Improvements in Apparatus, for Grinding and Finishing Balls into True Spheres of the Proper Size.
Year: 1898

page_text: Date of Application, 16th Aug., 1898-Accepted, 17th Sept., 1898
Improvements in Apparatus, for Grinding and Finishing Balls into
True Spheres of the Proper Size.
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A communication by ROLLIN HENRY WHITE, of 56, Hillburn Avenue, Cleveland
Cuyahoga, County Ohio, United States of America, Mechanical Engineer.
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I WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign
Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street; Manchester, hoth "in
the County of Lancaster, 118, New Street, Birmingham, in the County of Warwick,
and. 322, High Holborn; in the County of Middlesex, Civil Engineer, 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:-
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The invention relates to a machine for grinding and finishing balls so that they
will be true spheres of the proper size.
In the drawings, Figure 1 is a side elevation of a machine, containing the
invention; Figure 2 is a sectional side elevation of the mechanism above. and
including the bed plate; Figure 3,is, an enlarged front view of that part of. the
mechanism which automatically operates the belt shifter to stop the machine;
Figure 4 is an enlarged sectional view on line 4-4 of Figure 3; Figure 5 is a
sectional plan on line 5-5 of Fig. 3; Fig. 6 is a plan view of the movable
block D; and Figure 7 is a plan view of the grinder C.
The balls to be ground, which are imperfect and irregular both as to size and shape,
are placed in an endless ball groove d¹ formed in the hard metal bottom of a recess d,
which is adapted to contain a sufficient quantity of oil and emery; or some like
substance, to wholly or nearly submerge the balls. This ball groove must not be a
circle concentric with the axis of the grinder, but it, may be circular, if during the
grinding operation, it is eccentric to the axis of the grinder. But the best results
are obtained when this groove is sinuous, that is to, say, when it is curved in and out
toward and from the axis of the grinder as shown. The engagement of the rotary
grinder with the balls causes them to roll around in the endless ball groove; and,
because, the groove is shaped as described, the axis upon which each ball turns
in rolling is constantly changing. This causes every part of the surface of each ball
to: be brought repeatedly into contact with the grinding surfaces, (viz., the surface of
the ball groove on which the halls rest, and. the lower face of the grinder) the result
heing that the balls in the groove are ground to the same size and into perfect
spherical form.
The recess d for containing oil and emery is preferably formed in the top of a
metal block D, which rests upon the bed A of the machine, and may be moved
thereon out from under the grinder. This makes it easy to fill the sinuous ball
groove (which is cut in the bottom of this recess) with balls to be ground, and to
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page_text: remove them therefrom after the grinding operation is finished. The grinder C,
which has a horizontal grinding face, is secured to the lower end of a vertical rotary
shaft B. This shaft is suitably mounted in horizontal bracket arms ff f², which are
parts of a standard F. The shaft is vertically movable to withdraw the grinder from
the recess d so that the block may be inoved as described. The shaft passes through
and rotates in a sleeve E which is mounted on the lower bracket arm f, but is
prevented from rotating therein by a feather f³ which enters a longitudinal surface
groove e in the sleeve. A rack e¹ formed in one side of this sleeve is engaged by a
gear segment J, which is pivoted to ears fo which are parts of the bracket ari f.
This gear segment is provided with an operating lever j, by means of which said
segment is turned more or less to raise or lower said sleeve. The upper end of the
sleeve engages with a collar 62, which is screwed on the shaft, wherefore the vertical
movement of the sleeve causes the shaft and the grinder to move upward.
A pulley G lies between the two bracket arms f¹ f2, and is thus prevented from
moving up or down. Its hub g, which extends in both directions, is mounted in said
bracket arms. The shaft passes through the pulley; and the feathers g¹ carried by
the pulley enter longitudinal grooves 63 in the shaft, whereby the shaft is compelled
to rotate with the pulley, but may move vertically through it. A belt Y drives the
pulley, and this drives the shaft and grinder.
When the shaft has been raised by the action of the gear segment J and the
sleeve E, said sleeve and shaft are held up by the engagement of a spring latch j, on
lever, with a notch in one of the ears . When the ball groove has been filled
with balls, the block D is moved upon the bed A until it is in proper position
beneath the grinder. Then the lever j is unlatched and the sleeve E and shaft B
are allowed to descend by their own weight. The lower edge of the grinder enters
the recess d, and its lower surface rests upon the balls which are ground by the
subsequent rotation of the grinder. When the balls have been ground to the desired
size the machine is stopped, the sleeve and shaft raised by the gear segment, the
block D is drawn from under the grinder, the finished balls are removed, the ball
groove is filled with a new charge to be ground, and the operations described are
repeated.
