Improvements
Year: 1887

page_text: Improvements III
I, WILLIAM FRAZER COCHRANE, residing at Cambridge City, in the County of
Wayne, and State of Indiana, one of the United States of America, Gentleman,
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 more especially to improvements in that class of roller mills
now generally employed for grinding or crushing grain wherein two rolls, smooth or
dressed, are adjusted in close proximity and driven at a high speed and in opposite
directions, are employed to act upon material fed between them, and my said inven-
tion consists in certain improved constructions and arrangements of the several parts
as hereinafter fully described and pointed out in the claims.
Fig. 1. is a top plan view, partly in section, of a mill containing an embodiment of
my invention.
Figure, 2, is an end view, and,
Figure, 3, a front view of same.
Figure, 4, is a detail view of a portion of the adjusting and relief mechanism,
Similar letters of reference in the several figures indicate the same parts.
The frame of the mill may he made of any desired form or construction and in the
illustration given comprises two vertical end pieces or standards, A, connected near
the bottom by stays, B, and on opposite sides by webs of plates, C, and brackets or
offsets, D.
At the tops of the uprights, A, are formed flanges, E, for the reception and
support of the rear roll, the front roll being mounted on pivotal carriers as will
hereinafter be explained.
The frame shown is specially designed for the reception of two pairs or sets of
rolls, but as the corresponding parts in each set are duplicates, it will be sufficient to
describe one set, together with such parts as connect or are common to both.
The rear roll, 1, is provided with the usual collars, 2, and journals, 3, and is
supported in journal boxes, 4, resting upon the flange, E, of the frame. The journal
boxes, 4, are rigidly connected by a cross har or yoke, 5, which latter serves to
preserve the alignment of the boxes.

page_text: Passing through the flanges, E, and bearing against the under surface of the
boxes, 4, are two or more set screws, 6, by means of which the boxes can be adjusted
vertically, while bolts, 9, passing through elongated openings in the flanges, E, serve
to clamp and hold the boxes in adjusted position. The hoxes are adjusted horizontally
on the frame by means of bolts, 7, passing through the plate, C, and threaded into
lugs, 8, projecting from the sides of the boxes and between the flanges E. These
bolts are extended through and take a bearing in the plate, C, in order that the
adjustment of the rear roll may be made from the front of the machine, and as said
bolts supplement the action of the bolts, 9, in holding the boxes firmly in adjusted
position and support them against horizontal displacement while being adjusted
vertically, they are provided with jamb nuts or equivalent means for securing them
against rotation.
The front or movable roll, 10, is supported at each end in the curved and over-
hanging end of a lever or carrier, 11, each of the latter being provided with a
journal box, 12, for the reception of the journal of the roll.
The roll carriers or levers, 11, are preferably so located and arranged that their
boxes will stand in line and parallel with the boxes of the rear roll, and to this end
said levers are fulcrumed upon bolts or pivots, 13, on the side of the brackets, D.
Beneath the rolls and journalled in the upright, A, is located a rock shaft. 14,
towards which the lower ends of the roll carriers, are bent or curved. The lower
extremity of the carriers, 11, are slotted or recessed as at, 15, for the reception of a
crank pin, 16, located in the arms of a collar, 17, secured to the rock shaft, so that as
the latter is oscillated it will vibrate both carriers simultaneously and equally.
By adjusting the collars, 17, on the rock shaft either or both ends of the roll, 10,
can be advanced or retracted, but when said collars are secured in position the
movement imparted to them by the rock shaft will be substantially equal.
The tension and releasing mechanism for actuating the roll carriers is connected to
the rock shaft, 14, and through the latter distributed and applied to the carriers as
follows.
At or near the centre of the rock shaft an arm or lever, 18, is secured and to the
outer end of said arm, a link or rod, 19, is pivoted, the onter end of said link being
passed through an opening in the plate, C, of the frame.
The outer end of the link is screw threaded for the reception of an adjusting
nut, 20, between which latter and the plate, C, is interposed a cam lever, 23, a co-
operating cam plate, 22, and a tension spring, 21, resting within a case, 19 a.
The spring acting through the cam plate and lever and against the nut, 20, tends
to force the link outwards thereby pressing the roll, 10, towards the roll, 1, but by
the interposition of suitable stops, such as set screws, 29, passing through lugs, 26,
on the carriers and abutting against a fixed portion of the frame-the roll, 10, is
prevented from coming in contact with roll, 1. Were it not for the interposition of
the lever and cam plate, the spring would at all times and according to the degree of
pressure placed upon it by the adjusting nut press and hold the rolls in working
position, so that in order to spread the rolls or withdraw the spring pressure it would
he necessary either to apply force sufficient to compress the spring or run back the
nut and thereby disturb the adjustment of tension.
The proximate surfaces of the lever and cam plate are furnished with two or more
cam or wedge surfaces, 24, whereby as the one is rotated upon the other they will be
caused to separate or be permitted to approach. The lever constitutes the rotating
member, hence the cam plate should be held from rotation as by a feather and
groove connection with the link, and in order that the lever, when rotated, to cause it
to move out from the cam plate, may be held and maintained in that position, notches
or recesses, 28, are formed in one series of cams into which the heel or rear end of
the opposite cams project or are received to prevent further rotation of the lever
without the application of considerable pressure.
The operation of the device just described is as follows:-
The position which the roll is to occupy when grinding having been determined,
and the lever, 23, rotated until its cams rest on the notches in the cams of the

