A New or Improved Tool or Appliance to be used as a Tube Cutter.
Year: 1892

page_text: Date of Application, 28th Nov., 1892-Accepted, 31st Dec., 1892
COMPLETE SPECIFICATION.
A New or Improved Tool or Appliance to be used as a Tube Cutter.
I, HERBERT GRAHAM BELL, of 3, Wellington Terrace, Stockton-on-Tees, in
the County of Durham, Locomotive Manager, 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 :-
This invention relates to a tool or appliance to be used for cutting tubes, and is
especially applicable for cutting tubes when fixed in position, such as the flue tubes
of locomotive boilers, which are of small diameter and closely pitched together as
fixtures between two tube plates.
These tubes require to be removed from time to time when the boiler has to be
cleaned and examined, which operation when carried out by hand consists of first
staving the tube in at each end to get sufficient play in the tube hole to withdraw
first one end of the tube and then the other end; the damaged tube ends are then
cut off by a circular or hand saw. This operation results in injury to the tube
plates, the tube holes in which are liable to be enlarged and put out of shape each
time it takes place; in addition to which more time is absorbed in getting a tube
out than is afterwards required for cutting both ends off.
The object of my invention is to provide a portable tool or appliance by which
the tubes can be cut in the manner required before removal, the said tool or
appliance to be operated by hand or mechanical power according to circumstances.
In order that my invention may be fully understood and readily carried into
effect I will now proceed to describe the same by referring to the accompanying
drawings in which
Figure 1 illustrates my improved tube cutter as designed to be worked by hand,
with its several parts fitted together ready for use, corresponding to which
Figure 2 is a sectional view with the cutters withdrawn from the cutting position,
and
Figure 3 is a similar sectional view with the tool inserted into a tube and the
tube cut through.
Figures 4 and 5 illustrate the tube cutter as designed to be worked by machine
power.
Referring to Figures 1, 2, and 3, the tool consists of a hollow shaft a into which
is fitted a mandril 6 and spring backed cutters c. The cutters c are seated on and
secured to the springs c¹ by which they are kept in constant contact with the
mandril 6 whether wedged out to the cutting position or not. The part of the
mandril 6 is tapered so that as the mandril 6 is drawn into the shaft a in the direction
of the arrow the cutters c are gradually forced outwards, and when the mandril is
moved back in the opposite direction the resilience of the springs c draw the
cutters in again. In this way the cut is put on or withdrawn according as the
nut d is screwed round on the thread 62 in one direction or the other. In Figure 3,
e represents a tube plate, and e¹ a tube fixed therein to which a cut has been applied,
the cutters being shown in their extreme position with the tube cut through. a' is
an adjustable collar which is screwed up in any required position to form a shoulder
abutting against the tube to steady the tool in one position. The spiral grooves g
lead from each cutter c to the end of the hollow shaft a to serve as conveyors of
the material which is cut to waste. The nut d is intended to be turned by hand as
the feed is required to be applied or withdrawn. Although the tool is shown in
Figure 3 as making an accurate fit in the tube e', in practice this is not essential,
so long as the size of the tube does not exceed the reach of the cutters.
The part a is shown square to take the leverage of a ratchet fitted thereon for
working the tool by hand when such an appliance can be conveniently used, buit

page_text: where mechanical power is to be applied to the tool, as for instance by a flexible
shaft, I construct the tool as shown in Figures 4 and 5, the object being to enable
a flexible shaft or the like means for transmitting mechanical power to be attached
to the square part a² clear of the feed nut d. To effect this the feed nut d is
screwed onto the shaft a, and interlocks with the mandril 6 by means of a cottar f
working in slots f in the hollow shaft a, through which it extends into the cylindrical
space provided in the feed nut d, so that the rotation of the feed nut d imparts a
linear movement to the cottarf and adjusts the feed of the cutters c.
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 :-
-
Firstly A tool or appliance consisting of a mandril enclosed in a hollow shaft
in which it is laterally adjustable by means of a hand screw or its equivalent, so
that cutters inserted in openings in the hollow shaft may be wedged out to put a
cut on as the tool rotates, all combined, arranged, and operated together, substantially
as hereinbefore described with reference to the accompanying drawings.
Secondly-A tool or appliance, the several parts of which are combined,
arranged and operated together to be used as a tube cutter, substantially as
herein before described and illustrated in Figures 1, 2, and 3, of the accompanying
drawings.
Thirdly-A tool or appliance, the several parts of which are combined,
arranged and operated together to be used as a tube cutter, substantially
as hereinbefore described and illustrated in Figures 4 and 5 of the accompanying
drawings.
Dated this 26th day of November 1892.
G. J. CLARKSON,
Stockton-on-Tees, Agent for the Applicant.