AN IMPROVED MACHINE FOR ROUNDING AND POLISHING SHOT, SHELL, AND OTHER BALLS OR SPHERES
Year: 1865

page_text: Sealed the 1st September 1865, and dated the 4th April 1865.
PROVISIONAL SPECIFICATION left by the said William Clark at the
Office of the Commissioners of Patents, with his Petition, on the 4th
April 1865.
I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex,
Engineer and Patent Agent, do hereby declare the nature of the said
Invention for "AN IMPROVED MACHINE FOR ROUNDING AND POLISHING SHOT,
SHELL, AND OTHER BALLS OR SPHERES," to be as follows:-
This Invention consists of a machine composed of four (more or less)
different longitudinally sliding rotary mandrils, radiating from a common
centre and provided with chucks at their inner ends, in combination with
suitable mechanism to force these chucks alternately up against the ball to be

page_text: turned or ground, and a milling tool or grinding wheel, in such a manner
that two of the chucks will clamp the ball at a time, and whereby the ball
is turned in either direction, while the grinding wheel or milling tool is held in
contact with the surface of the ball by means of one or more screws, or by an
adjustable weight. The force with which the grinding wheel or tool is forced
against the surface of the ball can thus be regulated at pleasure. The position
of the revolving chucks and the time when the same grasp the ball are
governed by a double cam and by weights or springs, and said chucks are so
shaped that they grasp the general surface of the ball, and that cavities and
projections occurring on the surface of said ball will not be liable to disturb the
correct central position of the same. In a frame of cast iron, or any other
suitable material in the form of a cross, are four (more or less) guide ways,
radiating from a common centre. These ways form the guides for sliding
carriages in which mandrils are fitted in bearings; each of these mandrils
carries on its inner end (that towards the centre) a chuck, which is made in
the form of a cup to fit the surface of the ball to be turned round, or polished,
and these chucks operate in pairs opposed to each other and are connected to
the mandrils so that they can be readily removed and replaced by others made
to fit balls of different diameters. The tool which acts on the surface of the
ball may either be a milling tool of a toothed cup-like form, or it may be a
grinding wheel. This wheel is mounted on a shaft which has its bearings
in a secondary frame below the first (supposing the first to be in a
horizontal plane), and this secondary frame is hinged at one end to hangers
suspended from the main frame, so that the front end is free to swing up and
down, and so that the grinding surface of the wheel can be forced up to the
surface of the ball or removed therefrom at the pleasure of the operator. The
'position of the swinging frame is regulated by a toothed segment, which is
secured to its loose end and gears in a pinion mounted on a shaft which has
its bearings in the lower part of the main frame. One end of the said shaft
passes through the frame and bears a lever, to which a weight is attached by
means of a set screw, so that it can be adjusted closer to or farther from the
fulcrum of the lever, whereby the power which forces the working face of the
wheel up against the ball is decreased or increased as circumstances may make
it desirable. The grinding wheel is used more particularly for grinding or
polishing, and its working face is hollowed out to correspond to the balls to be
ground; it is attached to its shaft so that it can be readily replaced by another
the face of which corresponds to balls of a large or smaller diameter. The
shaft of grinding wheel receives a rapid rotary motion by means of a bel

page_text: passing over a pulley mounted on the same. If the milling tool is to be used
the binged frame before mentioned and the grinding wheel are removed and
an upright frame with guides adjusted in proper position under the ball; this
frame forms the guide ways for a carriage, in which a vertical shaft carrying
the milling tool has its bearings. A rotary motion is imparted to said shaft by
a belt stretched around a pulley thereon, while a set screw operating on the
carriage serves to set up the working face of the milling tool against the ball
to be turned. The secondary frame may be either made separate from the
main frame, or it may be connected thereto, and it may be situated above or
below said main frame. The position of the ball in relation to the grinding
or cutting tool is continually changed by the action of the chucks, as herein-
after described. The mandrils.on which the one pair of chucks are mounted
receive a continuous rotary motion by means of belts extending from drums
on the driving shaft and over pullies mounted on the ends of the chuck
mandrils. Whenever the one pair of chucks are brought to grasp the ball the
said ball is compelled to revolve either in the direction in which the grinding
wheel revolves, but much slower than the same, or in the direction opposito
to said grinding wheel as may be most desirable. At certain stated intervals
the said pair of chucks release the ball, and the other pair of chucks are
caused to grasp the sanie and to turn it in a direction transversely to the
working face of the grinding wheel, and at right angles to the plane of the
motion imparted to it by the first pair of chucks. In order to effect this
purpose, a direct rotary motion is imparted to one or both of the second pair
of chuck mandrils by a belt from a shaft in communication with the driving
shaft before mentioned, by means of a bevil gear or by any other equivalent
means. The motion of the chucks towards and from the surface of the ball
(towards or from the common centre before mentioned) is governed by two
cams mounted on a vertical arbor to which a slow rotary motion is imparted
from the driving shaft by means of an endless screw and worm wheel; the one
cam is situated close over the other cam on the vertical arbor, and acts on
a toe, and through it on the first pair of mandril and chuck carriages, and
while the lower cam acts on another toe and through it on the other pair of
mandril and chuck carriages. The first toe slides back and forth towards and
from the first cam in a bracket secured to the main frame, and it is pivotted to
the upper end of a lever which is mounted on the end of a rock shaft and
connects it by a rod with an eccentric wrist pin projecting from the face of a
disc, which is also mounted on a rock shaft. These two rock shafts have their
bearings in the main frame under the first pair of chuck carriages, and each

