Improvements in Ball Grinding Machines.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Ball Grinding Machines.
We, WILLIAM HENRY LOCK, Manager and Secretary of The Linotype Company
Limited, of No. 188, Fleet Street, in the City of London, and CHARLES WALTER
PASHLEY, of The Linotype Works, Broadheath, in the County of Chester, Engineer,
do hereby declare the nature of this invention to be as follows:-
The present invention relates to improvements in ball grinding machines and
is applicable to all machines for grinding either spheres, or spheres, which by
reason of having diametrical holes through them, have limited portions of their
surfaces to be ground and can be supported on a mandrel. It consists principally
in a novel combination by which the grinding wheel and the ball to be ground
are both rotated about their respective axes during the operation of grinding.
The respective rates of rotation and directions thercof too, so far as their being
opposite to each other is concerned, may be as heretofore.
The invention may be embodied as an independent machine, or as a lathe
attachment, whichever may be preferred.
The axes of both grinding wheel and ball are preferably both horizontal, the
wheel then revolving in a vertical plane. It is driven by any suitable means.
The driving mandrel of the ball carriage is driven by any suitable means.
The ball carriage has two standards in which are the bearings for the ball
supporting device. The journals and bearings of the latter-cups or mandrel,
as the case may be are of a suitable type to allow of the device in question
being readily dismounted and mounted again.
The said carriage is mounted upon a base which may be adjustable by means
of a suitable slide device, to and from the grinding wheel. The base is held in
its adjusted position upon the bed of the machine or upon the lathe bed, as the
case may be. The carriage can be rotated upon the said base about a vertical
axis which is coincident with the vertical axis of the ball, and through the arc
of the ball surface to be ground. The rotating device consists of a horizontal
worm turning in bearings in the base and gearing with a worm wheel fast upon
the carriage journal. This latter and its bearing are preferably coned. The
worm axle projects beyond the base where it is fitted with a winch handle or
the like.
Within the base of the carriage, there are mounted so as to revolve freely
about a vertical axis coincident with the vertical axis of the sphere to be ground,
two pulleys fast together. Their function is to receive the motion of the above
mentioned driving mandrel of the ball carriage, speed it as may be required, and
transmit it to the ball supporting device. A belt is therefore passed round a
pulley on the said driving mandrel and the bottom one of the two pulleys within
the base of the carriage. If the pulley on the driving mandrel is vertical, the
belt is led over an intermediate pair of antifriction pulleys. A second belt is
passed round the other of the two pulleys over a pair of vertical antifriction

page_text: pulleys carried by the ball carriage and round a pulley on the ball supporting
device.
Dated this 29th day of September 1898.
Improvements in Ball Grinding Machines.
We, WILLIAM HENRY LOCK, Manager and Secretary of The Linotype Company
Limited, of No. 188, Fleet Street, in the City of London, and CHARLES WALTER
PASHLEY, of The Linotype Works, Broadheath, in the County of Chester, 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:-
The present invention relates to ball grinding machines and is applicable to all
machines for grinding either balls, or balls which by reason of diametrical
holes through them, have limited portions of their surface to be ground and can
be supported on a mandrel or spindle.
It consists in a novel combination by which both the ball and grinding wheel
are rapidly rotated while the ball only is being slowly rotated about an axis which
intersects that of its rapid rotation.
Convenient rates and directions of rotation may be adopted for both grinding
wheel and ball. The invention may be embodied as an independent machine
or as a machine tool attachment, and with its axis of rapid rotation at any angle.
The accompanying figures illustrate it in the form of a machine tool attachment.
They are to be taken as part of this specification and read therewith.
Figure 1 is a front elevation, partly in section, of the invention.
Figure 2 is a detail on an enlarged scale, of the ball, tightening sleeve and
spindle.,
Figure 3 is a side elevation from the left hand of Figure 1.
Figure 4 is a side elevation from the right hand of the same figure.
Figure 5 is a plan of the ball carriage and the guide pulley bracket…,
Figure 6 is a plan of the bed, base and ball carriage rotating gear..
Figure 7 is a detail illustrating a modified form of spindle..
ا,
1.1
1 is the ball to be ground. The means by which it is chucked for grinding
depends upon whether it has or has not a diametrical hole through it. If it has
not, it is chucked between two cups 2, 2, fast on the ends of a pair of aligned
spindles 3, 3, as illustrated in Figure 7. If it has, it is chucked by being held
on a single spindle 4, by a tightening sleeve 5, as illustrated in Figures 1 and 2.
The central portion 4° of the spindle 4 is tapered from the diameter of the portion
next to the fixed standard of the ball carriage to a smaller one, the portion next
to the detachable standard being of the same diameter throughout as the smallest
diameter of the tapered portion 4". There is a flat 4 on one side of the taper
and the inner surface of the tightening sleeve 5 is shaped to correspond with.
the contour of the central portion 4°. Which of the two standards is, fixed and
which is detachable, is explained further on.
r
The dot and dash line 6 represents the grinding wheel or rather, its annulus of
contact with the ball 1. The details of the mounting of that wheel and the, means
by which it is rotated, may be of any convenient kind. They do not form any
part of the present invention, and for that reason they need not be specified ti
7 is the ball carriage having standards of a suitable height, 8, 9, at each end
to furnish bearings consisting of tapered bushes, 10, 11, for the spindles or

