IMPROVEMENTS IN ROLLER-MILLS FOR GRINDING CORN AND OTHER SUBSTANCES
Year: 1881

page_text: LETTERS PATENT to William Lloyd Wise, of 7, Whitehall Place, in the City
of Westminster, for an Invention of "IMPROVEMENTS IN ROLLER-MILLS FOR
GRINDING CORN AND OTHER SUBSTANCES." A communication from abroad
by Messrs. Seck Brothers, Machine Makers, Dresden, Kingdom of Saxony,
Empire of Germany.
"
PROVISIONAL SPECIFICATION left by the said William Lloyd Wise at the
Office of the Commissioners of Patents on the 13th April 1881.
WILLIAM LLOYD WISE, of 7, Whitehall Place, in the City of Westminster.
IMPROVEMENTS IN ROLLER MILLS FOR GRINDING CORN AND OTHER SUBSTANCES."
(A communication from abroad by Messrs. Seck Brothers, Machine Makers,
Dresden, Kingdom of Saxony, Empire of Germany.)
This Invention relates to that class of grinding mills in which two rollers revolve
in opposite directions at different circumferential speeds, and has reference to the
employment of an endless chain for driving the said rollers, and to means for
simultaneously slackening the said chain and removing or shifting the one roller
from the other, and also to arranging, vibrating, or reciprocating fingers in the
hopper above the rollers of a grinding mill, for the purpose of preventing obstruction
in such hopper.
According to this Invention one of the two rollers in a mill, which is larger than
the other, receives rotary motion by means of a pulley fixed on its axis; this motion
is transmitted by a chain running over and connecting two chain wheels, the first
of which is on the axis of the large roller, and the second on the axis of the small
roller. The diameter of the two chain wheels is by preference such that a
differential circumferential velocity is established between the two rollers in the
proportion of 71/2 to 1. In order to allow of the two rollers or cylinders working
in opposite directions, a third chain wheel, which turns loosely on a pin forming the
pin of a crank, is provided to act as a tightening wheel.
In order to permit of the removal or the shifting of the small roller from the
large roller, it is necessary that the chain should be simultaneously slackened.

page_text: This is effected by means of a handle on a shaft which runs across the framing;
on one end of this shaft is an eccentric situated within the forked end of a rod
connected to the pin upon which the chain tightening wheel revolves loosely. As
this pin (as hereinabove mentioned) forms the pin of a crank, the turning of the
eccentric causes an. alteration of the position of said crank and of the tightening
wheel in such a direction that the chain is slackened, and allows the small roller to
be moved or shifted. This shifting of the small roller is caused by cranks fixed at
each end of the cross shaft. Each of the crank pins is embraced by a bearing that
forms one end of a connecting rod, and when the shaft is turned the respective
crank pin pushes against the lower end of the rod that embraces it. At its upper
end the rod is connected to a lever upon which a bearing is provided, in which one
end of the axis of the small roller revolves.
It follows from these arrangements that if the cross shaft is turned there will
be effected simultaneously both the slackening of the chain by the eccentric and
the shifting of the small roller by the crank pins,
In order to regulate the exact position of the small roller with reference to the
large roller, hand wheels are provided, forming nuts working upon screws cut upon
the rods hereinabove mentioned as connecting the crank pins to the levers. These
rods are compound rods of peculiar construction, and are formed in two portions
connected by a strong helical spring, so that they are capable of extension. By the
arrangement of parts adopted according to this Invention, the attendant is enabled
to regulate the exact position of the small roller, and at the same time to shift it if
necessary for the passage of a hard body or bodies between the two grinding
surfaces.
