Year: 1899

page_text: Date of Application, 1st Sept., 1899
Complete Specification Left, 1st June, 1900-Accepted, 7th July, 1900
We, TILE EDISON ORE MILLING SYNDICATE LIMITED, of No. 189, Fleet Street,
in the City of London, do hereby declare the nature of this invention to be as
follows: :-
In the roller crushing mill described in the Specification of Letters Patent
8530 of 1898 each upper roll is pulled downwards upon the one immediately
underneath it by an endless rope passed over sheaves on the ends of the shafts
of the top and the bottom rolls and also over a moveable one adapted to control
the tension of the rope, the object being to make the stress between the rolls
dependent upon the tension in the rope.
When the rolls are intended particularly for crushing dry pulverizable
material, it is desirable that they should be of a comparatively small diameter
in order that the available crushing surface may be reduced sufficiently for the
pulverizing action to take place, without producing prohibitive strains in the
mill. With such rolls, the gap or angle between the two adjacent grinding
surfaces is necessarily great, so that in the operation of such rolls there was
always a tendency for the material to slip relatively to the crushing surfaces,
and in consequence the feed was comparatively slow. As a result of this action,
it was found impracticable to employ chilled surfaces on the rolls, and with
such rolls the best results, so far as the quantity of feed is concerned, were
secured by the employment of relatively soft peripheries. The present inven-
tion makes it possible to construct them with chilled peripheries, and hence of
great durability, and wherein the tendency of the material, however dry, to slip
relatively to the grinding surfaces, is entirely overcome, so that in consequence
a maximum feed of material can be secured. This result is effected by cor-
rugating or otherwise roughening the surfaces of the rolls, whereby the rolls
themselves will cause the material to be drawn positively down into the throat
between the rolls and to be crushed by such rolls. In order to prevent the
corrugated or roughened surfaces of the rolls from engaging together, smooth
separating rims are employed, which roll upon each other without friction and
which allow for a gap of about one thirty-second of an inch between the crushing.
surfaces.
The new rolls are fully shown in the attached drawings, in which
Figure 1 is a plan view, partly in section, of the preferred embodi-
ment of the present invention, showing the same in use in connection with a set
of three rolls of the general type described and claimed in the patent above
mentioned; Figure 2 a side view of the same; Figure 3 an end view; Figure 4
an enlarged longitudinal section through one of the crushing rolls and its shaft;
Figure 5 a similar view illustrating a modification; Figure 6 a section on the

page_text: line 66 of Figure 3; Figure 7 a diagram illustrating the action which takes
place with crushing rolls having smooth crushing surfaces in the crushing of
dry pulverizable material; and Figure 8 a similar view illustrating the operation
which takes place with crushing rolls constructed in accordance with the present
invention. In all of the above views, corresponding parts are represented by
the same numerals of reference.
1, 1 represents two heavy side girders secured to a suitable foundation, and
2,2, cross frames connecting the side girders at their ends. 3, 3, are top braces
extended between the ends of the frames 2, 2 parallel with the girders 1 1.
The parts are all held together by heavy tie-bolts 4. The space at each side of
the machine between the girders 1 and top braces 3, comprises a longitudinal
guide for bearing-boxes 5, 5, in which are mounted the shafts 6 of the three
rolls 7, 7, 7. These bearing-boxes do not receive any of the thrust of the work,
and are employed solely for the proper guiding of the rolls. The bearing-
boxes 5 for one of the end rolls are fixed against longitudinal movement, and
the shaft of that roll carries a belt-wheel 8, to which power is applied. Loosely
mounted on the shafts of the end rolls are the independent sheaves 9, 9, around
which extends the endless wire rope 10, one bight of which passes over the
stationary guide pulleys 11, and the other over the guide pulleys 12, 12, 12,
one of which is connected to the piston 13 of the pressure cylinder 14, as in the
previous patent. By admitting a suitable fluid pressure to the cylinder 14,
the three rolls will be forced tightly together with an increased pressure due
to the number of turns given to the wire rope 10, and in operation the said wire
rope will be permitted to move with the rolls, whereby a practically friction-
less bearing will be secured.
