Improvements in Tools for Lathes and the like.
Year: 1899

page_text: Date of Application, 27th Apr., 1899-Accepted, 2nd June, 1899
Improvements in Tools for Lathes and the like.
A communication from the GEOMETRIC DRILL COMPANY, a corporation under the
laws of the State of Delaware, with its principal office at Westville, in the
State of Connecticut, United States of America.
I, Alfred Julius Boult, of 111, Hatton Garden, in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:--
This invention relates to tools for milling circular rods, projections, or openings,
and consists of a milling tool adapted for application to a lathe or turret or other-
wise, and constructed as set forth hereinafter and as illustrated in the accompany-
ing drawing, in which:
Fig. 1 is an external side elevation of my improved milling tool; Fig. 2 is a face
view in part section; Fig. 3 is a transverse section; Fig. 4 is a face view of the head
portion, the cap and all but one of the cutters removed; Fig. 5 is a perspective
view of one of the cutters for external milling; and Fig. 6 is a sectional view
illustrating the tool as constructed for internal milling.
The tool is provided with a head A which may be upon a hollow or solid stem C,
and adapted for being secured in a lathe or turret or otherwise, and at the outer
face of this head is an annular projection 1, radially slotted for the reception of
cutters D.
Each of the said cutters has at the outer end a cutting edge a, parallel to the axis
of the cutter head, and also a lug 4 for the purpose described hereinafter.
The projection 1 and the cutters therein are covered by a cap B having a central
opening into which the inner ends of the cutters extend, and with curved cam
grooves 5 each adapted to receive one of the lugs 4 so that by turning the cap
upon the projection 1, the cutters may be carried inward or outward according to
the direction in which the cap is turned.
It is important that the tools shall be secured positively and firmly, and to this
end, means are used to lock the cap after adjustment. Thus, there is a series of
screw bolts each of which passes through the cap and through a curved opening
or slot 3 in the head, and into a ring E at the back of the head, which ring turns
freely upon the stem C. By loosening the screw bolts the cap may be turned to
any desired position, and by tightening the bolts the cap is clamped firmly upon the
projection 1 and holds the cutters immovably in position.
When the milling tool is to operate upon the interior of an opening or socket
to mill the same, say a tapering opening, the cutting edges of the cutters may be
at the outer edges of projections 7 thereof, as shown in Fig. 6, these projections
extending beyond the head to any desired extent, and the slotted projections 1"
cap B.
also extending through and beyond the
In order to adjust the cutters to any determined extent the cutter head is pro-
vided with graduations as shown in Fig. 1 and index line or point o, on one part
and a series of divisional lines upon the other.
It will be seen that in the above tool the operating parts are all covered and
protected from dust and prevented from becoming inoperative by accumulation of
matter, and that the cutters while readily movable are firmly supported in each