AN IMPROVED
Year: 1882

page_text: LETTERS PATENT to Alexander Melville Clark of 53, Chancery Lane, in the
County of Middlesex, Patent Agent. for an invention of AN IMPROVED
A communication from abroad by Léon Louis Théophile
POCKET-FILTER.
Fincken d'Autemarche of Paris, France.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents on the 18th April 1882.
ALEXANDER MELVILLE CLARK of 53 Chancery Lane in the County of Middlesex,
Patent Agent, "AN IMPROVED POCKET-FILTER." [A communication from abroad
by Léon Louis Théophile Fincken d'Autemarche of Paris, France.]
This Invention relates to an improved portable or pocket filter for the use of the
army, sportsman, travellers and others. Such filters have not hitherto been
capable of being taken to pieces to allow of the frequent cleansing of the filtering
medium, notwithstanding that the water is often drawn from rivers and marshy
places in a very impure condition and the filtering material after only a few hours
use consequently becomes charged with all the impurities of the water passing
through it, which after a time decompose and taint the water subsequently passed
through the filter and ultimately clog up the pores of the filtering material and
render the filter unserviceable.
The improved portable filter of this Invention is designed to obviate these
disadvantages while it possesses the further advantage of purifying the water.
In order that the Invention may be more readily understood, I will proceed to
describe it with reference to the accompanying drawings which illustrate one
example of the filter.
Figure 1 represents a central vertical section of the filter with the loose covers.
removed. Figure 2 shows an external view of the filter complete as carried in the
pocket, trunk, knapsack, or in slings. In this figure the bottom loose cover is
represented in dotted lines to show more clearly the bayonet joint by which the
perforated bottom is secured, but any other mode of securing it may be adopted.
Figure 3 represents the perforated bottom of the filter. The same letters of
reference are used to denote the same parts in the three figures.

page_text: The filter is contained in a cylindrical case m made of any metal or alloy, or of
stoneware, chinaware, or other suitable material. a is a space above the upper
end plate in which the suction tube k is coiled when the filter is not in use. The
plate b is soldered or otherwise fixed to the cylindrical case m and in its centre is
fixed a plug c provided with a nozzle to which the suction tube is attached. Or
the nozzle may be formed on the plate b and the plug e dispensed with. The
bottom end of the casing is closed by a perforated plate g (figure 3) flanged and
provided with à cross pin whose ends project through the flange and engage in
the bayonet slots i as shown in Figure 2 to retain the perforated bottom in place.
Two notches in the edge of the casing m at right angles to the cross pin h allow
of the inflow of the water when the filter is in a vertical position. The perforated
bottom is easily removed by unlocking the pin / from the bayonet slots i.
The filter proper is composed as follows:-The casing is inverted and an india-
rubber ring fand then a disc p of felt are placed in the order named against the
end plate b; a plate e of porous stone or other suitable composition is next
introduced and upon this is placed a layer of a mixture of vegetable and animal
charcoal granulated or pulverised, which is in turn covered by a second plate of
porous stone or other composition e upon which is placed another ring of india-
rubber fand then the perforated plate g which is secured in the manner described.
The indiarubber rings fare chiefly intended to prevent oxidation when the casing m
and its heads are of metal liable to rust and to make a tight joint.
In use, the filter is placed in the water to be filtered which is sucked up through
tube provided with a glass, porcelain, bone, or other mouthpiece the water
passing through the whole thickness of the filtering medium whereby it is
perfectly purified.
The tube k may be made to form a syphon by which the filtered water may
be run into a drinking cup which might form a loose cover of the filter. To close
the filter as shown in Figure 2, the tubo k is coiled up within the space a and
cap or cover n applied, the bottom end being also closed by similar cap or cover o.
To cleanse the filter the perforated plate g and lower porous plate e are removed,
the filtering material d washed in water and afterwards replaced as before
described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Melville Clark in the Great Seal Patent Office on the
17th October 1882.
ALEXANDER MELVILLE CLARK of 53 Chancery Lane in the County of Middlesex,
Patent Agent. "AN IMPROVED POCKET FILTER." A communication from abroad
by Léon Louis Théophile Fincken d'Autemarche of Paris, France.
This Invention relates to an improved portable or pocket filter for the use of the
army, sportsmen, travellers, and others. Such filters have not hitherto been
capable of being taken to pieces to allow of the frequent cleansing of the filtering
medium, notwithstanding that the water is often drawn from rivers and marshy
places in a very impure condition, and the filtering material after only a few hours
use consequently becomes contaminated with all the impurities of the water passing
through it. After a time these impurities decompose and thenceforth taint the
water drawn through the filter and ultimately clog up the pores of the filtering
material and render. the filter unserviceable.
The improved portable filter of this Invention is designed to obviate these
disadvantages being so made that it can be readily taken to pieces for cleansing
while it possesses the further advantage of purifying the water.
In order that the Invention may be more readily understood, I will proceed to
describe it with reference to the accompanying drawings which illustrate one
example of the filter..
Figure 1 represents a central vertical section of the filter as it appears when in
use, that is to say, with the loose covers removed. Figure 2 shows an external
view of the filter as carried in the. pocket, trunk, knapsack, or in slings. In this
figure the bottom loose cover is represented in dotted lines to show more clearly
the bayonet joint, by which the perforated bottom is secured. Any other mode of
securing this cover may however be adopted. Figure 3 represents the perforated
bottom of the filter. The same letters of reference are used to denote the samo
parts in the three figures.
L
The filter is contained in a case m of cylindrical or other convenient form and
dimensions and made of a suitable metal or alloy, or of stoneware, chinaware, or
other suitable material. a is a space left vacant above the upper end plate b in
which the suction tube k is coiled when the filter is not in use. The plate b is
soldered or otherwise fixed airtight to the cylindrical case m, and in its centre is
fixed a plug c provided with a nozzle to which the suction tube k is attached. Or
plug c may be dispensed with and the nozzle be formed on the plate 6 when the
metal of which the latter is made, is sufficiently malleable to permit of this being
done. The bottom end of the casing is closed by a perforated plate g (figure 3)
cupped or flanged and provided with a cross pin h whose ends project through the
flange and engage in the bayonet slots i, as shown in Figure 2, to retain the
perforated bottom in place. Two notches q in the edge of the casing m at right
angles to the cross pin h allow of the inflow of the water when the filter is
standing upon a flat surface. The perforated bottom is easily removed by
unlocking the pin h from the bayonet slots i. To close the filter, as shown in
Figure 2, the tube is coiled up within the space a and the cap or cover n applied,
the bottom end being also closed by a similar cap or cover o.
The filter proper is composed.as follows: The casing m is inverted and an
india-rubber ring or washer f and then a felt disc p are placed in the order named
against the top end plate b; a plate e of porous stone or other suitable composition
is next introduced, and upon this is packed a thick layer d composed of a mixture

