IMPROVED PORTABLE APPARATUS FOR PREPARING INFUSIONS OF COFFEE, TEA AND OTHER VEGETABLE SUBSTANCES
Year: 1884

page_text: DIEVLERATION.
I, DAVID HARRY SHUTTLEWORTH-BROWN of 5 Huggin Lane, Queen Victoria
Street in the City of London, Engineor do hereby declare the nature of my inven-
tion for IMPROVED PORTABLE APPARATUS FOR PREPARING INFUSIONS OF COFFEE,
TEA AND OTHER VEGETABLE SUBSTANCES, to be as follows:-
The chief object of this invention is to provide a pot for domestic use suitable
for producing infusions of coffee, tea or vegetable matters in an efficient and
economical manner. The pot, whether made of metal or earthenware, will take
internally a cylindrical form, having a lateral curved swelling near the bottom of
the pot, which increases its diameter, and provides a shoulder for retaining any
floating matters that may have a tendency to pass away with the infusion, when
the pot is tipped to discharge the infusion from the pot.
The bottom of the pot I fit internally with a coned seat, or its equivalent, for
receiving a central guide rod, which is supported at its upper end by a cross bar
fastened to the top of the pot by a bayonet joint or its equivalent. This guide rod
is intended to receive a floating disc or equivalent device of somewhat smaller
diameter than the cylindrical portion of the pot, and which is free to rise up the
rod as the water for making the infusion is poured into the pot. A lid may be
fitted to the pot, and the lip of the pot may be fitted with a removable strainer.
In making an infusion of coffee, the freshly ground coffee is first placed in the
pot, then the rod with the floating disc strung upon it is inserted in place and
secured by the cross bar. Boiling water is now poured upon the disc, which lies
upon the ground coffee, and the water flowing over the edge of the disc, accumulates
below it, and gradually raises it on the rod, any grains of coffee appearing above
the disc being immediately carried below it by the descending current.
The object of this floating disc is to prevent the escape of the aroma and the loss
of flavour arising therefrom. It will also serve to prevent the escape of heat from
hot infusions. Besides this, it ensures the saturation of every particle of the coffee,
and removes the tendency which light particles have to float on the surface of the
liquid.

page_text: When it is desired to further maintain the heat of the infusion, the pot may be
formed with a hot water jacket, and if this jacket is provided with an inlet and
outlet, it may be used to apply a current of cold water to carry off the heat.
The pot, it will be understood, is capable of ornamentation to suit a variety of
tastes, and the body of the pot may be enclosed in an artistic envelope of metal
work.
In addition to infusions of coffee and tea, decoctions of various drugs for domestic
use may be made in pots of this character.

page_text: I DAVID HARRY SHUTTLEWORTH-BROWN of Belle Vue Villa South Wimbledon
in the County of Surrey Engineer do hereby declare the nature of my invention
of IMPROVED PORTABLE APPARATUS FOR PREPARING INFUSIONS and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement and accompanying Drawings:-
The chief object of this invention is to provide a Pot for domestic use suitable
for producing infusions of Coffee Tea or other Vegetable matter in an efficient and
economical manner The Pot whether made of Metal Earthenware or any other
substance will take internally a Cylindrical form having a lateral curved swelling
near the bottom of the Pot which increases its diameter and provides a shoulder
for retaining any sediment that may have a tendency to pass away with the
infusion when the Pot is tipped to discharge the infusion from the Pot.
The Pot I fit internally with a Coned Seat at the bottom or its equivalent as an
annular step or shelf at a higher point for receiving a central guide rod which is
supported at its upper end by a cross bar, fastened to the top of the Pot by a
bayonet joint or its equivalent and at its lower end stands in the coned seat or
ending in a perforated plate or wheel with radial webs rests upon the annular step
or shelf.
This guide rod is intended to receive a floating disc or equivalent device of some-
what smaller diameter than the Cylindrical portion of the Pot and which is free to
rise up the rod as the water for making the infusion is poured into the Pot it is
also of such a form that it can slide obliquely down the rod floating on the surfaco
of the infusion as it is being decanted and is secured to the rod by means of a ball
or peg or radial webs or the perforated plate or wheel with radial webs attached to
the rod.