page_text: opposite section, nut, 20, is screwed down and as it acts through the two cams upon
the spring, the latter is compressed and the roll, 10, forced towards the roll, 1, until
the desired degree of pressure is obtained a pressure sufficient to hold the roll to
its work and at the same time not enough to prevent the roll from yielding should
the feed be too great or a foreign substance fall between the rolls. "When now, for
any reason it is desired to quickly relieve the roll from the pressure of the spring
the lever, 23, is turned back so that as the cam surfaces ride upon each other, they
will no longer interpose the same length of material between the spring nut, but
will permit the spring to expand and thus relieve the pressure on the roll
The amount or degree of pressure which is exerted by the spring upon the rock
shaft and transmitted through the latter to the roll carrier and roll, 10 is determined by
the adjustment of the link and the amount of relief afforded when the cam lever is
thrown back is determined by the pitch of the cam surfaces and the compression of
the spring.
It will be observed that the roll carriers, although independently pivoted are so
united and connected through the rock shaft and its crank pins, that neither can
move or oscillate independently of the other, and they both simultaneously and
equally partake of the motion of the rock shaft, hence by causing the tension spring
and releasing mechanism to act upon said rock shaft, the roll will be carried and held
under an elastic pressure to its work, the force of the spring being distributed equally
between the carriers, and when it is desired to release the pressure so that the rolls
may spread, a single turn of the cam lever is all that is required.
Heretofore in operating mills of this kind, wherein the rolls rotate at high rates of
speed, it has been the almost universal custom to employ a more or less complicated
While
system of belting with the usual multiplicity of bearings, tightness, etc.
direct acting gearing is confessedly more positive and reliable and less complicated
than belting, it has heretofore been regarded as inapplicable to the purpose owing
to the fact that the two rolls being adjustable and movable with respect to each other,
it was impossible to preverve the uniform pitch centres of the gears and the inevitable
result was that the teeth rapidly wore out or became broken besides occasioning much
noise owing to the looseness of the connection and irregularities in the teeth produced
by wear.
To overcome these defects and at the same time preserve all the advantage attending
the use of direct acting gears, I have devised the following system whereby both rolls
are driven positively and form a single pulley, and at the same time perfect liberty of
adjustment is permitted.
In carrying out this part of my invention, I make use of a universal coupling
similar to that described in my prior patent, No. 11584, of September, 29, 1885,
which adapt and apply as follows:-
A yoke or support, 30, is applied to each end of the roll frame, the lower ends of
the yoke being secured to the upright A, as by tubular stays, 31, and through bolts, 32,
while the two yokes are united by a hollow brace or stay, 33, and through bolt, 34.
At one end and opposite the journal of the roll, 10, a short stud axle or bearing, 35,
is secured in the yoke, and upon it is mounted the driving pulley, 36, provided with
an elongated boss, 37, and a collar, 38. Upon the exterior of this collar a series of
teeth, 39. are formed, while the end of the collar is rounded to form a part spherical
bearing, 40, to receive one end of the toothed sleeve or coupling, 11. The opposite
end of this coupling rests upon a part spherical bearing formed on a collar, 44,
provided with teeth similar to those on the pulley, said collar being secured to the
end of the journal of roll, 10.
At the opposite end of the frame the yoke is provided with two stud axles or
bearings, 47, the one opposite the journal of roll and the other opposite that of
roll, 1, and upon these axles are mounted the gear wheels, 48, meshing together and
each provided with a series of teeth and a spherical bearing similar to those on the
pulley.
The journals of the rolls, 1, and, 10, are also furnished with collars, 49, similar in

