An Improved Tool-holder or Cutter-bar.
Year: 1890

page_text: Date of Application, 3rd June, 1890
Complete Specification Left, 2nd Mar., 1891-Accepted, 4th Apr., 1891
PROVISIONAL SPECIFICATION.
An Improved Tool-holder or Cutter-bar.
1, ROBERT WILLIAM PAUL, of Frith Knowl, Elstree, in the County of Hert-
fordshire, Electrician and Instrument Maker, do hereby declare the nature of this
invention to be as follows:-
My invention consists of an improved tool-holder or cutter bar for use in turning,
planing, etc., in place of the usual forged tools. The disadvantages of the cutter
bars in ordinary use for these purposes, which are obviated by this invention are
that they are usually capable of outside work only, whereas mine may be used
for either inside or outside work; that the cutter has to be removed from the stock
for sharpening whereas in this bar the cutter may be sharpened like an ordinary
lathe tool that the means for clamping the cutter are inefficient and clumsy,
involving the use of loose parts liable to get lost, that they require cutters of
special section, whereas this invention requires only the ordinary square steel.
There are other advantages incidental to this invention.
A
In order to carry out the invention 1 employ a metal stock of cast or wrought
iron which carries a removable boring bar at one end and the cutter for outside
work at the other. The stock may be of square section, thickened and bent down
at an angle with the length of the stock at the latter end. A square hole is formed
near this end, at an angle of about 55° with the length of the stock, and in this a
square cutter is placed so that it tilts forward and its cutting edge is clear of the
stock and is there clamped by an eccentric which may be formed as follows.
hole is drilled at right angles to the square hole and partly opening into it, the
hole being drilled from side to side of the stock and behind the square hole.
round steel pin with one end projecting and bearing a square head for convenience
in turning is fitted into the hole and has a groove cut round the middle of its length
but eccentric to the axis of the pin. When the pin is turned so that the deeper
part of the groove is in front, a clear passage is left through the square hole, but
when further turned the pin partly closes that hole and therefore clamps a cutter
previously placed therein. Moreover any downward pressure on the cutting point
tends to further turn the eccentric and tighten the grip.
A
The opposite end of the stock has a hole drilled up lengthwise and a lug formed
near the end at one side. A saw kerf is made down that side of the bar
and a setscrew through the lug enables the hole to be contracted slightly so as to
clamp a parallel steel bar fitting the hole, enabling the projecting part to be
lengthened or shortened. The distal end of the bar carries a small cutter formed
preferably to steel wire and fixed in a hole at an angle with the axis of the bar
by means of the following device. A hole is drilled at right angles with the first
and with the axis of the bar and tapered to fit a taper pin, which when driven
home projects slightly into a notch in the cutter and thus fixes it firmly. Or I may
use ether means as for example eccentrics or setscrews for clamping in either of the
above cases.
The boring bar may be removed when not in use and the tool may
be made with one cutting end only.
For turning the eccentric and setscrew I provide a steel spanner one end of
which forms a gauge for setting and grinding the cutters to the correct angles.
Dated this 3rd day of June 1890.

