Year: 1886

page_text: Date of Application, 26th May, 1886.
Complete Left, 26th Feb., 1887.
Complete Accepted, 29th Mar., 1887
We, JAMES BINGHAM ALLIOTT, Engineer and JOHN MCCLURE CALDWELL PATON,
Engineer, both of Bloomsgrove Works in the Borough of Nottingham in the County
of Notts do hereby declare the nature of this invention to be as follows:—
Our improvements in Filter Presses and in apparatus connected therewith, relate to
improvements or the arrangement of Filter presses and apparatus connected therewith
invented by James Bingham Alliott and for which Provisional Protection was granted
on the 15th day of September 1885 under number 10,942 and in the first instance to
improvements in that kind of Filter Press in which the plates of the Filter Press are
forced into contact or approximate contact with each other and the end plate is with-
drawn when necessary by means of a Piston working in a suitable cylinder and
actuated by water or other fluid pressure.
Our improvements consist in so arranging and proportioning the piston, the cylinder
and their connections to the press that the piston may be capable, not only of forcing
the plates into contact or approximate contact with one another, but also of maintaining
then in such contact without the assistance of nuts and screws or of movable distance
pieces while the press is in use for filtering under pressure.
In order that this work may he performed with the least expenditure of power, we
usually cause the plates to be forced into approximate contact by means of a very
moderate water or other fluid pressure sufficient to move the plates into their places,
but not to hold them firmly in their places when the press is at work filtering under
pressure, and we then place the hydraulic cylinder into communication with water or
other liquid under a high pressure maintained in an accumulator or obtained in any

page_text: other ordinary convenient way sufficient to keep the press securely closed while
filtering under pressure, so that only a very small quantity of liquid under high
pressure will be used.
In some cases we apply arrangements for producing this increased pressure within
the cylinder itself. For this purpose it is usually most convenient to arrange a small
auxiliary plunger working through a gland in the cylinder cover. This auxiliary
plunger may be forced in by means of a screw thread cut upon that portion of it which
is outside the gland and working in a nut secured in a suitable bracket attached to the
cylinder cover. In some instances we make the piston rod hollow so that this
auxiliary plunger can project into the hollow and thus we are able to increase the
length and the stroke of the plunger. The cylinder may, when this arrangement is
used be furnished with means for preventing the pressure within it rising too high
and this may be most conveniently arranged by causing the pressure to act upon a
weighted plunger, which the pressure, when it exceeds the desired limit, will cause to
rise. We cut grooves or flutings on the lower part of this plunger so that after it has
risen to a certain point part of these grooves or flutings will be exposed, and thus the
escape of fluid from the cylinder will be permitted. It is obvious that by means of
such a weighted plunger the pressure in the cylinder can be maintained for some time
even though there should be some leakage past the piston or through the glands.
In some cases we dispense with the auxiliary plunger with screw threads herein
before described and employ only one weighted plunger for producing and maintaining
the high pressure.
When this arrangement is used the weight may be taken or raised
off this plunger by lifting tackle or balanced by counterweights while the water or
other fluid under the lower pressure is admitted to the cylinder, which will then force
out this plunger simultaneously with the piston till it comes against suitable stops
arranged to limit its stroke, after which the valves are closed and the weight is again
put on this plunger, which then produces and maintains the higher hydraulic pressure
on the piston...
Another part of our improvements consists in an improved arrangement of flanged
thimbles or collars, such as are referred to in the provisional specification of the herein
before mentioned invention and which are there described as being used to secure the
filtering cloth to the plates of the press and as being employed to carry the projections
by means of which one plate of the press is enabled to receive support from other
plates.
These flanged thimbles or collars which are applied on each side of each of the
loose plates in the press, and on one side of the end plates when these have a central
hole through them, are described as being screwed the one into the other from opposite
sides of the plate. When thus arranged these flanged thimbles or collars take a
considerable time to attach or to remove while the friction of the flanges upon the
filtering cloth during the screwing home of the thimbles or collars is objectionable.
In our improved arrangement, instead of screwing the one flanged collar into
the other, we make the one flanged collar with a slightly bellied interior projecting
almost through the plate, and upon the other collar we arrange two or more projections
of such dimensions that they can only pass through the bellied interior of the first,
collar by springing slightly inwards, while immediately on passing through the belly
they again spring back into their original position and so each collar is held in place.
In withdrawing the collars from one another the projections again are made to spring
slighly inwards as they pass the bellied part.
The flanges of these flanged thimbles or collars have hitherto been made stiff and
unyielding they have pressed stiffly upon the filtering cloth they have held in position
and have not provided for irregularities, in its thickness.
In our improved flanged thimbles or collars we make the flanges of larger diameter
than has been usual and we generally make that portion of the flange next the thimble
stiff so as to bear firmly upon the filter plate. The outer edge of the flange however
we make thin and slightly curved towards the plate and we usually divide the edge of
the flange with radial slits, which may be cut with a saw or cast in or produced in any

