IMPROVEMENTS IN SIFTING OR BOLTING MACHINES
Year: 1872

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, Gentleman, for the Invention of
"IMPROVEMENTS IN SIFTING OR BOLTING MACHINES."-A communication
from abroad by Henri Cabanes, of Paris, in the Republic of
France.
.
Sealed the 23rd August 1872, and dated the 27th June 1872.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition,
on the 27th June 1872.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN SIFTING OR BOLTING MACHINES," a com-
munication to me from abroad by Henri Cabanes, of Paris, in the
Republic of France, to be as follows :—
This Invention relates to mechanical sifters or "bolters," and consists
in the addition to any of the mechanical sifters or "bolters" now in use
of an air compressing apparatus in the form of a double bellows with a
rising and falling air chest or reservoir for supplying the air to perforated
conduits or passages which distribute the same in thin sheets under the
bolting frames and on to the ordinary sieve tables. The same arrange-

page_text: ment of bellows and air reservoir is also made by a self-acting
contrivance to direct the sifted flour or other substance down one or the
other of two descending spouts according as the machine is working in
its normal condition or otherwise.
In carrying out this Invention, two bellows both in communication
with a rising and falling air reservoir, situate above them are placed in
the machine, the said bellows being worked from cranks and connecting
rods on a shaft driven by a strap from the axis of one of the exhaust
fans of the machine. The air reservoir rises and falls more or less
according as the machine is driven, faster or slower, and weighted with
several moveable weights for the purpose of forcing the air out by two
pipes, which conduct it to a series of perforated air conduits disposed
just under the frame which carries the " bolting" silk. The said
bellows and air reservoir are enclosed within a zinc or light metal casing
mounted on a special framing in order to admit of their ready application
to existing sifters or "bolters" without necessitating any material
alteration therein. The air distributing conduits are disposed round the
sides of the frame carrying the "bolting" silk and longitudinally along
the centre thereof, whereby a uniform distribution of the air underneath
the sieve or "bolting" silk is effected. The table of the sieve like those
of the ordinary construction is formed with a series of inclined surfaces
for conducting the material which passes through the "bolting silk to
the exhausting fans, but it has been found that the compression of the
air above the table could never be effected with regularity by reason of
the surface of the table not being parallel to the bolter frame,
consequently the air was less compressed towards the lower end of the
incline than it was towards the upper ends. In order to overcome this
objection it is proposed, according to this Invention, to cover each of the
original inclined surfaces with a horizontal surface which shall be
parallel to the under surface of the bolting frame, whereby the
compression of the air is uniform from one end to the other.
"
Heretofore the sifted or "bolted" material passed by a series of
apertures or solutions of continuity and fell in the form of sheets into
the entrances to the exhausting fans, but as the material escaped the
compressed air escaped along with it, consequently the degree of
compression of the air was not sufficient as the air constantly escaped
through the lower openings. This defect is remedied according to this
Invention, and the whole of the air compelled to escape through

page_text: or is
the bolting or sifting surface or cloth, by providing the openings made
in the before-mentioned horizontal surfaces with adjustable spring valves
or doors, which reduce the size of such openings so that they are not
proportionate to the quantity of material which ought to pass through
them, and consequently the passage becoming blocked no air can
possibly escape along with the material. The air reservoir above the
bellows herein-before referred to is caused to operate upon a spring
actuated lever in such a manner as to release a sliding rod actuated by a
spring, and cause the mouths of the vertical directing spouts for the
material to be inclined to one or other of two descending spouts,
according as the machine is working in its normal manner
operating too slowly, in the former case a stop piece on the air reservoir
will maintain the spring lever in such a position as to ensure the locking
of the sliding rod in a certain position, the material being directed to the
receptacle for the best quality, but should the air reservoir fail to be
adequately supplied with air, its descent or collapse will release the
spring lever, lift the locking bolt or catch, and allow the sliding rod to
be drawn in such a direction as to incline the moveable spout mouths to
the descending spouts which lead to the receptacles for the material of
inferior quality. The same result is effected should the material in the
supply hopper become too low; in this case a plate hung to the end of a
weighted lever inside the hopper being relieved from the superincumbent
weight of the material is lifted by the counterweight, and the consequent
tipping of the lever draws a string which is connected to the locking
bolt before referred to, thereby lifting the same and releasing the sliding
rod as before explained.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Seal Patent
Office on the 19th December 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-seventh day of June, in the year
of our Lord One thousand eight hundred and seventy-two, in the
36th year of Her reign, did, for Herself, Her heirs and successors, give

