IMPROVE- MENTS IN MACHINERY OR APPARATUS FOR GRINDING BONES, ORES, AND OTHER SUBSTANCES, A PART OF WHICH IMPROVEMENTS IS APPLICABLE TO FOOTSTEP BEARINGS GENERALLY
Year: 1867

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, Gentleman, for the Invention of "IMPROVE-
MENTS IN MACHINERY OR APPARATUS FOR GRINDING BONES, ORES, AND OTHER
SUBSTANCES, A PART OF WHICH IMPROVEMENTS IS APPLICABLE TO FOOTSTEP
BEARINGS GENERALLY."-A communication from abroad by Edwin Pugh
Baugh, of Philadelphia, Pennsylvania, United States of America.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents, with his Petition, on
the 29th November 1867.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, Gentleman, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN MACHINERY OR APPARATUS FOR GRINDING BONES, ORES,
AND OTHER SUBSTANCIS, A PART OF WHICH IMPROVEMENTS IS APPLICABLE TO FOOT-
STEP BEARINGS GENERALLY.".
This Invention relates to improvements in that class of cast-iron grinding
mills the cutting or reducing and grinding surfaces of which are made in the
form or approximating to the form of a frustum of a cone, and has for its
object the rendering of such mills more effective and capable of being readily
adapted to the grinding or reducing of various kinds of substances, and of
being economically repaired in case of damage or injury to the grinding or

page_text: reducing surfaces. The most important feature of this Invention consists in
constructing the shell and the burr of a number of cast-iron or Bessemer steel
grinding sections fitted to a suitable backing or caseing by rings, projections,
bolts, or otherwise, and capable of being readily removed and replaced. I
sometimes employ a ring bolted down on to the upper inner projecting ends
of the sections attached to the burr, which ring may be used as a grinding
surface by having grinding teeth formed on its edge. A projecting arm or
breaker is fitted on to the vertical shaft of the burr so as to be detachable
therefrom, which breaker as it revolvès tends to break up or crush the bones
or other substances, after which the reduced fragments enter between the
burr and the surrounding shell, and there become thoroughly reduced. The
vertical shaft above referred to rests on a footstep bearing onto the lower
extremity, which bearing may be made adjustable vertically if the burr be
required to yield when encountering any extra hard substance. For this
purpose the footstep is supported upon a lever, the lift or rise of which is
'controlled by an adjustable stop screw. This lever is connected by a link to
a second lever, which is weighted so as to keep the first lever and the burr
elevated. The upper end of the vertical shaft is supported in a collar bearing
on the cap or top plate of the mill, which plate by being screwed down upon
the upper head of the grinding sections in the upper portion of the shell
serves to bold them in their places. This cap plate is provided with a
bracket, through which a vertical screw spindle fitted with a band wheel
passes so as to bring its lower extremity when screwed downwards to bear
upon the upper end of the vertical burr shaft. The object of this screw is
by screwing it down to elevate the cap plate and shell, and thereby facilitate
the removal of the grinding sections when found requisite. In order to effect
a better lubrication of the journal of the vertical shaft working in the foot-
step bearing a double cone of steel is interposed between the base of the
journal and the bottom of the footstep, the result being a better distribution
of the oil contained in the footstep over the journal of the shaft, whilst at the
same time undue friction at the points subjected to the greatest shocks and
strains is prevented. This interposition of a double cone of steel between
the bottom of the shaft and the footstep bearing may be applied with advan-
tage to the footstep or lower bearings of the vertical shafts of other
machinery, also to the pivots or bearings of swing bridges, tȧrntables, and
other objects having a vertical 'bearing subjected to great strains.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Henry Johnson in the Great Seal Patent Office on
the 27th May 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman, send greeting..
.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of November, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said John Henry Johnson, Her special license that I, the said John Henry
Johnson, my executors, administrators, and assigns, or such others as I, the
said John Henry Johnson, my executors, administrators, or assigns, should
at any time agree with, and no others, from time to time and at all
times thereafter. during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN MACHINERY OR. APPARATUS FOR GRINDING BONES, ORES,
AND OTHER SUBSTANCES, A PART OF WHICH IS APPLICABLE TO FOOTSTEP BEARINGS
GENERALLY," a communication from abroad by Edwin Pugh Baugh, of Phila-
delphia, Pennsylvania, United States, America, upon the condition (amongst
others) that I, the said John Henry Johnson, my executors or administrators,
by an instrument in writing under my hand and seal, should particularly
describe and ascertain the nature of the said Invention, and in what manner
the same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said John Henry Johnson, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the accompanying Drawings,
and to the letters and figures marked thereon, that is to say :-
The said Invention relates to improvements in that class of cast-iron
grinding mills the cutting and triturating surfaces of which are made in
the form or approximating to the form of a frustrum of a cone; and these
improvements consist,-
Firstly. In constructing the shell and burr of a conical or nearly conical
grinding mill of a number of cast-iron grinding sections fitted
and held

