Year: 1886

page_text: Date of Application, 20th Aug., 1886.
Complete Left, 4th May, 1887.
Complete Accepted, 7th June, 1887.
[Communicated from abroad by HENRY WILLIS CUTLER, Gentleman, of North
Wilbraham, in the County of Hampden, and State of Massachusetts, United
States of America.]
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of this Invention to be as follows :—
Vertical disc grinding mills are for many purposes superior to the ordinary form of
horizontal disc mill, but such vertical mills have not been generally adopted because
of the many defects in their construction. Some of the principal defects are that
heretofore these mills have not been supplied with any proper suitable stopping or
starting device, nor have the stones been so mounted and arranged that they could
be put in proper alignment, without a great deal of trouble.
This invention relates to the construction of a mill wherein the loose pulley, usually
carried by the driving shaft, is dispensed with, the whole case and frame work of the
mill being supported by trunnions mounted in bearings so that by tilting the frame
and case upon the bearings of the trunnions, the driving belt may be tightened or
loosened to start or stop the machine.
And the invention further relates to a peculiar and novel construction of the mill
case or means for mounting the stationary stone therein; also to an arrangement and
combination of parts for adjusting the running stone towards, or from the stationary
stone, whereby the grade of the meal may be regulated; to an arrangement whereby
the running stone can be thrown back from the stationary stone when it is necessary
to separate said stones, or stop the grinding; to means whereby, when the stones are
separated, the feed from the hopper will be discontinued ; to an arrangement whereby,
although normally held in the required position for proper grinding, the stones will
be allowed to separate should any hard substance such as iron, accidentally come
between the meeting faces of the stones so that the hard substance will pass from
between the stones without materially injuring them, or changing their set, the stones

page_text: being arranged to automatically return to their original position. And finally, the
invention relates to an improvement in the means for mounting the driving shaft,
and to certain other details of construction and combinations of parts, hereinafter
explained.
The mill is supported in vertical standards rising from a suitable base plate by
means of trunnions on the mill case which are mounted in bearings in the standards.
This mill case is made in the ordinary manner to form a short, cylindrical covering
for the stones and is provided with four equidistant radial outside flanges, parallel to
its axis.
The stationary stone is provided with four radial trunnions placed at equal distancos
in the periphery of the stone and extending through apertures in the case. These
trunnions ride in boxes which are formed with a base and with a boss, which projects
from the base in a line at right angles to the trunnion.
In the flanges of the case are slots in which the bosses of the trunnion boxes are
fitted so as to slide parallel to the axis of the said casing, the under-side of the base of
cach trunnion box being held against the face of the flange by a bolt which passes
through a washer into the boss. In practice I prefer that two of the trunnions should
be in a vertical plane, while the other two are in a horizontal plane, so that when it
becomes necessary to adjust the stationary stone, in order to bring it into proper
alignment with the running stone, it is simply necessary to loosen the bolts of the
boxes of the trunnions in order that the stone may be left free to turn upon said
trunnions; and it will be easily understood, when the stationary stone is hung in this
way that as it changes position in coming to alignment with the running stone
vertically, the trunnions that are in the horizontal plane will turn in their boxes,
while the trunnions that are in the vertical plane will slide slightly in their boxes
end wise the latter sliding along the slot in the flanges upon the casing, the boxes
turning somewhat on their bosses.
In aligning horizontally, the reverse of this takes place, that is, the vertical
.trunnions will turn and and the horizontal trunnions and boxes will slide in their slots.
During these movements the centre of the stationary stone will not be changed from
the centre line of the shaft, the bearings of which have a rigid connection with the
case; In this way a very accurate and nice adjustment of the stones may be obtained;
and when the alignment is correct and the running stone bearing fairly against the
stationary stone, the bolts are again tightened.
In order that the stationary stone may be kept in place, when being adjusted upon
its trunnions, 1 provide a semi-circular bar, which extends outward in front of the
mill, its ends being secured by bolts to the ends of the horizontal trunnions. This
bar bears against a roller which is carried by a rigid arm that projects forward from
a bracket on the front of the mill case, such arrangement affording a fixed point
against which the stationary stone rests, when being forced into alignment.
The shaft upon which the running stone is mounted is supported at its forward_end
in a bearing carried by the bracket above referred to, and at the other end by a
bearing carried by a bar supported by arms, which project from the rear of said case.
The shaft carries a fixed pulley which is preferably formed with a high crown.
From the foregoing it will be seen that the stones, mill case, pulley and driving
shaft are mounted so that they are free to swing together upon the trunnions of the
mill case.
The mechanism for stopping and starting the mill consists of a toggle interposed
between the rear bearing of the shaft and the bed of the machine, said toggle being
connected by a rod to a crank shaft at the front of the machine which is operated by
a lever in such manner that when the lever is moved in one direction it will lower the
rear end of the driving shaft and slacken the belt on the pulley and stop the mill and
when moved in the opposite direction the shaft will be raised, and the belt tightened
on the pulley. A ratchet and pawl is provided to maintain the shaft in position when
raised. In order that the running stone may be held to its work but at the same
time be free to recede from the stationary stone should any hard substance accidentally
pass between the surfaces of the stones, the shaft which carries the running stone