The grinder shown consists of a short tubular cylinder, which is removably secured
to a disk c on the lower end of shaft B; the grinder cylinder has on its upper end an
inwardly turned flange c¹; and in the edge of this flange are three, more or less,
notches c². In vertical sockets, in the lower face of the disk c are the dogs I which
may pass through the notches c2 in the grinder flange c¹. The grinder is then
turned a little, which causes the dogs to engage with this flange. The dogs are then
drawn upward by means of the bolts i, and the grinder is thus firmly fixed to the
disk c.
This makes it possible and easy to remove one grinder when it shall become
worn and to substitute a new one.
In the economical operation of machines of this character one workman will take
care of a number of machines. He is liable to forget to stop a machine when he
should, and he is also liable to be busy with one machine when another ought to be
stopped. The result will be, that in either case the machine will remain too long in
operation, whereby the balls will be ground too small. To prevent this undesirable
result, means are provided which will automatically stop the machine when it has
operated as long as it ought to. The means consist of a pivoted arın N, mechanism
which causes said arm to rotate upon its pivot simultaneously with the grinder shaft,
but at very slow speed; and belt shifting mechanism, or other mechanism of
analogous character, which will be engaged and set into operation by said arm after
the grinder shaft has rotated a predetermined number of times. It will be under-
stood, of course, that the arm might operate a clutch or any other mechanism which
would break the communication between the grinder shaft and the power. There would
also be a distinct gain if the arm N merely operated an alarm bell which
would call the operator's attention to the fact that the machine ought to be
stopped.

page_text: The following is a description of the particular mechanism contained in the
machine shown for accomplishing the result stated. The operating arm N is pivoted
on a stud H which is screwed into a plate o, this plate being the back plate of a gear
case O which is fast to the frame work of the machine. This gear case contains and
supports a train of speed reducing gears, the gear K being the last gear, and the
gear m being the first gear in said train of gears.
This train of gears is
clearly shown in Figures 2 and 3. The gear m is made fast to the shaft m¹, which is
mounted in a sleeve of which extends rearward from and is a part of the gear
case 0. On the rear end of this shaft is a worm wheel M, which is on mesh with a
worm L, which is secured to the hub of the pulley G. The rotation of the
pulley therefore causes the rotation of the train of gears referred to, of which as
before stated, the gear K is the last one. This gear is made fast to a disk K¹ which
is rotatably mounted on the same stud H upon which the arm N is mounted. In
this disk is an annular row of holes k, placed suitable distances apart. A spring
pin n mounted in the arm N is adapted to engage in any one of these holes, where-
fore when the pin does so engage, the arm N will rotate in unison with the disk .K¹
and the gear K. .
A bar V is placed in the path of the arm N, so that when said arm is moved far
enough it will strike this bar. V. This bar V is connected with the belt shifting
mechanism, or any other mechanism which is adapted to stop the operation of the
machine, or sound an alarm.
To adjust the described mechanism for work with any lot of balls, it is necessary
for the operator to find out by experience with balls from said lot, how much angular
advance the arın N will make while the machine is grinding said balls to the proper
size. Having so determined, the said arın is moved backward the proper distance
and fastened to the disk K¹ by means of the spring pin n. Then the machine is
set in operation, grinding another batch of balls, and the revolution of the grinder,
transmitted back through the train of gears, causes the slow advance of the arm N.
This arm engages with the bar V when the grinder has rotated times enough to
properly grind balls, and this as before stated, caused the machine to stop.
As an indicator for indicating which hole k in the disk K' the spring pin %.
should be caused to engage to properly set the arm, a pointer W is mounted
upon the stud H, and it is clamped to this stud between a shoulder h thereon
and the end of a sleeve h upon which the arm N is mounted, by means of a
nut h³. To set the machine, therefore, the arm N is swung backward and the spring
pin is placed in the first hole k to the right of this pointer. The distance between
this pointer and the arm N at the time the machine stops, indicates the angular
advance measured in holes k which the arm N has made during the grinding
operation. If it is found upon gauging the balls that they have been ground too
much, or too little, this pointer can be readjusted to indicate the proper hole for
the spring pin n to engage with, so that the next grinding operation shall be
more nearly exact.
