IMPROVE- MENTS IN GRINDING, CLUSHING, OR REDUCING DRY SUBSTANCES. AND IN THE
Year: 1866

page_text: LETTERS PATENT to Hermann Wedekind, of Dunster Court, Mincing
: Lane, in the City of London, Engineer, for the Invention of "IMPROVE-
MENTS IN GRINDING, CLUSHING, OR REDUCING DRY SUBSTANCES. AND IN THE
LETTERS PATENT to Hermann Wedekind, of Dunster Court, Mincing
Lane, in the City of London, Engineer, for the Invention of "IMPROVE.
MENTS IN GRINDING, CLUSHING, OR REDUCING DRY SUBSTANCES. AND IN THE
APPARATUS OR MEANS EMPLOYED THEREIN OR IN CONNECTION THEREWITH."
A communication from abroad by Frederick Hoffmann, of Berlin, in the
Kingdom of Prussia Enginoon.
Sealed the 24th April 1867, and dated the 30th October 1866.
PROVISIONAL SPECIFICATION left by the said Hermann Wedekind at
the Office of the Commissioners of Patents with his Petition, on the
30th October 1866.
1, HERMANN WEDEKIND, of Dunster Court, Mincing Lane, in the City
of London, Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN GRINDING, CRUSHING, 02 REDUCING DAY SUBSTANCES, AND IN
THE APPARATUS OR MEANS EMPLOYED THEREIN OR IN CONNECTION THEREWITH," a
communication to me from abroad by Frederick Hoffmann, of Berlin, in the
Kingdom of Prussia, Engineer, to be as follows:-
This Invention relates to certain peculiar constructions and arrangements
of machinery or apparatus for grinding, crushing, or reducing dry substances,
combined with a peculiar mode of and apparatus for feeding or supplying the
substances to be ground, crushed, or reduced, and removing such substances
when sufficiently reduced from the grinding or reducing surfaces and depositing
it in convenient receptacles.

page_text: According to one arrangement of combined apparatus suitable for pulverizing
or reducing cement, sulphate of lime, brickdust, and similar hard and dry
substances, it is proposed to employ a heavy or weighted rocking surface
consisting of a segment of a cylinder supported on and rocking or rolling to
and fro over a stationary horizontal or flat surface or table of metal or other
suitable hard material, the material or substance to be reduced being suitably
fed in as herein-after described between the rocking surface or "rocker," as I
shall herein-after call it, and the flat surface. Any suitable mechanical con-
trivance may be adopted for imparting a rocking or to-and-fro rolling motion
to the "rocker," and the material may be fed in either externally to the
"rocker" or from the interior of the same, in which latter case the "rocker"
would be made hollow or in the form of a trough. In order to keep the
rocker in its proper path whilst rocking over the table, and to prevent it
slipping thereon, it is proposed to employ curved guide rods secured to the
table for the opposite edges of the "rocker" to work along, or a trunnion
may be secured to the lower part of the "rocker" at each end, and taking
into a slotted seat on each side of the table, or (which is preferred) spur
teeth may be fitted to or formed on each end of the "rocker" gearing into
straight racks secured to or formed on the edges of the table. It is obvious,
however, that various contrivances may be adopted for the purpose referred to.
A longitudinal reciprocating horizontal frame surrounding the "rocker" and
running upon wheels along guide rails carried by the table contains the
appliances for feeding the material, for stirring or loosening the same between
the crushing surfaces, and for removing the said material as fast as it is
reduced to a fine powder. The longitudinal reciprocating motion of this
frame should be in concert with the rocking motion of the "rocker," and
therefore it should derive such motion from the "rocker" itself, suitable
connecting rods serving to unite the frame to the "rocker" at a point corre-
ponding to the centre or axis of the cylinder, of which the "rocker" is a
segment. To one end of the said frame there is fitted a feeding. hopper which
discharges its contents on to an inclined surface which projects some distance
under the "rocker," and continuously supplies the materials to be crushed or
reduced, whilst at the opposite end of the frame there is fitted a set of rakes
or stirrers, the ends of which pass to and fro along the surface of the table,
serving to loosen the crushed particles. In conjunction with these rakes there
is a blast pipe and an exhaust pipe, the former serving to direct a number of
small but powerful currents of air generated by a fan blower into and amongst
the crushed material immediately behind and underneath the rakes, thereby
blowing up or separating the ready dust or powder directly it is formed from