page_text: is mounted so as to permit of a limited movement in a horizontal direction. To
this end, the extremity of said shaft revolves in contact with a block which is
connected to a transverse bar by a stirrup piece pivoted to the block and provided
with a head that is bolted to the bar. This transverse bar is provided at one end with
a short longitudinal rod which is free to slide through the bar which supports the rear
bearing of the shaft, and it is provided with a spring and the other end of the
said transverse bar is supported on a longitudinal shaft mounted in arms projecting
from the mill case. This shaft is made in two portions connected by a right and left
handed screw-nut. One of the arms of the casing is provided with a sleeve through
which the shaft passes. A second sleeve formed with spiral grooves is pinned or
keyed to the shaft in position to overlap the first sleeve which sleeve is provided with
projecting pins which ride in the grooves of the outside sleeve. In order that the
running stone may be yieldingly held adjustable to the stationary stone, the tension of
the spring is regulated by a nut. In accordance with the direction in which it is
desired to adjust the running stone when grinding, movement is imparted to the
opposite end of the bar by means of the double threaded nut and when it is desired to
throw the running stone back and away from the stationary stone and out of contact
therewith, the sleeve on the shaft is thrown over by means of a handle with which it
is provided, this movement at the same time partially rotating the shaft, which partial
rotation stops the motion of an agitator which is attached to a shoe which is hung in
the usual manner beneath the hopper. The agitator is connected by means of a
spring and a strap to a bobbin which is carried by the shaft, so that as the shaft is
turned over toward the mill case, the strap will be unwound, and the agitator allowed
to full back from the driving shaft which carries a cam face.
A. MELVILLE CLARK.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.

page_text: I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Win. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of this Invention (a communication to me from.
abroad by Henry Willis Cutler of North Wilbraham, in the County of Hampden and
State of Massachusetts, United States of America Gentleman) and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement :—
Vertical disc grinding mills are, for many purposes, superior to the ordinary form
of horizontal disc mill, but such vertical mills have not been generally adopted
because of the many defects in their construction. Some of the principal defects, are,
that heretofore these mills have not been supplied with any propor suitable stopping
or starting device, nor have the stones been so mounted and arranged that they
could be put in proper alignment without a great deal of trouble on the part of the
operator.
This Invention relates to the construction of a mill wherein the loose pulley, usually
carried by the driving shaft, is dispensed with, the whole case and frame work of the
mill being supported by trunnions mounted in bearings, so that by tilting the frame
and case upon the bearings of the trunnions, the driving belt may be tightened or
loosened to start or stop the machine.
The Invention further relates to a peculiar and novel construction of the mill
case,
or means for mounting the stationary stone therein; also, to an arrangement and
combination of parts for adjusting the running stone towards or from the stationary
stone, whereby the grade of the meal is regulated; to an arrangement whereby the
running stone can be thrown back from the stationary stone when it is necessary to
separate said stones or stop the grinding; to the construction of an apparatus
whereby, when the stones are separated, the feed from the hopper will be discontinued ;
and to an arrangement whereby, although normally held in the required position for
proper grinding, the stones will be allowed to separate should any hard substance,
such as iron, accidentally come between the meeting faces of the stones, so that the
iron or hard substance will pass from between the stones without materially injuring
them or changing their set, the stones being arranged to automatically return to their
original position.
The Invention relates, finally, to an improvement in the means for mounting the
driving shaft and to certain other details of construction and combinations of parts,
hereinafter explained, and specifically pointed out in the claims.
Reference is to be had to the accompanying drawings forming a part of this
Specification, in which figure 1 is a side view of the improved grinding mill.
Figure 2 is a plan view of the same. Figure 3 is a vertical sectional view, taken on
line of figure 2. Figure 4 is an enlarged view of the stationary stone, the mill
case being shewn in section. Figure 5 is an enlarged view of a portion of the