page_text: all respects to that on the opposite end of roll, 10, and hetween said collars and the
gears are interposed toothed sleeves or couplings, 50.
It will be observed that as the driving pulley and the gears are mounted upon
bearings secured permanently to the yokes they are held maintained in a fixed relation,
while the rolls carrying the toothed collars are free to move independently of the
former. the toothed sleeves or couplings permitting this movement to take place
without however disturbing the driving connection for as the rolls are moved said
collars are oscillated on their bearings at opposite ends without disengaging the teeth
which latter always remain in contact and transmit the rotary motion of the driving
collar to the driven collar at the opposite end.
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 the journal boxes supporting the rear roll and the
connecting bar, the levelling screws, clamping screw and the horizontal adjusting
screws extended through and taking a bearing in the front plate of the frame,
substantially as described.
2. The combination with the frame and the rear roll of the journal boxes connected
together and provided with dependent lugs and the adjusting screws engaging said
lugs and passing through the front of the frame, substantially as described.
3. The combination in a roller mill such as described of the front or movable roll,
the pivoted carriers, and the rock shaft bearing pins engaging slots in the carriers,
substantially as described.
4. The combination in a roller mill such as described of the frame, the rear roll
supported thereon and the front roll mounted
bring the boxes in line, substantially as describuon carriers pivoted upon brackets to
5. In a roller mill such as described, the combination with the pivoted roll carriers
and the rock shaft the collars movably secured to the rock shaft and provided with
pins entering and engaging the walls of slots in the lower ends of the carriers, to
actuate the latter and adjust the roll, substantially as described.
6. In a roller mill such as described, the combination with the pivoted roll carriers,
the rock shaft, and independent crank pins engaging said carriers, a tension device
applied to said rock shaft to hold the roll in adjusted position, substantially as
described.
7. In a roller mill such as described, and in combination with the movable roll, its
pivoted carriers and the rock shaft engaging both of said carriers to simultaneously
adjust the latter, an arm secured to said rock shaft, a link connected to said arm and
bearing a nut or stop, a spring and an expansible connection interposed between the
spring and nut or stop, substantially as and for the purpose set forth.
8. In a roller mill such as described and in combination with the pivoted roll
carriers the rock shaft controlling the movement of said carriers and the arm secured
to sail rock shaft the pivoted link provided with the adjusting nut, the cam lever,
the cam plate and the tension spring, substantially as described.
9. In a roller mill such as described and in combination with devices for supporting
the movable roll, le link, or rod connected to the roll adjusting mechanism and
carrying a stop, the tension spring and the cam lever and cam plate, the cams or
inclines on one of the latter provided with notches or shoulders for engaging the
opposite inclines, substantially as described.
10. In a roller mill such as described and in combination with the rolls thereof,
connecting gears mounted upon the frame and supported in fixed relation to each
other, and hollow toothed couplings engaging toothed sections on the gears and rolls
to communicate motion from one to the other and permit the roll to be adjusted
laterally of the gears, substantially as described.
11. In a roller mill such as described and in combination with the rolls thereof the
gears for communicating motion from one roll to the other mounted upon independent
Bearings or studs and connected to the rolls by flexible couplings substantially as
described.

page_text: 12. In a roller mill and in combination with the rolls thereof the driving pulley
and connecting gears mounted on independent supports at opposite ends of the rolls
and flexible couplings such as described for connecting the driving pulley to one of
the rolls and each of the latter to one of the gears, substantially as and for the
purpose set forth.
13. In a roller mill such as described and in combination with the adjustable rolls
thereof provided with coupling sections, the yoke secured to one end of the frame
and carrying a stud axle on which a pulley is mounted said pulley being connected to
the coupling section on one roll by a tubular coupling and a yoke secured to the
opposite end of the frame and provided with stud axles and gears the latter connected
to the end of the rolls by flexible couplings, substantially as described.
Dated this 8th day of November 1887.