page_text: together substantially as herein-after described, so that the said sections.can be
readily removed to make way for others, the "dress" of the mill being thus
rendered changeable to suit the substances to be ground, while the mill.itself
is more economical, both as regards its original construction and its lasting
properties and the variety of substances which it may be arranged to grind
than mills of the ordinary construction.
Secondly. In a peculiar manner, herein-after described, of backing the grind-
ing sections of the shell by an exterior casing, between which and the base
to which the said casing is secured are confined the said sections, so that the
latter can be readily disconnected from the mill.
Thirdly. In a mode of securing the cast-iron grinding sections of the burr
to a block between a lip or ring or other projection at or near the lower edge
of the latter, and a ring fitted to the vertical shaft which carries the burr,"
all substantially as herein-after described, so that the said sections can be
readily detached.
Fourthly. In forming on the said ring which aids in securing the grinding
sections. of the burr grinding teeth for the purpose berein-after described.
Fifthly. Of a certain breaker fitted to and turning with the said vertical
shaft, and secured to and rendered detachable therefrom in the manner herein-
after set forth, so that different forms of breakers may be applied to the mill.
Sixthly. Of certain detachable sections acting in conjunction with the said
breaker for preliminary grinding, the said sections being fitted to and backed
by a casing and held in position by a cap plate secured to the same, and
carrying the bearing for the vertical shaft which carries the burr, all as
herein-after described.
Seventhly. Of a screw and stationary nut, the latter being so connected to
the cap plate that on operating the screw the casing or backing of the shell as
well as the cap plate can be elevated (the fastenings having been previously
detached) leaving the grinding sections of both shell and burr to be removed.
Eighthly. In interposing between the bottom of the vertical shaft and the
bottom of the step in which the shaft turns a double cone of steel, by which
the oil is effectually distributed to the bearing surfaces and the friction is
disninished.
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose shall
refer to the several Figures on the annexed Sheet of Drawings, the same
letters of reference indicating corresponding parts in all the Figures.
Figure 1 of the Drawings is a side elevation of the improved grinding mill.
Figure 2 is a vertical section of the same; Figure 8 is a sectional plan taken

page_text: along the line 1, 2, in Figure 2 ;- Figure 4 is a sectional plan taken along the:
line 3, 4, in Figure 2; Figures 5 and 6 are detached views of parts of the
mill; Figure, 7 is a vertical section of the footstep bearing for the vertical:
shaft of the mill; Figure 8 is a diagram illustrative of Figure 7.; and Figures,
9, 10, and 11 are views of the detachable sections which. form the grinding.
portions of the milk
A is the base plate of the mill secured to a substantial foundation B, and on.
this plate are suitable boxes a, a, for the horizontal shaft C, the latter being:
furnished at one end with an appropriate fly wheel between the boxes a, a,
with fast and loose pulleys band b', and at the opposite end with a bevilled
pinion F gearing into a level wheel G, which is so secured to a vertical shaft.
H that both must turn together, while the shaft is at liberty to slide up and.
down through the hub of the wheel. This shaft bas its lower bearing in a
step I in a casing V, which is more fully referred to herein-after, and which,
is secured to the base plate A, as are also four columns J,,J, J, J, which
support the lower plate K of the mill and its superstructure. To the vertical
shaft His secured the burr of the mill, which consists of the block L of cast.
iron and the detachable cast-iron grinding sections e, the block being of the
form or approximating to the form of the frustrum of a cone, and the sections
conforming in shape to that of the block, and being secured thereto in the
following manner :-Round the lower edge of the block there is a ring f, and!
against the inside of the upper projecting portion of this ring bear the lower
ends of the detachable cast-iron sections e, the latter having at. their upper
ends lips or flanges bearing on the top of the block and confined thereto by
set screws or bolts h. The form of each section, illustrated by Figure 10) is.
such that one section will fit snugly against the adjacent section, the whole of
the sections thus forming a continuous grinding surface. The shell of the
mill also consists of a number of cast-iron grinding sections fitted together
edge to edge and backed by an outer casing M of the form or approximating
to the form of a frustrum of a cone, to which casing the said sections are
fitted, and by which they are held in place, for the lower ends of the sections
are confined between the flange of the casing M and the flange k of the
cast-iron ring N by bolts m, which secure together the casing and the ring;
the latter being confined to the plate K by bolts n. In the present instance
the case M is carried upwards in the form of an inverted frustrum of a cone,
and is lined with detachable cast-iron sections p, which are held in place
by the cap plate, P. secured to the top of the casing M₁, this plate having
openings s, s, and a central hub g through which the shaft H passes, and in
which it turns. A stationary nut Q connected to the hub of the cap plate P