page_text: the coarser particles, which require still further reducing. The exhaust pipe
serves to withdraw the dust or powder from the working surfaces whilst held
in mechanical suspension in the air, and conveys it into a depositing chamber
where the fine particles are collected and gathered into receptacles, whilst the
air still carrying with it a certain amount of very fine dust passes on to the
same fan that produced the air jets, a portion of it thence passing into a
second depositing chamber as herein-after described. The mouths of the blast
and exhaust pipes are separated from each other by an inclined plate, to which
the rakes are secured. And in order to check as much as practicable the
inlet of fresh supplies of air to the exhaust pipe over and above that which
is discharged from the blast pipe, and to avoid any inconvenience from the
escape of pulverulent matter into the workshop, it is proposed to enclose the
space wherein the air and exhaust pipes operate by means of side plates or
cheeks attached to the frame and fitting close against the ends of the "rocker,"
a flap of leather or other suitable flexible material serving as a packing
between the periphery of the "rocker" and the upper side of the mouth of
the exhaust pipe, whilst a similar flap encloses the space between the surface
of the table and the rear of the blast pipe. It will thus be seen that
supposing the packing above described be perfectly air-tight the same air will
be caused to circulate constantly through the apparatus, 'that which is forced
in through the blast pipe being carried off with the powder or dust held in
mechanical suspension therein along the exhaust pipe and through the
depositing chamber back to the fan to be returned through the blast pipe as
already explained; those particles which are too heavy to be carried away by
the exhaust drop on to the inclined separating plate, and are returned to the
crushing surfaces again. The separation of the dust from the air is assisted
by wire gauze screens extended vertically across the depositing chambers.
The air almost freed from the dust or powder arrives at the centre of the fan
casing through a tube connected with the end of the first depositing chamber,
when the fan forces the greater portion of it through the blast pipe back to
the working surfaces of the crushers, the remainder being expelled through a
separate orifice provided with a regulating valve into a second depositing
chamber. The small portion of dust that may have been carried through the
first chamber is deposited in the second, which is similarly provided with
vertical gauze screens for the air to pass through, whilst that portion of
fine dust which may have been conveyed back to the crushing surfaces with
the blast is not lost but 'drawn back again through the exhaust tube into the
depositing: chambers: The second depositing chamber has an outlet into the
atmosphere, the air discharged therefrom being equivalent to the fresh air

page_text: which enters by leakage through the packing enclosing the working surfaces
of the crushers, and as this will vary occasionally the regulating valve in the
inlet pipe to the second depositing chamber must be adjusted so as to allow
an amount of air to enter such chamber corresponding to that which leaks
through the packing. The above-described depositing chambers, with the
blowing and exhaust apparatus, may be applied to other forms or constructions
of crushing, grinding, or reducing apparatus, as, for example, to stampers and
crushing rollers whether conical or cylindrical, the advantage obtained being
an increased effective power by the instant removal of the dust or powder
from between the working surfaces. In the conical roller mill a circular
revolving table is employed in combination with, say, four pairs of conical
rollers revolving in fixed bearings over the table. The first pair of rollers are
grooved or fluted longitudinally, and should be raised from one half to one
inch clear above the surface of the table, so as only to operate on pieces of
larger dimensions than those given. The second pair should be grooved cir-
cumferentially, and situate at from one quarter to half an inch above the table,
so as to crush those fragments which may have passed under the preceding
rollers. The remaining two pairs of rollers may be plain and in actual
contact with the table. It is immediately behind these pair of rollers that the
rakes and pneumatic blowing and exhaust apparatus are situate.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Hermann Wedekind in the Great Seal Patent Office on the
30th April 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HERMANN
WEDEKIND, of Dunster Court, Mincing Lanc, in the City of London,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, hearing date the Thirtieth day of October, in the year of our Lord
One thousand eight hundred and sixty-six, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Hermann Wedekind, Her special license that I, the said Hermann
Wedekind, my executors, administrators, and assigns, or such others as I,
the said Hermann Wedekind, 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

