Improved Means for Undercutting or Forming Dowel Holes in Wood, Metal, or other Material.
Year: 1888

page_text: Date of Application, 2nd Oct., 1888
Complete Specification Left. 2nd July. 1889-Accepted, 7th Sept., 1889
PROVISIONAL SPECIFICATION.
Improved Means for Undercutting or Forming Dowel Holes in
Wood, Metal, or other Material.
DAVID CLOHESY, 43 Edward Street, Limerick, Ireland, Stone-cutter carver. do
hereby declare the nature of this invention to be as follows:-
A centrifugal' boring drill, so constructed that, after the entrance to any substance
whatever has been effected in the form of a hole of any required size, the drill expands,
by a contrivance within the borer & under perfect control of the operator or original
motive power that made the entrance & thus an enlarged interior cavity of circular or
conical form can be hollowed out-into which, if molten metal or cement of any
nature be poured, it is so held by the surrounding substance as to be impossible_of
extraction.
ديو
1000
Per pro J. T. KING,
J. Johnson,
A gent
COMPLETE SPECIFICATION.
Improved Means for Undercutting or Forming Dowell Holes in
Wood, Stone, Metal, or other Material.
[DAVID CLOHESY 43 Edward Street Limerick Ireland Stone Cutter and Carver,
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:-
Hitherto great difficulty has been experienced in cutting holes in stone and other
materials larger in diameter internally than at the surface especially where such
holes had to be cut in angles and like positions where room for working was
limited.
The object of my invention is to provide means for cutting holes such as above
mentioned readily and with certainty so that bolts or other contrivances inserted in
the said holes may be effectually held therein when surrounded by cement or
suitable binding agent.
Means under my invention for undercutting or forming dowell holes consists of a
centrifugal or rotating drill having pivotted or jointed thereto a cutting tool holder so
disposed that the distance of the cutting tool from the centre of rotation may be
varied at will.
In order that my invention may be readily understood I have appended a sheet of
drawings illustrative thereof.
Figs. 1 and 2 are side elevations at right angles to each other of my improved
apparatus. a is the drill. lever pivotted to the drill a at c. d cutting tool formed
with the said lever or attached thereto in any usual inanner. e set screw passing freely
through one end of the lever into the drill shank. As the hole is being drilled the set
screw is turned so as to draw the end of the lever towards the drill sbank and move
the cutting tool d away from the centre of rotation. According to the speed and
time of movement of the cutting tool outwards so will the shape of the hole vary.
Figs. 3, 4, 5, 6 and 7 show some of the shapes which may be made. The apparatus
above described may be used for shaping holes after they have been formed by drills
of any usual construction.
It will be obvious that many mechanical devices may be used to give the desired
motion to the cutters d without departing from my invention and that the drill may
have a movable or detachable point or cutting edge.

page_text: Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is.
First. Means for undercutting or forming dowell holes substantially as herein
setforth.
Second. The combination of a drill with a cutting tool holder substantially in the
manner and for the purpose setforth.
Dated this 1st day of July 1889
Per pro J. T. KING,
J. Johnson,
Agent.