page_text: stationary stone and one of its supporting devices. Figure 6 is an enlarged elevation
of one of the trunnion boxes, shewing its base and boss. Figure 7 is a view of the
under side of the same. Figure 8 is a sectional "plan view of the spirally grooved
sleeve and attachment by which the running stone is thrown back from the stationary
stone. Figure 9 is a sectional view of the same. Figure 10 is a view of the agitator
and its operating mechanism. Similar letters of reference indicate corresponding
parts in all the figures.
Referring now to the general construction, as best illustrated in figures 1 and 2,
A is the base or bed of the mill, which bed is provided with two vertical standards B B
formed with bearings in their upper ends in which the trunnions CC of the mill
case D are mounted. This inill case D is made in the ordinary manner to form a
short cylindrical covering for the stones, and is provided with four equidistant outside
flanges.
The stationary stone E, which is best seen in figures 3 and 4, is provided with four
radial trunnions bb placed at equal distances in the periphery of the stone and
extending through apertures in the case. These trunnions ride in boxes F (sce
figures 5, 6, and 7) each being formed with a base c and a boss d which projects from
the base in a line at right angles to the general line of the box.
The flanges a a of the case D are slotted, as shewn at e, and in these slots the
bosses are fitted, the under side of each base c being held against the face of the
flange by a tap bolt f which is passed through a washer gand engages with a threaded
socket formed in the boss d. In practice, I prefer that two of the trunnions b should
be in a vertical plane while the other two are in a horizontal plane so that when it
becomes necessary to adjust the stationary stone, in order to bring it into proper
alignment with the running stone G mounted in a manner to be hereinafter described,
it is simply necessary to loosen the bolts of the boxes of the trunnions, in order that
the stone may be left free to turn upon said trunnions, and it will be easily understood,
when the stationary stone is hung in this way that, as it changes position in coming
to alignment with the running stone vertically, the trunnions that are in the
horizontal plane will turn in their boxes, while the trunnions that are in the vertical
plane will slide in their boxes end wise, the boxes turning somewhat on the bosses d.
In aligning horizontally, the reverse of this takes place, that is, the vertical trunnions
will turn and the horizontal trunnions will slide in their respective boxes. During
these movements, the centre of the stationary stone will not be changed from the
centre line of the shaft, the bearings of which have a rigid connection with the caso.
In this way, a very accurate and nice adjustment of the stones may be obtained, and
when the alignment is correct and the running stone bearing fairly against the
stationary stone, the bolts f are to be again tightened.
In order that the stationary stone may be kept in place when being adjusted upon
its trunnions, I provide a semi circular bar J which extends outward in front of the
mill and is secured by bolts to the ends of the horizontal trunnions. This bar J bears
upon a roller J which is carried by a rigid arm J₁ that projects forward from the
bracket i of the mill case D, such arrangement affording a fixed point against which
the stationary stone rests when being forced into alignment. The shaft H upon which
the running stone G is mounted, rests in bearings h h', the bearing h being carried
by the bracket i above referred to, which projects from the front of the mill case D,
while the bearing h¹ is carried by a bar k supported by arms which project from
the rear of said case. The shaft H carries a fixed pulley K which is preferably
formed with a high crown.
From the foregoing description it will be seen that the stones, mill case, pulley, and
driving shaft, are mounted so that they are free to swing together upon the
trunnions C. C.
In order that the frame in which the parts named are arranged, may be adjusted as
the necessities of the case require, I provide such adjustable mechanism as will now
be specifically described. To the bed A there is fixed a lever arin m and a ratchet
wheel n which is engaged by a pawl o. The upper link p of a toggle lever P iş