page_text: spindle above described to turn in. The latter (or one of them if there are two)
projects beyond one of the standards-the left hand one, 8, in the figures,—and
there carries a driving pulley 12. The opposite standard 9, is detachable from
the rest of the ball carriage 7 along the line 13, to provide for the ball 1 being
chucked or unchucked without it being necessary to interfere with the bushes 10,
11, (or either of them), the respective end of the spindle being free from projec-
tions to allow of the bush 11 in the standard 9 being drawn over it.
by which the detachable standard is held to the rest of the carriage 7.
14. is a screw
15 is a flat bed plate from which there springs upwards the base 16. The said
bed 15 and base 16 further serve to carry between them the mechanism through;
which the ball 1 receives the rapid rotation above mentioned, and the ball
carriage 7, its slow rotation upon the base 16. 36 is a longitudinal slot in the
bottom face of the bed plate 15, and 37, 37 are blocks fixed therein one near
each end of the said plate, and both projecting beyond the said bottom face, to
fit into corresponding recesses in the bed of the machine tool. The combination
of the projecting blocks 37 and the said recesses provides for the attachment being
fixed in its exact working position each time that it is placed upon the bed of the
machine tool. 17, 17, are holes in the bed plate 15 to receive bolts for holding
the attachment down upon the machine tool.
20, 21, are two pulleys fast together and capable of rotating at the same
angular velocity about a vertical axis above the bed plate 15. The said vertical
axis is shewn as provided by a stud 22 fixed to and standing up from the bed
plate 15. 23 is a headed screw in the stud 22 to hold the pulleys 20, 21, down
thereon. 24 is a bracket fast to and pendant from that end of the ball carriage 7
which is next to the spindle pulley 12. Its object is to carry a pair of guide
pulleys 25. The pulley 20 is driven by any suitable means a portion of its
driving cord 26 is included in Figures 1, 3 and 6. 27 is a cord passing over
the pulleys, 21, 25, 12 and 25. The respective diameters of the two pulleys 20, 21,
are adjusted to rotate the spindle 4 at the proper speed.
The ball carriage 7 is held and rotated slowly upon the base 16, by the
mechanism next described. 28 is a cone, its top flush with the top of the base 16,
turning in a seating therein, and projecting from its under side in the direction
of the pulleys 20 and 21 far enough to carry the worm wheel 29. The cone 28
and wheel 29 are concentric with each other." The carriage 7 rests upon the said
top of the base 16 and has the cone 28 made fast to it by a screw 30 and steadying
pins 31, 31. 32 is a worm engaging with the worm wheel 29. It is fast, on a
shaft 33 turning in a bearing 34 in the base 16, the outer end of the shaft being
fitted with a winch handle 35. The worm wheel 29 and the ball carriage 7 have
a common axis and the unground ball must be chucked so that that axis, if pro-
longed, would pass through the desired centre of the ground ball.
'There may be combined with the bed 15, or with the mounting of the grinding
wheel, any suitable mechanism for advancing the said wheel and the unground
ball towards each other. When they have been brought into proper grinding
contact and the cord 26 has been started, the handle 35 is turned until every
point on the meridian through the point of contact between the wheel and the
ball 1, has been moved past the wheel 6. As the effective peripheral speed at
the point of contact between the grinding wheel and the ball, is very much
higher than the rate at which the latter is turned by the handle 35, it follows
that the grinding will be thorough and as the two rotations of the ball are
respectively about axes that intersect each other in the desired centre of the
ground ball, it follows that the ground surface of it must be truly spherical to
that centre.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is : —
1. The hereinbefore described combination of mechanisms, for rotating the

page_text: chucked ball at respectively different speeds about two axes which intersect each
other in the desired centre of the ground ball.
2. The hereinbefore described combination of ball carriage; base upon which
it can be rotated about, an axis containing the desired centre of the ground ball;
mechanism for effecting such rotation; spindle or spindles for chucking the ball
to be ground and mechanism for rotating said spindle or spindles at a high
rate of speed about an axis which intersects the axis above mentioned.
3. The hereinbefore described combination of grinding wheel driven by any
suitable means and mechanisms for rotating the chucked ball at respectively
different speeds about two axes which intersect each other in the desired centre
of the ground ball.
4. The herein before described combination of ball carriage; standards and
spindle or spindles; base to support the ball carriage; cone fast to the ball
carriage and turning on the base; worm wheel fast upon the cone and worm
carried by the base and engaging therewith; means for turning the worm;
speeded pulleys to receive the driving motion; and band and driving pulley
to transmit it to the spindle or spindles, as set forth with reference to the accom-
panying drawings.
Dated
£T.
1000
CHAS. S. WOODROFFE,
Fel. Ch. Inst. P. A.,
Agent for the Applicants.