Year: 1897

page_text: Date of Application, 31st Aug., 1897
Complete Specification Left, 28th May, 1898-Accepted, 30th July, 1898
A communication by LA SOCIÉTÉ INTERNATIONALE DE MEUNERIE ET DE PANIFICATION
(SYSTÈME SCHWEITZER,) of 81, Boulevard Anspach, Brussels, in the Kingdom of
Belgium, Manufacturers.
I, GEORGE CECIL DYMOND, M.I.M.E., of W. P. Thompson & Co., the Agency for
Foreign Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester,
both in the County of Lancaster, 118, New Street, Birmingham, in the County of
Warwick, and 322, High Holborn, in the County of Middlesex, Patent Agent, do
hereby declare the nature of this invention to be as follows:-
66
This invention relates to that class of flour mills in which the grinding of
the grain is obtained by means of so-called grinding discs," and it consists
essentially
(1) Of a special kind of channels or furrows arranged in a suitable manner on the
discs, with a view to realizing the advantages of the so-called progressive grinding
by a single passage of the material between these discs; (2) of an improved form of
construction of the grinding dises; (3) of a special arrangement for mounting and
regulating the discs enabling them to be maintained exactly parallel during their
running as will be hereinafter explained.
In order to obtain the well known advantages of progressive grinding, the discs
are provided with a continuous series of groups of channels or furrows cut obliquely
in such a way that their prolongations are tangential to a circle concentric to the
disc and that their depth increases and their number diminishes from the exterior
to the interior of the said disc where their width and depth must be sufficiently
great to allow of an easy entrance of the grain. Further, each group of channels or
furrows is composed of a principal furrow or channel which is divided into two or
more shorter furrows or channels, which are in their turn divided into two or
more still shorter channels or furrows sufficiently close together to produce fine
flour.
The result of this arrangement of furrows is that their action on the grain
corresponds precisely with the succession of operations of the so-called progressive
grinding, in fact the part of the disc near its interior where the furrows are wide and
deep, produces the cracking of the grain and the removal of the skin or husk. The
centre part of the disc where the furrows are less wide and deep will produce the
division of the grain into groats and semolina, and the part of the disc nearest to its
periphery where the furrows are very close together will reduce these groats into fine
flour.
These furrows or channels are obtained in the following way:
The disc or flat metallic ring which it is desired to cut or groove is mounted on a
revolving plate, and the tool employed for cutting the furrows is fixed at the
extremity of a bar having a reciprocating motion and which is inclined more or less
according to the increase of depth which the furrows or channels must have from the
periphery of the disc up to its internal edge, and after each stroke of the tool the

page_text: disc is turned to an extent corresponding to the distance between one furrow or
channel and the next.
It is evident the same result would be obtained if the plate carrying the disc
remained immovable and the inclined bar carrying the tool received after each stroke
or operation an angular displacement equal to the interval between two successive
furrows or channels. It may however be pointed out that each movement forward of
the bar carrying the tool which cuts a channel or furrow operates on a straight line
and that all these straight lines thus successively produced remain always equally
inclined and at an equal distance from a vertical axis passing through the centre of
the disc on which the operation is performed. But it is shown by mathematics that
a straight line inclined and revolving round an axis which it does not encounter
produces a left hand surface known. under the name of hyperboloid of revolution.
The result is therefore with this method of operating that all the furrows or
channels of the disc from their bottom up to their upper projecting edge form
surfaces in the form of a hyperboloid of revolution.
It is evident therefore that the grain being subjected to the action of left hand
surfaces which cannot be developed is rubbed and disintegrated by their contact
under different conditions to those of ordinary mills and which ensure a notable
increase in the yield, a rapid discharge of the flour and an important reduction in
motive power consumed.