On the axis of the small roller a chain wheel is fixed, which communicates rotary
motion by means of an endless chain to the feeding roller; this feeding roller
carries at one end a crank, the pin of which works in a slot in a vibrating lever
fixed to the outer end of a rocking shaft situated horizontally in the hopper. This
shaft is provided with one or more fingers by which the material in the hopper is
agitated and thrown down to give a constant feed to the rollers. When two pairs
of rollers are combined in one machine, the arrangements for slackening the chain
and shifting or moving of the small rollers as hereinabove described require to be
modified. The first pair of rollers and the large roller of the second pair are driven
by one chain. The small roller of the second pair is driven by a second chain from
the axis of the large roller of the first pair at the appropriate circumferential
velocity. Two chain tightening wheels are so arranged at the crossing point of the
two chains as to support them and to keep thein tight. The axis of these
tightening wheels and the bearings of the two outer rollers are capable of being
shifted by rods connected to cranks on a cross shaft, as already described with
reference to the previous modification.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Lloyd Wise in the Great Seal Patent Office on the
13th October 1881.
WILLIAM LLOYD WISE, of 7, Whitehall Place, in the City of Westminster.
"IMPROVEMENTS IN ROLLER MILLS FOR GRINDING CORN AND OTHER SUBSTANCES."
(A communication from abroad by Messrs. Seck Brothers, Machine Makers,
Dresden, Kingdom of Saxony, Empire of Germany.)
This Invention relates to that class of grinding mills in which two rollers
revolve in opposite directions at different circumferential speeds, and has reference
to the employment of an endless chain for driving the said rollers, and to a means
for simultaneously slackening the said chain and removing or shifting the one
roller from the other, also to arranging vibrating or reciprocating fingers in the
hopper above the rollers of a grinding mill for the purpose of preventing obstruction
in such hopper.
Referring to the accompanying Sheets of Drawings, in Sheet 1,
Fig. 1 is an end elevation; Fig. 2, a front elevation; Fig. 3, a vertical cross
section; and Fig. 4 is a plan of a roller mill embodying the improvements, the
subject of this Invention; Fig. 5 is a diagram shewing the way in which the
endless chain runs, and shewing at the same time the device for slackening
the chain, and the method of removing or shifting the small roller or cylinder from
the larger one.
The two working rollers or cylinders & and f are supposed to be of diameters in
proportion of 5 to 2.
The large roller d receives rotary motion by means of a pulley fixed on its axis ;
this motion is transmitted by a chain running over and connecting the chain
wheels on its (the roller's) axis with the chain wheel s¹ fixed on the axis of the
small roller f. The diameters of the two chain wheels s, s¹, are such that a
differential circumferential velocity is established between the two rollers d and f
in the proportion of 71/2 to 1. In order to allow of the two rollers or cylinders
working in opposite directions, as indicated by the arrows in Fig. 3, the position of
the chain on the two chain wheels must correspond to such direction of motion, as
clearly shewn in Fig. 1, and in the diagram, Fig. 5. In order to render possible
such an arrangement of the chain, a third chain wheel 82 is applied, around which
the chain is laid or carried in the manner illustrated in Figs. 1 and 5. This chain
wheel 82, which turns loosely on a pin forming the pin of a crank, is provided to
act as a tightening wheel.
By the above described arrangement a steady and noiseless working of the gear
is ensured, and the difficulty of producing rollers or cylinders of an exact diameter,
in order that the pitch lines of the driving toothed wheels may accurately gear or
roll together, is avoided.
In mills with cog wheels, the teeth have to be remodelled every time the surfaces
of the rollers or cylinders are renewed or repaired, and the said teeth are often
visible or marked, as indicated on the fine fluted surfaces of the rollers.
Also when the two rollers are suddenly removed the one from the other to
allow hard substances to pass between them, the proper pitch of the teeth of the
wheels is disturbed.
In order to permit the removal or the shifting of the small roller from the large
roller, it is necessary that the chain should be simultaneously slackened.
This is effected by means of the handle n¹ on the shaft n which runs across the
framing. On one end of this shaft n is the excentric situated within the forked
end of the rod y. This rod at its other end is fixed to or takes around the pin

page_text: upon which the chain tightening wheel s² revolves loosely. As this pin (as herein-
above mentioned) forms the pin of a crank, the turning of the excentric causes an
alteration of the position of said crank and of the tightening wheel in such a
direction that the chain is slackened and allows the small roller f to be moved or
shifted. The shifting of the small roller f is caused by the cranks w fixed at each
end of the cross shaft n. Each of the crank pins is embraced by a bearing v that
forms one end of a connecting rod, and when the shaft n is turned the respective
crank pin pushes against the lower end of the rod that embraces it. At its upper
end the rod is connected to the lever t, upon which a bearing is provided in which
one end of the axis of the small roller revolves.