page_text: Britain and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN GRINDING, CRUSHING, OR REDUCING DRY SUBSTANCES, AND IN
THE APPARATUS OR MEANS EMPLOYED THEREIN OR IN CONNECTION THEREWITH," a
communication to me from abroad by Frederick Hoffman, of Berlin, in the
Kingdom of Prussia, Engineer, upon the condition (amongst others) that I.
the said Hermann Wedekind, my executors or administrators, by an instru-
ment 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 Hermann Wedekind, 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 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 certain peculiar constructions and arrangements
of machinery or apparatus for grinding, crushing, or reducing dry substances,
combined with a peculiar mode of and apparatus for feeding or supplying the
substances to be ground, crushed, or reduced, and removing such substances
when sufficiently reduced from the grinding or reducing surfaces and depositing
it in convenient receptacles.
According to one arrangement of combined apparatus suitable for pulverising
or reducing cement, sulphate of lime, brickdust, and similar hard and dry
substances, it is proposed to employ a heavy or weighted rocking surface
consisting of a segment of a cylinder supported on and rocking or rolling to
and fro over a stationary horizontal or flat surface or table of metal or other
suitable hard material, the material or substance to be reduced being suitably
fed in as herein-after described between the rocking surface or "rocker," as
I shall herein-after call it, and the flat surface. Any suitable mechanical
contrivance may be adopted for imparting a rocking or to-and-fro rolling
motion to the "rocker," and the material may be fed in either externally to.
the "rocker" or from the interior of the same, in which latter case the
"rocker" would be made hollow or in the form of a trough. In order to
keep the rocker in its proper path whilst rocking over the table, and to
prevent it slipping thereon, it is proposed to employ covered guide rods secured
to the table for the opposite edges of the "rocker" to work along, or a
_trunnion may be secured to the lower part of the. "rocker" at end, taking
into a slotted seat on each side of the table, or (which is preferred) spur

page_text: teeth may be fitted to or formed on each end of the "rocker." gearing into
straight racks secured to or formed on the edges of the table. It is obvious,
however, that various contrivances may be adopted for the purpose referred
to. A longitudinal reciprocating horizontal frame surrounding the "rocker"
and running upon wheels or sliding along guide rails carried by the table or
suspended from a centre above contains the appliances for feeding the material
for stirring or loosening the same between the crushing surfaces, and for
removing the said material as fast as it is reduced to a fine powder. The
longitudinal reciprocating motion of this frame should be in concert with the
rocking motion of the rocker, and therefore it should derive such motion
from the "rocker" itself, suitable connecting rods serving to unite the frame
to the "rocker" at a point corresponding to the centre or axis of the cylinder,
of which the "rocker" is a segment, or in lieu of being a segment of a cylinder
the rocker may be otherwise curved so as to enable it to rock to and fro.
To one end of the said frame there is fitted a feeding hopper, which discharges
its contents into an inclined surface which projects some distance under the
rocker, and continuously supplies the materials to be crushed or reduced,
whilst at the opposite end of the frame there is fitted a set of rakers or stirrers,
the ends of which pass to and from along the surface of the table, serving to
loosen the crushed particles. In conjunction with these rakes there is a
blast pipe and an exhaust pipe, the forming serving to direct a number of
small but powerful currents of air generated by a fan blown into and amongst
the crushed material immediately behind and underneath the rakes, thereby
blong up or separation the ready dust or powder should directly it is formed from
the coarser particles which require still further reducing. The exhaust pipe
serves to withdraw the dust or powder from the working surfaces whilst held
in mechanical suspension in the air, and conveys it into a depositing chamber
where the fine particles are collected and gathered into receptacles, whilst the
air still carrying with it a certain amount of very fine dust passes on to the
same fan that produced the air jets, a portion of it thence passing into a second
depositing chamber as herein-after described. The mouths of the blast and
exhaust pipes are separated from each other by an inclined plate to which the
rakes are secured. And in order to check as much as practicable the inlet of
fresh supplies of air to the exhaust pipes over and above that which is discharged
from the blast pipe, and to avoid any inconvenience from the escape of
pulverulent matter into the workshop, it is proposed to enclose the space
wherein the air and exhaust pipes operate by means of side plates or cheeks
attached to the frame and fitting close against the ends of the "rocker," a
flap of leather or other suitable flexible material serving as a packing between