A lid may be fitted to the Pot and the lip of the Pot may be fitted with a
removable Strainer.
In making an infusion of Coffee the freshly pounded Coffee is first thrown into
the Pot then the Rod with the floating disc strung upon it is inserted in place and
secured by the cross bar Boiling water is now poured upon the disc which lies
upon the Coffee or at the lower end of the rod and the water flowing over the edge
of the disc accumulates below it and gradually raises it on the rod any grains of
Coffee appearing above the disc being immediately carried below it by the descending
current.
The infusion may be agitated if desirable by suddenly twisting the guide rod or
momentarily depressing the floating disc.
"
The object of this floating disc is to prevent the escape of the aroma and the loss
of flavour arising therefrom it will also serve to prevent the escape of heat from
hot infusions. Besides this it ensures the saturation of every particle of the Coffee

page_text: removing the tendency which light particles have to float on the surface of the
liquid as when attached to minute bubbles forming froth by wetting and drowning
them.
When it is desired to further maintain the heat of the infusion the Pot may be
formed with a jacket and if this jacket is provided with an inlet and an outlet it
may be used to apply a current of cold water to carry off the heat or of Steam or
hot water to raise or maintain it.
The Pot it will be understood is capable of Ornamentation to suit a variety of
tastes and the body of the Pot may be enclosed in an artistic envelope of Metal
Work (which would form an Air Chamber) or other material.
In addition to infusions of Coffee and Tea decoctions of various drugs for domestic
use may be made in Pots of this character.
No (i) Represents for the most part a section of a cheap and simple form of
portable infusing apparatus or Pot for domestic use suitable for making Coffee
of average strength for drinking as poured out of the Jug the general proportions
being well adapted to this purpose. The relative proportions by volume of loose
ground Coffee and water used in the making of infusions as drunk in this Country
vary in extreme cases from 2 of Water to 1 of Coffee (poison) to 20 of Water to
1 of Coffeo (dishwater) but in order to under stand how to vary the porportions of
the several parts of the Pot and what modifications of them may be necessary
to adapt them to such variations in the relative proportions by volume of Coffee
and Water and to the exigencies of other substances that may require to be infused
(for without this under standing a Specification of the Invention cannot be com-
pleted i e. the nature of the invention and in what manner it is performed cannot
be particularly described and ascertained) it is necessary to consider as an example
what takes place when Coffee is made in the most usual way vizt by pouring boiling
water upon ground Coffee.
During the process of roasting which the Coffee bas already undergone it has lost
nearly 20% in weight and increased 50° in volume owing to the expansion by
heat of the contents of its Cells which have been enlarged and burst whereby water
converted into Steam together with a considerable amount of organic matter has
passed away and the essential oils before encysted permeate the charred porous and
absorbent mass and have developed aroma a peculiarly delicious and invaluable
but subtle and almost imponderable essence a volatile oil which is freely exhaled
when the Coffee is pounded and is extremely susceptible to the action of any
further application of heat such as "by pouring boiling water upon it."
What takes place therefore when boiling water is poured upon the Coffee is this
the fragmentary particles of roasted and pounded Coffee being as just observed
porous and absorbent take up the water by imbibition and the air in their bibulous
Cells richly charged with the Aroma is instantly displaced it is expanded by the
heat of the water and rises as a copious froth in minute but innumerable bubbles
which carry up to the surface a considerable amount of the Coffee.
.
The particles of this Coffee adhere to the bubbles and ride upon them as on a
raft and thus exposed to the atmosphere and to the action of the heat give off the
aroma which pervades and permeates their cellulous mass and which is being lost
to the infusion whilst they are but slowly absorbing the liquid film or envelope of
the bubbles to which they adhere and which is also undergoing the process of
evaporation so that the bubbles one by one burst and disappear and the aroma
which they contained and had derived from the pores of all the mass of sediment
at the bottom of the infusion escapes into the air and is almost entirely lost-As
the bubbles burst the particles of Coffee that adhered to them losing their support
sink into the dense liquid in which as they absorb it (with diminished avidity) they

page_text: gradually descend and continue to muddle the infusion till the last bubble has
burst if not till the last particle of Coffee lies saturated at the bottom.
The following considerations may also be taken into account.