Experience has shown that the part of the furrows or channels situated towards the
internal edge of the disc and which act on the skin of the grain wear away more
rapidly than that part of the furrows situated towards the exterior where the
reduction of the groats into fine flour takes place. For the purpose of economy it
has been found preferable to form these discs in two concentric parts, the external
one having the fine furrows or channels cut with precision in a ring of steel and the
other, the interior part, bearing the wider and deeper furrows or so-called prepara-
tory furrows is formed of hard cast metal or any other hard moulded material
such as silex, quartz, corundum or the like reduced to small fragments which are
agglomerated by means of a resistant cement. Further, by taking care to form the
preparatory furrows on the two faces of the ring of cast metal or other hard
material, the advantage is obtained of being able to reverse it when one of its faces
is worn. A great economy in the manufacture and use of these channelled or
furrowed discs is thus obtained.
The two concentric discs herein before mentioned are preferably mounted on a
plate in such a way as to allow of their respective levels being adjusted at will. For
this purpose the exterior ring is fixed on this plate by means of screws, whilst the
interior reversible ring is maintained by means of bolts screwed into the support
plate and provided with an adjusting nut. Any other suitable arrangement however
may be employed for the same object.
•
The discs are caused to revolve in such a direction that during the operation the
inclined faces of the furrows cut in the form of teeth of a saw advance one toward
the other in such a way that the grist is pressed and disintegrated between these
inclined faces. It has however been found that when the discs are formed in two
concentric parts as described, it is preferable to incline the oblique faces of their
respective furrows in different directions and to mount them on the common plate in
such a way that it is the cutting edges of the preparatory furrows or channels
formed in the interior ring which advance one towards the other during the operation,
whilst the inclined faces of the fine furrows or channels of the external ring act on the
grist in the manner herein before described. The removal of the skin is thus
facilitated as well as the splitting or cracking of the grain and its reduction to
groats which increases the production of the apparatus and reduces the motive
power employed.
It is evident that the discs thus provided with furrows formed with precision, must
be mounted in the framework of the mill in a special manner which ensures both
their remaining exactly parallel during their running and the parallel adjustment of

page_text: the fixed dise when it has to be raised or lowered according to the nature of the work
to be produced and to make up for wear and tear.
With this object the upper non-revolving disc is fixed under a plate or cover, the
edge of which is provided with a guide crown capable of sliding or telescoping into
the upper part of the frame which for this purpose is exactly circular in form. On
the other hand in order to allow of the upper disc being raised or lowered in a parallel
direction, the said plate or cover rests on three or more screws bearing equal pinions
and gearing with a cogwheel capable of revolving freely in a circular recess formed
with this object in the upper part of the frame. In this manner by revolving by
hand any one of the screws by means of a hand wheel fixed on its axis the cog wheel
will transmit to the other screws an equal angle of rotation and consequently the
upper disc will receive a parallel rising or descending motion.
In case the discs are formed of two concentric rings as herein before explained it is
of importance to be able to regulate in an independent manner the distance apart of
the two parts of these discs which correspond respectively during the running.
For this object the upper plate or cover of the frame is formed of two concentric
pieces, and the external part of this cover which receives the ring bearing the fine
furrows is arranged in the manner herein before described, and in addition the other
part of the cover which receives the internal ring bearing the preparatory furrows is
arranged in such a way as to be able to slide or telescope in the external cover and
its parallel movements of rising and descending are also obtained in the same manner
as before, that is to say that the internal cover rests on screws arranged in the
external cover and which are also provided with equal pinions gearing with a second
toothed wheel movable in a groove or circular recess formed in the said external
cover.
It is therefore evident that the two channelled or furrowed rings forming, the
fixed working crown of the mill disc may thus be independently adjusted in a parallel
direction.
communication by LA SOCIÉTÉ INTERNATIONALE DE MEUNERIE ET DE PANIFICATION
(SYSTEME SCHWEITZER), of 81, Boulevard Anspach, Brussels, in the Kingdom of
Belgium, Manufacturers.
