Improvements in Machinery or Apparatus for Drilling Square or other Shaped Holes, also applicable to Shaping Nuts or other Operations of the like kind.
Year: 1891

page_text: Date of Application, 4th July, 1891
Complete Specification Left, 4th Apr., 1892-Accepted, 4th July, 1892
PROVISIONAL SPECIFICATION.
Improvements in Machinery or Apparatus for Drilling Square or
other Shaped Holes, also applicable to Shaping Nuts or other
Operations of the like kind.
I, ARTHUR PICKARD, of 62, Leadenhall Street, in the City of London, Engineer,
do hereby declare the nature of this invention to be as follows:-
My present invention relates to drilling machinery or apparatus by which square
or other shaped holes may be drilled or the sides of square or other nuts shaped, or
other operations of the like kind effected.
My present invention may be applied to different kinds of drilling machines, but
supposing it to be applied to a hand drilling machine by which square holes are to
be drilled, I arrange upon the frame or standard of the machine à bevilled toothed
wheel of suitable size and strength, turning upon a centre and having a handle or
wheel by which it can be made to revolve.
This toothed wheel gears with and drives another bevilled toothed wheel which
drives a vertical bar turning in bearings in the frame, and provided with means by
which it can be fed downward as the depth of the hole which is being drilled
increases.
The lower end of this revolving bar is provided with a flange or disc at right
angles to it against the lower face of which a frame, which carries the device here-
inafter described is held by a central screw having a large flat head or disc, between
which and the disc at the end of the bar the frame fits freely. The frame is
provided with an arm projecting laterally which is engaged by a corresponding pin
or crank extending downward from the lower side of the horizontal bevilled wheel
already described, so that as the latter is turned round it causes the frame also to
revolve, and as the hole through the latter is made of considerably larger size than
the central disc which holds it to the flange of the revolving bar, the frame can
not only turn round but can also move for a sufficient distance laterally in any
direction.
To the lower side of the moveable frame described is firmly fixed the upper end
of a cylindrical bar of sufficient length, to the lower end of which the drilling tool,
or cutter is fixed. Upon the cylindrical bar are fixed a sufficient number of guiding
discs or plates of the kind hereinafter described, which fit and revolve with the bar
inside a square tubular guide of sufficient length. This guide is held or fixed so
that it cannot turn round, and consequently when the frame carrying the cylindrical
bar and guiding plates is made to revolve by the means first described, the latter
are guided by the square guide in such a manner that the cutting tool below cuts
a square hole or a hole of other desired shape which may be continued to any
desired depth by screwing down the revolving bar as first described.
The shape of the guiding discs or plates upon the cylindrical bar is determined
as follows:-
Three circles are first described, their centres being the angles of an equilateral
triangle of a size depending upon the size of the square hole required. The peripheries
of the circles are connected together at two sides by a straight line tangential to
them, whilst at the third side they are connected by a curved line consisting of
a segment of a circle struck from one of the triangle points.
The position of the edge of the cutting tool below is so arranged that its
cutting point corresponds with the centre of the circle opposite to the rounded
side which connects the peripheries of the other two circles as described..
By varying the size of the equilateral triangle from the angles of which the three
circles are described, as explained above, the size of the square hole to be drilled

page_text: can be varied the size of the hole decreasing as the triangle decreases and the
radius of the circles increases.
In order that the hole may be perfectly square and its corners sharp, I arrange
above or below or between the square guides one or more similar secondary guides
at an angle of 45 degrees to the former ones, the corners of the former square
corresponding with the centre of the sides of the secondary one, and upon the
bar which carries the guiding plates first described I fix one or more guiding plates
which work in the secondary squares, these last described plates being fixed directly
above the curved line which connects two of the circles in the original guiding
plates as already described.
The guiding plates which work in the secondary square or squares are suitably
curved at their outer edges so that they remain in contact with the edges of the
outer square, and in this way a perfect movement of the drilling bar is obtained
without play or shake, and perfectly square holes are drilled.