page_text: receives a screw R, the upper eind of which is provided with a suitable hand
wheel S. It will be seen that the shaft H has a feather adapted to a groove:
in the block L of the burr and to a similar groove in the ring 9,.above which.
a sleeve T is fitted to and turns with the shaft as it has a groove to. receive
the feather. To the sleeve is fitted. what may be termed the breaker, which
consists of a hub U having one or more projections u, the sleeve having
grooves adapted to keys or feathers in the hub of the breaker. Both the
breaker U and the sleeve T as well as the ring 9 and the burr are confined
by a nut v adapted to screw threads on the vertical shaft H. The step I
previously alluded to consists of a cast-iron box arranged to slide in the
cylindrical casing V secured to the base plate A, and is furnished with a steel.
brush w, in which turns the lower end of the vertical shaft H. Between.
the bottom of the shaft and bottom of the bush intervenes a double cone x¹
of hardened steel (Figures 7 and 8), made somewhat less in diameter than
the shaft, and referred to more fully herein-after. A lever W passing through
a slot in the casing V is hinged at one end to a pin on a study secured to
the said casing, and bears against the under side of the step I, the lever being.
connected at its opposite end by a link X to another. link X', which is
arranged for receiving a moveable weight, and is hinged to a. bracket. Y
secured to the plate K, a set screw 2-adapted to a nut on a stand 3. secured
to the base plate A serving to limit the upward movement of the lever. X.
The action or mode of operation of this mill is as follows:-Prior to setting
the mill in motion the lever X¹ is so weighted as to more than balance the
vertical shaft with its burr and breaker, so that the said shaft. may have an
upward tendency, which however is limited by. the set screw 2, the latter
determining the distance apart of the grinding surfaces of the shell and burr.
By this arrangement the grinding surfaces are maintained in sufficient
proximity to each other to act properly on the material to be ground, but will
not come in contact with each other; at the same time should a piece of iron
br steel find its way between the grinding surfaces the burr and shaft will
yield and prevent injury to the mill. The shaft H and its burr and breaker
having been caused to revolve in the direction of. the arrow, Figure, 3, the
bones, quartz, or other material to be ground are passed. through the openings
S, S, in the cap plate P to the conical space bounded by the detachable
sections p; here by the combined action of the teeth or dress, on these
sections, and the revolving breaker U, the material is fractured and reduced to
comparatively small lumps when it has reached the ring 9 by the combined
action of the teeth, on the periphery of which, and the teeth near the lower
portions of the sections p, the material is reduced to a condition which permits

page_text: it to enter the space between the grinding sections e of the burr and those of
the shell. As this space becomes gradually narrower towards the lower end
of the shell and burr the material becomes gradually reduced, and finally.
leaves the grinding surfaces in the desired pulverized condition and falls.
into the space within the ring N on to the slightly concave surface of the
plate K, where it is acted on by the revolving sweep 4, the latter causing
the discharge of the ground material through a spout 5 into any suitable
receptacle.
The most important feature of the Invention is the grinding surfaces com-
posed of cast-iron sections. In ordinary conical or cylindrical grinding mills.
having cast-iron grinding surfaces, or, as it is technically termed, cast-iron
"dress," the character of the latter is limited owing to the necessity of
making the grooves for the formation of cutting edges in straight lines parallel
to the axis of the mill, so that in moulding the patterns can be withdrawn
from the sand with facility. Moreover, when the teeth are cast on and form
a part of the shell or burr it is almost impossible to make the latter perfectly.
round and true. By making the grinding surfaces in sections, however, not
only can both shell and burr. be made truly round, but the teeth can be made
of the most irregular character; for instance, the teeth or dress can be formed
by grooves crossing each other, as shown by lines in Figures 9, 10, and 11,
or some of the grooves may be straight, some curved, others diagonal, and
others cross each other according to the nature of the material to be operated
on. An indefinite number of changes may be made in the character of
the dress when this mode of constructing the grinding surfaces of conical
mills is employed, an important advantage, as the dress must be made to
suit different materials, and in many cases different qualities of the same
material to be ground; a dress for grinding bones, for instance, would be
unsuitable in some respects for grinding quartz, and in operating on other
substances it may be advisable for the dress of one section to differ from that.
of another in the same mill. It will thus be seen that the character of the
mill may be entirely changed by a simple and speedy change of sections, and
that when the teeth of one or more sections have become worn, broken, or
otherwise inoperative their removal and the introduction of new sections
renews the mill, whereas an ordinary cast mill would under similar circus.
stances have to be discarded. It should be bere understood that the sections
may be cast of Bessemer steel. In removing the grinding sections the screw
R plays an important part, for should it be desired to remove the sections i of
the shell and the sections of the burr, all that is necessary is to first detach
the nuts of the bolts m, loosen the nuts of the bolts h and the nut W, and
-------