I, GEORGE CECIL DYMOND, M.I.M.E., of W. P. Thompson & Co., the Agency for
Foreign Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester,
both in the County of Lancaster, 118, New Street, Birmingham, in the County of
Warwick, and 322, High Holborn, in the County of Middlesex, Patent Agent, 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 to that class of flour mills in which the grinding of the
grain is obtained by means of so-called "grinding discs" and it consists essentially
(1) of a special kind of channels or furrows arranged in a suitable manner on the
discs, with a view to realising the advantages of the so-called progressive grinding by
a single passage of the material between these discs; (2) of an improved form of
construction of the grinding dises; (3) of a special arrangement for mounting and

page_text: regulating the discs enabling them to be maintained exactly parallel during their
running as will be hereinafter explained with reference to the accompanying drawings,
in which,
Figure 1 is a plan view of a portion of a grinding disc;
Figure 2 is a section along a furrow;
Figures 3, 4 and 5 are diagrams showing the shape and plan of the furrows;
Figures 6, 7, 8 and 9 relate to the way in which these furrows act on the
grain;
Figure 10 is a plan view of a portion of a special grinding disc formed of two
concentric rings;
Figure 11 is a section of the same arrangement;
Figure 12 is a sectional view showing a method of mounting these two concentric
rings;
Figure 13 is a vertical section of an arrangement of parallel regulation or
adjustment;
Figures 14 and 15 are respectively vertical section and sectional plan of an
arrangement for parallel adjustment applied to a grinding disc in two parts.
As may be seen in Figure 1, the discs A are provided with a continuous series of
groups of channels or furrows cut obliquely and with precision in such a way that
their prolongations are tangential to a circle of radius o a concentric to the disc and
that their depth increases and their number diminishes from the exterior to the
interior of the said disc where their width and depth must be sufficiently great to
allow of an easy entrance of the grain.
Each group of channels or furrows is composed of a principal furrow or channel 112
which is divided into two or more shorter furrows or channels 1 which are in their
turn divided into two or more still shorter channels or furrows sufficiently close
together to produce fine flour.
The result of this arrangement of furrows is that their action on the grain
corresponds precisely with the succession of operations of the so-called progressive
grinding, in fact the part of the disc near its interior edge n where the
furrows are wide and deep, produces the cracking of the grain and the removal of the
skin or husk. The centre part of the disc where the furrows are less wide and deep
will produce the division of the grain into groats and semolina, and the part of the
dise nearest to its periphery m where the furrows are very close together will
reduce these groats into fine flour.
。
These furrows or channels are obtained in the following way :-
The disc or flat metallic ring which it is desired to cut or groove is mounted on a
revolving plate, and the tool employed for cutting the furrows is fixed at the
extremity of a bar having a reciprocating motion and which is inclined more or less
according to the increase of depth which the furrows or channels must have from the
periphery of the disc up to its internal edge, and after each stroke of the tool the
disc is turned to an extent corresponding to the distance between one furrow or
channel and the next.
It is evident the same result would be obtained if the plate carrying the disc
remained immovable and the inclined bar carrying the tool received after each
stroke or operation an angular displacement equal to the interval between two
successive furrows or channels. It may however be pointed out that, as shown in
Figure 3, each movement forward of the bar carrying the tool which cuts a channel
or furrow operates on a straight line, such as a band that all the straight lines thus
successively produced remain always equally inclined and at an equal distance from a
vertical axis b¹ passing through the centre o of the disc on which the operation is
performed. But it is shown by mathematics that a straight line which is neither
parallel to nor meets an axis round which it revolves produces a surface which can-
not be developed known under the name of hyperboloid. The result is therefore with
this method of operating that all the furrows or channels of the disc from their
bottom up to their upper projecting edge belong to a series of surfaces in the form
of an hyperboloid,

page_text: As may be seen in Figure 4 it is the upper part of the hyperboloid which
corresponds to the upper face zz of the lower disc whilst the lower part of the same
hyperboloid will correspond to the lower face y y of the upper disc, the two discs
occupying in the mill the position shown in Figure 5. During the grinding the
rotary disc is caused to revolve in the direction indicated by the arcy: a (Figmes 6,
7 and 8) in such a way that it is the inclined parts of the grooves and not the
cutting edges of said grooves which advance one towards the other.