page_text: COMPLETE SPECIFICATION.
An Improved Tool-holder or Cutter-bar.
1, ROBERT WILLIAM PAUL, of Frith Knowl, Elstree, in the County of Hert-
fordshire, Electrician and Mechanician, 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 invention consists of an improved tool-holder or cutter-bar for use in turning,
planing, boring, etc., the object of which is to firmly hold tools or cutters in the
best position for acting on the work, either on its outside, as in turning, or on its
inside as in boring, while the cutters shall be readily ground without removal from
the holder or stock if required, and shall be easily replaceable.
In order to carry out my invention 1 employ a metal stock of suitable shape
for clamping in the tool-post of the lathe or in whatever position it may be used,
and carrying a tool for outside work at one end and for inside work at the other.
The tool for outside work may consist of a piece of steel of suitable form,
preferably clamped by means of a special form of cam, so as to be adjustable in
height when the stock is placed horizontally, as in turning. The stock may be
perforated longitudinally from the opposite end to receive a tool for inside work
and provided with a means of clamping it in such a way that only the required
length of the same projects, thus saving unnecessary spring in the tool when in
use. This tool may be forged in one piece or preferably consists of a round bar
in which is inserted a cutter, the latter being firmly clamped to the former. I
may also use the clamping devices hereinafter described in tool-holders for inside
work only, or for outside work only.
In order that the method of carrying out my invention may be better under-
stood I will describe the accompanying drawings illustrating the same.
Fig. 1 shows a side view of a tool-holder or cutter-bar constructed according to
my invention in the position in which it would be used for turning ;
Fig. 2 shows a plan of the same when in the same position;
Fig. 3 shows a plan of the same in the position in which it would be used for
boring or internal work.
In these figures A is a stock of square section thickened and cranked downwards
at one end and provided with a splitting B at the other. The former end has a
hole in it placed at an angle of about 55° with a horizontal line and shown
square in the drawings and containing the tool or cutter for outside work D. This
is clamped by the cam E, which carries a square at one end for convenience in
turning, though tommy-holes or other convenient means of turning may be used.
The form of the cam is more clearly seen in Fig. 5 which shows near the middle
of its round portion a groove which is turned excentric to its main axis. When
the cam is placed in position in a hole formed to receive it at right angles to the
square hole and opening into it, it either allows the cutter to be placed in position
freely when the deepest portion of the excentric groove is turned towards the
tool, or on further turning by means of a key or spanner applied to the square
head it clamps the cutter firmly on the higher portion of the groove; and being
so arranged that the excentric groove is never turned so far as to bear on the tool
at its dead centre, any pressure on the point of the tool tends to draw round the
cam, thus further tightening the tool in position. I do not confine myself to tools
of square section, they may be round as in Fig. 6 if required. A hole is drilled
in the other end of the stock A as shown in dotted lines in Fig. 1 and in this hole
slides the bar C which may be drawn out to suit the length of the hole to be
bored and clamped, firmly by tightening the setscrew F, which causes the stock A
to firmly grip the bar C, the stock A having a longitudinal saw-cut down one side
to give the necessary amount of spring. The other end of C carries the cutter (
placed in a hole which is preferably at an angle with the bar C so as to cause the
point of the cutter G to project beyond its end; the cutter G as shown in Fig. 7

page_text: has one or more notches in one or both sides and when placed in position one of
these being opposite to a small hole in the bar C at right angles to the cutter &
a taper pin H fitting both hole and notch, is firmly clamped so that it can neither
turn nor slide out, and wear is allowed for by enabling the cutter to be drawn
out further and refixed. The cutter G may be of any form required but preferably
consists of a piece of round steel wire or rod for convenience of renewal; it may
be clamped by a setscrew or other means than that described if preferred or may
be in one piece with the bar as shown in Fig. 4.
When required the cutter D and clamping device E substantially as shown
may be employed in combination with a suitable stock alone, or the form of boring
tool shown at C, G, H may be used in combination with the clamping device
substantially as described and shown at B, F, and a suitable stock alone, or the
method shown at G, H, of clamping a cutter may be used in an independent stock
if desired.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. In a tool-holder or cutter-bar the combination of tools for outside and inside
work in one stock.
2. The method of clamping a tool or cutter substantially as described with
reference to Figures 1, 2, 3 and 5 of the accompanying drawings.
3. The method of clamping an adjustable boring tool in a hollow stock or shank
substantially as described with reference to Figures 1, 2 and 3 of the accompanying
drawings.
4. The method of clamping a removable cutter in a bar by means of a pin and
notch substantially as described with reference to Figures 1, 2, 3 and 7 of the
accompanying drawings.
5. The tool-holder or cutter-bar substantially as described.
Dated this Second day of March 1891.
ROBERT W. PAUL.