measuring
vessel b, fills it and the surplus quantity is partly collected in the bulb e aud
partly in the pipe g. The cock or valve c is then so adjusted that the liquid
contained in b can run out through k, the surplus quantity of liquid remaining
in bulb e or in the pipe g respectively without entering into the short tube d.
When the measuring vessel is again filled, the air contained therein will be
forced away from the liquid flowing in, whereby the air contained in bulb e being
compressed seeks an outlet and thus forces the quantity of liquid in g and e
through h back into the reservoir a. This can of course only take place if the
pressure of air in b and e is greater than the pressure of the liquid in the
pipe gh, this is always the case as long as the distance between the level of
liquid in the reservoir a and the cock or valve c is greater than the distance y
between the highest and lowest point of the pipe gh. If the distance is less

page_text: than the distance Y the liquid in the pipe ŋ h is not raised by the pressure of air
to the highest point of the pipe so that it is not possible to send the surplus
quantity of liquid back into the reservoir a by the air displacement. As in
the receiver shown in Fig. 1 the level of the liquid sinks with the consumption
of the same, the distance becomes shorter than y if such is not prevented. This
may be done, for instance, by making the measuring vessel b so long that the
distance y when the reservoir is nearly empty, remains smaller than distance r.
The most simple method however, is to use a reservoir a as shown in Fig. 2.
In such a reservoir the level of liquid sinks also with the consumption thereof,
but the atmosphere not being able to come into the space above the level but
only into the neck m a second level of liquid remains in the neck m which is
constant until the level in the reservoir comes to the same height. The distance r
remains consequently also constant up to this time. The neck m being further
arranged low down the pipe gh may also be made very short, consequently the
distance y remains always shorter than x.
The arrangement above described for sending back the surplus quantity of
liquid has moreover the advantage that the pipe f can be left open after the
measuring vessel b has been filled without fear of any loss of liquid till the vessel
is empty, even if the emptying should take place later on, because the air in
the bulb e above the surplus liquid hinders a further running over.
This is an
advantage over the known measuring vessels in which the flowing in after the
measuring vessel is filled must immediately be stopped in order to avoid a loss
of liquid.
The cock or valve can of course be replaced by two cocks or valves one
independent of the other, one for inlet and the other for outlet, but the three-
way-cock has the advantage that after the measured liquid is poured out the
opening of the inlet and the closing of the outlet can be done by one and the
same movement of the hand.
Having now particularly described and ascertained the nature of this said
invention and in what manner the same is to be performed I declare that what
I claim is—
1. A liquid measuring apparatus having a measuring vessel b which ends at
the top in a short pipe d which reaches into a bulbe at whose lowest point a
surplus pipe gh is arranged whose other end passes above the liquid level of the
reservoir a into the latter, through which pipe g h the surplus liquid is forced
back into the reservoir a by the pressure of the air contained in the bulb e and
the measuring vessel b as soon as the said quantity of air is forced away by the
liquid flowing in when the measuring vessel 6 is again filled.
2. A form of liquid measuring apparatus as in Claim 1 having as a reservoir a
a vessel closed at the top whose neck m is arranged immediately above the
bottom at the side thereof and a surplus pipe g h passing into said neck to keep
in the same a second constant level of liquid.
Dated this 1st day of August 1899
HERBERT HADDAN & Co.,
Agents to Applicant, 18, Buckingham Street, Strand, W.C.