It follows from these arrangements that if the cross shaft n is turned, there will
be effected simultaneously both the slackening of the chain by the excentric x,
rody, and crank pin upon which the chain wheel s² turns, and the shifting of the
small roller by the crank pins w, w, bearings v, rods u, u, and levers t, t.
In order to regulate the exact position of the small roller f with reference to the
large roller d, the hand-wheels 1, 7, are provided, forming nuts working upon screw
threads cut upon the rods u, u, hereinabove mentioned, and as connecting the
crank pins to the levers; i is a jam nut for securing the hand wheels in the exact
position; a second screw m provided with two nuts is used for the same purpose.
Through the rod u a cotter u¹ is driven, upon which the plate u² rests. The two
rods u³, u³, connected to the block v extend in an upward direction, and are
connected together at the upper end. by plate u. Between the plate u² and the
plate u a spiral spring is arranged surrounding the rod u. By this arrangement
of parts the attendant is enabled to regulate the exact position of roller f, and at
the same time to shift it, if necessary, for the passage of a hard body or bodies
between the two grinding surfaces.
On the axis of the small roller a chain wheels is fixed, which communicates
rotary motion by means of an endless chain to the feeding roller r; this feeding
roller carries at one end a crank r³, the pin of which works in a slot in the vibrating
lever. This lever is fixed to the outer end of a rocking shaft 3 situated
horizontally in the hopper. This shaft is provided with one or more fingers r³, to
which is imparted a swinging or reciprocating motion, whereby the material in the
hopper is agitated and thrown down to give a constant feed to the rollers.
Fig. 6 is a diagram shewing when two pairs of rollers are combined in one
machine the arrangements for slackening the chain and shifting or moving of the
small rollers. The one pair of rollers is represented by d, f, the other by d¹, f¹.
In this arrangement the first pair of rollers d and f and the large roller d' of the
second pair are driven by one chain, the direction of motion of which and of the
surfaces of these rollers is indicated by arrows. The diameters of the chain
wheels or discs is such that the required differential circumferential velocities are
given to the said rollers. The small roller f¹ of the second pair is driven by a
second chain a¹ from the axis of the large roller d with the appropriate circum-
ferential velocity. Two chain tightening wheels or discs s, 81, are arranged at the
crossing point of the two chains, so as to support the latter and to keep them tight
when working. The axes of the tightening wheels 8, 81, and the bearings of the
two outer rollers or wheels f. f1, are capable of being shifted by rods, of which one,
marked u, is shewn connected to a crank disc won the cross shaft, as already
described with reference to the previous modification. To this crank disc w two
rods u¹, u, are connected, which cause the levers u³, u, to turn at u, u, and
thereby to shift the small rollers f, f', as will be seen by the diagram.
In this arrangement means for simultaneously slackening the chains by lowering
the wheels or discs 8, s¹, and shifting the small rollers f, f¹, by means of the rods
u, u², and levers u³, u, are provided. k, ², indicate spiral springs which are
designed for the same purpose as the spring k in Figs. 1 and 2.
In Fig. 7, which is an end elevation of the grinding mill, I have shewn a
modification of the arrangement for shifting the chain wheel s², and thereby
slackening the chain if necessary. In this instance the said chain wheel s² rests

page_text: with its axis within a double or forked lever 83 pivotted at 84. The end of this
lever is provided with an ear, through which the rod 8 passes, which is provided
with thread and nuts at its upper end, against which a spiral spring presses, which
rests with its lower end upon the ear of the lever 83. The rod s is extended in a
downward direction, and is provided with a stirrup extending to one side of said
rod. In this stirrup is situated the eccentric x, which is fixed upon the shaft n,
the situation of which has been described above with reference to Figs. 1 and 2.
