An improved Tube-plate Hole-cutter.
Year: 1894

page_text: Date of Application, 2nd Feb., 1894-Accepted, 3rd Mar., 1894
An improved Tube-plate Hole-cutter.
1, THOMAS WILLIAM FELTON, of Addington in the Provincial District of
Canterbury and Colony of New Zealand, Government Workshops Manager, do
hereby declare the nature of my invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
5 statement:-
This invention relates to a very simple tool for cutting tube holes in boiler
tube-plates. The following are some of its advantages and capabilities.
17 Simplicity of construction; no complicated parts to get out of order.
2.) Absolute accuracy in its work; (an important item in tube-plate drilling.)
3.) Marking off the work entirely superseded.
4.) No centring required; consequently "drawing" the centre, (a most expensive
and slow process) abolished.
5.) Multiple drilling made possible and easy.
6.) Skill in working reduced to the lowest limit.
66
CAPABILITIES WITH A "SINGLE" DRILL.
Copper-plate," five eighths of an inch (8") thick ninety seven holes, one and
three quarters of an inch (14") in diameter per hour.
"Steel plate," same thickness, thirty seven holes of same diameter per hour.
"Lowmoor plate," same thickness, thirty six holes of same diameter per hour.
No tool that I am aware of at present is sufficiently simple in its construction as
to enable six or eight drills to be run at the same time by one man.
Now this can be accomplished by the use of my improved cutter.
Briefly my improved cutter consists of a tube or barrel enclosing a spiral spring
aud moveable centre, and having a tubular cutter screwed to the lower end; the
upper end being screwed to a socket having a stem fitting the machine.
In order that my invention may be more easily understood I will now proceed
to describe the same, and for that purpose shall refer to the annexed sheet of
drawings illustrating same wherein :
Fig. 1 is a view of my improved cutter drawn half in section and half in
elevation.
Fig. 2 is a view of the spiral spring, while
Fig. 3 is a section of cutter through line A. B.
C is the tube or barrel into the lower end of which the tubular cutter D is.
screwed; this cutter has four vertical slots or openings a forming the end of cutter
into four distinct cutting edges. The centre E is placed inside the tube or barrel C
from the top side, the shoulder 6 fitting a corresponding rim c inside said tube
or barrel; the bottom point of said centre projecting beyond the face of cutter.
The spiral spring F (Fig. 2) is then placed inside the tube or barrel C above the
said centre.
The upper and larger part of the centre E has a vertical groove (shown by dotted
lines) into which the end of a screw d is inserted through the tube or barrel C, to
prevent the said centre turning independently of the cutter during its action.
The upper end of the tube or barrel C is screwed into the socket G, a flange

page_text: being formed on said tube or barrel to make a butt joint; this socket has a tapered
stem e fitting the machine which operates the tool.
The socket G is made detachable to enable the centre E and spiral spring F to
be inserted in the tube or barrel C and also that sockets having different sized
stems to suit different machines may be used.
It will be readily seen that when the pressure is applied by the machine to which
the tool is attached, the spiral spring F allows the centre E to recede until the face
of the cutter D comes in contact with the plate to be cut, and also enables the
said centre to support the said cutter during the whole process of cutting. The
improved cutter can of course be made different sizes according to requirements.
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
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The general combination and arrangement of parts constituting my improved
tube-plate hole-cutter" consisting of the tube or barrel C the tubular cutter D,
the centre E, the spiral spring F and the socket G substantially as hereinbefore
described and illustrated in the annexed drawings.
Dated this 23rd day of December A.D. 1893.
THOMAS WILLIAM FELTON.