page_text: and grant unto me, the said John Henry Johnson, Her special license
that I, the said John Henry Johnson, my executors, administrators, and
assigns, or such others as I, the said John Henry Johnson, my executors,
administrators, or assigns, should at any time agree with, and no others
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN SIFTING
OR BOLTING MACHINES," a communication to me from abroad by Henri
Cabanes, of Paris, in the Republic of France, upon the condition
(amongst others) that I, the said John Henry Johnson, my executors
or administrators, by an instrument in writing under my hand and
seal, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said John Henry Johnson, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and a
by the following statement, reference being had to the accompanying
Drawings, and to the letters and figures marked thereon, that is to
say :-
"
"
The said Invention relates to mechanical sifters or "bolters," and
consists in the addition to any of the mechanical sifters or
" bolters
now in use of an air compressing apparatus in the form of double action
bellows with a rising and falling air chest or reservoir for supplying the
air to perforated conduits or passages, which distribute the same in thin
sheets under the bolting frames, and on to the ordinary sieve tables.
The same arrangement of bellows and air reservoir is also caused by a å
self-acting contrivance to direct the sifted flour or other substance down
one or the other of two descending spouts, according as the machine is
working in its normal condition or otherwise.
And in order that the said Invention may be fully understood, I
shall now proceed more particularly to describe the same, and for that
purpose shall refer to the several Figures on the annexed Sheet of
Drawings, the same letters of reference indicating corresponding parts in
all the Figures.

page_text: Figure 1 is a side elevation of a complete sifting or bolting machine
constructed according to this Invention, and intended more particularly
to illustrate the additional mechanism for directing the sifted substance
to one side or the other, according as the apparatus is in proper or
| normal working, or is working at a speed which is not sufficient to
produce the best results; Figure 2 is a view looking upon the end
containing the hopper for receiving the semolina to. be sifted; a
portion of this Figure is shown in section taken along the lines 1—2, and
3-4, in Figure 1; Figure 3 is a sectional elevation of the apparatus,
the hopper being removed; Figure 4 is a corresponding horizontal
section taken along the line 5-6, in Figure 3; and Figure 5 is a
transverse section taken along the line 7-8, in Figure 3; and Figure 6
is an enlarged detail herein-after more fully referred to.
S and S¹ are two bellows which force air into the reservoir R situate
3 immediately. above them, and which rises more or less according to the
pressure, that is to say, according to the speed at which the apparatus
is working; this reservoir, which constitutes, as herein-after explained,
the regulator or governor, is provided with two boxes r, r¹, in which are
deposited weights in the form of plates p, which rest one on the top of
another. Each plate may weigh about ten pounds, or rather more, so
that by placing twenty of such plates in the boxes the reservoir R may be
weighted to about two hundred or more, which is sufficient for the proper
working of the apparatus. The said bellows and reservoir are enclosed
in a light zine casing mounted on a small special framing, which affords
facility for applying the whole to an existing sifting machine without
altering or changing the original parts. The bellows are driven by
wooden connecting rods 8, 8³, coupled to a crank on a small shaft 8*,
which carries the pulley 8³ driven by a pulley fixed on the shaft of one of
the aspirators I (Figure 1). The air compressed in the reservoir R is
distributed by the two tubes B, B¹, into the conduits C of triangular
section, arranged as shewn in Figure 4, and which spread it in thin
streams beneath the frame E, which carries the silk, and above the
sifting table. A central tube C¹ branching from the transverse tube C,
and supported by small cross bars assists in spreading the air in a
uniform manner.
The particular arrangement of the sifting table D is an important
feature in this Invention; hitherto it has consisted of a frame with four
inclined pannels (as shewn in Figure 3), in order to conduct the sub-

