Improvement in Cutters for Mining Machines.
Year: 1890

page_text: compito opocitation Cont
COMPLETE SPECIFICATION.
Improvement in Cutters for Mining Machines.
I, EDWIN ENOCH CARTER, Machinist, residing in Pittsburgh, in the County of
Allegheny, State of Pennsylvania, and United States of America, 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 present invention relates to an improvement in the cutting or drilling tools, and
bas for its object certain changes in the shape or construction of the tool, whereby an
increase in strength and rigidity is attained, and whereby a sharp cutting-edge is
more easily maintained.
In the accompanying drawings, forming a part of this Specification,
Fig. 1 is a sectional end elevation of the tool, the plane of section being indicated
by the line x, x, Fig. 2.
Fig. 2 is a view in side elevation.
Fig. 3 is a sectional elevation of the tool on the line y, y, Fig. 2; and
Fig. 4 is an end elevation.
It has been ascertained in practice that when the cutter comes in contact with a
hard spot or knot in the coal the sudden resistance presented will sometimes cause a
fracture or break extending from a point at or near the junction of the cutting-point 2
and the supplemental cutting-lip 5 diagonally across to a point below the outer end of
the cutting-lip. In order to strengthen the tool or cutter, the portion of the tool
forming the lip 5 is so swaged or bent as to interpose a curved brace 6 between the
cutting-edge of the supplemental lip 5 and the portion of the tool inclosed in the
socket or holder 7. This brace 6, as shown in Fig. 3, extends from the cutting-edge
of the lip in a rearward direction, and then slightly forward to the general plane of
the cutter, thereby presenting somewhat of an edgewise rather than a lateral resistance
to the strains to which it is subjected. The increased strength and rigidity gained by
this construction do not in any way increase the weight or size of the tool.
By reference to Fig. 3, it will be observed that the wall of the lip 5 under the
cutting-edge inclines rearwardly or under such edge, so that said edge is maintained
in a sharp condition by the wearing away of the metal.
As heretofore constructed both the cutting-points 2 are arranged on the same side
of a plane passing through the axis of rotation of the cutter as the lip 4, and hence
one of the cutting-points will not have such a relation to the coal as to be most effective
in cutting. In my improved tool, however, the cutting-edges of the lips 4 and 5 are
located in the same plane passing through the axis of rotation of the tool, as shown in
Fig. 4, and the cutting-points are so bent in opposite directions that their edges will
be in or approximately in a common plane, but that such plane while passing through
the axis of rotation of the tool will form an acute angle with the cutting-edges of the
lips 4 and 5.
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 cutter having two cutting-points located at opposite sides of a central recess.

page_text: a preliminary lateral cutting-lip located in a plane below one of said cutting-points, a
supplemental lateral cutting-lip located on the opposite side of the axis of the cutter,
with its outer end in a plane below that of the preliminary cutting-lip, and at a greater
distance from the axis than the outer end of said preliminary lip, and extending to
the base of the adjacent cutting-point and wholly below the plane of its outer end, and
a curved brace interposed between the cutting-edge of the supplemental lip and the
portion of the cutter inclosed in the tool-holder, substantially as set forth.
2. A cutter having two cutting-points located at opposite sides of a central recess,
and with their edges in or approximately in a common plane passing through the axis
of rotation of the cutter, a preliminary lateral cutting-lip located in a plane below one
of said cutting-points, and a supplemental lateral cutting-lip located on the opposite
side of the axis of the cutter, with its outer end in a plane below that of the preliminary
cutting-lip and at a greater distance from the axis than the outer end of said pre-
liminary cutting-lip, and extending to the base of the adjacent cutting-point and
wholly below the plane of its outer end, the cutting-edges of both of said lips lying in
a common plano passing through the axis of rotation of the cutter and forming an
acute angle with the plane common to the edges of the cutting-points, substantially as
set forth.
Big at fourg, I., U.D.A., tms Eighth day or November 1890.
EDWIN ENOCH CARTER.
In the presence of
.
DARWIN S. WOLCOTT,
R. H. WHITTLESEY.