Improvements in the Method of Jointing Tubes in Tube Plates.
Year: 1895

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Method of Jointing Tubes in Tube Plates.
I, JOSEPH WILLIAM REED of Mayfield Jarrow in the County of Durham,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to the jointing of tubes in tube plates of boilers and
especially of water tube boilers and consists in improvements on the arrangements
described in the Specification of my Letters Patent No. 24,124 A.D. 1893;
therein 1 described the use of more or less spherically formed connections between
the tubes and tube plates with the object of allowing the tubes to diverge slightly
from the correct lines without affecting the security of the joints.
The object of my present improvements is to attain the same result with
greater simplicity and economy.
To this end instead of screwing on the tube as I before proposed a separate
ferrule I obtain the enlarged spherical surface required near the tube end to fit
into a corresponding countersink in the tube plate in sundry manners; I may
swell it out of the material of the tube at or about the inner side of the tube
plate and screw the outer end for the nut; or I may thicken the tube end for a
certain distance and machine down the outer surface at the proper place to any
required spherical shape the bore of the tube in this case remaining plain; or by
another method I may reduce the body of the tube from a larger to a smaller
diameter at or about the tube plate the reduction of the diameter forming the
required semi-spherical or convex surface which is fitted into a corresponding recess
in the tube plate.
In these arrangements the outer nut for securing the tube inay either rest on
the plate or a washer with a spherically formed back may be interposed and the
nut turned out to fit thereon as in my before cited specification and by these means
a certain amount of "play or movement at the joint is allowed.
""
When however such play is not called for I may swell out the walls of the tube
ncar its end to the form of a somewhat concave sided collar; or I may so form the
exterior surface only leaving the bore parallel; or I may further form the tube
of a less diameter at the end than the body the intervening part fitting in the plate
making a more or less coucave or arched surface for which a corresponding recess
is formed.
Instead of making the sides of the tube concave as in the latter arrangements
I may make them straight like a conc.
In all of the arrangements described herein the tube plates are countersunk with
recesses shaped convexly concavely or conically as the case may be to correspond
with the contour of the part of the tube intended to fit well thereinto.
By these methods of forming the joint there is only one surface to be kept tight
while there is less liability of the joint suffering from high temperatures because
there is less material between the fire and the water and also because the
material of the tube usually steel is more adapted to stand great heat than the
ferrule usually made in gun metal.
Dated this 12th day of September 1895.
A. CRAWHALL CHAPMAN,
3 St. Nicholas Buildings, Newcastle-on-Tyne, Patent Agent.

page_text: Improvements in the Method of Jointing Tubes in Tube Plates.
I, JOSEPH WILLIAM REED of Mayfield, Jarrow in the County of Durham,
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 relates to the jointing of tubes in tube plates of boilers and
especially of water tube boilers and consists in improvements on the arrangements
described in the Specification of my Letters Patent No. 24124 A.D. 1893; therein
I describe the use of more or less spherically formed connections between the
tubes and tube plates with the object of allowing the tubes to diverge slightly from
the correct lines without affecting the security of the joints.
The object of my present improvements is to attain the same result with greater
simplicity and economy.
To this end instead of screwing on the tube as I before proposed a separate
ferrule I obtain the enlarged spherical surface required near the tube end to fit
into a corresponding countersink in the tube plate in sundry manners which I will
now proceed to fully describe with reference to the accompanying drawings in
which Figures 1, 2 and 3 show sectional views illustrative of my improvements
and in the following description like marks of reference indicate like parts.
Referring to the drawings in Figure 1 is shown a spherical enlargement E
swelled out of the material of the tube T at or about the inner side of the tube-
plate P, the outer end of the tube being screwed to take the nut N. The tube
plate is spherically recessed as shown to take the spherical enlargement on
the tube.
In Figure 2 the tube end is thickened for a certain distance and machined down
to the required spherical shape the bore of the tube in this case remaining
plain.
The dotted lines in this figure show an alternative form or design the spherical
portion of the tube away from the spherical recess not being necessary.
In Figure 3 the body of the tube is reduced from a larger to a smaller diameter
at or about the tube plate the reduction of diameter being utilised to form the
required semi-spherical or convex surface which fits into a corresponding recess in
the tube plate.
In these arrangements the outer nut for securing the tube may either rest on
the plate as shown in the drawings or a washer with a spherically formed back
may be interposed and the nut turned out to fit thercon as in my before cited
specification and by these means a certain amount of play or movement at the
joint is allowed.
By these methods of forming the joint there is only one surface to be kept tight
while there is less liability of the joint suffering from high temperatures because
there is less material between the fire and the water and also because the material
of the tube usually steel is more adapted to stand great heat than the ferrule
usually made in gun metal.
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 :-
1. The spherical method of jointing tubes in tube plates substantially as set
forth with reference to Figure 1 of the drawings.
2. The spherical method of jointing tubes in tube-plates substantially as set
forth with reference to Figure 2 of the drawings.

page_text: 3. The spherical method of jointing tubes in tube plates substantially as set
forth with reference to Figure 3 of the drawings.
4. The spherical method of jointing tubes in tube plates substantially as
herein set forth.
Dated this 11th day of June 1896.
A. CRAWHALL CHAPMAN,
3 St. Nicholas Buildings, Newcastle-on-Tyne, Patent Agent.