Improved Method of and Means for Drilling Square or Polygonal Holes.
Year: 1890

page_text: Date of Application, 29th Aug., 1890
Complete Specification Left, 14th Oct., 1890-Accepted, 22nd Nov., 1890
PROVISIONAL SPECIFICATION.
Improved Method of and Means for Drilling Square or Polygonal
Holes.
We, JAMES MELLING, Engineer, and JOHN ROBERT HUGHES, Horological Mechanician
both of Dashwood House, New Broad Street, in the City of London, do hereby
declare the nature of this invention to be as follows:-
The object of our invention is to construct and apply a simple apparatus to an
ordinary lathe or milling machine, for the purpose of drilling square, triangular or
polygonal holes, and we effect this object by employing a rigid cutting tool, which
essentially differs in construction and application from any apparatus hitherto con-
structed and used for such purpose.
We
In carrying out our invention we fix the work upon the chuck of a lathe or milling
machine, and also place over the face which is to be drilled, a templet which is
pierced with a square or polygonal hole, the sides of which may or may not be
adjustable. The corners of the square or polygon are cut away for the purpose of
affording the requisite clearance so that the work is not clogged by cuttings.
use a bit or cutter, the section of the cutting edge thereof being preferably shaped
like the ace of spades upon an ordinary playing card. Said bit or cutter is passed
through the templet, and fed into the work by means of the back centre or poppet
head of the lathe or milling machine, or an equivalent device, and is kept rigid, and
prevented from rotating by a clip, carrier, hand vice, spanner or the like. Or in cases
where the lathe or milling machine is fitted with a saddle or slide rest, said bit or
cutter may be held firmly by the tool post or holder, and the feed communicated by
the hand or the automatic feeding mechanism.
The point, or cutting edge of the bit or cutter is adapted to the templet either by
making this adjustable, or by providing a separate templet for each size of bit or
cutter. Said templet in any case is furnished with screws or clips for attaching it to
the work which is to be operated upon.
We may modify the cross section of the bit or cutter to suit various circumstances
or conditions of its application but the chief feature of our invention is that a
templet or guide is attached to, and revolves with the work, while the bit or cutter
is rigidly held, and is simply fed into the work by the back centre or poppet head,
slide rest or saddle of an ordinary lathe milling machine or the like.
Datad this 90th day of August 1890
FREDK. WALKER,
11, Furnival Street, London, E.C., Agent for the Applicants.
COMPLETE SPECIFICATION.
Improved Method of and Means for Drilling Square or Polygonal
Holes.
We, JAMES MELLING, Engineer and JOHN ROBERT HUGHES, Horological Mechanician,
both of Dashwood House New Broad Street, in the City of London, 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:
The object of our invention is to construct, and apply a simple apparatus to an
ordinary lathe or milling machine for the purpose of drilling square or polygonal
holes, and we effect this object by employing a rigid cutting tool, so far as rotary
motion is concerned, but which may be fed inwards and is capable also of a slight

page_text: lateral movement. This method, and the means for applying it differs essentially
from any other appliance and the use thereof, hitherto employed for the purpose.
In order that our said invention may be clearly understood, we have appended
the accompanying sheet of drawings, in which
Figure 1 represents an elevation of the cutter or bit, with the templet in section.
Figure 2 is an end elevation of the same, drawn to a larger scale shewing the cutting
edge of the cutter or bit in section.
Figure 3 is an alternative device for cutting other polygonal holes, representing
an end elevation of the templet, and a cross section of the cutter or bit in situ.
Similar letters of reference indicate corresponding parts in the several views.
In carrying our invention into effect we attach the work upon or within the
chuck of a lathe or milling machine, and place over the face of said work which is to
be drilled a templet C, Figures 1, 2 and 3, which may be truly adjusted by means of
set screws a a¹ all a¹11, or an equivalent device. Said templet is provided with a
square or polygonal hole, the sides of which may be adjustable if necessary, so as to
reduce or enlarge the dimensions of the polygon or square-preferably, however,
we employ a separate templet for each cutter or bit, and cause this to be tempered
to resist abrasion or wear while in use. The corners of the square or polygonal hole
in the templet are provided with a certain clearance, 661 Figure 2 and also in
Figure 3, which represents a templet and cutter suitable for a hexagonal hole. Said
clearance prevents the clogging of the templet during the progress of the work, which
would cause the cutter or bit to break, or prevent the formation of clearly defined
corners in the polygonal hole. The cutter or bit A Figure 1 may be made of tool
steel of any suitable section, but the cutting portion B is formed in the manner
shewn by the cross section B Figures 2 and 3, which is similar to the ace of spades
upon an ordinary playing card. Said bit or cutter is passed through the square or
polygonal hole in the templet C, and being held by a carrier, driver, spanner or other
device to prevent rotation, it is fed into the work by means of the back centre D, or
poppet head of the lathe or milling machine, or in fact any adjustable fixed or
non-rotating centre that may be adapted to such machines. Such a centre may be
held firmly by the tool post or holder, upon the slide rest or saddle, and the feed may
be communicated by the hand screws, or by the ordinary automatic feeding
mechanism.
The cutting portion B of the cutter or bit A is adapted to fit freely within the
orifice in the templet C by either providing adjustable or sliding sides to the polygonal
hole, as hereinbefore referred to, or by providing a separate templet for use with each
size of bit or cutter.
We may modify the cross sectional formation of said bit or cutter to meet the
requirements of different circumstances of application, but in all cases thereof,
according to our present invention, the templet C is constructed so as to be attached
to the work to be drilled, and adjusted truly thereupon, and revolves with said work,
the bit or cutter A B being held, and capable only of the necessary feeding motion,
and of the lateral movement upon the fixed centre hereinbefore described.
In this manner, and by these means a square or polygonal hole may be drilled
through, or partially through any piece of metal or any other substance with the same
ease and facility as a round hole is drilled in a lathe or milling machine, and the
simplicity of the device comprised by the bit and templet renders it a useful adjunct
to a lathe or milling machine outfit.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is ;-
First. In a device for drilling square or polygonal holes by means of a lathe or
milling machine, the combination of a templet with a bit or cutter A. B. substantially
as described, with reference to the drawings.
Second. In a device for drilling square or polygonal holes, the combination of a
templet which revolves with the work to be drilled, and is adjustable thereupon,

page_text: with a bit or cutter A. B. which does not revolve but is fed by a centre D, substantially
as described and with reference to the drawings.
Third. In a device for drilling square or polygonal holes the combination of a
templet C with clearance at the corners, 6 61 61 6 Figures 2 and 3, with a bit or
cutter shaped as shown by the cross section B, substantially as described and shewn
by the appended drawings.
Dated this 13th day of October 1890.
FREDK. WALKER,
11, Furnival Street, Holborn, E.C., Agent for the Applicants.