page_text: of vegetable and animal charcoal granulated or pulverised (or of any other filtering
material or composition best suited to the particular qualities of certain waters)
which is in turn covered by a second plate of porous stone or other composition e
upon which is placed another washer of indiarubber and then the perforated
plate g which is secured by the bayonet joint in the manner described. The
india-rubber washers fare chiefly intended to prevent oxidation when the casing m
and its heads are of metal liable to rust, and they also serve to make a tight joint.
To cleanse the filter, the. perforated plate g.and lower porous plate e are removed,
the filtering material d washed in water and the whole afterwards replaced as
before described.
In use, the covers no are removed and the filter is placed in the water which is
sucked up through tube k provided with a glass, porcelain, bone, or other mouth-
piece l, the water necessarily passing through the whole mass of the filtering
imedium whereby it is perfectly purified. Instead of sucking the water through a
mouth piece 7, the tube / may be made to act as a syphon by which after the
syphon is started, the filtered water may be drawn off into a drinking cup for
which purpose the loose covers of the filter might be used.
Having described the nature of the said Invention and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
herein before in part recited Letters Patent is.
1st. A portable or pocket filter constructed substantially as herein shown and
described, so that it may be readily taken to pieces for cleansing.
2nd. In a portable or pocket filter, the arrangement of the top end plate b so as
to leave a space a above it, in combination with the plug c and suction tube k,
substantially as and for the purpose specified.
3rd. A portable or pocket filter having a removable perforated bottom plate
secured by a cross pin h and bayonet fastening i, substantially as shown and
described.
4th. A portable or pocket filter consisting of a casing provided with a fixed top
plate and removable perforated bottom plate enclosing porous plates e and filtering
material d, substantially as shown and described.
In Witness whereof I the said Alexander Melville Clark have hereunto set
my hand and seal this sixteenth day of October, A.D. 1882.