IMPROVEMENTS IN FILTERS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by the said George Frederick Marshall
at the Office of the Commissioners of Patents on the 9th November 1883.
GEORGE FREDERICK MARSHALL, of Battersea, in the county of Surrey,
Manufacturer, "IMPROVEMENTS IN FILTERS
"
This invention relates to improvements in filters, the improvements having for
object to so simplify the construction as to allow the filtering medium to be more
easily removed for cleansing or renewal than hitherto, and whereby all cement
joints are dispensed with, and no removeable or loose pan is required, the improved
construction also allows of the whole of the body of the filter being inspected and
cleaned when the filtering medium is removed.
In carrying out my invention the body of the filter is provided on its interior
circumference with the usual projecting Blange but I form or provide this flange
with a cross piece adapted to carry a vertical spindle in the centre thereof, this
spindle is formed with a screw thread; the filtering medium may be of any
suitable material and is formed with a central holo passing right through it
vertically so as to allow the said medium to be passed over the said spindle, the
size of the filtering medium must be such that the outer part of its underside
will rest on the flange in the body of the filter. The upper surface of the said
flange is preferably formed with a rim or projection so as to form a channel for
receiving a corresponding projecting edge of the filtering medium. To form a
water-tight joint between the filtering medium and the flange I place an elastic
seating preferably of tubular rubber in the herein before described channel in the
flange, against which elastic seating the projecting edge of the filtering medium
is pressed by means of a screw nut on the herein before described central spindle.
Suitable elastic packing is also provided between the filtering medium and the
spindle.
By this construction it will be obvious that to remove the filtering medium for
cleaning, renewal, or otherwise it is simply necessary to unscrew the said scrow
nut; the filtering medium having been removed the whole of the interior of the
6lter will be open to inspection.
To increase the efficiency of the filter I manufacture the filtering medium 50
that the water or other liquid to be filtered cannot pass directly through it; this
I effect by forming the top or other parts of the filtering medium solid, thereby
diverting the stream of liquid so as to increase the length of its passage through
the filtering medium.
:
:

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said George Frederick Marshall in the Patent Office on the 9th May
1884.
GEORGE FREDERICK MARSHALL, of Battersea, in the County of Surrey,
Manufacturer "IMPROVEMENTS IN FILTERS "
This Invention relates to improvements in filters, the improvements having for
object to so simplify the construction as to allow the filtering medium to be more
easily removed for cleansing or renewal than hitherto and whereby all cement
joints are dispensed with and no removeable or loose pan is requirod, the improved
construction also allows of the whole of the body of the filter being inspected and
cleaned when the filtering medium is removed.
In carrying out my invention the body of the filter is provided on its interior
circumference with the usual projecting dange but I form or provide this flange
with a cross piece adapted to receive or carry a vertical spindle in the centre
thereof, this spindle is formed with a scrow thread; the filtering medium may be
of any suitable material and is formed with a central hole passing right through
it vertically, the size of the filtering medium must be such that the outer part of
its underside will rest on the flange in the body of the filter. The upper surfaco
of the said flango is preferably formed with a rim. or projection so as to form a
channel for receiving a corresponding projecting edge of the filtering medium.
To form a watertight joint between the filtering medium and the flange I place
an clastic seating preferably of tubular rubber in the herein before described
channel in the flange, against which elastic seating the projecting edge of the
filtering medium is pressed by means of a screw nut or bolt head on the herein-
beforo described central spindle. Suitable elastic packing is also provided between
the filtering medium and the spindle.
To increase the efficiency of the filter I manufacture the filtering medium so
that the water or other liquid to be filtered cannot pass directly through it; this
I effect by forming the top or other parts of the filtering medium solid or non
porous thereby diverting the stream of liquid so as to increase the length of its
passage through the filtering medium."
In order to enable my invention to be fully understood I will proceed to describe
the same by reference to the accompanying drawing in which figure 1, is a sido
elevation of a filter constructed according to my invention; figuro 2, a plan of the
same the cover of the filter being removed; figure 3, is a vertical section on
line A B of figure 2; figure 4, is a plan of the filter the cover and filtering
medium being removed. Similar letters in all the figures represent similar parts.
a, is the body of the filter formed with the usual projecting flange b; c, is the
cross piece having a central hole d, formed with a screw thread to carry the
scrow threaded spindle e, formed with a head f,; the spindle e, is made of suitable
material such as porcelain and may be formed hollow to receive a metal rod to
strengthen the same; g, is the rim or projection on the flange b; h, is the filtering
medium formed of suitable porous material such as that known as silicated carbon;
i, is the projecting edge of the filtering medium, j, the central hole in the filtering
medium through which passes the spindle e; k, is the seating of suitable elastic
material such as tubular india rubber the said seating being placed in the channell;
m, is the elastic packing between the head f, of the spindle e, and the filtering
medium h; n, n, shew the parts of the filtering medium which I find it
advantageous to form solid or non-porous for the purpose herein before described;
o, is the usual tap for drawing off the filtered water; p, the usual cover; q, is the
usual passage for air to the lower chamber of the filter,

page_text: To fit up a filter of this construction the seating k, is placed in the channel Z,
of the projecting flange b, the filtering medium h, is placed so that its projecting
edge i, rests on the seating k, the spindle e, is then screwed into the hole d, of the
cross piece c, and a watertight joint will be formed between the filtering medium h,
and the flange b, and between the head f, of the spindle e and the top of the
filtering medium h
By forming the top of the filtering medium solid or non-porous the water in
the upper part A of the filter will have to pass down through the space between
the outside of the filtering medium h, and the inside circumference of the filter
and through the filtering medium as shewn by the arrows into the chamber B
whence it can be drawn off through the tap o, and it will be obvious that to
remove the filtering medium h, for cleaning, renewal or otherwise it is simply
necessary to unscrew the said vertical spindle c; the filtering medium having
been removed the whole of the interior of the filter will be open to inspection.
Having thus described my said invention and the manner of performing tho
same what I claim is :-
Firstly. The improved filter herein before described and represented in the
accompanying drawing.
Secondly. Forming parts of the filtering medium solid or non-porous as and for
the purpose herein before described.
In Witness whereof I the said George Frederick Marshall have hereto set
my hand and seal this ninth day of May in the year of our Lord one thousand
eight hundred and eighty four
MADGITA