Year: 1887

page_text: Date of Application, 10th Nov., 1887
Complete Left, 10th May, 1888
Complete Accepted, 29th June, 1888
HENRY JOHN ROGERS of Lavington Watford in the county of Hertford
Engineer do hereby declare the nature of this invention to be as follows:-
This Invention relates firstly to improvements in strainers for straining paper pulp
and consists in a novel method of actuating the diaphragm under the strainer plate
and also of altering the stroke of the vibration and the number of vibrations of the
said diapraghm.
Hitherto this object has been attained by cams, excentrics or cranks revolving at a
very rapid rate beneath the strainer, the motion from such cams, excentrics or cranks
being transferred to the diaphragms under the strainer plates by means of connecting
rods and levers; this necessitates a great expense in the first construction of the
strainer and very frequent repairs, besides considerable expenditure of power to
overcome the friction caused by the rapid revolution of the mechanism and also a
very unnecessary and objectionable noise.
The object of the first part of this Invention is to dispense with the whole of the
expensive machinery, to save some part of the power required to drive the strainer
and to enable the operator to alter the length of the stroke of the diaphragm and
also the number of strokes of the said diaphragm, and therefore the quantity of
pulp passing through the strainer surface, without stopping the machine; the part of
this invention relating to working the diaphragms by an Electric current being also
partially described in my application No. 4073/87.
Beneath the diaphragm of the strainer I place an armature of soft Iron and at a
suitable distance therefrom I place magnets (or solenoids) round the coils of which

page_text: passes a current of electricity from any source of electrical supply, either a dynamo
or battery or any other generator. The current passing round the coils of the
magnets or solenoids, of which there may be two or more, polarizes the cores of the
said magnets or solenoids, which (in the case of the magnets) attract the said
armature thereby depressing the diaphragm and causing a suction in the ordinary
way beneath the strainer plate, by which means the pulp is drawn through the slits
of the strainer plate; as the diaphragm is depressed the end of a rocking bar at
the same side of the strainer is also depressed and the opposite end of the said rocking
bar correspondingly raised, thus raising also the diaphragm on the opposite side of
the strainer, & clearing the slits ready for the next downward motion which is effected
by the current immediately passing from the magnets on one side to the magnets on
the other side and the same operation as before described takes place. The reversal
of the current is effected by a "make and break" action which consists of a solid roll
conveying current from the source of supply to an axle on which is fixed a disc
partly insulated from and partly in contact with the said axle the contact segments
of the said disc alternately conveying the current to the two sides of the strainer
by suitable wires. The strainer is divided in the centre so that the vacuum on the
one side will not affect the vacuum on the other side. It is also desirable to alter the
number of the vibrations of the diaphragm while the strainer is running and this is
simply effected by fixing cone or speed pulleys on the axle of the "make and break"
action.
It is of great importance to be able to alter the length of the stroke of the
diaphragm of the strainers, while the strainer is running and this I effect in my
"Electric" strainer by simply adjusting a screw or screws by which means the bed
on which the magnets rest can be moved nearer to or farther from the armatures of
the diaphragms (or the position of the arinatures themselves with relation to the
magnets can be altered) thereby giving a shorter or longer stroke as required. To
effect this alteration of stroke in an ordinary strainer I adopt an apparatus consisting
of a curved bar or quadrant projecting from the central link pivot on each side of
the strainer, the main connecting rod being attached at one end, as usual, to the crank
shaft and at the other end to this curved bar, the position of the connecting rod being
altered on the bar or quadrant by means of a handle and links, it being evident that
the higher the rod is raised on the bar the shorter will be the stroke of the
diaphragm.
The second part of this Invention relates to improvements in strainer plates to be
used with the above or with any ordinary flat or revolving strainer and consists of a
method of cleaning the slits of the strainer plates at any time without stopping the
working of the machine and at the same time of increasing the slit area of the
strainer plate.
For this purpose I use as a base plate the corrugated plate referred to in my
application before mentioned and above this plate I place a moveable plate, or plates
having conical or other shaped projections pointing downwards and corresponding
with the slits in the lower plate both in number & shape, the said upper plate or
plates being actuated either by a carefully adjustable train of gear wheels acting on
a cam or cams pressing in bearings on the surface of the moveable plate, the said
gear wheels being actuated by a milled wheel on which are marked the gauges to
which it is desired to close the slits; or by a more simple method, pieces or strips
of brass or other metal of the exact gauge to which it is desired to close the slits
are inserted in the lower plate at suitable intervals so that the upper plate may be
depressed by any ordinary mechanical means upon the lower plate, the spaces left
in the slits exactly corresponding with the brass or other gauges inserted as above
described. It will be. observed that the slits in the lower plate are conical to
correspond with the male conical wedges of the upper plate and it will be apparent
that the pulp can flow through on both sides of the wedge shaped projections on the
upper plate thus exactly doubling the amount of pulp that can pass through the same
area of plate surface.
It is evident that the upper or moveable plates can be raised by the same method