page_text: of them bears a pinion, which gears in a toothed rack secured to said car-
riages. The rock shaft passes clear through the main frame, and mounted on
its end opposite the disc before mentioned is a lever on which an adjustable
weight is secured by a set screw, or any other suitable means. By the action
of this weight the point of the first toe is held in contact with the surface of
the first cam, and the first pair of chucks are made to grasp the ball until the
high portion of the cam comes opposite the end of the toe and causes the same
to recede. As soon as this takes place the pinions rotate in a direction
causing these chucks to release the ball. The second toe is arranged precisely
like the first toe, and it is connected to a lever which is mounted on a rock
shaft, and likewise connects by a rod with an eccentric wrist pin secured in a
disc which is mounted on the end of a rock shaft. These rock shafts
extend through the frame under the second pair of carriages; pinions mounted
on these shafts gear into toothed racks which are secured to the said chuck
carriages. A lever, which is mounted on a rock shaft, bears an adjustable
weight, which holds the point of the second toe in contact with the cam lever
before mentioned; when the high portion of this cam is opposite the point of
the toe the second pair of chucks are forced back from the surface of the ball,
but when the low portion of said cam comes opposite the point of the toe the
weighted lever forces the first pair of chucks up against the ball and causes them
to grasp the same. The upper and lower cams, before mentioned, are so
situated in relation to each other that when the high portion of the upper cam
is opposite the point of the first toe, the low portion of the lower cam is opposite
the second toe, and vice versa. It may be observed that the high portion of
the lower cam extends nearly two-thirds around, whereas the high portion of
the upper cam is very short. From this it follows that the first pair of chucks
hold the ball for the largest portion of the revolution, whereas the second pair
of chucks are allowed to grasp the same for a short time only when it is
released by the first pair of chucks.
The object of this arrangement is to impart to the ball a nearly continuous
rotary motion in the plane in which the grinding wheel revolves, by the action
of the first pair of chucks, and to change the position of the said ball occasionally
in a direction at right angles with the plane in which the grinding wheel
rotates by the action of the second pair of chucks.
of the two pairs of chucks the position of the ball in relation to the grinding
surface of the wheel or to the cutting surface of the milling tool is continually
changed and a perfectly round and true ball is produced. The chucks grasp
the general surface of the ball and keep the same in the centre without
By the combined action

page_text: reference to small projections or cavities which may occur in the rough ball.
The weights may be replaced by springs, and the mechanism may be changed
in various minor details without changing the result. This machine is
particularly intended for grinding shot and shell, but it can be used with
great advantage for turning, grinding, and polishing balls of any other
description.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Clark in the Great Seal Patent Office on the 2nd
October 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CLARK, of 53, Chancery Lane, in the County of Middlesex, Engineer and
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourth day of April, in the year of our Lord One
thousand eight hundred and sixty-five, in the twenty-eighth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
William Clark, Her special licence that I, the said William Clark, my
executors, administrators, and assigns, or such others as I, the said William
Clark, my executors, administrators, and 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 "AN IMPROVED MACHINE FOR
ROUNDING AND POLISHING SHOT, SHELL, AND OTHER BALLS OR SPHERES," a com"
to me from abroad by William Davis Winsor, of the City and County of
Philadelphia, State of Pennsylvania, United States of America, upon the
condition (amongst others) that I, the said William Clark, my executors or
administrators, by an instrument in writing under my, or their, or one of
their hands and seals, 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 William Clark, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-

