Improvements in Machines for Milling and Grinding Balls.
Year: 1895

page_text: Date of Application, 1st June, 1895-Accepted, 6th July, 1895
COMPLETE SPECIFICATION.
Improvements in Machines for Milling and Grinding Balls.
I, FRIEDRICH FISCHER of Schweinfurt on the Main Germany Ball
Manufacturer 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 machines heretofore used for milling or grinding balls consist of two parallel
horizontal discs which turn round the same vertical axis in opposite directions and
are on their faces near their outer edge each provided with a ring having a groove
wherein the approximately ball-shaped metal bodies are placed for the purpose of
being milled or ground true. If the grooves are to do milling they are provided
with cutting edge surfaces like a file or otherwise. If the grooves are to do
grinding they are supplied with grinding material when metallic or otherwise made
of grinding material such as emery, burnt stoneware or the like.
-
Fig. 1.on the accompanying drawing is a vertical section through the two rings
and shews a ball between the rings in their grooves. This machine has the defect
that the round-milling or round-grinding of the ball-like metal bodies is effected
comparatively slowly because the metal bodies by the motion in opposite directions
of the ring carrying discs are chiefly turned round their horizontal axis and hence
the grooves which do the milling or grinding do not attack the part of their surface
which is next to the horizontal axis until the diameter of the body has been
sufficiently reduced.
This defect is overcome in the machine forming the subject of this invention by
dividing in two halves one of the rings (the upper or the lower one) or both the
rings vertically centrally through the circular groove, one of the halves being
moved only, or both of the halves being moved but with different angle velocity or
in opposite directions.
By this division of the rings and the motion of one or both ring halves the
approximately globular metallic bodies placed between the ring grooves will be so
turned about that the position of their originally horizontal axis alters continually,
and hence the originally middle zone of the surface of the body will soon after the
starting of the machine be exposed to the action of the milling or grinding grooves..
Such a new machine is shewn in the vertical section Figure 2 and as an example
I have chosen the form in which the lower ring only is made in halves and both
ring halves rotating in opposite directions. Each ring half of the lower ring is on
a separate disc; the inner half a is on a disc 6 which is fixed on the spindle c; the
outer half d is on a disc e which with its boss f is loosely mounted on the spindle c
and by means of the bearing 9 entering a neck in the boss is kept in its proper
place vertically. The two discs b and e receive motion in opposite directions by
bevel wheel gearing, the driving wheel d gearing below with a bevel wheel i fixed
on the spindle c and above with a bevel wheel k fixed on the boss f. The upper
ring has the usual form and is fixed on a disc m which is mounted loosely on the
spindle c. This disc presses with its own weight, aided if required by additional
weight, the upper ring against the bodies placed in the lower divided groove
and is caused to turn by the friction produced between the, bodies and: the upper
groove or by special meaus or else held fast..

page_text: In the machine thus described as an example the two halves of the lower groove
ring have the tendency to turn the ball like bodies round their vertical axis, while
the upper groove ring has the tendency to roll the said bodies round their horizontal
axis. Consequently other diameters of the bodies continually come into the
direction of the said axes, so that the rings always act upon other parts of the body
surfaces.
By this means the round milling or round grinding of the bodies is much
accelerated.
The machine shown in Fig. 2 may also be used in the opposite manner that is to
say so that the divided ring with its two discs and driving gear is above, and the
undivided ring with its disc below.
Both rings, the upper as well as the lower, may be divided as shown in the
sectional view Fig. 3. In this case the effect of the machine is increased. The
upper ring halves as well as the lower ring halves are driven, and the two driving
gears suitably combined.
The turning about of the round metal bodies in the groove rings in such manner
that the position of their originally vertical axis changes continually may also be
attained by giving one of the two ring halves a or d Fig. 2 a smooth guiding
groove instead of a milling or grinding one, and also by giving the undivided ring
Fig. 2 a smooth guiding groove for the friction to which the bodies are subjected
between the two smooth grooves in combination with the friction caused by the
grinding groove suffice for turning about the metal bodies so that no onesided or
irregular grinding can take place. Thus arises for instance the arrangement
shown in Fig. 4 where a is a guide ring, d a milling or grinding ring and a guide
ring. The arrangement shown in Fig. 4 may also be reversed, see Fig. 5 where a
and are the guide rings and d a milling or grinding ring.
Also in the arrangement shown in Fig. 3 the inner or the outer upper ring half
and the outer or inner lower ring half may be formed as guide ring. This results
for instance in the arrangement shown in Fig. 6.
Finally one or both the milling or grinding rings may be divided into three
parts as shewn in the upper part of Fig. 7. In this case the narrow middle part o
serves as a guide ring which may be stationary or be moved slower or quicker than
the two outer parts a and d which serve to mill or grind.
By this arrangement is attained that both the outer parts a and d may rotate,in
the same direction and at the same speed.
The guide rings may be of any suitable material as for instance wood, metal,
vulcanite, papier mache or the like.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what
I claim is.
1. A machine for milling or grinding balls in which the lower or the upper
milling or grinding disc or both discs provided with grooves for receiving the globe
like bodies are divided parallel to the axis of rotation and one half of each groove
ring is rotated against the other with a relatively different angular velocity for the
purpose of turning about the said bodies to be milled or ground, substantially.as
described.
2. A ball milling or grinding machine with divided groove ring, in which the one
half of the divided groove ring is formed to act as guide groove ring and the
undivided groove ring similarly as guide groove ring substantially as and for the
purpose described.
3. A ball milling or grinding machine with two divided groove rings, in which
the inner or outer half of the one ring and the outer or inner half of the other
ring serve as guide groove rings, substantially as and for the purpose described.
4. A ball milling or grinding machine in which one or both the groove rings are
divided in three parts, of which the middle part forms a guide ring substantially:as

page_text: described and for the purpose of turning about the bodies to be operated upon and
in order that the two outer milling or grinding parts may run in the same direction
and at the same speed.
Dated the 1st day of June 1895.
JENSEN & SON,
77 Chancery Lane, London, W.C., Patent Agents.