page_text: the periphery of the rocker, and the upper side of the mouth of the exhaust
pipe, whilst a similar flap encloses the space between the surface of the table
and the rear of the blast pipe. It will thus be seen that supposing the
packing above described to be perfectly air-tight the same air will be caused
to circulate constantly through the apparatus, that which is forced in through
the blast pipe being carried off with the powder or dust held in mechanical
suspension therein along the exhaust pipe and through the depositing chamber
back to the fan to be returned through the blast pipe as already explained.
Those particles which are too heavy to be carried away by the exhaust drop
on to the inclined separating plate, and are returned to the crushing surfaces
again. The separation of the dust from the air is assisted by wire gauze
screens extended vertically across the depositing chambers. These screens may
be shaken by clastic bands or other convenient contrivance outside the
chamber to free them from the dust adhering to them. The air almost freed
from the dust or powder arrives at the centre of the fan casing through a
tube connected with the end of the first depositing chamber, when the
fan forces the greater portion of it through the blast pipe back to the working
surfaces of the crushers, the remainder being expelled through a separate
orifice provided with a regulating valve into a second depositing chamber.
The small portion of dust that may have been carried through the first
chamber is deposited in the second, which is similarly provided with vertical
wire gauze screens for the air to pass through, whilst that portion of fine dust
which may have been conveyed back to the crushing surfaces with the blast
is not lost but drawn back again through the exhaust tube into the depositing
chambers. The second depositing chamber has an outlet into the atmosphere,
the air is discharged therefrom being equivalent to the fresh air which enters
by leakage through the packing enclosing the working surfaces of the
crushers, and as this will vary occasionally, the regulating valve in the inlet
pipe to the second depositing chamber must be adjusted so as to allow an
amount of air to enter such chamber corresponding to that which leaks
through the packing. The above-described depositing chambers with the
blowing and exhaust apparatus may be applied together or separately to
other forms or constructions of crushing, grinding, or reducing apparatus, as
for example, to stampers and crushing rollers whether conical or cylindrical,
the advantage obtained being an increased effective power by the instant
removal of the dust or powder from between the working surfaces. In the
conical roller mill a circular revolving table is employed in combination with,
say, four pairs of conical rollers revolving in fixed bearings over the table.
The first pair of rollers are grooved or fluted longitudinally. and-should-be.

page_text: raised from one-half to one inch clear above the surface of the table so as only
to operate on pieces of larger dimensions than those given. The second
pair should be grooved circumferentially, and situate at from one quarter to
half an inch above the table, so as to crush those fragments which may have
passed under the preceding rollers. The remaining two pairs of rollers may
be plain and in actual contact with the table. It is immediately behind these
pair of rollers that the rakes and pneumatic blowing and exhaust apparatus
are situate. In some cases the feeding apparatus may be omitted and the
feeding effected by hand, or the second depositing chamber may be omitted
and the blast taken direct from the atmosphere.
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 corresponding
Figures.
In all apparatus heretofore used for grinding or reducing substances the
dust or powder produced is not immediately separated from the granular
unfinished coarse materials or substances, but remains in contact with them,
and is exposed to the useless effect of the working machinery, which of course
reduces the effective power to a large extent, this effective power being partly
absorbed by the finished dust and pulverised materials; this is carefully
avoided in the construction of the improved apparatus herein-after more
particularly described. The substances to be acted upon are spread on a plain
surface and are gradually crushed by a weight or a roller moving along the
surface so as to press always on the materials to be pulverised.
This apparatus consists essentially as shown in Diagrams A, B, on Sheet 1
of the Drawings annexed of a weight W, the lower surface consisting of a
circle or some other suitable curve resting upon a fixed horizontal bed B.
If the weight W be pressed down on either side and then released it will
move backwards and swing to and fro until its motion counterbalanced by the
resisting friction is totally absorbed. The resistance caused by friction is very
slight as a rolling friction only is produced. If the materials to be reduced
are thrown into the path B within the limits in which the action of the rocker
takes place they will either (if sufficient power be not employed) effectually
resist the rocking motion of W, or if sufficient force be employed the weight
W will lift itself on to the top of the materials and thereby crush them. In
this operation a complete developement of the surfaces is prevented by the
fragments between them, and a displacement of W takes place, which depends
on the thickness of the layer of fragments produced at each rocking of the