The loss of aroma from the surface of a liquid charged with it (pressure and
temperature and the varying tensions of the different vapours, of course below the
point of ebullition, having their due allowances) will be nearly proportional to the
surfaco exposed and layers of bubbles presenting to the atmosphere each in turn
spheroidal surfaces innumerable until evaporated or absorbed offer a combined
surface so intensely magnified as, (if it were not for the Aroma escaping from the
floating particles of Coffee and from the bursting bubbles themselves) almost alone
to account for that delicious aroma which pervades a whole house whon Coffee is
making.
If a Vossel containing a hot infusion of Coffee be closed by a lid the aroma will
still be lost to the infusion though it may not escape from the lid it will simply
condense as a grease (which thence becomes filth) on the interior of the walls and
lid of the Vessel and a small residue of the lost or vapourized aroma will condense
and appear liko stars on the surface of the infusion if it is left to go cold in the
Vessel.
The surface of a hot infusion when covered with layers of minute bubbles
presents as has just been observed an intensely magnified area which considered as
an evaporating surface not only rapidly reduces the temperature of the liquid (the
power of which to extract is (so far) proportional to the power of its heat to
increase the tension of the vapour of the aroma that is in the Coffee) but this
intensely magnified area coextensively evolves and dissipates the aroma the elastic
force of which created by the heat is nearly proportional to the quantity which the
liquid has extracted.
The subjection of the surface so magnified of a hot infusion to the action of tho
atmosphere is said to cause the Tannin of the infusion to be altered by the oxygen
of the air to which it is exposed (In Tea the surface is not so magnified but the
Tannin is much more abundant than in Coffee.)
Given two infusions of Coffee A and B in the same condition and at the same
temperature and let A be under pressure the aroina will escape more freely from
the surface of B than from that of A.
It is obvious from the above considerations:-1st That the total number of
bubbles formed (and the amount of Coffee that will rise up to the surface and ride
upon them (when boiling water is poured upon pounded coffee will largely
depend upon the amount of coffee used and very little upon the amount of water
and therefore in order that the floating disc may have the requisite power to sub-
merge the bubbles of aroma and particles of Coffee that float upon them it should
have an amply sufficient diameter and its displacement should be in excess of the
sum of that of all the bubbles taken together-i e their entire united contents.
Now taking Cylinders of different diameters and considering the fact that the
width of an annulus sufficient to give clearance for the floating disc, in a Cylinder
of large diameter will not require to be appreciably greater than in a Cylinder of
small diameter, the surface exposed on account of clearance in a Cylinder of large
diameter is relatively to the area of the Cylinder (or of the floating disc) much
less than the surface exposed on account of clearance in a Cylinder of small
diameter, this clearly indicates an advantage in using Cylinders of relatively
large diameter (relatively to their length or contents) and floating discs of
relatively large diameter (relatively to the depth of their displacement).
Now as to the confirmation and proportions of the floating disc in regard to
displacement it will be further obvious on an inspection of figure (i) that in order
that the infusion may be decanted the jug will have to be tipped and that
then the disc floating on the liquor will assume a position oblique to that of the
rod and the Cylinder and therefore it is necessary for the disc (which is an
annular sealed chamber) to have a shape in great measure similar to that in the
figure.

page_text: [It will also be obvious on inspection of figure (ii) that when the jug is canted
the greater the relative length of the Cylinder the greater the obliquity of the
float] the average line of Botation is shewn in figure (i) by a dotted line but
the bubbles tend to buoy up the float so that the annulus of surface exposed varies
hence for another reason the proportions of the floating disc require to be such that
the large amount of displacement necessary to well submerge the bubbles is
obtained rather by increasing its diameter than its depth Some margin of depth
however is required to prevent the disc itself from being submerged by the
descending torrent of boiling water which runs over the edge driving down the
bubbles of aroma and particles of Coffee as they appear and reappear on the surface
of the annulus.
(The annulus of necessarily greater clearance round the guide rod I have omitted
from specific consideration on account of the smallness of its diameter.)