page_text: that is used for depressing them and it is also evident that this process for cleansing
the slits and increasing the area of slit surface can be applied to any existing
strainer plate by simply enlarging the present slits and adding the upper plate and
the requisite raising and depressing motion.
Or the upper plate may rest on the brass gauges before described by its own
gravity, the weight of the said plate being proportioned to the amount of upward
pressure required to clear the slits; and to make this cleansing apparatus automatic in its
action, especially when applied to my Electric Strainer, I place above the upper
plate an armature of soft Iron in electrical contact with one pole from the source of
electrical supply and in this circuit I place a resistance coil so that when the slits
become stopped up and a greater amount of current is required to form the suction
beneath the lower plate, the current passes through the resistance coil to the
armature and attracts the top plate thus clearing the slits in the lower plate
immediately; the current then becomes normal and the plate returns by gravity to
its required position; the upper plate is, of course, placed in circuit with the
opposite pole of the source of electrical supply so that the circuit is closed immediately
the current passes through the resistance coil and attracts the upper plate to the
armature above it.

page_text: COMPLETE SPECIFICATION.
Improvements in Strainers for Straining Paper Pulp and in Strainer
Plates therefor.
I HENRY JOHN ROGERS of Lavington Watford in the County of Hertford
Engineer 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 :-
This Invention relates firstly to improvements in strainers for straining paper pulp
and consists in a novel method of actuating the diaphragm under the strainer plates
and also of altering the stroke of the vibrations of the said diaphragm. My method of
actuating the diaphragm of a strainer by an Electric Current is fully explained in my
patent 407387; as a modification thereof I dispense with the rocking bar rs (see fig. 3.
407387) and arrange the magnets ab fig. 1. sheet 1 so that the pull is upwards the two
sides of the strainer being worked simultaneously or alternately by means of the "make
and break" action shewn in figs. 4 and 5 in the patent above quoted the armature
being depressed by the magnets a¹ b¹.
It is of great importance to alter the length of the stroke of the diaphragm while
the strainer is running and this I effect in my Electric Strainer by simply adjusting a
screw or screws c acting on the sliding magnet cases ef by which means the bed on
which the magnets rest can be moved nearer to or farther away from the arma-
tures gg of the diaphragms hh (or the position of the armatures themselves with
relation to the magnets may be altered) thereby giving a shorter or longer stroke as
required.
To effect this alteration in an ordinary strainer I adopt the apparatus shewn in
Fig. 2, where i is a curved bar or quadrant projecting from the central link pivot j
on each side of the strainer, the main connecting rod k being attached at one end, as
usual, to the crank shaft and at the other end to the said curved bar i the position of
the connecting rod k being altered on the bari by means of the handle mand links n. o,
it being evident that the higher the rod is raised on the bar i the shorter will be the
stroke of the diaphragm.
The second part of this Invention relates to improvements in Strainer Plates to be
used with the above or with any ordinary strainer and consisting of a method of
cleansing the slits of the strainer plates at any time without stopping the working
of the machine and at the same time of increasing the slit area of the strainer
plate.
I am acquainted with the patent granted to Joseph Thompson No. 405887 and I
particularly desire to state that I do not claim the horizontal notion of the various
segments of the strainer plate. I find in practice that I can entirely dispense with
any mechanism for moving or regulating the distance between the two parts of the
plate in order to increase or diminish the gauge of the slits and that by my method of
arranging the said parts I considerably increase the area of slit surface in comparison
with the area of the strainer plate.
In the said patent 405887 although certain mechanism is mentioned for actuating the
segments yet none is shewn or described, and any such mechanism would have to be
beneath the plate and therefore working in a bath of pulp which would speedily clog
the said mechanism and form innumerable "hanks" beneath the plate and thus cause
"retree."
It is also mentioned in the printed spec 405787 (page 4 line 29) that "in some
cases the inventor may arrange one part of the plate to be moved in a vertical

