Improvements in Tube Cutters.
Year: 1899

page_text: Date of Application, 16th Jan., 1899-Accepted, 18th Feb., 1899
Improvements in Tube Cutters.
I, BERNDT AUGUST HJORTH, of 5, Klara Norra Kyrkogata, Stockholm, in the
Kingdom of Sweden, Merchant, 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:-
In removing the tubes of steam-boilers it has heretofore been necessary to
loosen one end of the tube with a chisel and then compress it so as to dislodge
it from the tube plate and cause it to clear the inside of the latter, the tube
being subsequently twisted loose at the other end of the boiler and taken out
through the man-hole or cleaning-holes.
This operation, which is a very tedious and troublesome one, can be rapidly
performed in an easy manner with the present tool by means of which it is easy
to cut off the tubes to be taken out and replaced with new ones. The short
tube-end left in the plate can then be removed without difficulty on being
compressed by a few light knocks around it on its projecting shorn-off end. The
tubes proper are removed in the usual manner through the man-holes or cleaning-
holes.
In the accompanying drawing such a tube-cutter is illustrated, Figure 1 being
a longitudinal section,
Figure 2 an elevation, and
Figure 3a transverse section on line ab of Figure 2.
The tool is composed essentially of the following parts, viz. an adjustable
guide-ring d, d suitably composed of two parts inserted one within the other
so as to be shiftable with reference to each other, a sleeve f rotatably journalled
in the guide-ring, a ratchet-lever adapted to be rotated about the sleeve f and
provided with a pawl g engaging with a ratchet-wheel rigidly secured to the
sleeve f, an internally-threaded sleeve-nut i rotatably arranged at the outer
end of the ratchet-sleeve f, a sliding-piece wedge-shaped at its forward end and
provided with a screw or threaded spindle entering the sleeve-nut, and a sliding
support m for the circular cutter n, said support being movable in a recess,
suitably extending radially, at the inner end of the ratchet-sleeve.
In the form of the tool shown in the drawing the guide-ring consists of
rings d, coupled by means of a set-screw e, the outer one d of said rings
bearing on the tube plate c by means of an enlarged portion of suitable shape,
while the inner one d, on slackening the set-screw, may be adjusted and
secured by said screw in different positions, according to the thickness of the
tube plate, it being thus possible to so adjust the cutter that it will cut as close
to the inside of the tube plate as possible. During the cutting-operation the said
guide-ring remains stationary in contact with the boiler-end, while all other parts
of the tool are set into intermittent rotation when the ratchet-lever is oscillated
to and fro. The ratchet-lever with the ratchet wheel may of course be replaced
by any other suitable arrangement, for instance by a hand-wheel, but the
ratchet-motion described is especially suitable for effecting the rotation of the
tool in narrow places difficult to get at. The ratchet-lever g is retained in its
D
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page_text: place by means of a collar f' located on the outer end of the ratchet-sleeve.
Said sleeve is provided at its outer end with inside threads for receiving a
tubular piece 2 screwed into it and serving to retain in place the sleeve-nut i,
which is provided with a ring-shaped flange. At the inner end of the ratchet-
sleeve f there is a radial slot (Figures 2 and 3) for the slide m which is held in
place by an end-collar o secured by screws to the said end. Two symmetrically
arranged guide-rollers r serve for centering the tool and reducing the friction.
The feed-wedge of the slide m is composed of an obliquely-cut cylinder which
by means of an extension in the shape of a screw or threaded spindle enters the
sleeve-nut i and is provided on its plane portion with a longitudinal groove for
the dove-tailed flange of the slide m. The sleeve-nut i is provided at its outer
end with a hole for a pin (not shown in the drawing) by means of which the
sleeve-nut i can be independently rotated, the wedge being thereby shifted in
one direction or the other thereby compelling the slide m together with the cutter
to move correspondingly in a radial direction. During the rotation of the tool
by the aid of the ratchet-lever the rotary cutter consequently is fed into the
tube by independently rotating the sleeve-nut by means of the pin.
The details of the tool described may, of course, be varied in many ways with-
out departing from the leading idea of the invention. Thus, for instance, the
groove of the wedge may be replaced by a feather or the like entering in a
corresponding groove in the slide m; for the ratchet-lever may, as stated above,
be substituted other suitable arrangement, the adjustment of the guide-ring may
be effected in some other manner that that described, and so forth.
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:
An improved tube-cutter forming a combination of the following parts viz.
a sleeve (f) adapted to be rotated in an adjustable guide-ring (1) by means of
ratchet-lever and ratchet or the like a sleeve-nut (2) mounted in a threaded
portion at the end of the sleeve (f) and adapted to be rotated with the latter and
also to be independently rotated, a wedge (E) adapted to be shifted lengthwise in
the sleeve (f) and provided with a screw or threaded spindle engaging with the
threads of the sleeve-nut, and a sliding piece (m) provided with a cutting-disc (n)
and connected with the wedge (k) by means of a dove-tailed groove and flange,
said sliding piece being arranged to be moved in a radial slot in the sleeve (f),
when, by independently rotating the sleeve-nut, the wedge is shifted in relation
to the sleeve.
Dated this 16th day of January 1898
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.