Instead of forming a complete square, the secondary guiding square may consist
only of four plates of sufficient length adjoining the angles of the first square.
Or instead of plates, four fixed rollers may be used the peripheries of which
correspond with the parts of the secondary square against which the guiding plate
works. Or, instead of rollers, four fixed points similarly arranged may be used.
In a modified form I do not use the secondary square guides, but I determine
the shape of the guiding dises or plates upon the cylindrical bar as follows :-
Three circles are first described, their centres being the angles of an equilateral
triangle of a size depending upon the size of the hole to be drilled and the' circles
being of such diameter that they together fill the square tubular guide.
The peripheries of two of the circles are connected together by a curved line
forming a segment of a circle struck from a centre where the two circles to be
connected cut one another at the other side of their peripheries.
This curved line after touching the peripheries of the circles which it connects,
is carried on until its ends meet two similar curved lines struck respectively from
the other two angles of the triangle.
The peripheries of the two circles described are connected with' that of the
third circle by curves struck from the point of intersection of the extended curves
described.
The three circles are therefore connected at their peripheries by curved lines
which outside two of the circles are continued forward and meet so as to form
pointed projections, whilst the outer periphery of the third circle remains without
such projection.
The position of the cutting edge of the cutting tool below is preferably so arranged
that its cutting point corresponds with the centre of the circle last described.
Different sized and shaped holes may be produced by altering the position of the
cutting edge.
When the bar with the guiding plates shaped as described is made to revolve in
the square tubular guide, the cutting edge below will cut a square hole in any work
fixed below, and the corners of such square hole will be sharp and not 'rounded and
the guiding plates will fit in the square guide in every position without play.
The square tubular guide may be formed in a plate or bar which may be carried
upon the vertical support of the machine.
Where deep holes have to be drilled, the drilling bar may be made to pass
through guiding plates or cams formed as described, which are retained 'in their
position in the square guide without moving down, the drill bar passing through
them but being prevented from turning round by a longitudinal key or feather
passing through the guiding plate, or equivalent means.
I am aware that square holes have been made somewhat in the manner described
by the use of guiding plates or discs all the three sides of which connecting the
circles have been made curved, but it has been found impossible to cut holes truly
square and without rounded corners, with guiding plates or discs so shaped.
The details of the apparatus may be varied more or less. For instance instead

page_text: of a cylindrical bar having the guiding plates or discs fixed upon it as above
described, the bar itself. may be made of a shape in cross section similar to that
described. Or instead of this the bar may be cylindrical but having an arm pro-
jecting from it which arm is guided by a cam of the required shape.
Where it is desired to drill a triangular hole instead of a square one, I use
elliptical guiding plates revolving in a hollow triangular guide, the edge of the
cutting tool being arranged in a line corresponding with the longer diameter of the
ellipse.
Where polygonal holes are to be drilled, the centres of the circles, instead of
forming an equilateral triangle, form an isosceles triangle, the base of which is
reduced in length as the number of sides of the hole to be drilled increases.
The triangle is formed by connecting the ends of one of the sides of the polygon
with the centre of the opposite side, and the sides of the triangle whose angles form
the centres of the circles are made parallel with the triangle thus obtained, but of
a size dependent upon the size of the hole which is to be drilled. Where polygonal
holes of an uneven number of sides are to be drilled, the guiding triangle is formed
by connecting the ends of one of the sides of the polygon with the opposite angle,
and the projecting points formed by the extension of the curves connecting the
circles are omitted. In all cases the guiding plates revolve in a guide having as
many sides as the hole to be drilled.
By my invention perfectly shaped holes are drilled and the drill is steadily and
evenly guided without play during the operation.
Dated this 2nd if J. 1001
EDWARDS & Co.,
35, Southampton, Buildings, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Machinery or Apparatus for Drilling Square or
other Shaped Holes, also applicable to Shaping Nuts or other
Operations of the like kind.
I, ARTHUR PICKARD, of 62 Leadenhall Street, in the City of London, 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, that is to say :-
My present invention relates to drilling machinery or apparatus by which square
or other shaped holes may be drilled or the sides of square or other nuts shaped,
or other operations of the like kind effected.