The shaft 6 of each of the rolls is provided at its center with an enlarged
boss 15 having a keyway therein, and keyed upon said boss is the shell 16 of the
roll, said shell being preferably cast in one piece. In order to prevent longi-
tudinal movement of the shell with respect to the shaft, the boss 15 is provided
with recesses 17, 17, within which are placed the split collars 18 which bear
against the ends of the shell 16 and practically lock the latter rigidly to the
shaft. Longitudinal movement of the shafts 6 with respect to their bearing-
boxes 5 is prevented by means of thrust bearings 19 of any suitable type. In
the preferred embodiment of the invention the shell 16 of each roll is provided
at its ends with smooth rims 20, 20, bearing on corresponding rims of the
adjacent rolls, as shown. The space on each roll between these rims constitutes
a surface upon which are secured a plurality of plates 21 having corrugated or
roughened surfaces 22, as shown. Preferably these corrugations extend entirely
across the plates 21 from side to side, With the present invention it will be
entirely possible and desirable to make the plates 21 with chilled surfaces. The
plates 21 are held in place in any suitable way, but preferably by means of
bolts 23, which are provided with locks of any suitable type to prevent accidental
loosening. The parts will be so proportioned that the engaging rims 20 of the
rolls will maintain the corrugated surfaces 22 of the grinding plates of adjacent
rolls separated to a very slight extent, say about one thirty-second of an inch
whereby the corrugated surfaces of the rolls will be kept out of engagement,
without interfering, however, with an effective grinding operation.
Instead of forming the smooth bearing rims 20 directly on the shells 16 of
the crushing rolls, said rims may be formed entirely independently of the said
rolls and may be keyed to the shafts 6 on the outside of the bearing-boxes 5,
as shown in Figure 5, it being only necessary for the carrying out of the inven-
tion that the rolls should be suitably roughened, and that smooth supporting
rims should be employed, however they may be located, for keeping the cor-
rugated or roughened surfaces of the crushing rolls out of engagement.
In operation power is applied to the belt wheel 8 for directly driving the roll
connected to its shaft, and the other rolls are driven by friction therefrom, or by
the friction between the rolls and the passing stream or streams of material.
"

page_text: With ordinary crushing rolls having smooth peripheries, as shown in Figure 7,
assuming the depth of material between the rolls to be represented by the
line, it will be seen that the angle of the throat or gap between the rolls
is comparatively great, and in consequence there is an inevitable tendency on
the part of the material to slip relatively to the grinding surfaces, whereby
the quantity of feed is comparatively small. By providing the crushing rolls
with corrugated or roughened surfaces, as shown in Figure 8, it will be observed
that any tendency on the part of the material to slip relatively to the rolls is
entirely overcome, since the adjacent surfaces of the rolls constitute pockets for
drawing the material positively downwards between the rolls.
It will be, of course, understood that the crushing rolls provided with roughened
or corrugated peripheries and with smooth bearing rims for keeping the said
roughened or corrugated peripheries out of engagement may be applied in con-
nection with other devices than the specific type illustrated; for example, with
the ordinary crushing rolls the shafts of which are carried in non-rotatable
bearings upon which the thrust of the crushing strains is received. It will
furthermore be understood that when the invention is employed in connection
with three rolls of the type illustrated, the material may be caused to pass
successively between one of the end rolls and the central roll and back again
between the said central roll and the other end roll, as in the previous patent.
Or instead of either of these arrangements, it will be advantageous in some
instances to place the rolls in a horizontal plane and to pass the material only
between two of them, in which case the corrugated or roughened crushing
surface of one of the end rolls may be dispensed with, the shaft of that roll being
only provided with the smooth separating rims 20 for engagement with the
corresponding rims of the central roll. It will furthermore be understood that
only two rolls may be employed, connected together by an endless moving rope,
the latter being crossed between each of the independently mounted sheaves,
as in the previous patent, although such an arrangement is not so desirable as
the employment of three, shafts carrying either two or three rolls with the end-
less rope extended between independently mounted sheaves on the ends of the
outer shafts.