It is evident therefore that the grain being subjected to the action of surfaces
which cannot be developed is rubbed and disintegrated by their contact under
different conditions to those of ordinary mills and which ensure a notable increase in
the yield. Further by referring to Figure 9 it will be seen that the movement of
rotation is effected in such a direction that the extremities m' and m² of the grooves
approach while the extremities n' and n² separate and the result is that the grain of
wheat which is crushed or gripped at d is at the same time forced towards the outer
periphery of the disc as indicated by the arrow causing a rapid discharge of the flour
and an important reduction in motive power consumed.
Experience has shown that the part of the furrows or channels situated towards the
internal edge of the disc and which acts on the skin of the grain wears away more
rapidly than that part of the furrows situated towards the exterior m. where the
reduction of the groats into fine flour takes place. For the purpose of economy it
has been found preferable to form these discs in two concentric parts, as may be
seen in Figure 10, the external one A¹ having the fine furrows or channels r cut with
precision in a ring of steel, and the other, the interior part A², bearing the wider and
deeper furrows or so-called preparatory furrows is formed of hard cast metal or any
other bard moulded material such as silex, quartz, corundum or the like reduced to
small fragments which are agglomerated by means of a resistant cement. Further,
by taking care to form the preparatory furrows on the two faces of the ring of cast
metal or other hard material the advantage is obtained of being able to reverse it
when one of its faces is worn. A great economy in the manufacture and use of these
channelled or furrowed discs is thus obtained. .
The two concentric discs herein before mentioned are preferably mounted on a plate
B in such a way as to allow of their respective levels being adjusted at will. For
this purpose the arrangement shown in Figure 12 is preferably employed. The
exterior ring A' is fixed on this plate B by means of screws whilst the interior
reversible ring is maintained by means of bolts of screwed into the support plate at a
suitable height supporting the ring by means of a collar f¹ and provided with an
adjusting nut g. Any other suitable arrangement however may be employed for the
same object. The ring A2 is also provided with tenons h which engage in mortices
formed in the plate B and which have for their object to prevent any lateral dis-
placement. As was herein before stated the discs are caused to revolve in such a
direction that during the operation the inclined faces of the furrows, cut in the form
of teeth of a saw, advance one towards the other in such a way that the grist is
pressed and disintegrated between these inclined faces. It has however been found
that when the discs are formed in two concentric parts as described, it is preferable
to incline the oblique faces of their respective furrows in different directions and to
mount them on the common plate in such a way that it is the cutting edges of the
preparatory furrows or channels formed in the interior ring which advance one
towards the other during the operation, whilst the inclined faces of the fiue furrows
or channels of the external ring act on the grist in the manner herein before
described. Under these conditions the discs act as if the grooves revolved respectively
in the direction indicated by the arrows x¹ in Figures 6, 7 and 8. The removal of
the skin is thus facilitated as well as the splitting or cracking of the grain and its
reduction to groats which increases the production of the apparatus and reduces the
motive power employed.
It is evident that the discs thus provided with furrows formed with precision, must
be mounted in the framework of the mill in a special manner which ensures both
their remaining exactly parallel during their running and the parallel adjustment of

page_text: the fixed disc when it has to be raised or lowered according to the nature of the work
to be produced and to make up for wear and tear.
With this object the upper non-revolving disc C Figure 13, is fixed under a plate
or cover E, the edge of which is provided with a guide crown e capable of sliding
or telescoping into the upper part F of the frame which for this purpose is exactly
circular in form. On the other hand in order to allow of the upper disc being raised
or lowered in a parallel direction, the said plate or cover rests on three or more
screws provided with collars land bearing equal pinions K and gearing with a
cogwheel G capable of revolving freely in a circular recess formed with this object
in the upper part of the frame. In this manner by revolving by hand any one of the
screws by means of a hand wheel J fixed on its axis the cog wheel will transmit to
the other screws an equal angle of rotation and consequently the upper disc will
receive a parallel rising or descending motion.