My present invention may be applied to different kinds of drilling machines, but
supposing it to be applied to a hand drilling machine by which square holes are
to be drilled as illustrated in Figure 1 of the accompanying drawing, 1 arrange
upon the frame or standard á of the machine a bevilled toothed wheel of suitable
size and strength, turning upon a centre and having a handle or wheel e by which
it can be made to revolve.
This toothed wheel gears with and drives another bevilled toothed wheel d which
drives a vertical bar e turning in bearings in the frame, and provided with means
by which it can be fed downward as the depth of the hole which is being drilled
increases (as shewn at f).
The lower end of this revolving bar is provided with a flange or disc g at right
angles to it against the lower face of which a frame h which carries the device
hereinafter described is held by a central screw i having a large flat head or disc,
between which and the disc at the end of the bar the frame fits freely. The frame
is provided with an arm projecting laterally which is engaged by a corresponding
pin or crank k extending downward from the lower side of the horizontal bevilled
wheel d already described, so that as the latter is turned round it causes the frame

page_text: also to revolve, and as the hole through the latter is made of considerably larger
size than the central disc which holds it to the flange of the revolving bar, the
frame can not only turn round but can also move for a sufficient distance laterally
in any direction. The bare need not necessarily.revolve.
To the lower side of the moveable frame described is firmly fixed the upper end
of a cylindrical bar of sufficient length, to the lower end of which the drilling tool,
or cutter m is fixed. Upon the cylindrical bar are fixed a sufficient number of
guiding discs or plates of the kind hereinafter described, which fit and revolve with
the bar inside a square tubular guide of sufficient length n, n'. This guide is held
or fixed so that it cannot turn round, and consequently when the frame carrying
the cylindrical bar and guiding plates is made to revolve by the means first
described, the latter are guided by the square guide in such a manner that the
cutting tool below cuts a square hole or a hole of other desired shape which may
he continued to any desired depth by screwing down the revolving bar e as first
described.
The shape of the guiding discs or plates upon the cylindrical bar is determined
as follows, (see Figure 1).
Three circles are first described, their centres being the angles of an equilateral.
triangle of a size depending upon the size of the square hole required. The
peripheries of the circles are connected together at two sides by a straight line
tangential to them, whilst at the third side they are connected by a curved line P
consisting of a segment of a circle struck from one of the triangle points.
The position of the edge of the cutting tool below is so arranged that its
cutting point corresponds with the centre of the circle opposite to the rounded side
which connects the peripheries of the other two circles as described.
By varying the size of the equilateral triangle from the angles of which the
three circles are described, as explained above, the size of the square hole to be
drilled can be varied the size of the hole decreasing as the triangle decreases and
the radius of the circles increases.
In order that the hole may be perfectly square and its corners sharp, I arrange
above, or below, or between the square guides one or more similar secondary guides
at an angle of 45 degrees to the former ones, the corners of the former square
corresponding with the centre of the sides of the secondary one, and upon the bar
which carries the guiding plates first described I fix one or more guiding plates
which work in the secondary squares, these last described plates being fixed
directly above the curved line which connects two of the circles in the original
guiding plates as already described.
The guiding plates which work in the secondary square or squaress are
suitably curved at their outer edges so that they remain in contact with the edges
of the outer square, and in this way a perfect movement of the drilling bar is
obtained without play or shake, and perfectly square holes are drilled.
Instead of forming a complete square, the secondary guiding square may consist
only of four plates of sufficient length adjoining the angles of the first square.
Or instead of plates, four fixed rollers may be used the peripheries of which
correspond with the parts of the secondary square against which the guiding
plate works. Or, instead of rollers, four fixed points similarly arranged may
be used.
In a modified form I do not use the secondary square guides, but I determine the
shape of the guiding discs or plates upon the cylindrical bar as follows (see
Figure 2): :-
Three circles are first described, their centres being the angles of an equilateral
triangle of a size depending upon the size of the hole to be drilled and the circles
being of such diameter that they together fill the square tubular guide.