page_text: weight W. If the substance to be acted upon are equally distributed over
the surface each time W moves backwards or forwards the displacements of
W will compensate themselves, but if this symetrical distribution of the
substances does not occur the weight W should be provided with curved
guides, trunnions, or dented segments, as shown in diagram C, D, E, especially
if the materials are continually thrown on B from one and the same side.
The momentum and weight of W should be in direct proportion to the bulk,
solidity, and power of resistance of the materials or substances to be acted
upon, and can easily be ascertained for each individual case. The only require-.
ment is to impart to the weight W a continuous swinging or rocking motion,.
and to supply sufficient power to lift it on to the surface of the materials or
substances and to overcome the rolling friction and other resistance caused
by the air and by the guiding appliances if used. To this crushing apparatus
there is added at one side a feeding apparatus which continually supplies the
materials to be crushed, whilst at the opposite side a discharging apparatus is
provided which separates or draws off the completely reduced product from
the coarse materials. As will be seen on referring to diagrams F and G, in
which a, b, represents the working path, the feeding of the apparatus or the
supply of fresh materials takes palce always from one side whilst the rocker
is in the position C, and likewise the clearing of the fully reduced or crushed
product from the other side whilst the rocker assumes the position C¹ (Diagram
G), but the feeding and removal of the material may also be effected from
both sides, in which case, as before stated, the forward movement.or displace-
ment produced is neutralized each time the newly supplied materials are being
crushed. The feeding apparatus may be differently constructed in accordance
with the nature of the substance to be crushed, but it receives its motion direct
from the cradel or rocker or from the motor of the same at intervals corres-
ponding with the swinging or rocking motions of the rocker. The material
may be fed in either by a jolting motion or otherwise, and the supply may
take place from the outside or inside of the cradle or rocker, in which latter
case a hollow rocker is to be provided. The discharging or evacuating apparatus
has a twofold function; first, to separate the fine dust or powder directly
it is formed from the coarse unfinished materials; second, to extract the
same from the working surfaces and deposit it in separate chambers or
receptacles. Rakes, points, or similar contrivances stir the crushed material.
and keep it open on the bed or path of the rocker, whilst at the same time air
currents from below act upon these loose masses and separate and
mise-the dust while the coarse materials fall back and remain on the working

page_text: pipes into chambers or receptacles where the powder or dust drops or is
deposited. The current of air freed from the dust is brought back to the
working apparatus, to be used in the same manner over again. As the supply
of fresh material to the working surface of the rocker does not admit of an
hermetic enclosure thereof, it would be impracticable to prevent a part of the
dust-laden air from escaping, and so causing a loss in material if the air
current attracted by the pneumatic depositing chamber did not allow part of
it to escape freely through the second chamber into the atmosphere. The dust
still remaining in the air current passing through the second chamber has
ample opportunity to deposit there and allow the air freed from the dust to
escape. In this manner less air is supplied to the working surfaces than is
taken from the pneumatic chamber, and the consequence is that a vacuum being
formed within the enclosure of the working surfaces air is drawn in through
the openings, and hence a loss or escape of dust or powder cannot take place.
The rakes or points are compelled to follow the motion of the. rocker, and move
in correspondence with the feeding apparatus. As a deviation in the regular
performance of the rocker takes place through the supply of material to the
horizontal working plane, provision must be made to remedy this defect, which
can be done by employing a rack and pinion, sliding curves, or guides. If it
is intended to reduce the material to grains of a given size the apparatus may
be constructed with parallel curves and horizontal planes or beds, the bed
on which the work is to be performed being at such a distance from the
corresponding rocker curve that the grain already reduced to the desired size
may be kept there without any further pressure, whilst the other horizontal
planes with the corresponding curves only serve as travelling planes for the
swinging of the rocker (see Diagram H).
Sheet of the Drawings shows a rocker with the feeding and the pneumatic
discharging apparatus for crushing Portland cement stones. Figures 1, 2, 3,
and 4 show the rocker D with the horizontal travelling plane P on which it
works, the feeding apparatus k, the pneumatic discharging apparatus l, as well
as the connection of the latter with the pneumatic depositing chamber through
the pipe a which leads the dust-laden air into the chamber, and the pipe c
which leads the air almost free from dust back again between the working
planes. The lower working surface of the rocker D forms part of a circle, of
which the centref will move in a horizontal direction during the swinging of
the rocker, and the moving power can be communicated to the rocker by the
connecting rod g, or in any other convenient way. The rods z, z, suspended
on the axis communicate the oscillating motion to the frame i, i, moving on
wheels and rails, on which frame rest the feeding apparatus through which