page_text: formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Sheet of Drawings hereunto annexed,
and to the letters and figures marked thereon (that is to say)
Fig. 1 represents a plan or top view of this Invention; Fig. 2 is a
transverse vertical section of the same, taken in the plane indicated by the
line a, a, Fig. 1; Fig. 3 is a similar section of the same, the plane of section
being indicated by the line y, y, Fig. 1; Fig. 4 is a detached front elevation
of a milling tool used in turning balls; Fig. 5 is a transverse vertical section
of the same, the line ;, Fig. 4, indicating the plane of section; Fig. 6 is
a plan or top view of the same; similar letters of reference indicate cor-
responding parts.
This Invention consists of a machine composed of four (more or less) different
longitudinally sliding rotary mandrils, radiating from a common centre and
provided with chucks at their inner ends in combination with suitable
mechanism to force these chucks alternately up against the ball to be turned
or ground, and with a milling tool or grinding wheel, in such a manner that
two of the chucks will clamp the ball at a time, and the ball is thereby turned
in either direction, while the grinding wheel or milling tool is held in contact
with the surface of the ball by means of one or more screws, or by an
adjustable weight. The force with which the grinding wheel or tool is forced
against the surface of the ball can thus be regulated at pleasure. The position
of the revolving chucks and the time when the same grasp the ball are
governed by a double cam and by weights or springs, and said chucks are so
shaped that they grasp the general surface of the ball, and that cavities and
projections occurring on the surface of said ball will not be able to disturb the
corrcet central position of the same.
A represents a frame made of cast iron or any other suitable material in
the form of a cross, with four (more or less) guide ways B, radiating from a
common centre; these ways form the guides for carriages C, C', which form
the bearings for mandrils D, D', as shown clearly in Fig. 1 of the Drawing.
Each of these mandrils carries on its inner end a chuck E or E', which is
made in the form of a cup to fit the surface of the ball to be turned, ground, or
polished, and these chucks are connected to the mandrils so that they can be
readily removed and replaced by others made to fit balls of different diameters.
The tool which acts on the surface of the ball may either be a milling tool F*,
such as shown in Figs. 4, 5, and 6, or it may be a grinding wheel F, such
as shown in Figs. 2 and 3. The wheel F is mounted on a shaft a, which has
its bearings in a secondary frame G, and this frame is hinged at one end to

page_text: angers b, suspended from the main frame A, as shown in Fig. 3, so that the
ront end of the same is free to swing up and down, and the grinding surface
of the wheel F can be forced up to the surface of the ball or removed there-
rom at the pleasure of the operator. The position of the swinging frame G
s regulated by a toothed segment c, which is secured to its loose end and
gears in a pinion d, mounted on a shaft e, which has its bearings in the lower
part of the main frame A. One end of said shaft passes through the frame
and bears a lever f, to which a weight g is attached by means of a set screw h,
as shown in Fig. 1, so that it can be adjusted closer to or further from the
fulcrum of the lever f, and the power which forces the working face of the
wheel up against the ball is decreased or increased as circumstances may make
it desirable. The wheel Fis used more particularly for grinding or polishing,
and its working face is hollowed out to correspond to the balls to be ground.
It is attached to its shaft so that it can be readily replaced by another, the
face of which corresponds to balls of a larger or smaller diameter The shaft a
receives a rapid rotary motion by means of a belt stretched over a pulley i,
mounted on the same, as shown in Fig. 2. If the milling tool F* is to be used, the
binged frame G and the grinding wheel are removed, and the frame G*, (Fig. 4,)
is adjusted under the ball in the proper position. This frame forms the guido
ways for the carriage C, in which the vertical shaft a has its bearings, and
attached to the top of this shaft is the milling tool, as clearly shown in
Figs. 4 and 5. A rotary motion is imparted to said shaft by a belt stretched
around a pulley i*, and a set screw f* serves to set up the working face of the
milling tool against the ball to be turned. The secondary frame G* may
either be made separate from the main frame A, or it may be connected thereto,
and it may be situated above or below said main frame. The position of the
ball in relation to the grinding or cutting tool is continually changed by the
action of the chucks E, E. The mandrils D, on which the chucks E¹ are
mounted, receive a continuous rotary motion by means of belts j extending
from drums k on the driving shaft H over pullies e mounted on the ends of the
mandrils D; whenever the chucks E are brought to grasp the ball, therefore,
said ball is compelled to revolve either in the direction in which the grinding
wheel revolves, but much slower than the same, or in the direction oppo-
site to said grinding wheel, as may be most desirable. At certain stated
intervals the chucks E release the ball, and the chucks E¹ are caused to grasp
the same and to turn it in a direction transversely to the working face of the
grinding wheel, or at right angles to the motion imparted to it by the
chucks E. In order to effect this purpose, a direct rotary motion is imparted