The bubbles of aroma being driven down by the water are not only subjected
to a repeating impulse of considerable pressure but are separated from each other
and divided throughout the whole body of the infusion which they are caused to
retraverse as long as the pouring down of the boiling water continues during this
time they will impart much of their aroma to the liquid owing to the combined
action of the laws of pressure and heat and when the pouring down of the boiling
water has ceased the same beneficial effects are produced less forcibly but more
continuously (owing to an identical combination of the same laws) by the floating
disc which exerts a pressure on the surface of the liquid commensurate with the
average depth of its displacement but effective (as is deducible from the previous
observations) according to its proportions and configuration and its being an air
chamber gives it the property of retaining in the surface of the liquid in contact
with the bubbles of aroma the heat which favors their disengagement with, and
the absorption by the liquid of, their aroma, while it largely prevents the liquid
from cooling by the evaporation that would otherwise take place all over an
intensely magnified surface.
But these effects of the floating disc are subsidiary to that which is due to its
being a seal which approaches the absolute as the annulus of clearance approaches
nil, and so far prevents the escape of all that volatile organic matter which is
taken up by the infusion from the. whole mass of sediment that lies at tho
bottom of it.
(To illustrate how great and continuous must be the escape of volatile organic
matter from the surface of a hot infusion even when the lid is shut down a common
test used every day to ascertain the quality of Milk may be cited. A glass
containing somo milk, a liquid which cannot be said to be pungently aromatic at
the ordinary temporature of the atmosphere is covered with the hand and after
a little time the quality and quantity of the aroma which is ascertained by smelling
to have accumulated between the surface of the milk and the hand is a test of the
quality and freshness of the milk.)
So effectively is all this process carried out in ordinary practice with a pot
constructed very nearly on the lines of figure (i) that when an infusion of Coffee
has stood 10 or 15 minutes if the floating disc be slightly depressed, it is found
that the water which appears above the annulus is pale in colour, and to equalise
the strength of the infusion it is necessary either to push the disc vigorously down
at the expense of the aroma which then momentarily escapes, or to twist the guide
rod which can be done without any expenso of aroma (An inspection of figure (iii)
will make it obvious that the guide rod can bo twisted without unshipping it or
even raising the lid.) So thoroughly saturated are all the particles of Coffeo
owing to the action of the floating disc, that they readily subside after such a
disturbance.
The object of the swelling at the base is as has been explained to hold back the
sediment when the ius is tinned and the infusion'decanted the proportions of this

page_text: plate at that moment the bubbles are wiped by the plate and particles adhering
to the surfaces of the swelling bubbles are left below.
Especially useful is this plate when the whole apparatus is bound to have the
smallest possible dimensions as when it has to be packed in the knapsack of the
Soldier or of the Traveller when time and space are of the utmost value and weight
is abhorrent-then the swelling at the base is reduced in the utmost degree (to nil)—
and is only represented, see figure (iii), by the space beneath the annular step or
shelf on which the perforated plate, attached to the guide rod rests.
In such a case a concentrated infusion (to be afterwards diluted) is required to
be made in the shortest possible time-the parallel folding handle will enable the
jug with its contents to be heated in water boiled in any other vessel that may be
at hand e.g. it may be crammed into a disused potted meat tin, however it may be
used, the displacement of the floating disc can be slightly reduced in depth-but
⚫ this necessitates (as a proportionately large amount of Coffee is used) a reduction
in the size of the holes in the perforated plate, which however diminishes circula-
tion between the body of the infusion and that of the sediment-and this
necessitates the active acceleration of the infusing process which is effected by
twisting the core of the guide rod during its progress.
The bayonet joint is not shewn in position in figure (iii) (to avoid complicating
the diagram) but the spring or cross bar is given as a detail above it-it is
depressed in the centre in order that the floating disc may not rise so high as to
expose the surface of the infusion to the atmosphere in the lip which it would
inevitably do if it rose till the line of flotation was quite at the top of the Cylinder-
this will be obvious on inspection of fig: (ii).
The lip in figure (iii) need not be so deep as there represented, it is for the sake
of compactness shewn as shorter than those in the other figures and may, when
for the same reason it is reduced in depth, be made of unusual width.
The strainer shewn in the lips is a perforated crescent shaped plate and slides into
a groove and being removable, it and the acute angled corners in the lip which
when fixed strainers are used are usually left dirty, can be easily and thoroughly
cleaned.