page_text: fresh material is supplied, and also the pneumatic discharging apparatus / for
the withdrawal of the finished dust. Figure 3 shows the plan of the frame i, i;
Figure 4 shows the vertical section of the exhauster on a larger scale. Both
the apparatus k and I are by this arrangement maintained at the same distance
from the working surfaces of the rocker D; Figures 1 and 2 show the rocker
in the central position; the working surfaces of the same extend from z to v,
the whole length of which is covered with material by the feeding board k.
After the rocker has passed over this material the rakes p, p, loosen the same.
The dischargers q, q, of the pipe c work in such a manner between the teeth
of the rake that a number of fine but powerful air currents pass out under
these teeth, and in ascending they carry with them and hold in mechanical
suspension the lighter particles of dust or powder, whilst the heavier parts of
the material are again dropped on to the working plane, where they will be
further crushed or reduced on the return of the rocker. The pipe a on the
other hand being above the rake draws in the cloud of dust produced by the
scraper or rake, and conveys it to the depositing chamber. In order to
separate the working space from the outer atmosphere the packings r, r, and
the thin plates 8, s, are provided. To the rocker are fixed on each side a
toothed segment z, which, works in a rack placed in or on the horizontal
plane P, to prevent the displacing of the rocker. The pneumatic chambers
are shown at Figure 5. A is the first depositing chamber; C is a fan; B is
the second depositing chamber. The fan when in motion produces a partial
vacuum in A, and thus draws the air laden with dust or flour from the working
surfaces by means of the suction pipe a into the chamber A. The length and
section of A must be of such dimensions that the air entering through a will
move so slowly through A that the dust has sufficient time to sink to the
bottom and fall into receptacles placed under hoppers o, o. The separation of
the dust from the air is assisted by the wire gauzes or nettings m, m, which
compel the air to move equally through the whole section of the chamber and
arrest part of the dust should the same come against the wire forming the
gauze or netting, which should be regularly shaken by springs at x, x, x, to
prevent the closing of the openings in the gauze. The air almost freed from
the dust reaches the fan C through the tube b, which blows it partly through
the tube c back to the working surfaces, and partly into the second chamber B
through the tube d. The small portion of dust that the air carries from A
deposits in the second chamber B, which is provided like A with gauzes or
fine nettings n, n, n, of such dimensions that even the, last particle of dust
will have time to settle before the purified air is allowed to return to the
atmosphere through the opening e. -The-small quantity of dust which returns to