It is obvious that by rocking the shaft n the chain wheel s³ will be lifted for
slackening the chain. As experience as shewn that a certain increase of tempera-
ture may be caused within the wooden box which surrounds or incloses the
grinding rollers or cylinders d and f by the friction of said rollers it is preferred to
evacuate the air by an exhaust. The air is drawn out by the tube 2, which may
be periodically closed by the throttle 2¹. For retaining the fine particles within
the mill, which otherwise may be drawn out by the exhaust, there is arranged a
filter n between the two partitions n¹, n². The filter, which may be made of felt
or flannel stretched over a frame, is hinged at its lower end at n³, and the frame is
connected by felt or flannel at the inner side to the partitions n¹ and n³, which
connection allows a periodical vibration of the filter frame for cleaning the
inside surface of the filter at intervals. For this purpose the filter is
situated in an inclined position, as shewn, so that by vibrating the filter
the fine particles covering the inside of the filter will be caused to fall
off. In order to effectually clean the inside surface of the filter the tube
must be shut off by the throttle z' during the cleaning operation. The arrangement
for closing the throttle and simultaneously vibrating the filter is clearly shewn
in Fig. 7. On the shaft o¹, which is one of the two screw shafts o¹ and o³ for
transporting the material produced by the grinding operation, a worm o³ is keyed,
taking into a worm wheel of keyed on shaft o³. At the outer end of this shaft a
cam ois keyed, shewn in end view in Fig. 7a. Upon this cam a rod o² rests,
which, dropping into the recess of the revolving cam o, will by means of a hook
draw the lever 08, one end of which is fastened to the axis of the throttle, the
other end being provided with a weight oº, which adds to the falling or shutting
movement of the throttle. On the shaft o" a cam o¹0 is keyed, shewn in end view,
Fig. 7b. This cam takes underneath an angle piece o" and lifts the same, taking
with it at the same time the horizontal arın of the bell crank lever o¹². The
upright arm of this lever is connected by a rod o¹s to the filter frame. If the
cam oo is in a downward position the horizontal arm of the bell crank lever o¹²
will by its bent end o¹ rest on the triple cam 015, which is keyed to the above
mentioned shaft o². It will be obvious from the description of this arrangement
that when the shaft o³ has turned the cam o10 into such a position that the bell
crank lever rests upon the triple cam o, the revolution of such cam will cause the
filter to vibrate, and at the same time the cam o will have come into such a
position as to cause the throttle to shut up the tube z during the vibrating
movement of the filter. As soon as the rotation of shaft o lifts the bell crank
lever, and thereby stops the vibrating motion of the filter, the throttle will be
opened again, so that the exhaust of heated air may be continued. I may add
that a spring o¹ is arranged to keep the filter frame tight against its seat.
Having now described the nature of the said Invention, and explained the
manner in which it is to be or may be carried into practical effect, as commu-
nicated to me as aforesaid, I would have it understood that what is considered to
be novel and original, and is therefore claimed as secured to me by the Letters
Patent herein before in part recited is,―
1. The use of chains for driving the rollers or cylinders of grinding mills,
substantially as described.
2. In a grinding mill in which the rollers or cylinders are driven by chains, the
combination of parts, constructed, arranged, and operating substantially as described
with reference to Figs. 1, 2, 3, and 4 of the Drawings, for simultaneously

page_text: slackening the chain or chains and removing one roller or cylinder from the
other.
3. Providing in the hopper of a grinding mill vibrating or reciprocating
fingers, so arranged as to prevent obstruction in such hopper, substantially as
described.
4. In grinding mills in which two pairs of rollers driven by chains are used,
the arrangement, substantially as described, with reference to and shewn in Fig. 6
of the Drawings for simultaneously slackening the chains and removing the small
rollers from the large ones.
5. The modification, shewn in Fig. 7 and described, for shifting at will the chain
wheel s² and thereby slackening the chain.
In witness whereof, I, the said William Lloyd Wise, have hereunto set my
hand and seal, this Twelfth day of October, in the year of our Lord One
thousand eight hundred and eighty one.