page_text: to one or both of the mandrils D' by a belt j¹ extending from a drum k¹, over
a pulley mounted on the end of said mandril, as shown particularly in Figs.
1 and 3. The drum is mounted on a shaft II', to which motion is imparted
from the driving shaft H by means of a bevil gear m, m³, or by any other
equivalent means. The motion of the chucks E, E', towards and from the
surface of the ball is governed by two cams o, p, mounted on a vertical arbor
I, to which a slow rotary motion is imparted from the driving shaft by means
of an endless screw 9, and worm wheel 2. The cam o, which is situated close
over the camp on the shaft I, acts on a toe s, and through it on the carriages
C, which form the bearings for the mandrils D, and the camp acts on a
toe t, and through it on the carriages C, which form the bearings for the
mandrils D'; the cam s¹ slides back and forth towards and from the cam o, in
a bracket s¹, secured to main frame A, and it is pivotted to the upper end of a
lever s², which is mounted on the end of a rock shaft s³, and connects by a
rods with an eccentric wrist pin projecting from the face of a disc s³, which
is mounted on a rock shaft so. These two rock shafts have their bearings in
the frame A, under the carriages C, and each of them bears a pinion s7, which
gears in a toothed rack s³, secured to the carriages C, as clearly shown in
Fig. 2. The rock shaft se passes clear through the frame A, and mounted on
its end opposite the disc s³ is the lever so, to which an adjustable weight so is
secured by a set screw or any other suitable means; by the action of this
weight the point of the toe s is held in contact with the surface of the cam s,
and the chucks D, E, are made to grasp the ball until the high portion of the
cam comes opposite the end of the toe and causes the same to recede; as soon
as this takes place the pinions s' rotate in the direction of the arrows marked
thereon in Fig. 2, and the chucks E are caused to release the ball. The toe t
is arranged precisely like the toe s, and it is connected to a lever t', which is
mounted on a rock shaft t, and connects by a rod with an eccentric wrist
pin secured in a disc t', which is mounted on the end of a rock shaft t. The
rock shafts and to extend through the frame A under the carriages C, and
pinions to mounted on them gear into toothed racks t, which are secured to
the carriages C¹, as clearly shown in Fig. 3; a lever , which is mounted on
the rock shaft t', and bears an adjustable weight to, which holds the point of
the toc t in contact with the cam p. When the high portion of this cam is
opposite the point of the toe the chucks E' are forced back from the surface
of the ball, but when the low portion of said cam comes opposite the point
of the toe, the weight forces the chucks E up against the ball and causes
The cams o and p are so situated in relation to each
them to grasp the same.

page_text: other that when the high portion of the camo is opposite the point of the toes,
the low portion of the camp is opposite the toe t, and vice versa, and it will
be noticed by referring to Fig. 1, where said cams are shown in dotted lines,
that the high portion of the camp extends nearly two-thirds around, whereas
the high portion of the cam o is very short. From this it follows that the
chucks E hold the ball for the largest portion of the revolution of the shaft
I, whereas the chucks E' are allowed to grasp the same for a short time only,
when it is released by the chucks E.
The object of this arrangement is to impart to the ball a nearly continuous
rotary motion in the plane in which the grinding wheels revolve, by the action
of the chucks E, and to change the position of said ball occasionally in a
direction at right angles with the plane in which the grinding wheel rotates by
the action of the chucks E'. By the combined action of the chucks E, E,
the position of the ball in relation to the grinding surface of the wheel or to
the cutting surface of the milling tool is continually changed and a perfectly
round and true ball is produced. The chucks grasp the general surface of the
ball and keep the same in the centre without reference to small projections or
cavities which may occur in the rough ball. The weights g, so, and to may be
replaced by springs, and the mechanism may be changed in various minor
details without changing the result. The driving shaft has its bearings in
standards K rising from the frame A, and motion is imparted to it by a belt
running on the pulley u, or in any other suitable manner.
This machine is particularly intended for grinding shot and shell, but it can
be used with great advantage for turning, grinding, and polishing balls of any
other description.
Having described the nature of this Invention, and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
herein-before in part recited Letters Patent is,--
First, the method herein described of imparting to the ball while being ground
or turned an intermittent rotary motion in two or more directions by means
of four (more or less) longitudinally sliding rotary mandrils D, D', radiating
from a common centre, and provided with chucks at their inner ends, or any
other equivalent means, constructed and operating substantially as and for the
purpose set forth.
Secondly, the combination of four (more or less) chucks E, E¹, made to
grasp the work at stated intervals with a grinding wheel or milling tool, applied
and operating substantially as and for the purpose described.
Thirdly, the weighted lever f or its equivalent, in combination with the

page_text: hinged frame G, supporting the grinding wheel F, substantially as and for the
purpose described.
Fourthly, the cams o, p, and toes s, t, in combination with the carriages
C, C, chucks E, E¹, and weighted levers 5%, to, or their equivalents,
constructed and operating substantially as and for the purpose described.
In witness whereof, I, the said William Clark, have hereunto set my
hand and seal, this Second day of October, in the year of our Lord
One thousand eight hundred and sixty-five.
Witness,
JAMES DAISH,
53, Chancery Lane,
London.
W. CLARK.
L.S.)