Improvements in Cutters used in Machinery for Boring, Tunnelling, and Cutting Out Coal and other Minerals.
Year: 1891

page_text: Date of Application, 29th Sept., 1891—Accepted, 31st Oct., 1891
COMPLETE SPECIFICATION.
Improvements in Cutters used in Machinery for Boring, Tunnelling,
and Cutting Out Coal and other Minerals.
I, GEORGE WILLIAM ELLIOTT of 160 Shirebrook Road, Heeley, Sheffield,
Mining and Mechanical 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 improvements in cutters used in machinery for boring,
tunnelling, and cutting out coal and other minerals.
The excessive wear of the steel cutters as now used for such machines is a source
of great expense, as the cost of making them is thrown away when they are worn
down too short for further use, and the cost of resharpening is also sometimes
great.
To obviate these defects I make the actual cutting parts of chilled cast iron so
formed that they are easily fixed firmly into holders, or detached from them.
These cutting parts are made as small as desirable to do the work required of
them, so that when they become blunted they are easily replaced, and in most cases
are so cheap that it is less expensive to replace them by new ones than to resharpen
them by grinding or otherwise.
When one part of these cutters becomes blunted they may be taken out of their
holders and replaced so as to present another cutting part for use.
The mode which I prefer for securing these cutters to their holders is to form
their holders with a hole of a suitable taper, and the part of the cutter which is
made to enter this hole, with a corresponding taper so proportioned that when the
cutter is forced into its place in the holder it is firmly held there by it.
The pressure on the cutter when in use tends to keep it in the holder and when
necessary, it can be removed by a slight tap on its thin end.
The cutters may be made with any desired form of cutting edge.
To render the mode of carrying out this invention clearly understood, I annex
one sheet of drawings, in which like letters in each figure refer to like parts.
Figs. 1. 2 are side and front views of a cutter with a circular cutting edge a, the
centre part 6 is hollowed out to make the angle of the cutting edge sufficiently acute.
c is the tapered part whereby it is secured to the holder.
Figs. 3.4 are side and front views of a cutter formed with diamond shaped cutting
edges a. " is the tapered shank whereby it is secured to its holder.
Fig. 5, is a.side view of two circular edged cutters fixed into the end of a flat
sectioned bar d, entering the holes in the bar at opposite directions, so as to form
cutting points for a drill. The angle at which these cutters enter the bar d. may be
changed as desired.
Fig. 6. is a plan of Fig. 5.
Figs. 7. 8. are side and end views showing a diamond shaped cutter, a, fixed in a
holder h, suitable for fixing in a cutter-bar.
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. Making cutters of chilled cast iron, in the form and for the purpose substantially
as herein illustrated and described.
Dated this 28th day of September 1891.