page_text: other ordinary convenient way. Between the outer edge of the flange and the thimble
we arrange a circumferential recess which serves to receive the hem or other thickened
part around the central hole in the filter cloth. The thin slightly curved edge of the
flange of our improved collars possesses a slight degree of flexibility which may be
increased by radial slits made in it, and we so arrange the flanged collars that when
these are in position the flange edge bears upon the filtering cloth with a slight
pressure, which may somewhat increase as pressure arises within the press in
working.
These improvements are applicable also to flanged thimbles or collars, which are
not provided with projections for enabling one plate of the press to obtain support
from other plates, as well as to those which have such projections.

page_text: COMPLETE SPECIFICATION.
Improvements in Filter Presses and in Apparatus Connected
therewith.
.
We JAMES BINGHAM ALLIOTT Engineer and JOHN MCCLURE CALDWELL PATON,
Engineer both of Bloomsgrove Works, Nottingham in the County of Notts, 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 improvements in filter presses and in apparatus connected therewith relate to
improvements on the arrangements of filter presses and apparatus connected
therewith invented by James Bingham Alliott and for which letters patent were
granted to him dated the 15th day of September 1885 and numbered 10942, and in
the first instance to improvements in that kind of filter press in which the plates of
the filter press are forced into contact or approximate contact with each other,
and the end plate is withdrawn when necessary by means of a piston working in a
suitable cylinder and actuated by water or other fluid pressure.
Our improvements consist in so arranging and proportioning the piston, the cylinder
and their connections to the press that the piston may be capable not only of forcing
the plates into contact or approximate contact with one another but also of
maintaining them in such contact without the assistance of nuts and screws or
moveable distance pieces, while the press is used for filtering under pressure. In
order that this work may be performed with the least expenditure of power, we
usually cause the plates to be forced into approximate contact by means of a very
moderate water or other fluid pressure sufficient to move the plates into their places,
but not to hold them firmly in their places when the press is at work filtering under
pressure, and we then place the hydraulic cylinder into communication with water or
other liquid under a high pressure maintained in an accumulator or obtained in any
other ordinary convenient way sufficient to keep the press securely closed when
filtering under pressure, so that only a very small quantity of liquid under high
pressure is used.
In order that our invention may be more readily ascertained and carried out we
have hereunto appended a sheet of drawings marked with letters of reference.
Figure 1 shows a plan of a press cylinder arranged for carrying the improvement
herein before described into effect. a is the cylinder, the piston with piston rod e to
which the end plate of the filter press is attached. d is the inlet pipe for the water or
other fluid under the lower pressure connected to a three way cock with branch
pipes and to the front and back end of the cylinder respectively. e is the outlet
pipe connected to the three way cock e¹ with branch pipes and to the front and
back end of the cylinder respectively. is the inlet pipe for the fluid under higher
pressure, with a stop cock. In working, the press the cocks d¹ and el are turned
into the positions shewn on the drawing, when the low pressure fluid will flow from
pipe through the cock d¹ and branch into the cylinder and push the piston b
out, the fluid contained in front of the piston escaping through e, e¹ and e.
When