It is scarcely necessary when making infusions of coffee as described in connection
with figure (i). The perforated plate at the foot of the guide rod in figure (ii)
prevents such foreign mattor as stalks from rising to the surface and clogging the
action of the float when making infusions of other substances such as Tea.
Some substances require to be constantly agitated whilst an infusion is being
made, an inspection of figure (iii) will at once show how easily this may be effected
by twisting the core of the guide rod, by means of the knob outside the lid and
the simple form of coupling beneath it, this coupling is so constructed that when
the lid is shut down the member's engage no matter at what angle their faces may
happen to meet each other the lighter member or that which moves, with the
greater ease, simply twists round to the right position so that the lid may be shut
down closely, if there be no lip, all direct contact with the atmosphere may (as
far as practicable) be avoided, whilst a substance is being thus agitated.
The guide rod (which is here a sleeve or tube with a solid core to which the
webs are attached) it is necessary to make as thin as possible because the central
annulus which has otherwise been omitted from consideration increases in rapid
ratio with every increase in the diameter of the rod if the floating disc, is to bo
free to describe. So large an angle with the rod that opposite sides of the upper
and lower cones may be in contact with it.
It will be readily perceived that if for the purpose of infusing some substances
it were required the core could be removed, a stop cock applied and steam admitted
by the guide rod to act directly upon the solid matter which it would sufficiently
agitate without the webs whilst in operation. It will be equally clear that in such
a case steam would have to be admitted very gradually to avoid ebullution and
the consequent escape of aroma and that if either steam or water were admitted

page_text: pounded Coffee used if it is annular the sediment spreads pretty evenly over the
whole of it, sides, back and front, and only a superstratum falls forward as the jug
is canted if therefore the swelling were wholly at the front as it might be (in the
relation in which the front of a riding boot stands to the leg of the boot) its
capacity would naturally have to be greater, there is a limit to the capacity of or
rather perhaps confirmation and proportions of the back part of an annular swelling
-which it may be observed has been just exceeded in figure (ii) for the purpose
of shewing what may take place when the cylindrical part of the jug is half full
and while it is to a certain extent less, than half full-if the jug be canted the
plane of the surface of the liquid will pass through the dotted diagonal lines and
when it reaches the lower line, an amount of air depending on the capacity of the
swelling passes into it, then when the jug is righted the air rises in the form of a
large bubble which disturbs the infusion and makes a blobbing noise.
As it is only a super stratum of the sediment which tends to fall forward when ⚫
the jug is canted it is obvious when the swelling is annular that even a small
projection inwards at foot and in front of the Cylinder will keep back a large
amount of sediment-but if in figure (i) such a projection were made not only
would the webs which keep the floating disc on the rod have to be raised in order
to support it in a level position to receive the torrent of boiling water and cover
the coffee but an avoidable objection would arise owing to the filthy condition in
which the making of an infusion of Coffee leaves a vessel if not cleaned immediately
after use it is desirable to have the vessel so constructed that every appreciablo
portion of its interior surface is accessible to both eye and hand.
When therefore it is desirable to diminish the proportions of the swelling without
at the same time diminishing its power of holding back the sediment or the
amount of sediment it is required to hold back as e. g. when a jug is to have the
cylindrical part of relatively greater proportions (and since as inst observed it is
always desirable to avoid such surfaces as a projection would Lave and renders
inaccessible the alternative method of seating the foot of the guide rod shewn in
figure (ii) is resorted to.
In this figure (ii) it is at once obvious that the swelling is the same as that in
figure (i) but that the cylinder, being longer (as mere taste may have dictated)
is of relatively far greater capacity, and therefore that tho relations thus established
are the same as if the proportions of the swelling had been diminished-now to
increase its power of holding back the sediment and yet to avoid any appreciable
projection, a wheel, or an annular plate with wobs is fixed on the end of the guide
rod and rests on air annular step or shelf at the bottom of the cylinder then it is
clear that a removable visible and cleanable projection is formed by that part of
the wheel or plate which is towards the front of the jug, or if instead of such
wheel or annular plate a perforated plate be used the perforations need not reach
the front part of the plate.