The peripheries of two of the circles are connected together by a curved line
forming a segment of a circle struck from a centre where the two circles to be.
connected cut one another at the other side of their peripheries.

page_text: .. This curved line after touching the peripheries of the circles which it connects,
is carried on until its ends meet two similar curved lines struck respectively from
the other two angles of the triangle.
The peripheries of the two circles described are connected with that of the third
circle by curves struck from the point of intersection 1 and 2 of the extended
curves described.
The three circles are therefore connected at their peripheries by curved lines
which outside two of the circles are continued forward and meet so as to form
pointed projections, whilst the outer periphery of the third circle remains without
such projection.
The position of the edge of the cutting tool below is preferably so arranged
that its cutting point corresponds with the centre of the circle last described.
Different sized and shaped holes may be produced by altering the position of the
cutting edge.
When the bar with the guiding plates shaped as described is made to revolve in
the square tubular guide, the cutting edge below will cut a square hole in any
work fixed below, and the corners of such square hole will be sharp and not
rounded and the guiding plates will fit in the square guide in every position without
play.
The square tubular guide may be formed in a plate or bar which may be carried
upon the vertical support of the machine.
Where deep holes have to be drilled, the drilling bar may be made to pass
through guiding plates or cams formed as described, which are retained in their
position in the square guide without moving down, the drill bar passing through
them but being prevented from turning in them by a longitudinal key or feather
passing through the guiding plate, or equivalent means, as illustrated in Figure 1ª
at n n¹.
I am aware that square holes have been made somewhat in the manner described
by the use of guiding plates or discs all the three sides of which connecting the
circles have been made curved, but it has been found impossible to cut holes truly
square and without rounded corners, with guiding plates or discs so shaped.
The details of the apparatus may be varied more or less. For instance, instead
of a cylindrical bar having the guiding plates or discs fixed upon it as above
described, the bar itself may be made of a shape in cross section similar to that
described. Or instead of this the bar may be cylindrical but having an arm
projecting from it, which arm is guided by a cam of the required shape.
Where it is desired to drill a triangular hole instead of a square one (see
Figure 3) I use elliptical guiding plates to revolving in a hollow triangular guide f
the edge of the cutting tool being arranged in a line corresponding with the longer
diameter of the ellipse.
Where polygonal holes are to be drilled (see Figure 4), the centres of the circles,
instead of forming an equilateral triangle, form an isosceles triangle, the base of
which is reduced in length as the number of sides of the hole to be drilled
increases.
The triangle is formed by connecting the ends of one of the sides of the polygon
with the centre of the opposite side, and the sides of the triangle whose angles form
the centres of the circles are made parallel with the triangle thus obtained, but of
a size dependent upon the size of the hole which is to be drilled. The circles are
connected by curved lines as shewn. Where polygonal holes of an uneven number
of sides are to be drilled, the guiding triangle is formed by connecting the ends of
one of the sides of the polygon with the opposite angle, and in polygons the pro-
jecting points formed by the extension of the curves connecting the circles are
omitted.
In all cases the guiding plates revolve in a guide having as many sides as the
hole to be drilled.
By my invention perfectly shaped holes are drilled and the drill is steadily and
evenly guided without play during the operation.

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 :-
1. In machinery or apparatus for drilling square or other polygonal holes, or
shaping nuts or other operations of the like kind, the methods of determining the
shape of guiding plates carried by the drill and working in guides having as many
sides as the hole to be drilled substantially as herein described.
2. In combination with the drill spindle having guiding plates formed as
described in Claim 1 and working in guides the method of driving such drill spindle
by means of a bar carrying a flange or disc and a frame which carries the drill
spindle and is held by a central screw having a large flat head or disc between
which and the disc at the end of the revolving bar the frame fits freely substantially
as described.
Dated this 4th day of April 1892
:
EDWARDS & Co.,
35, Southampton Buildings, London, Agents for the Applicant.