1000
CHAS. S. WOODROFFE,
Chartered Patent Agent.
Improvements in Roller Crushing Mills.
We, THE EDISON ORE MILLING SYNDICATE LIMITED, of No. 189, Fleet Street,
in the City of London, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
In the roller crushing mill described in the Specification of Letters Patent
8530 of 1898 each upper roll is pulled downwards upon the one immediately
underneath it by an endless rope passed over sheaves on the ends of the shafts
of the top and the bottom rolls and also over a moveable one adapted to control
the tension of the rope, the object being to make the stress between the ros
dependent upon the tension in the rope.
When the rolls are intended particularly for crushing dry, pulverisable
material, it is desirable that they should be of a comparatively small diameter
in order that the available crushing surface may be reduced sufficiently for the

page_text: pulverizing action to take place, without producing prohibitive strains in the
mill. With such rolls, the gap or angle between the two adjacent grinding
surfaces is necessarily great, so that in the operation of such rolls there was
always a tendency for the material to slip relatively to the crushing surfaces,
and in consequence the feed was comparatively slow. To prevent this, the rolls
are corrugated from end to end, the troughs or grooves in one roller registering
with those in the other respectively, whereby the rolls themselves will cause the
material to be drawn positively down into the throat between them and to be
crushed by such rolls. In order to prevent the corrugated surfaces of the rolls
from engaging together, smooth separating rims are employed, which roll upon
each other without friction and which allow for a gap of about one thirty-second
of an inch between the crushing surfaces.
The new rolls are fully shown in the drawings filed with the Provisional
Specification which are to be taken as part of this specification and read therewith
and in which Figure 1 is a plan view, partly in section, of the preferred embodi-
ment of the present invention, showing the same in use in connection with a set
of three rolls of the general type described and claimed in the patent above
mentioned; Figure 2, a side view of the same; Figure 3, an end view; Figure 4
an enlarged longitudinal section through one of the crushing rolls and its shaft;
Figure 5, a similar view illustrating a modification: Figure 6, a section on the
line 6-6 of Figure 3: Figure 7, a diagram illustrating the action which takes
place with crushing rolls having smooth crushing surfaces in the crushing of
dry pulverisable material; and Figure 8, a similar view illustrating the operation
which takes place with crushing rolls constructed in accordance with the present
invention. In all of the above views, corresponding parts are represented by
the same numerals of reference.
1, 1 represent two heavy side girders secured to a suitable foundation, and
2,2, cross-frames connecting the side girders at their ends. 3, 3, are top braces
extended between the ends of the frames 2, 2, parallel with the girders 1 1.
The parts are all held together by heavy tie-bolts 4. The space--at each side of
the mill between the girders 1 and top braces 3, comprises a longitudinal
guide for bearing-boxes 5, 5, in which are mounted the shafts 6 of the three
rolls 7, 7, 7. These bearing-boxes do not receive any of the thrust of the work,
and are employed solely for the proper guiding of the rolls. The bearing-
boxes 5 for one of the end rolls are fixed against longitudinal movement, and
the shaft of that roll carries a belt-wheel 8, to which power is applied. Loosely
mounted on the shafts of the end rolls are the independent sheaves 9, 9, around
which extends the endless wire rope 10, one bight of which passes over the
stationary guide-pulleys 11, and the other over the guide-pulleys 12, 12, 12,
one of which is connected to the piston 13 of the pressure cylinder 14, as in the
previous patent. By admitting a suitable fluid pressure to the cylinder 14,
the three rolls will be forced tightly together with an increased pressure due
to the number of turns given to the wire rope 10, and in operation the said wire
rope will be permitted to move with the rolls, whereby a practically friction-
less bearing will be secured.