The bar V, which is engaged by the arm N is, in the particular construction shown
in the drawing, pivoted to the upper end of a lever U which is itself pivoted to the
standard F of the machine. The bar V rests upon the lower part of a guide strap f
which is made fast to the gear case; and a notch in the lower end of this bar V
engages with this strap, as shown in Figures 1 and 3, thus preventing endwise
movement of said bar V. The lower end of the lever U is connected with a collar u
which embraces a longitudinally movable rod R and lies between two collars
thereon. This rod R carries the belt shifting forks r r which engage with a belt S
and move it from a pulley p¹ onto a pulley p², or vice versa. Both of these pulleys
are loosely mounted on a short stub shaft P. The pulley p¹, however, is rigidly
connected with a pulley over which runs the belt Y which drives the grinder shaft
pulley G. This belt passes over the idle pulleys Q. A spring r¹ which surrounds
the bar R and thrusts endwise against a fixed bracket a², and a collar 2, exerts its force
constantly to move the bar R in the direction to shift the belt S onto the pulley p²,-

page_text: under which conditions the grinder, shaft will not be driven. A handle on the
bar R affords.ineans for drawing the bar in the reverse direction on the pulley p²,
under which conditions the grinder shaft is. driven.. When the bar R is so moved, its
motion transmitted through the lever U. to the bar V inoves said bar endwise until
its notch v will engage with the strap f, which engagement temporarily latches. the
belt shifting mechanism so as to hold the belt upon the operative pulley p¹. When
by the operation, of the grinder shaft the arm N is caused to engage with the bar. V,
this bar is lifted so that, its notch no longer engages with the strap f, whereupon
the spring moves the rod R, which causes the belt to be shifted onto the
inoperative pulley p² and the rotation of the grinder shaft, as a consequence,
ceases.
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Having now particularly described and ascertained the nature of the said inven-
tion, as communicated to me by my foreign correspondent, and in what manner the
same is to be performed, I declare that what I claim is -
1.
:
1. In a machine for grinding balls, the combination of a grinder rotatable upon a
vertical axis, with a block below the grinder having in its top a recess adapted to
contain a mixture of oil and emery, or like substance, and having in the bottom of said
-recess an endless ball groove which, when the parts are in operative relation, is not
a circle concentric with the axis of the grinder, substantially as described.
.
2. In a machine, for grinding balls, the combination of a rotatable grinder, and a
bed plate, with a block adapted to slide upon said bed plate, and having in its top a
recess adapted to contain a mixture of oil and emery, or like substance, and having
in the bottom of said recess an endless ball groove which, when the parts are in
operative relation, is not a circle.concentric with the axis of the grinder, and means for
moving the grinder vertically to permit the withdrawal of the block from and its
réplacement beneath the grinder, substantially as described.
:
. 3. In a machine for grinding balls, the combination of a bed plate and a block
movable upon said bed plate, having in its top a recess adapted to contain a mixture
of oil and emery, or like substance, and having in the bottom of said recess an end-
Jess sinuous ball groove, with a rotary grinder adapted to engage with the balls in
said sinuous groove, substantially as described.
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4. In a ball grinding machine, the combination of a grinder. rotatable upon a
vertical axis, a rotatable arm adapted by its position to indicate when the grinder has
rotated the proper number of times, with mechanism for driving said grinder and
an arm simultaneously but at different speeds, the movement of the arm being the
slower, substantially as described.
5. In a ball grinding machine, the combination of a rotatable grinder, mechanism
for transmitting motion from the source of power to said grinder, with a rotatable
arm and mechanism whereby it is turned simultaneously with the grinder but at
much slower speed, and means whereby this arm will cause some part of the power-
transmitting mechanism to be disconnected when the grinder has made the desired
number of revolutions, substantially as described.
6. In a ball grinding machine, the combination of a rotatable grinder, its operating
mechanism, a rotatable arm, and mechanism for operating the same simultaneously
with the grinder but at a slower 'speed, with a spring actuated belt shipper, and
a latching. device which holds the belt shipper in proper position to cause the belt
to drive the machine, said latching device being in the path of said arm, whereby
it is released by said arm, substantially as described:
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7. In a ball grinding machine; the combination of an endwise movable grinder
shaft, a sleeve which turns with the shaft but has no endwise movement, a worm on
said sleeve, a pivoted disk and mechanism driven by said worm for turning said disk,
with an arm mounted on the same axis with said disk, means for adjustably connecting
said disk and arm, and belt shipping mechanism adapted to be set in operation by
said arm, substantially as described. <
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8. In a ball grinding machine, the combination of a rotatable grinder, a worm
which rotates simultaneously therewith, a rotating disk, mechanism intermediate of

page_text: said worm and disk whereby the latter is driven at comparatively slow speed, an arm
pivoted upon the same axis as the disk and means for adjustably securing said arm
to said disk with an adjustable pointer pivoted upon the same axis with the disk,
means for fixing the pointer in different positions relative to said disk and a device
adapted to be moved by said arm, substantially as described.
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