page_text: the working surfaces through the tube c is not lost, but is drawn again
through the tube a into the chamber A. Thus the air is constantly circulating
through the apparatus, and it is evident that the quantity of air escaping out of
the chamber B corresponds with the air which is allowed to enter through the
imperfect closing of the packings at the mouth of the suction tube l, but as
these imperfections cannot be accurately determined and will not always be
uniform, the pipe d is provided with a regulator, by means of which the section
of the pipe can at any time be altered from the outside. If it were possible
to avoid these imperfections in the packings the air drawn in by the fan
would all be blown on to the working surfaces again, and in that case the same
air would be used over and over again.
The above-described pneumatic chambers, as well as the blowing and exhaust
apparatus may also be connected with other crushing and grinding apparatus
or appliances, for instance, with stampers, crushing rollers, or collar stones,
whether conical or cylindrical, as shewn in Sheet 2 of the Drawings, and will
afford considerable advantages by increasing the effective power through the
instant removal of the dust or powder from between the working surfaces.
The sucker when in connection with the rocker is compelled to follow the
movements of the same; this, however, may be obviated by connecting the
sucker as shewn in Figures 1, 3 (Sheet with the stationary collar stones
and revolving base plate, thereby securing the advantage of more perfect
junctions of the packings with the mouth of the then stationary suction pipe.
Figure 1 (Sheet 2) is a front elevation, Figure 2 a ground plan, and Figure 3
is a view of part of the above apparatus projected on a flat plane. This
apparatus is provided with four pairs of conical rollers W, W, up to W, and
two pneumatic suckers or exhausters L and L. The rollers W¹ and W2 are
grooved lengthways, and are placed according to the requirement from in. to
1 in. above the revolving bottom stone; these rollers are only set in motion if
larger pieces than from in. to 1 in. are thrown on the bottom stone at K,
and have to pass under the cones W3 and W, are grooved annularly, and are
placed in. to in. above the bottom stone, and likewise revolve only when
larger pieces than in. to in. are passed under them; there will therefore
be very little dust produced under the rollers W' and W. The other rollers
W to W rest upon the bottom stone, and will be made to revolve even
though the bottom revolve empty. Behind W there is a stationary
pneumatic sucker L', with rakes, as shewn in Figure 4 (Sheet 1). The
material left behind on the bottom stone by the sucker is again passed over
and crushed by the cones W7 and WB, and drawn by the sucker L into the
chambers A and B. All that remains uncrushed after passing L is taken by

page_text: the revolving bottom under the rollers again. In this arrangement the feeding
apparatus is also stationary, and the feeding is always effected at K. Figure 4
shows a common stamper, and Figure 5 shows three pairs of crushing rollers
placed above each other, to illustrate the mode of connecting the above-
described pneumatic sucker and blower with these apparatus. Rakes are not
required in these cases. The pneumatic apparatus may obviously be con-
nected with any machinery used for crushing or grinding dry substances, and
by that means materially increase the effective power of such machinery by
the instant removal of the finished dust or finely reduced material or substance
as fast as it is produced.
Figures 6 and 7 and 8 (Sheet 2) represent the application of the improved
blowing and exhaust apparatus to a pair of collar stones revolving on a sta-
tionary bottom B. Each collar A, A, stone is to be provided with a feed
apparatus, rack, and blowing and sucking apparatus, as before described;
C is a cover having openings made therein for the collar stones to work
through, such cover revolving horizontally with the stones, it being attached
to the framing which carries the axes of the collar stones. In the eye of the
bottom stone there are provided two concentric pipes a and b, the pipe a serving
as the blowing pipe for conveying air through the ducts c, c, to the rakes,
whilst the pipe b serves as the exhaust or suction pipe for removing the pul-
verized material as fast as it is produced, and conveying it to the depositing
chamber or chambers herein-before referred to; d is an annular trough filled
with mercury or other suitable material for forming an air-tight joint or packing
between the revolving ducts c, c, and the stationary central pipe a. In
Figure 7 I have shewn two suction pipes b, but in practice one pipe b only
will be requisite. If desired the blast and exhaust may be effected from the
circumference in lieu of from the centre of the apparatus.
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,-
1st, the combination of a pneumatic blowing and exhaust apparatus, sub-
stantially such as herein described, with a crushing or reducing apparatus,
whereby the working or reducing surfaces of the crushing apparatus are
relieved from the dust or pulverized matter, and the useful effect of the crusher
is materially improved.
2nd, the combination of the rake-or-scraper-with-the-crusher-or-rocker -D,-
frame i, and bed P, substantially as-and for the purpose herein-before described.

page_text: 3rd, the combination with a crushing apparatus of one or more depositing
chambers containing gauze screens, and the herein described pneumatic
exhaust and blowing apparatus, arranged and operating substantially in the
manner for the purpose herein specified.
4th, the general construction, arrangement, and combination of apparatus
for grinding, crushing, or reducing substances, and the means for removing
the crushed material as fast as it is produced, substantially as herein-before
described and illustrated by the accompanying Sheets of Drawings.
In witness whereof, I, the said Hermann Wedekind, have to this. my
Specification set my hand and seal, the Thirtieth day of April, One
thousand eight hundred and sixty-seven.
HERMANN WEDEKIND. (L:S.)