The shaft 6 of each of the rolls is provided at its centre with an enlarged
boss 15 having a key-way therein, and keyed upon said boss is the shell 16 of the
roll, said shell being preferably cast in one piece. In order to prevent longi-
tudinal movement of the shell with respect to the shaft, the boss 15 is provided
with recesses 17, 17, within which are placed the split collars 18 which bear
against the ends of the shell 16. Longitudinal movement of the
shafts 6 with respect to their bearing-boxes 5 is prevented by means
of thrust bearings 19 of any
suitable type. In the preferred em-
bodiment of the invention, the shell 16 of each roll is provided
at its ends with smooth rims 20, 20, bearing on corresponding rims of the
adjacent rolls, as shewn. The space on each roll between these rims constitutes
a surface upon which are secured a plurality of plates 21 having corrugated

page_text: surfaces 22, LS shewn. Preferably, these corrugations extend entirely
across the plates 21 from side to side. With the present invention it will be
entirely possible and desirable to make the plates 21 with chilled surfaces. The
plates 21 are held in place in any suitable way, but preferably by means of
bolts 23, which are provided with locks of any suitable type to prevent accidental
loosening. The parts will be so proportioned that the engaging rims 20 of the
rolls will maintain the corrugated surfaces 22 of the grinding plates of adjacent
rolls separated to a very slight extent, say about one thirty-second of an inch,
whereby the corrugated surfaces of the rolls will be kept out of engagement,
without interfering, however, with an effective crushing operation.
Instead of forming the smooth bearing rims 20 directly on the shells 16 of
the crushing rolls, said rims may be formed entirely independently of the said
rolls and may be keyed to the shafts 6 on the outside of the bearing-boxes 5,
as shewn in Figure 5, it being only necessary for the carrying out of the inven-
tion that the rolls should be corrugated and that smooth supporting rims should
be employed, however they may be located, for keeping the corrugated surfaces
of the crushing rolls out of engagement.
In operation power is applied to the belt wheel 8 for directly driving the roll
connected to its shaft, and the other rolls are driven by the friction between
them and the passing streams of material. With ordinary crushing rolls
having smooth peripheries, as shewn in Figure, assuming the depth
of material between the rolls to be represented by the line,
it will be seen that the angle of the throat or gap between the rolls is com-
paratively great, and in consequence there is an inevitable tendency on the part
of the material to slip relatively to the grinding surfaces, whereby the quantity
of feed is comparatively small. By providing the crushing rolls with corrugated
surfaces, as shewn in Figure 8, it will be observed that any tendency on the
part of the material to slip relatively to the rolls is entirely overcome, since
the adjacent surfaces of the rolls constitute pockets for drawing the material
positively downwards between the rolls.
It will be, of course, understood that the crushing rolls provided with
corrugated peripheries and with smooth bearing rims for keeping the said
corrugated peripheries out of engagement, may be applied in con-
nection with other devices than the specific type illustrated: for example, with
the ordinary crushing rolls the shafts of which are carried in non-rotatable
bearings upon which the thrust of the crushing strains is received. It will
furthermore be understood that when the invention is employed in connection
with three rolls of the type illustrated, the material may be caused to pass
successively between one of the end rolls and the central roll and back again
between the said central roll and the other end rolls, as in the previous patent.
Or instead of either of these arrangements, it will be advantageous in some
instances to place the rolls in a horizontal plane and to pass the material only
between two of them, in which case the corrugated crushing surface
of one of the end rolls may be dispensed with, the shaft of that roll being
only provided with the smooth separating rims 20 for engagement with the
corresponding rims of the central roll. It will furthermore be understood that
only two rolls may be employed, connected together by an endless moving rope,
the latter being crossed between each of the independently mounted sheaves,
as in the previous patent, although such an arrangement is not so desirable as
the employment of three shafts carrying either two or three rolls with the end-
less rope extended between independently mounted sheaves on the ends of the
outer shafts.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:
The hereinbefore described combination with pairs of rollers of comparatively

page_text: small diameter, of crushing surfaces corrugated from end to end, the corruga-
tions in one 1oll registering with those in the fellow roll of the pair and a
separating rim at each end of each roll bearing against a similar rim at each
end of the fellow roll.
Dated this 1st day of June 1900.
CHAS. S. WOODROFFE,
Chartered Patent Agent.