page_text: the filter press plates have been brought into contact or approximate contact, the
cock dis turned so as to close the communication from pipe to the cylinder and
the cock is opened, when the fluid under higher pressure will force the filter press
plates into close contact and hold them so while filtering. When the plates are to be
separated, the cock" is closed, the cock e¹ turned so as to connect pipes and e and
the cock turned so as to connect the pipes d and d². The fluid under the low
pressure will then enter the cylinder at the front and force the piston back, the fluid
behind the piston escaping through es, el and e.
In some cases we apply arrangements for producing this increased pressure within
the cylinder itself. For this purpose it is usually most convenient to arrange a small
auxiliary plunger working through a gland in the cylinder cover or the cylinder side
which is forced into the cylinder. An arrangement for carrying out this improvement
is shewn by figure 2, which represents a vertical section through the cylinder. The
cylinder cover is provided with a stuffing box and gland for the auxiliary plunger i,
which has a screw thread cut upon that portion of it which is outside the gland. The
threaded part works in a nut & secured in the cross bar which is attached to the
cylinder cover by means of the nuts on the pillars and 12 or by equivalent
brackets. The cylinder is fitted with pipes for the inlet and outlet of the low pressure
liquid in a similar manner as hereinbefore described with reference to figure 1. After
the low pressure liquid has forced the piston forward until the filter press plates
have been brought into contact or approximate contact, the inlet cock d' is closed and
the plunger forced into the liquid contained in the cylinder by turning the hand
wheel m and the plunger spindle to which it is attached. The increased pressure of
the liquid produced thereby holds the filter press plates in contact while the filtering
is performed, after which the plunger is screwed out again and the cocks and a
turned so as to admit the low pressure liquid to the front of the piston and allow
the liquid behind the piston to escape, in a similar manner as hereinbefore described
with reference to figure 1.
i
In some cases we make the piston rode hollow so that the auxiliary plunger can
project into the hollow and thus we are able to increase the length and stroke of the
plunger.
The cylinder may, when the arrangement of an auxiliary plunger for producing
the increased pressure is used, be furnished with means for preventing the pressure
within it rising too high. This may most conveniently he arranged by causing the
pressure to act upon a plungern loaded with weights o or their equivalent, which the
pressure, when it exceeds the desired limit, will cause to rise. We cut grooves or
Hutings n' on the lower part of this plunger so that after it has risen to a certain
point, part of these grooves or flutings will be exposed above the packing gland p
and permit the escape of liquid from the cylinder a. It is obvious that by means of
such a weighted plunger the pressure in the cylinder can be maintained for some time
even though there should be some leakage past the piston or through the glands.
In some cases we dispense with the auxiliary plunger with screw threads and
employ only one weighted plunger n for producing and maintaining the pressure.
When this arrangement is used, the weights o may he raised or taken off this plunger
by lifting tackle or balanced by counter weights while the. low pressure liquid-is
admitted behind the piston b, which will force out the plunger simultaneously with
the piston till the plunger n comes against suitable stops arranged to limit its
stroke. The grooves or flutings a' are omitted in this case. The inlet cock is then
closed and the weight is again put on this plunger n, which then produces and
maintains the higher hydraulic pressure on the piston b.
It is obvious that the constructive details of the arrangements herein before described
may be varied and we do not confine ourselves to the details shewn on the drawings,
which may be replaced by their mechanical equivalents producing the same effect.
Another part of our improvements consists in an improved arrangement of flanged
thimbles or collars such as are described in the specification of James Bingham Alliott,
dated the 15th September 1885 and numbered 10942, with reference to figures 5, 6, 7
and Son sheet 2 of the drawings appended to the said specification and which are