In case the discs are formed of two concentric rings as hereinbefore explained, it is
of importance to be able to regulate in an independent manner the distance apart of
the two parts of these discs which correspond respectively during the running. The
arrangement shown in Figures 14 and 15 may then be employed.
The upper plate or cover of the frame is formed of two concentric pieces, and the
external part E¹ of this cover which receives an external ring C₁ bearing the fine-
furrows is arranged in the manner herein before described, and is supported by screws k¹
provided with collars, hand wheels j¹ and pinions K¹ gearing with a cog wheel G¹.
In addition the other part of the cover E2 which receives the internal ring C²
bearing the preparatory furrows is arranged in such a way as to be able to slide
or telescope in the external cover and its parallel movements of rising and
descending are also obtained in the same manner as before, that is to say that
the internal cover rests on screws 2 provided with collars 12 and arranged in the
external cover E¹ and which are also provided with equal pinions K2 gearing with
a second toothed wheel G2 movable in a groove or circular recess formed in the said
external cover.
T
It is therefore evident that the two channelled or furrowed rings forming the fixed
working crown of the mill disc may thus be independently adjusted in a parallel
direction.
Having now particularly described and ascertained the nature of the said inven.
tion and in what manner the same is to be performed, as communicated to me
by my foreign correspondents, I declare that what I claim is :-
1. In a flour mill in which grinding discs are employed, an arrangement of
suitable grooves or furrows, allowing the so-called "progressive" grinding to be
realised by a single passage of the grain through the discs, consisting of a series of
groups of channels cut in such a way that their depth increases and their number
diminishes from the periphery towards the centre, and characterised by the circum-
stance that all their similar parts from their bottom up to their upper projecting edge
belong to an hyperboloid such as herein before described, each group of grooves being
formed of a principal groove (r) divided into one or more shorter ones (1) themselves
divided into two or more still shorter grooves (72) substantially as herein before set
forth.
2. In a flour mill, a system of working surfaces for grinding discs consisting of two
independent and concentric grooved or channelled discs, the external one of which
has fine grooves and the internal one, formed by moulding, of cast, metal or other
hard cast or agglomerate material, has preparatory grooves substantially as herein-
before set forth.
3. In a mill disc formed of two concentric rings grooved independently, the
external one of which rings has fine grooves and the internal one preparatory grooves,
the combination of a moulded internal ring having grooves on both faces in order to
allow of its being easily reverse.l, substantially as hereinbefore described.
4. In a flour mill in which grinding discs are employed formed of two concentric
surfaces such as described, the arrangement of a pair of internal rings having

page_text: preparatory grooves or furrows, the sharp edges or teeth of which in the one ring
advance towards those in the other ring when at work, whilst the grooves or furrows
of the external rings have channels the oblique parts of which advance towards one
another, substantially as hereinbefore described and with the object set forth.
5. In a flour mill, a system of parallel mounting of the discs in which the fixed
dise is carried by a plate or cover (E) having a crown (e) telescoping in a corresponding
part of the frame, the vertical displacements of the said cover being regulated and
rendered parallel by means of screws (k) bearing pinions (K) gearing with a common
cogwheel (G) revolving freely in the frame substantially as described with reference
to Figure 13 of the accompanying drawings.
6. In a flour mill in which discs formed of concentric rings or surfaces are
employed, the arrangement for the independent parallel adjustment of the grooved
rings, in which the cover (E¹) carries the external-ring and is recessed to receive a
second cover (E2) the reciprocal positions of the two covers (E¹ and E²) being
regulated by means of screws (2) provided with pinions (K2) which gear with a
toothed wheel (G2) substantially as described with reference to Figure 14 of the
accompanying drawings.