A Method of Securing Tubes in Plates, and Apparatus for Preparing the Holes to Receive and Hold the Tubes.
Year: 1890

page_text: Date of Application, 15th Jan., 1890
Complete Specification Left, 17th Nov., 1890-Accepted, 20th Dec., 1890
PROVISIONAL SPECIFICATION.
A Method of Securing Tubes in Plates, and Apparatus for
Preparing the Holes to Receive and Hold the Tubes.
I, DAVID JONES, of Lochgorm Works, Inverness, in the County of Inverness,
Mechanical Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention has reference to a method of securing tubes in plates such as tube
plates of boilers, condensers and vacuum apparatus; also to apparatus for preparing
the holes in the plates to receive and hold the tubes.
To prepare a hole in a plate to receive and hold a tube I form in the wall or metal
surrounding the hole an annular groove or grooves of rounded or V shape, or impart
to the said wall a concave or convex shape as seen in section in a plane containing the
axis of the hole; and after the end of the tube has been inserted in the hole so
prepared I securely fix the tube in the hole by expanding or swelling the tube by
means of a suitably formed tube expander whereby the tube is made to conform
to and tightly fit the prepared hole. The end of the tube so secured may be beaded
over.
In some cases it may be found convenient to reduce one or both ends of a tube in
diameter to enable smaller holes to be used and more metal to be left between the
holes in the tube plate. Or one end of a tube may be so reduced in diameter, and
the other end be expanded to a greater diameter than that of the main part of the
tube. In this way the insertion of a tube in the holes of two tube plates will be
facilitated. One or both ends of a tube may be secured in the manner hereinbefore
described.
An apparatus according to my invention for preparing holes as above referred to
comprises a spindle or cutter holder (hereinafter called the holder) adapted to be
secured to the tool spindle of a drilling or boring machine. The holder is made with
a slot wherein is pivoted a lever having at one end a cutting edge the form of which
will depend on the grooved concave or convex shape to be imparted to the hole. This
cutting edge is normally within a recess formed in a reduced part of the holder which
part is of such a diameter as to fit an unprepared hole in a tube plate. In the
reduced part of the holder is a groove or recess for the escape of the metal removed
from the tube plate by the cutting edge. A screw jointed to one arm of the lever
and fitted with a nut arranged to work against a stop or abutment through which the
screw passes, serves as a convenient means for causing the cutting edge to project
sufficiently through the reduced part of the holder to cut the metal wall of the hole
to the required form when the holder is rotated in the proper direction. A spring
attached to the lever and to the stop or abutment serves to return the cutting edge
within the reduced part of the holder when the nut is turned in the reverse
direction.

page_text: COMPLETE SPECIFICATION.
A Method of Securing Tubes in Plates, and Apparatus for
Preparing the Holes to Receive and Hold the Tubes.
I, DAVID JONES, of Lochgorm Works, Inverness, in the County of Inverness,
Mechanical 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 :-
:―
This invention has reference to the hereinafter described method of securing tubes
in plates such as tube plates of boilers, condensers and vacuum apparatus; also
to apparatus for preparing the holes in the plates to receive and hold the tubes.
Referring to the accompanying drawings,
Fig. 1 shows in section parts of two tube plates 1 and 2 and a tube 3 secured
therein. The wall or metal surrounding each hole has formed in it an annular
groove 4 into which part of the metal of the tube is expanded or swelled by a tube
expander. The inner circular edge at each end of the tube is left square, and the
outer edge is beaded over onto the tube plate as shown at 30 and 3b.
The tube is reduced in diameter at one end to enable it to be more readily passed
into position through the tube plates and also in order to leave more metal between
the holes in the tube plate 1.
Fig. 2 is a similar view to Fig. 1 but showing the tube not only reduced in
diameter at one end 3 but also expanded at the other end 3d to a larger diameter
than that of the intermediate part of the tube.
Fig. 3 shows the tube reduced in diameter at the one end 3° only, this end being
secured in the tube plate 1 in the same manner as hereinbefore described with
reference to the tubes shown in Figs. 1 and 2. The other end 3d of the tube is
secured in the tube plate 2 by slightly expanding it in the ordinary manner,
but so that it retains approximately the same diameter as the intervening part of
the tube.
Fig. 4 shows partly in side elevation and partly in longitudinal section; and Fig. 5
partly in end elevation and partly in cross section, a tube expander suitable for
expanding the ends of the tubes into the grooves 4 in the tube plates and for beading
over the ends of the tubes. This tube expander comprises three segmental blocks 5
held within two rings 6 and mounted upon a tapered mandrel 7 by which they can be
expanded and rotated. Each block is formed with an external curved ridge or
projection 8 adapted to expand or swell the metal of the tube into one of the annular
grooves 4 in the tube plate, and with a flange 9 so curved at one side as to cause the
projecting end of a tube to be beaded over to the required form when rotated in
contact with such end.
Fig. 3 is a section of a tube plate in which the wall of the hole has a concave
shape.
Fig 3b is a similar view to Fig. 3ª but in which the wall of the hole is of convex
form. For securing tubes in holes thus formed, the tube expander must be corre-
spondingly modified.
Fig. 6 is a side elevation; and
Fig. 7 a plan of an apparatus according to my invention for preparing holes in tube
plates as above referred to.
Fig. 8 is an elevation at right angles to Fig. 6 of a spindle or cutter
holder alone.
This apparatus comprises a spindle or cutter holder 10 (hereinafter called the
holder) adapted to be secured at the part 11 to the tool spindle of a drilling or
boring machine. The holder is made with a slot 12 wherein is pivoted a lever 13
having at one end a cutting edge 14 the form of which will depend on the grooved
concave or convex shape to be imparted to the hole in the tube plate. This cutting
edge which may be formed on the end of the lever 13, or on a piece of steel removably
attached thereto, is normally within a recess 15 formed in a reduced part 16 of the

page_text: holder which part is of such a diameter as to fit an unprepared hole in a tube plate.
In the reduced part 16 of the holder is a groove or recess 17 for the escape of the
metal removed from the tube plate by the cutting edge. A screw 18 jointed to one
arm of the lever 13 and fitted with a nut wheel 19 arranged to work against an
arm 20 that acts as a stop or abutment through which the screw passes, serves as a
convenient means for causing the cutting edge 14 to project sufficiently through the
reduced part of the holder to cut the metal wall of the hole to the required form
when the holder is rotated in the proper direction. A spring 21 attached to the
lever 13 and to the stop or abutment 20 serves to return the cutting edge within
the reduced part of the holder when the nut wheel 19 is turned in the reverse
direction.
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 I do not claim
broadly the securing of a tube in a plate by forming in the inner surface or wall of
the hole destined to receive such tube an annular groove or grooves or by imparting
to the said inner surface or wall a concave or convex form and expanding or swelling
the tube so as make it conform to and tightly fit the prepared hole, but what I
do claim is:-
1. Reducing the tube end expanding it by the means described into a hole
previously prepared according to Fig. 1, Fig. 2, Fig. 3, Fig. 3ª or Fig. 3b and beading
over the end portion of tube projecting beyond the tube plate to the form indicated
at 3º 3b.
2. For grooving the holes in tube plates to receive tubes apparatus constructed
with a spindle or holder 10 arm stop or abutment 20, lever 13 with cutter, screw 18,
nut wheel 19 and spring 21 substantially as described.
Dated this 17th day of November 1890.
D. JONES.
By L. W., per F. B.