page_text: stances which traverse the silk frame to the mouth of the aspirators 1 ;
the compression of air was irregular by reason of the table not being
parallel to the surface of the frame, the air being less compressed at the
lower ends of the inclines than at their upper ends. Now I propose
colourably to do away with these inclined pannels by covering them
with the boards & placed parallel to the lower surface of the frame E,
whereby the compression of air is uniform from one end of the table to
the other.
Hitherto the substances to be sifted passes by four openings or
solutions of continuity, and fell in sheets at the entrance to the
aspirators I; but as the substances escaped it is evident that the com-
pressed air escaped also, consequently the compression was insufficient,
as the air found a more ready means of escape through the lower
apertures. To remedy this defect, and to compel the whole of the air to
pass through the openings in the silk or skin, I close these four aper-
tures made in the parallel boards d by four valves ƒ (one of which is
shewn in Figure 6), which may be so fitted as to be capable of being
completely or partially closed. These valves have a tendency to close
by the action of the helical springs f¹, the pressure of which may be
regulated. For this purpose each valve is connected by a cord f' to a
regulating screw v, which on being turned in the proper direction opens
the valve more or less; thus when it is desired to afford a greater
passage to the substances which travel along the surface d to fall into
the aspirators I the spring f¹ is compressed, and the valve opens. This
is not the sole object of these valves; their employment has further
the effect of ensuring that the openings shall not be proportional to the
quantity of the substances which should pass through them, so that the
said substances will be arrested in the cavity formed by the section of
the boards, and will thus effect a stoppage of the air which cannot pass
through such substances, and escape therewith. In this way all the air
produced by the bellows traverses the frame, and raises the substance
under treatment, of which none of the light portions will pass through
the silk or skin. This combination, which produces an obstruction to
the escape of the air, constitutes one of the leading features of these
improvements; the regularity of the speed of rotation is an essential point
for the proper working of sifting machines, and it has been found that
the bellows S, S¹, and their reservoir R constitute the best governor or
regulator.

page_text: The displacement of the air reservoir is utilized for directing the
sifted material into special receptacles, according as the apparatus is
working at an insufficient speed. For this purpose there are disposed
under each of the descending conduits G, which afford passage to the
sifted material, small metal funnels H, each provided with a jointed
tube or mouth piece h of conical form; these tubes which are sus-
pended, as shewn in Figure 1, are connected by a pin to a flat rod K
common to the series, which rod is guided in the supports k, k¹.
This rod has formed in it at one end a notch into which engages a
small vertical bolt provided with an enlargement ; the opposite
end of the rod K is connected to a helical spring J, which is in
tension so long as the rod occupies the position shewn in Figure 1,
and the tubes h are inclined towards the left; this position corresponds
to the normal speed of working of the machine. The regulating or
governing reservoir R is fitted with a wooden projection t (Figure 1),
which when the desired quantity of air is supplied by the proper
speed of working of the machine maintains in a vertical position the
bent lever M which oscillates on the centre m³, and is forked at its
lower end to receive a species of pall m, the free extremity of which
is in contact with the enlargement or collar P. So soon as the speed
of working diminishes the air, being forced in smaller quantity into
the reservoir R, allows such reservoir to descend or lower itself, where-
upon the lever M, no longer bearing upon the projection t, and being
acted upon by the spring u, moves on its centre, thereby elevating
the bolt through the intervention of the pall m, which bears against
the collar or enlargement F. The rod or bar K is then drawn by the
spring J in the direction indicated by the red arrow, and moves with it
the jointed tubes h, which being inclined towards the right cause the
indifferently sifted material or substance to fall into special receptacles.
The rod or bar K carries a button which enables it to be readily replaced
by hand to its original position so soon as the machine regains its proper
speed of working.
The same releasing of the rod or bar K is accomplished in the event
of the substances to be sifted getting too low in the hopper, with this
object the bolt is connected by a cord o̟ to another cord q¹ by means
of a small hook or swivel, which latter cord is connected to one end
of a lever V fitted inside the hopper T, as shewn in Figure 2. This

page_text: weight x. Now when there is not sufficient depth of material or
substance to be sifted over the surface of the said float X to maintain
the lever in the position indicated by black lines, the counterweight
draws down the opposite end of the lever into the position indicated
by the red line, thereby pulling the cords q and 9', and consequently
elevating the bolt 1, the rod K thus released is drawn by the spring J
so as to move the several tubes towards the right, and direct the
indifferently sifted material or substance into the same receptacles, as
when the apparatus is working too slowly.
Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be used
or carried into effect; I would observe in conclusion that what I
consider to be novel and original and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent is,—
First. The compression of the air in mechanical sifters or bolters, 1
whether of the herein described improved construction or otherwise
constructed, by means of double-action bellows in combination with
an air reservoir, such combination serving at the same time as a
regulator of the working of the machine, substantially as herein-before
described.
Second. The herein-before described mode of distributing the air over
the frames of mechanical sifters or bolters.
Third. The combination with mechanical sifters or bolters of the
herein-before described appliances for directing the sifted or bolted
produce to one side or the other, according as the machine is or is not a
in its proper or normal working condition.
In witness whereof, I, the said John Henry Johnson, have to this
my Specification set my hand and seal, the Eighteenth day of
December One thousand eight hundred and seventy-two.