IMPROVEMENTS IN RIVETTED JOINTS
Year: 1883

page_text: LETTERS PATENT to John Anthony Rowe of North Shields in the County of
Northumberland, Engineer and Shipwright Surveyor for an Invention of
IMPROVEMENTS IN RIVETTED JOINTS.
PROVISIONAL SPECIFICATION left by the said John Anthony Rowe at the
Office of the Commissioners of Patents on the 20th November 1883.
JOHN ANTHONY ROWE of North Shields in the County of Northumberland,
Engineer and Shipwright Surveyor, "IMPROVEMENTS IN RIVETTED JOINTS"
My invention relates to improvements in the method of forming and rivetting
the joints of steam boilers, receivers or other vessels constructed of plates of iron
or other metal subject to pressure of steam, water, air or other fluids or gases, or of
iron steamers, sailing ships or similar structures.' These rivetted joints are designed
with a view of obtaining a large percentage of strength of joint with a pitch of
rivets at the caulking edges, so small as to give a thoroughly tight boiler or other
vessel or structure under pressure.
The methods usually employed to unite plates of iron or other metal (methods
other than welding) are, first by lapping one plate over another and rivetting them
together and, second by bringing two plates butt to butt and then uniting them
by rivetting through single or double butt straps.
The method I propose would be most correctly described by the term open or
caulkable butt joints. Instead of bringing the butts of the plates together they
are left open, a sufficient (minimum) distance to allow of caulking being effected,
but may be close butted where they form the circumferential seams, or may be
welded together at these points. When single straps are applied (which are best
adapted to carry out my invention) they will be preferably fitted inside of a boiler
or other vessel under internal pressure or outside a ship or similar vessel, in fact on
the side where pressure is exerted, the object being to give the best caulking edges
on that side where caulking is always possible. The circumferential seams of a
boiler or other vessel under pressure may be constructed according to the method
Pris 37

page_text: already described but for the purposes of obtaining additional strength and more
efficient caulking and of saving material it is to the longitudinal seams that my
invention is specially applicable.
The butt straps must be so much thicker than the plates they unite as to ensure the
joint yielding in the shell plates or rivets before in the straps and this point must be
carefully observed. Any number of rows of rivets may be employed, but in order to
obtain a small caulking pitch, with a great percentage of strength of joint, at least two
rows must be used on each side, the row of rivets nearer to the caulking edge being
more closely pitched than the row of rivets more remote. In constructing the hulls of
iron steamers or sailing ships my invention will be applied by placing the butt
straps outside, the caulking space being left between the edges of the plates inside
the hull. In the case of the hulls of existing iron steamers or ships requiring
strengthening, I propose to fit single outside straps to the butt joints of hull,
wherever they shew signs of weakness, removing the old inside butt straps, and to
cut away the butt ends of the hull plates until caulking space is obtained. By
this means a stronger joint is obtained and one that can be kept tight by caulking
even when the vessel is at sea. In the case of ships as with boilers care must be
taken to have the butt strap of sufficient thickness as compared with the plates to
afford a margin of strength in favour of the strap as before named.
The value of the method of making and rivetting joints according to my
invention may be realised when it is stated that by its adoption, in addition to
increased tightness of joint, a saving of about 15 per cent in weight of material
used in the construction of the shells of iron or steel boilers may be effected.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Anthony Rowe in the Patent Office on the 20th May
1884.
JOHN ANTHONY ROWE of North Shields in the County of Northumberland
Engineer and Shipwright Surveyor. IMPROVEMENTS IN RIVETTED JOINTS
My invention relates to improvements in the method of forming and rivetting
the joints of steam boilers, receivers or other vessels constructed of plates of iron
or other metal subject to pressure of steam, water, air or other fluids or gases, or
of iron steamers, sailing ships or other similar structures. These rivetted joints are
designed with a view of obtaining a large percentage of strength of joint with a
pitch of rivets at the caulking edges, so small as to give a thoroughly tight boiler
or other vessel or structure under pressure.
The methods usually employed to unite plates of iron or other metal (methods
other than welding) are, first by lapping one plate over another and rivetting them
together and second, by bringing two plates butt to butt and then uniting them by
rivetting through single or double butt straps.
The method I propose would be most correctly described by the term open or
caulkable butt joints. Instead of bringing the butts of the plates together they are
left open a sufficient (minimum) distance to allow of caulking being effected but
may be close butted where they form the circumferential seams or may be welded
together at these points. When single straps are applied (which are best adapted
to carry out my invention) they will be preferably fitted inside of a boiler or other
vessel under internal pressure or outside a ship or similar vessel. The circumferential
seams of a boiler or other vessel under pressure may be constructed according to
the method already described but for the purposes of obtaining additional strength
and more efficient caulking and of saving material it is to the longitudinal seams
that my invention is specially applicable
The butt straps must be so much thicker than the plates they unite as to ensure
the joint yielding in the shell plates or rivets at the same time as (or before) in the
straps and this point must be carefully observed to insure equality of strength
between strap, shell plates and rivets. Any number of rows of rivets may be
employed, but in order to obtain a small caulking pitch with a great percentage of
strength of joint at least two rows must be used on each side, the row of rivets
nearer to the caulking edges of the plates being more closely pitched than the row
of rivets more remote. In constructing the hulls of iron steamers or sailing ships
my invention will be preferably applied by placing the butt straps outside; the
caulking space being left between the edges of the plates inside the hulls,
experience having shewn that, owing to deficient rivet holding power, the joints
become leaky and corrosion takes place unless accessible for " caulking" an
important advantage when the vessel is afloat. In the case of the hulls of existing
iron steamers or ships requiring strengthening I propose to fit single outside straps
to the butt joints of hull, wherever they shew signs of weakness removing the old
inside butt straps, and to cut away the butt ends of the hull plates until caulking
space is obtained. By this means a stronger joint is obtained and one that can be
kept tight by caulking even when a vessel is at sea. In the case of ships as with
boilers care must be taken to have the butt strap of sufficient thickness as compared
with the plates to afford equality of strength as before named
The value of the method of making and rivetting joints according to my
invention may be realised when it is stated that by its adoption in addition
to increased tightness of joint a saving of about 15 per cent in weight of material
used in the construction of the shells of iron or steel boilers may be effected