page_text: then operate the wheel S¹ so as to cause the end of the screw R to bear or
the top of the vertical shaft H, and continue to turn the screw until the entire
shell of the mill is elevated so far as to permit the withdrawal of the sections of
the burr and shell and the introduction of others, after which the shell is
lowered by turning the screw in a contrary direction, the nuts of the bults m
replaced, and the nuts of the bolts h as well as the nuts W tightened.. Should
it be necessary to remove the sections p only, the nuts are detached from the
bolts which confine the cap plate P, and the latter is elevated above the mill:
by operating the screw R, when the said sections are at liberty. After
elevating the cap plate clear of the shaft the nut W, breaker U, and ring g
may be readily removed. It has been found after repeated experiments that
the double conex¹ of steel performs most efficiently the duty of distributing
to the lower bearing the oil contained in the space 8 (Figure 8) between the
bottom 6 of the shaft and the bottom 7 of the step I, at the same time pre-
venting undue friction at the point subjected to the greatest shocks and strains.
This mode of interposing the double cone between the bottom of the shaft and
the bottom of the step may be applied to the lower bearings of all vertical
shafts, to the pivots of swing bridges and turntables, and other objects having
a vertical bearing to which great strains are subjected. For grinding some
materials it is not essential that there should be a superstructure M¹ and
detachable sections p or a breaker U above the shell M, a simple hopper
being in many cases all that is necessary to receive the material and direct
it to the grinding surfaces, the latter, too, may for grinding some materials)
be straight instead of curved, as they are shown in the Drawing Figure 2.
It is preferable in most cases, however, to form teeth on the periphery of the
ring g, as shown in the Drawing, so that it may serve the twofold purpose of
aiding in the preliminary or first grinding and of keeping the sections of the
burr in place. The lips of these sections e may, moreover, be dispensed with,
the ring 9 bearing directly on the upper edges of these sections; the casing
M, too, may be made in sections, or the grinding sections may be backed or
beld together by a suitable system of metal bands.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe in conclusion that what I consider to be novel
and original, and therefore claim as the Invention secured to me by the
herein-before in part recited Letters Patent is,-
First. Constructing the shell and burr of a conical or nearly conical grind-
ing mill of a number of cast iron grinding sections fitted and held together
substantially in the manner herein-before described.

page_text: Second. The detachable cast iron grinding sections i backed by the casing
M, and confined between the latter and the rings N or other base piece, sub-
stantially as berein-before described.
Third. The detachable cast-iron grinding sections fitted to each other
and to the block L, and confined by a ring or lip f on the latter, and a ring g,
all substantially as herein-before specified.
Fourth. Forming on the periphery of the ring 9, which aids in confining
the sections e, grinding teeth or projections for the purpose herein set forth.
Fifth. The application and use of the breaker U fitted to the vertical shaft
H, and secured to and rendered detachable therefrom substantially as herein-
before described.
Sixth. The detachable cast-iron grinding sections p fitted to the casing
M', and confined thereto by a cap plate P, in which or in a bearing attached
to which the vertical shaft H turus, all substantially as herein-before set
forth.
Seventh. The use of the screw R in combination with a nut Q secured
to the cap plate P of the mill, all substantially as and for the purpose herein
specified.
Eighth. Interposing, between the bottom of the vertical shaft of a grinding
mill or the vertical shaft or pivot of any other mechanism and the bottom
of the step in which such vertical shaft or pivot turns, a double cone of steel
for the purpose specified.
In witness whereof, I, the said John Henry Johnson, have to this my
Specification set my hand and seal, this Twenty-seventh day of May,
One thousand eight hundred and sixty-eight.
זותעימז
JOHNSON
J. HENRY JOHNSON. (..)