A Machine for Rolling, Cutting, and Grinding Balls.
Year: 1898

page_text: Date of Application, 11th Jan., 1898-Accepted, 5th Nov., 1898
COMPLETE SPECIFICATION.
A Machine for Rolling, Cutting, and Grinding Balls.
I, WILHELM RACKE, of Starnberg, Bavaria, in the German Empire, 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:―
This invention relates to a machine for rolling balls when hot or for cutting
or grinding them in the cold.
The chief feature of the machine is that the balls, which are fed into the thread
of a screwed spindle or of a worm or into a spiral groove in a disc, are, during
the motion imparted to them by the rotation of the spindle, worm or disc, rolled
along a straight guide which is provided with teeth or cuts for cutting purposes,
and is smooth for rolling and grinding. In the case of cutting, the grooves of
the spindle, worm or disc are also provided with teeth or cuts.
The grinding
is effected by means of a rotating roller arranged parallel to the said guide and
which can be formed of grinding discs placed adjacent to one another.
As an example of my invention I have illustrated in the accompanying draw-
ing a machine for grinding balls.
In the said drawing :—
Figure 1 is a diagrammatic front view of the main parts of the machine:
Figure 2 is a sectional side elevation of the complete machine:
Figure 3 is an end view:
Figure 4 is a vertical section on the line - Figure 2:
Figure 5 is a plan with the grinding roller removed: and
Figures 6, 7 and 8 are views of details.
Figures 1, 6, 7 and 8 are drawn to a larger scale than Figures 2, 3, 4 and 5.
a is the screwed spindle, the thread of which is of such a depth that the ball b
sinks to a half or two thirds of its diameter thereinto. On each side of the
spindle a there is arranged an adjustable guide c, the upper edges of which guides
approach one another and leave between them a space through which the ball b,
which is supported in the groove of the spindle a, projects slightly upwards,
Above the guides c, the spindle a and the ball b, there rotates a grinding-
roller d, the axis of which lies in the same vertical plane as that of the screwed
spindle to which it is parallel. The ball is fed in the spiral groove of the
spindle by an automatically operating device and is, by the rotation of the spindle,
rolled in a straight line between the guides and is abraded by the rotating grind-
ing roller. By the operation of the grinding roller the ball is pressed against
the one or the other of the two guides according to the direction of rotation of the
said roller, the spindle with the guides being raised to the necessary extent by
means of weights, springs or fluid pressure which can be suitably regulated.
The ball is, by the friction to which it is in this manner subjected, rotated on
its axis equally in all directions and as it is moved along in a straight line under
the grinding-roller the working line of which is made straight and parallel
[Price 8d.1

page_text: to the feed line, it is made perfectly round as only those parts of the ball can be
attacked and cut away which are more than a certain distance from the middle
point of the ball.
The spindle a and the guides c, c are mounted upon a common table e which
is guided by four bolts fin lugs on the frame g. The bolts are connected at
their lower ends by a double fork-shaped cross-piece (Figure 5) which is pro-
vided with a central roller i (Figure 2) against which one arm of a weighted
leverlies, the said lever being pivoted in the frame. The cross-piece h is
provided with four adjusting screws m, Figure 2, which are so arranged with
respect to four shoulders or projections n on the frame g, that the table e cannot
be raised by the weighted leverk beyond a predetermined limit.
The guides c, c can, after they have been set at the requisite distance apart,
be secured rigidly in position from above by screws o, Figure 4, which screws are
.supported in rigid angle pieces p upon the table e. The guides can also be
adjusted to the proper distance apart by the pressure of laterally operating
springs which are placed upon horizontal bolts in the table e.
The spindle a is rotated by the belt pulleys s, s (Figure 5).
The shaft of the grinding-roller d is supported in bearings in the frame g
above the spindle, the said roller being shewn formed of discs which are placed
upon the shaft t with a slight space between the adjacent discs and are held
together by nuts u screwed upon the said shaft t. The grinding-roller is rotated
by a pulley; instead of the said roller I can employ a rigid but adjustable
grinding strip.
It is to be noted that for effecting the best results the spindle should be cut
with a thread of the shape in cross section shewn in Figure 6.
The solid screwed spindle and the guides can also be replaced by the arrange-
ment illustrated in Figure 7 wherein a tube, which is perforated with a spiral
slot, rotates around a rigid cylindrical core in which a straight V-shaped guide
groove is cut.
The two guides can also be obtained by providing a tube enclosing the spindle
with a straight slot or slit of the desired shape.
In the case wherein the balls are to be rolled when hot, the grinding roller is
dispensed with and the two guides are replaced by a guide with a central longi-
tudinal groove as shewn in Figure 8.
Instead of the screwed spindle or the screwed tube, which in lieu of being
cylindrical can also be conical, a horizontal rotating plate can be employed, the
said plate being provided with a spiral groove. This plate is rotated underneath
the guides so that the balls when moved by the spiral groove are rolled in a
straight line.
When the machine is used for cutting, the grinding roller is removed and,
as mentioned in the opening paragraph of the description, both the straight
guide and the threads of the spindle (or their equivalent) are provided with
hardened cutting teeth or file-cuts, so that the ball is cut whilst being moved along
the guide by the rotation of the spindle as the file-cuts then act very efficiently
upon the ball. It is to be noted that only that guide arranged opposite the
direction of rotation of the spindle is provided with file-cuts.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. A machine for rolling, cutting or grinding balls wherein the balls, being
fed in the spiral groove of a screwed spindle, worm or disc, are rolled along a
straight guide whilst they are moved by the rotation of the spindle, worm or
disc, the said guide being provided with teeth or cuts for cutting the balls and
being smooth for rolling or grinding the same, substantially as hereinbefore
described.
2. A grinding-machine of the kind described in Claim 1 wherein a rigid grind-

page_text: ing strip is arranged or a grinding-roller is mounted in bearings parallel to
the guide, the said roller being formed for example of a number of grinding
discs arranged upon a common shaft, substantially as described.
3. A grinding-machine of the kind described in Claims 1 and 2 wherein the
spindle, worm or spirally grooved disc and the guide are mounted upon a common
adjustable table which can be approached to the necessary distance from the
grinding strip or roller by means of weights, springs or fluid pressure, substan-
tially as described.
4. The combination and arrangement of parts forming the improved machine
for grinding balls, hereinbefore described and illustrated in the accompanying
drawing.
Dated the 11th day of January 1830.
G. F. KEDFERN & Co.,
4, South Street, Finsbury, London,
Agents for the Applicant.
G. F. KEDFERN & Co.,
4, South Street, Finsbury, London,
Agents for the Applicant.