page_text: double rivetted in the ordinary manner. Figure 2 shews a sectional plan of same
on line A B of Figure 1. The caulking space between edges of plates P P¹ is shewn
by a, a; formed by cutting away the edge of plate P¹ to within a certain distance
of the circumferential seam, where the two plates butt close as at b. c is the butt
strap inside finishing against edge of next section of plate the joint being made
tight by a covering piece d rivetted through. Figure 24 shews another mode of
making the joint by working the butt strap itself over the next section of plate.
Figure 3 shews a portion of shell of a boiler with both longitudinal and
circumferential seams formed with improved joint. Figure 4 shews a sectional plan
of same on line C D. Figure 3; and Figure 5 a portion of a transverse section of
shell on line E F Figure 3. In this case a. a is the longitudinal caulking space
between plates P. P and e. e. is the circumferential caulking space between these
plates and the next Section the shell forming a perfect cylender of equal diameter
from end to end. In this illustration the ends of the plates P P¹ where they meet
the circumferential seam are shewn welded together at part marked w leaving the
open caulking space a. a. between them and this plan may of course be adopted
either with butt strapped circumferential seams as shewn or with lapped seams as
in Figure 1. c. c are the butt straps the caulking space a. a being outside on the
longitudinal seam and the caulking space e. e inside on the circumferential seam.
The arrangement of rivetting is such as I consider best for a double line of rivets
giving closely pitched rivets next the caulking edge and double the pitch on the
inner line. The shell plates in the illustration are one inch thick, the butt straps
13/8 inches thick, the rivets 10/8 inches diameter pitched 3/8 inches centres on outer
line next caulking edge and 73/4 inches centres on the inner line. Thus a perfectly
rigid caulking edge is obtained against the close pitched line of rivets with a joint
giving about 80 per cent of the strength of the plates while the rivet section is
equal to that of the plate. Figures 6, 7 and 8 shew three modes of rivetting
which I consider adapted to carry out the principle upon which my improved joint
is based namely obtaining a firm caulking edge to ensure tightness with a large per-
centage of strength of the rivetted joint relatively to the plate.
Care being
taken that the proportions between the thicknesses of shell plates and butt straps
as previously explained be observed
Having now fully described my invention and illustrated the modes in which it
may be carried out practically in the case of boilers or similar vessels under internal
pressure; the application to ships or similar structures being obviously the same in
principle, I declare that what I consider novel and therefore claim as the invention
secured to me by Letters Patent is ;
The construction of rivetted joints between plates of steam boilers, recievers or
other vessels required to resist internal or external pressure, so as to leave between
the edges of the adjoining plates, a space sufficient to allow of caulking the edges
of the plates against the butt straps with a closely pitched line of rivets next edges
thereby obtaining a thoroughly tight joint with a large percentage of strength
substantially as shewn and described
In witness whereof I the said John Anthony Rowe have hereunto set my
hand and seal this nineteenth day of May in the year of our Lord one thousand
eight hundred and eighty four.
JOHN, ANTHONY ROWE (L.S.)
Witness:
T. J DANSON F. Inst P. Agents
Consulting Engineer & Patent Agent
Newcastle on Tyne
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