Improvements in and relating to Milling Tools.
Year: 1889

page_text: Date of Application, 24th Dec., 1889-Accepted, 25th Jan., 1890
COMPLETE SPECIFICATION.
Improvements in and relating to Milling Tools.
I, THOMAS EYNON, of Kirtland Street, Cleveland, in the County of Cuyahoga, and
State of Ohio, one of the United States of America, 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 :-
My invention relates to certain improvements in "Milling Tools" for Milling
Machines, more particularly to that class of tools which are used in milling plane
surfaces. Heretofore, it has been usual in tools of this description to have the teeth or
cutters of the tool extend entirely across the face of the same. In the larger tools
of this class the maximum of power is required to operate the same, and the teeth
having such a long cutting edge, much friction is developed, causing the tool to
become overheated and seriously impairing its effectiveness in operation.
The object of my invention is to overcome these defects, and to produce a milling
tool in which the power is gradually applied, and which will develop the minimum
of friction between the tool and the surface of the material upon which it is
operating.
With these objects in view, my said invention consists in certain novelty in the
construction, arrangement and combination of the various parts of the tool, all of
which I will now proceed to point out and describe, reference being had to the
accompanying drawing in which-
Figure 1, is a perspective of the preferred form of my said invention;
Figure 2, is a cross-section taken through the center of the same ;
Figure 3, is a diagram, showing the arrangement of the teeth or cutters ;
Figure 4, illustrates a further embodiment of my invention, shown in cross-
section;
Figure 5, a still further embodiment of the same, shown in elevation ;
Figure 6, is a detail showing the cutter provided with projecting teeth, and―
Figure 7, a detail showing a tooth or cutter removed.
Referring to said drawing: A, represents a cylindrical head having a central
aperture, and is adapted to be secured on the spindle or arbor of a milling machine.
B, are independent removable teeth or cutters having shanks, B', preferably round
in cross-section and secured in radial sockets, C, formed in the face or periphery of
the head. Said teeth or cutters are preferably held in place by means of screws, D,
which are inserted in screw threaded holes, formed in the ends of the head and
communicating with the sockets, C. The screws, D, are counter-sunk.
The ends of the teeth or cutters are cut away or milled to form cutting edges, c,
and are beveled back of said cutting edges. All of the teeth or cutters are of the
same length and project the same distance from the face or periphery of the head so
that all points of the cutting edges of said teeth or cutters will be equi-distant from
the center of rotation of the head. Said teeth or cutters are preferably arranged in
parallel lines around the face of the head, so that they alternate, the teeth of one series
slightly overlapping the line of the teeth of the next series; so that, when in operation,
there will be no fin or unfinished portion left upon the surface of the material being
milled. This arrangement of the teeth is clearly shown in Figure 3. Any number
of teeth may be used, and, if desired, may be arranged in a continuous spiral line
around the face of the head. Any other arrangement of teeth may, however, be
adopted.
In milling tools of ordinary size, but one tooth will be in the same line drawn
across the face of the head parallel with its axis. In very large tools it may be
desirable to have two teeth in the same line drawn across the face of the head
parallel with its axis, as shown in Figure 5.

page_text: Any wear of the teeth may be taken up by loosening the retaining screw of the
worn tooth and moving it out the distance required to bring its cutting edge in line
with the others. Said teeth may be set so that their cutting edges will be at right
angles to the line of rotation of the head, or may be set so that the cutting edges will
be diagonal to said line of rotation in order to give a shearing cut.
It is sometimes necessary to mill between two walls, as in milling channels, or in
milling close to a shoulder for such work I provide teeth having enlarged heads, B2,
(Figure 6) with cutting edges which project over the ends of the face or periphery
of the head. The sockets for such teeth have to be formed close to the ends of the head,
and there would hardly be sufficient material left between the socket and end to stand
the strain when in operation. To strengthen the head I secure to its ends circular
plates, A', by means of screws, a. The cutting edges of said teeth project beyond
said plates, A.
If desired, the head may be formed of several plates F, as shown in Figure 4.
When using the plates, the sockets are formed partly in one plate and partly in
the adjoining plate. In this form of the head the retaining screws may be dispensed
with and the teeth clamped between the plates, which are held together by bolts or
screws, f.
Any other means may also be used to secure the teeth within their sockets.
If desired, the teeth or cutters may be formed integral with the head; I prefer,
however, to employ the removable teeth.
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 milling tool, for milling smooth surfaces, consisting of a head provided with
spirally arranged cutters projecting from its outer face, so located that but one cutter
will be in the same line drawn across the face of the head parallel with its axis and
having all points of the cutting edges of said cutters equi-distant from the centre of
rotation of said head, substantially as shown and described, whereby, when said tool
is in operation, but one cutter at a time will engage with the work.
2. A milling tool, for milling smooth surfaces, consisting of a head provided
with spirally arranged cutters projecting from its outer face, so located that hut one
cutter will be in the same line drawn across the face of the head parallel with its axis,
and having all points of the cutting edges of said cutters equi-distant from the centre
of rotation of said head, and the cutting edges of the cutters located in the same
circular row overlapping the line of cut of the cutters of the adjoining parallel row,
substantially as shown and described.
3. A milling tool, for milling smooth surfaces, consisting of a head provided with
independent and removable cutters spirally arranged upon its outer face, so located
that but one cutter will be in the same line drawn across the face of the head parallel
with its axis, and having all points of the cutting edges of said cutters equi-distant
from the centre of rotation of said head, substantially as shown and described.
4. A milling tool, for milling smooth surfaces, consisting of a head provided with
independent and removable cutters spirally arranged upon its outer face, so located
that but one cutter will be in the same line drawn across the face of said head
parallel with its axis, and having all points of the cutting edges of said cutters equi-
distant from the centre of rotation of the head and the cutting edges of the cutters
located in the same circular row, overlapping the line of cut of the cutters in the
adjoining parallel row, substantially as shown and described.
5. In a milling tool, the combination with a head, having radial sockets in its
outer face, arranged in parallel circular rows, of removable cutters secured in said
sockets and having all points of the cutting edges of said cutters equi-distant from
the centre of rotation of said head, substantially as shown and described.
6. In a milling tool, the combination with a head having radial sockets in its
outer face arranged in parallel circular rows, of removable cutters secured in said
sockets, and having all points of the cutting edges of said cutters equi-distant from

page_text: the centre of rotation of the head, and the cutting edges of the cutters located in
the same circular row overlapping the line of cut of the cutters of the adjoining
parallel row, substantially as shown and described.
7. In a milling tool, the combination with a head having radial sockets in its outer
face, arranged in parallel circular rows, of radially adjustable cutters secured in
said sockets, substantially as shown and described.
8. A milling tool, consisting of a cylindrical head having several series of independent
and removable teeth or cutters arranged in parallel lines upon and projecting the
same distance from its face or periphery, the outer series of teeth projecting over
the ends of the head, and each of said cutters extending only partially across said
face, substantially as shown and described.
9. The combination with the cylindrical head, A, having radial sockets, C, in
its face or periphery, and the screw-threaded holes communicating with the sockets, C,
of the independent and removable teeth or cutters, B, mounted in said sockets and
held in place by the retaining screws, D, and having the cutting edges of all of
said teeth or cutters equi-distant from the centre of rotation of the head, sub-
stantially as shown and described.
Dated this 24th day of Decembar 1980
JENSEN & SON,
77, Chancery Lane, London,, W.C., Patent Agents.