Where it is desirable to make a very strong infusion in a vessel of empirical
proportions (such as figure (ii)) that is to say, when for the sake of appearance or
for any other reason it is not allowable to increase the diameter of the Cylinder
but prolong it (eo facto not only the diameter but the conformation and displace-
ment of the floating disc are restricted for the reasons before pointed out) then
the perforated plate may be made to serve the purpose of compensating for the
restrictions hereby imposed upon the floating disc by preventing so large a number
of particles (which it has before been observed depends upon the amount of Coffee
used) from rising on the surfaces of the bubbles as might have the effect of clogging
or interfering with the free action of the floating disc, not that the perforations
act as a filter, the way in which the perforations act is very nearly as follows-in
the first instanco the boiling water falling over the edge of the floating disc as it
lies on the plate heats the plate in passing through it, the bubbles rise to tho level
of the plate and come into contact with it they are enlarged by the heat it
imparts especially at the moment when they are passing through the holes in the

page_text: (14) An arrangement of the above named parts or their equivalents and of
combinations of the same as shown in figure (ii) in the accompanying Drawings.
(15) An arrangement of the above named parts or their equivalents and of
combinations of the same as shown in figures (iii) in the accompanying Drawings.
Dated this day the 22nd of January 1885.

page_text: freely upon such a substance as coffee the floating disc would require to be packed
like a steam piston and therefore would not function on the rod but a tap would
be required to draw off the infusion.
It will hardly be necessary that any envelope in which it may be desirable to
encase the jug for the purpose only of raising or retaining the heat should reach
higher than the line of flotation of the disc,-the value of an envelope that will
retain the heat in an infusion of coffee may be judged from the amount of grease,
(in valuable aromatic oil) which (becoming filth) is found to be deposited on the
sides of the Vessel when emptied, apart from that which was deposited after
evaporation from the surface of the infusion, a large amount is due to the nature
and direction of the circulation of the hot liquid whilst heat is radiating from tho
sides of the Vessel in which it is contained, it may be accounted for very nearly
in this way, a tendency to depression round the edges of the surface of the liquid
owing to the loss of heat by contact of particles of the liquid with the material of
the Vessel, which is losing its heat by radiation, is augmented as this contact is
continued by the creation of a downward current the velocity of which is
proportionate to the loss of heat by radiation which causes the same set of particles
to traverse down the wall of the Vessel until they have parted with an amount of
heat proportionate to the depth of the Vessel and the rate of radiation from its
outer surface till they reach the bottom, where they lie, displacing particles of a
higher temperature which rise up the centre of the body of the liquid, to follow
the same course, the absorption by the wall of the Vessel of the heat of tho
liquid particles may accentuate its affinity for their aroma which they loso at the
same time as they part with their heat the one traverses, the other strikes and is
deposited on, the wall of the Vessel.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is
(1) A Cylinder with a swelling to contain sediment at the base and forming a
shoulder to retain solid matter when the jug is tilted.
(2) The same with a lip at the top of the cylinder.
(3) A removable strainor in the lip.
(4) A coned seat or its equivalent at the bottom of the pot to serve as a foot
step for and to centre a guide rod.
(5) An annular step or shelf or equivalent device at the base of the cylinder on
which to rest radial webs or a wheel or a perforated plate attached to the foot of
a guido rod.
(6) A guide rod centred and fixed by or centred in a crossbar and bayonet joint
or its equivalent at the top and by the coned seat or by the annular step and radial
webs or by their equivalents at the bottom.
(7) A guide rod centred by any device equivalent to these and having agitators
at the bottom.
(8) A tubular guide rod fitted by a stop cock at the top and open at the
bottom,
(9) A tubular guide rod with a solid core having agitators at the bottom and at
the top a member of a coupling capable of engaging at any angle with its fellow
on the bottom of a knob in the lid by which it may be revolved or the equivalent
of this coupling and knob.
(10) A floating disc or equivalent device within the cylinder.
(11) A floating disc of the conformation generally described in the accompanying
complete Specification and Drawings and capable of functioning upon the guide rod.
(12) A wheel or perforated plate or radial webs or a cross pin with or without
the same attached to the foot of the guide rod and resting on the annular step or
equivalent device at or near the foot of the cylinder.
(13) An arrangement of the above named parts or their equivalents and of
combinations of the same as shown in figure (i) in the accompanying drawings,
.