page_text: pivotally connected to the cross bar k directly beneath the bearing ', while the lower
link p is pivotally connected to the bed A, the central joint of the toggle lever being
connected to the crank of the shaft by means of the link q, so that as the lever
arm m is turned in the direction of the arrow shewn in figure 1, the rear of the shaft H
will be lowered thereby slacking off the belt L and stopping the mill, while if the
lever m is thrown in the opposite direction, the shaft and pulley will be raised and the
belt tightened, so as to drive the pulley forward and start the mill.
In order that the running stone G may be held to its work, but at the same time be
free to recede from the stationary stone should any hard substance, such as iron,
accidentally pass between the surfaces of the stones, I provide such mechanism as will
now be described. Upon one end of the shaft H, I form a fixed collar s, back of
which there is placed a loose collar s¹ through which pass the bolts t t by which the
collar is held to the horizontal step or block M against which the end of the shaft
abuts, said step being connected to a bar N mounted as will be presently described,
by a stirrup which is provided with a cross arm u³ mounted in bearings u² carried
by the bar N, the connection between the step M and the stirrup being formed by
means of pivot pins. One end of the bar N is supported by a short rod which
passes through the bar k, its projecting end being provided with a spiral spring v
while the inner end of the rod is threaded to engage with the nut a second nut
being arranged upon the rod on the outer side of the bar k. The other end of the
bar N is supported by a shaft a¹ which is carried by projecting arms a² which extend
from the case D. This shaft a¹ is broken at about the point 6, tho approaching ends
being threaded to engage with a double or right and left hand threaded nut R. One
of the arms a² is provided with a sleeve c¹ (figure 9) through which the shaft a¹ passes.
A second sleeve & formed with a spiral groove e¹ is pinned or keyed to the shaft a³ in
position to overlap the sleeve c¹ which sleeve is provided with projecting pins f¹ which
ride in the groove e' of the sleeve d¹.
In order that the running stone may be yieldingly held adjustable to the stationary
stone, the nut v² is loosened or tightened to regulate the tension of the spring v². In
accordance with the direction in which it is desired to adjust the running stone, when
grinding, movement is imparted to the opposite end of the bar N by means of the
nut R, and when it is desired to throw the running stone back and away from the
stationary stone and out of contact therewith, the sleeve d¹ is thrown over by means
of its handle d³, thus moving the bar a' in the direction of the arrow, and at the same
time partially rotating the bar, which partial rotation of the bar stops the motion of
the agitatory (figure 10) said agitator being attached to the shoe g³ which is hung in
the usual manner beneath the hopper T. As is best shewn in figures 1, 2, and 10, the
agitator g¹ is connected, by means of a spring h³ and a strap h³, to a bobbin S which
is carried by the shaft a', so that as the shaft a¹ is turned over toward the mill case,
the strap will be unwound and the agitator allowed to fall back from the shaft H
which carries a cam fuce 2.
Having now particularly described and ascertained the nature of the said Invention,
and in what manner the same is to be performed, I declare that what I claim is ;
1. The combination with a mill case having slotted flanges, a stone having the
trunnions b, of boxes F formed with bases c and bosses d washers g and tap bolts f
substantially as described.
2. In a vertical disc grinding mill, the combination with the casing D provided
with flanges a a slotted at e e, of a stationary stone provided with trunnions and
bosses formed with boxes which enter and are held in the slots formed in the flanges
of the mill case, substantially as described.
3. In a vertical disc grinding inill, the combination with a mill case formed with
trunnions and provided with arms, brackets, and bearings, of the driving shaft, its
pulley and adjusting devices whereby the mill case and its connections are tilted,
substantially as described.
4. In a vertical disc grinding mill, the combination with a mill case formed with

page_text: trunnions and provided with arms, brackets, and bearings, of the driving shaft, its
pulley, and adjusting devices consisting of the toggle lever P, link 7, crank shaft
and lever m, substantially as described.
5. In a vertical disc grinding mill, the combination with the case D provided with
flanges a a slotted at e e, of the stationary stone provided with trunnions, the boxes
secured to the flanges a a, a semi circular bar J carried by the horizontal trunnions,
a roller J2 and an arm J', substantially as described.
6. In a vertical disc grinding mill, the combination with the mill case, running and
stationary stones, of the shaft H mounted in bearings supported by the mill case
and formed with a collar s, a stop M, loose collars and bolts tt substantially as
described.
7. In a vertical disc grinding mill, the combination with the mill case, the stones
and brackets and arms of the shaft H, collar s, loose collar s¹, bolts tt, step M,
stirrup u, arm u¹, bar N, eyes u³, substantially in the manner described.
8. In a vertical disc grinding mill, the combination of the following elements―
vizt.-mill case D, stones E and G, shaft H, bearings h h³, collars and s¹, bolts tt,
step M, stirrup u, arm u³, bar N, eyes u³, rod v, spring v¹, nuts v³ ³, and a shaft a¹,
substantially as described.
9. In a vertical disc grinding mill, the combination with the main driving shaft, of
the shaft a', the sleeve d¹ secured to the said shaft a¹ and provided with the spiral
groove el and handle, the sleeve c¹ provided with pins f¹ projecting therefrom, and
entering the groove e¹ and a suitable connection between the main driving shaft and
the shaft a, substantially as set forth.
10. In a vertical grinding mill, the combination with the main driving shaft and
its holding mechanisin, substantially as described, of the shaft a', a spirally grooved
sleeve e and a pin ", the sleeve d' pinned or keyed to shaft a' and having a handle d'
projecting from the sleeve c¹ and entering the groove of the sleeve, as set forth.
11. In a vertical disc grinding mill, the combination with the mill case, stones,
main driving shaft and its supporting and holding mechanism, of the two part shaft a¹,
nut R, bar N, rod v, and spring v², substantially as described.
Dated this 4th day of May 1887
A. MELVILLE CLARK.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.