Improvements in or connected with Milk Cans.
Year: 1890

page_text: Date of Application, 8th Jan., 1890-Accepted, 15th Feb., 1890
COMPLETE SPECIFICATION.
Improvements in or connected with Milk Cans.
We JOHANN FRANZ HUGO GRONWALD, Apothecary of 33 Kaiser Strasse C, and
EMIL HEINRICH CONRAD OEHLMANN of 70 Dresdener Strasse S. both of Berlin in
the German Empire 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 :-
Our invention relates to vessels or cans for milk and consists in the combination
with a milk can provided with an outlet cock or tap of an air filter and of a through
way and hose pipe cock in the piping connecting the air filter with the interior of
the can by means of which arrangement sterilised milk can be transported without
refrigerating appliances and drawn off by the admission of air free from germs
without exposing the milk during the carriage or drawing off to risk of contami-
nation and which arrangement allows the sterilisation of the milk to be carried out
within the can or vessel itself and by means of suitable seals assures the sale of
really sterilised milk to the public, and in arrangements for producing a mixture of
the contents of the can while drawing them off so as to obtain a uniform mean
quality of milk.
On the sheet of drawings appended hereunto figures 1 and 2 show our improved
milk can with internal air filter in sectional elevation and top view, figures 3 and 4
the same with external air filter in sectional elevation and view from the underside.
The vessel or can A. is provided with a lid B. fixed by a hinge a. which can be
closed air tight by means of the swivel bolt b. fixed to the neck of the can and the
wing nut c. From the neck of the can a pipe d. fitted with a through way cock e. and a
hose pipe cock f. leads to an air filter C. arranged in the interior of the can A. and
filled with wadding or other suitable filtering material. The filter C. passes through
the bottom g. of the can and is closed outside by a screw plug h.
Inside the rim i. of the bottom an outlet ccck or tap k. is arranged.
Obviously the cocks shewn on the drawings may be replaced by equivalent taps of
different construction.
The manipulation of the can herein before described varies according to its being
used for transporting milk previously sterilised in other apparatus, or for sterilising
the milk in the can itself.
In the former case the can A. and filter C. are sterilised by connecting the
cock k with a steam supply pipe and opening the cock e. and the screw plug h.
The steam entering through the cock k. is allowed to flow through the can A,
thence through the pipe d. and air filter C. until they are safely sterilised. The
plug h. is then screwed up tight, the admission of steam stopped and the can A.
cooled. The water formed by con:lensation passes through the cock k into a water
collector inserted between this cock and the stop valve for the steam supply. The
cock k. is then closed and the steampipe connections are removed and the cock
connected by piping with the milk supply.
The vacuum formed in the can A. by its refrigeration can be utilized for effecting
or. facilitating the flow of the milk which has previously been sterilised in other
apparatus into the can A. After the can has been filled the plug h. is opened, so that
air free from germs can enter into the vessel at the top and destroy the vacuum.
After this has been done, the stop cock e. is closed and the plug h. screwed up
tight, and the nut cock e, hose pipe cock f. and drawing off cock k. are secured
by plumbing or sealing, when the can A. is ready for transport.
Arrived at its destination, the seals of the cocks k. and e. only are removed, those of
the nut c. and hosepipe cock f. remaining attached, so as to prevent adulteration
of the milk and contamination of the same by air not freed from germs entering

page_text: through the cock f. This forms the guarantee for the purchasers that the retailers
are prevented from selling inferior milk from cans known or announced to contain
sterilised milk.
If the milk is to be sterilised in the can itself, the air filter C. only needs to be
sterilised by connecting the cock. to a steam supply pipe and after opening the plug h.
allowing steam to flow through the filter until it is properly sterilised. The can A. is
sterilised simultaneously with the milk by heating the same with its contents in a water or
steam bath in the usual manner. While doing this the cock e. and plug h. are closed.
It is preferable to sterilise the filter C. immediately after sterilising the milk, because
it is then in a heated condition and the condensation of water in it is avoided. If the
can is intended only for previously sterilised milk, the hose pipe cock f. may be
omitted.
In the modified form of can shewn by figures 3 and 4 the air filter C. with its
screw plug h. is arranged outside the can under the bottom of the same, the hose pipe
cock f being arranged close to the filter and the through way cock e. close to the neck
of the can.
The manipulation of this modified apparatus in both cases, i.e. for
transporting previously sterilised milk or milk sterilised in the can itself, is the same
as hereinbefore described with reference to the can shewn by figures 1 and 2.
With these cans it is not necessary to refrigerate them during transport or drawing
off because all the ferments or germs in the milk which could produce decomposition
have been killed and in drawing off only air free from germs is admitted through the
air filter.
Before drawing off the milk, it is necessary to mix the different layers having formed
themselves during carriage or storage in consequence of their different specific gravity.
This may be done by shaking the vessel but by preference we apply a pipe 7. rising up
from the cock k. to the top of the can and perforated with lateral holes in such a
manner that in drawing off, milk from all the different layers or heights flows to the
cock k. This arrangement may be applied to ordinary milk cans.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is
Firstly, the combination with a milk can having an air tight lid and at the bottom
an outlet cock of an air filter connected to the upper part of said can by a pipe
fitted with a through way cock and when required a hose pipe cock substantially
as hereinbefore described and for the purposes set forth.
Secondly, the arrangement or construction of milk can with internal air filter,
connections and cocks substantially as herein before described with reference to
figures 1 and 2 of the drawings and for the purposes set forth.
Thirdly, the arrangement or construction of milk can with external air filter,
connections and cocks substantially as herein before described with reference to
figures 3 and 4 of the drawings and for the purposes set forth.
Fourthly, in cans or vessels for carrying or forwarding milk the arrangement of a
vertical pipe with lateral perforations and connected to the outlet cock or tap for the
purpose of mixing the milk substantially as hereinbefore described.
Dated this 7th day of January 1890.
EMMOTT & Co.,
Agents for the Applicants.