page_text: direction relatively to the other" but no means for effecting this object is shewn or
described.
In Figs. 3. 4. 5 & 6 is shewn my improved strainer Plate, a being the upper plate
with wedge shaped projections 6, which enter into grooves or slits c in the lower
plate.
This lower plate may be either in the form of my patented Corrugated Plate or any
ordinary flat plate; d is a strip of metal placed at suitable intervals between the upper
and lower plates this strip being of exactly the gauge it is desired to have the slits in
the strainer plate and it is evident that the gauge of slit can be altered in a few
moments by simply altering the strip of metal. The top plate a is simply superposed
on the lower plate the two being screwed down into the frame of the strainer together.
To cleanse the slits of the lower plate these screws are simply loosened and a jet of
water or steam passed through the slits as usual. As there is a slit on both sides of
the said V projections in the upper plate it is evident that about double the amount
of stuff will pass through a plate constructed by this method to that constructed by
Thompson's or any other method. It is evident that this method can be applied to
any existing strainer plate by simply enlarging the present slits and adding the upper
plate a or the upper plate a may rest on the lower plate by its own gravity the weight
of the said plate being proportioned to the amount of upward pressure required to
clear the slits, and to make this cleansing apparatus automatic in its action, especially
when applied to my Electric Strainer, I place above the plate a an armature of soft
Iron, above which is a magnet in electrical contact by means of wires with the source
of electrical supply and in one of these wires I place a resistance coil so that when
the slits become stopped up and a greater amount of current is required to form the
vacuum beneath the plate e the current will pass through the resistance coil to the
magnet and attract the armature attached to the top plate a, thus cleansing the slits in
the lower plate immediately, the current then becomes normal and the plate returns by
gravity to its original position.
I wish it to be understood that I do not claim the shape or configuration of the
strainer nor the diaphragm operating to induce suction under the strainer plates nor
the general principle of constructing a strainer plate in two or more segments moving
in relation to each other for the purpose described but I claim
1° The method of actuating the diaphragm of a strainer by means of the magnets a b
and the method of lengthening or shortening the vibrations of the said diaphragm
substantially as described and illustrated.
2° The method of altering the length of the vibrations of an ordinary strainer by
means of the position of the connecting rod k on the curved bar or quadrant i,
substantially as described and illustrated.
3° The construction of a strainer plate with one portion a superposed over the
other C, the upper part being simply screwed down over the lower without any
mechanical means for altering the gauge of slit, and the use of the strip of metal d for
adjusting the said gauge of slit, substantially as described and illustrated.
4° The adaptation of the upper plate a and the strip d to existing worn strainer
plates after enlarging the slits in the said worn plates substantially as described and
illustrated.
5° The method of increasing the slit area of strainer plates by forming a slit on
both sides of the projecting or V shaped bars substantially as described and
illustrated.
6° The method of automatically raising and lowering the upper plate in relation to
the lower by an Electric current substantially as described.
HENRY J. ROGERS.