page_text: there described as being used to secure the filtering cloth to the plates of the press and
as being employed to carry the projections by means of which one plate of the press
is enabled to receive support from other plates. These flanged thimbles or collars,
which are applied on each side of the loose plates in the press and on one side of the
end plates when these have a central hole through them, are described in the said
specification as being screwed the one into the other from opposite sides of the plate.
When thus arranged these flanged thimbles or collars take a considerable time to attach
or to remove, while the friction of the flanges upon the filtering cloth during the
screwing home of the thimbles or collars is objectionable.
7"
In our improved thimbles or collars, which are shown by figure 3 in section and by
figure 4 in end view these inconveniences are obviated. Instead of screwing the one
flanged collar into the other, we make the one flanged collar with a slightly bellied
interior projecting into or through the filter plates and upon the other collar we
arrange two or more projections of such dimensions that they can only pass
through the bellied interior by being slightly sprung inwards, while immediately on
passing through the belly they again spring back into or nearly into their original
position and so each collar is held in place. In withdrawing the collars from one
another the projections are again made to spring slightly inwards as they pass the
bellied part.
The flanges of such collars or thimbles have hitherto been made stiff and unyielding
and have pressed stiftly upon the filtering cloth they have held in position and have
not provided for irregularities in its thickness. In our improved flanged thimbles or
collars we make the collars of larger diameter than has been usual and we generally
make that portion of the flange next to the thimble stiff so as to bear firmly upon
the filter plate. The outer edge of the flange however we make thin and slightly
curved towards the plate and we usually divide the edge of the flange with radial slots
3, which may be cut with a saw or cast in or produced in any other ordinary
convenient manner. Between the outer edge of the Hange and the thimble we arrange
a circumferential recess which serves to receive the hem or other thickened part
around the central hole in the filter cloth. The thin slightly curved edge of the
Hange of our improved collars or thimbles possesses a slight degree of flexibility, which
may be increased by radial slits made in it, and we so arrange the flanged collars that
when these are in position, the edge of the flange bears upon the filtering cloth with
a slight pressure, which may somewhat increase as pressure is produced within the
press in working.
These improvements ars applicable also to flanged thimbles or collars which are not
provided with projections for enabling one plate of the press to obtain support from
other plates, as described in the specification herein before referred to with reference
to screwed collars, as well as to those which have such projections, and the
improvements in the flanges of the collars or thimbles are also applicable to thimbles
that are screwed upon each other.
Having now particularly described and ascertained the nature of our said invention
and in what manner the same is to be performed we declare that what we claim is
Firstly, the combination with a filter press of a cylinder and piston operated by
hydraulic or other fluid pressure so arranged that a moderate fluid pressure is employed
to open and to close the press and a higher fluid pressure is applied to one side of the
piston to keep the press closed while filtering, substantially as herein before described.
Secondly, the combination with a filter press of a cylinder and piston operated by
hydraulic pressure and so arranged that a moderate hydraulic pressure is employed to
close and open the press and provided with appliances for increasing regulating, and
maintaining the pressure within the cylinder itself to the pressure required to keep the
press closed while filtering..
Thirdly, the arrangement of increasing the pressure within hydraulic cylinders
combined with filter presses and arranged as specified in the preceding claim, by
means of a plunger forced into the cylinder by a screw, substantially as herein before
described with reference to figure 2 of the drawing.

page_text: Fourthly, the arrangement of a weighted plunger for regulating and maintaining
the increased hydraulic pressure produced within cylinders combined with filter presses
by means of plungers forced into the cylinders, substantially as herein before described
with reference to figure 2 of the drawings.
Fifthly, the arrangement of weighting a plunger for producing, regulating and
maintaining an increased hydraulic pressure within cylinders combined with filter
presses and arranged as specified in the second claim substantially as herein before
described.
Sixthly, the construction or arrangement of flanged thimbles or collars for filter
presses with a bellied interior to one of them and flexible projections to the other
substantially as herein before described and illustrated by figures 3 and 4 of the
drawings and for the purposes set forth.
or
Seventhly, in flanged thimbles or collars for filter presses the construction
arrangement of the flanges with a stiff portion next to the thimble or collar and thin
slightly curved and flexible edges, substantially as herein before described and
illustrated by figures 3 and 4 of the drawings.
.
Eightly, in flanged thimbles or collars for filterpresses the construction or formation
of the flanges with a circumferential recess, substantially as herein before described and
illustrated by figures 3 and 4 of the drawings and for the purpose set forth.
Ninethly, The combination of the improvement claimed in the sixth, seventh and
eight claim or any two of them in one pair of flanged thimbles or collars for filter
presses.