IMPROVEMENTS IN RIVETTED JOINTS
Year: 1884

page_text: I, JOHN ANTHONY ROWE, of Spring Terraco, North Shields, in the County of
Northumberland, Engineer and Shipwright Surveyor, do hereby declare the nature
of said invention for "IMPROVEMENTS IN RIVETTED JOINTS" to be as follows:-
This invention is a development, so far as relates to the system of rivetting, 'of a
patent granted to me in 1883 N° 5468 and is applicable to any form of rivetted
joint whether "lapped" or "butted." In all methods (except my own) of rivetting
together plates of metal to resist internal or external pressure, the pitch of rivets
which determine the plato sectional strength is the pitch which must be depended
upon for caulking and thus the strength of section of plate, and the closeness of
rivetting to be caulked against, are in direct opposition to each other.
Now the object of my invention is to construct a joint of great strength with
the rivets so arranged as to make the strength of the plate and that of one
caulking edge independent of each other, thereby obtaining a maximum per centage
of strength with a ininimum pitch of rivetting next one caulking edge to secure a
tight joint.
In the cases of "butted" joints I employ two "butt" straps, one (preferably the
inside strap) being wider than the other and I prefer to make these straps of samo
thickness of the plates. Two rows of rivets closely pitched, pass through both
butt" straps and through the shell plates and: form the caulking scam.
The
other two rows of rivets more widely pitched pass only through the under "butt"
strap and through the shell plates.
"
By this arrangement I obtain a joint about 20 per cent stronger than any now
in use (my own patented in November 1883 excepted) and possessing this great
advantage over any other (my own as above mentioned excepted) that iny caulking
pitch on one side is the small distance due to the close pitched rivets, the plate
strength of joint being determined by the wide pitch of rivets through shell plates
and one
butt" strap. The particulars of this joint are as follows and are given
by way of illustration,
Iron rivets 48" diam.

page_text: In a modification of my system I propose to use four rows of rivets passing
through both "butt" straps and through the shell plates, and two other rows
passing through the wide (preferably inside) "butt" strap and the shell plates only,
the spacing being as follows: viz:-the line of rivets next "butted" edges of plates
are closely pitched, the line next edge of outside "butt" strap are more widely
pitched and form the caulking seam, while the other two lines of rivets, passing
only through the wide strap and the shell plates, are still more widely pitched.
In another modification which I prefer to that just described, the outer "butt"
strap has two rows of rivets closely pitched and forming the caulking seam, the
wide "butt" strap having four rows of rivets, the two rows next edges of outer
"butt" strap being more widely pitched, and the other two rows next edges of
inner (and wider) butt strap still more widely pitched. In both these modifications
the result is a joint having about 90 per cent of the strength of shell plates.
-I-give-the-particulars of one such joint as just described, viz:-
The the Fivets are pitched wide apare to give 18° per
In order now to prevent rupture through the close pitched line of the under-
lying plate a strap is fitted underneath-taking all the rivets of the over-lapping und
underlying plates and an additional lino of wide pitched rivets through under-
lying plate only. The strap would generally need to be about one half the
thickness of the shell plate, but by preference I make it of the same thickness as
the shell plate.
As an illustration of the value of the joint I will furnish particulars :—
Iron rivets 1 inch dia:
Caulking seam rivets
2nd seam through both plates and strap
213 in: pitch.
3rd seam through underlying plate and strap only } 5%, in: do.
Iron shell plates 1/, in: thick.
Iron straps
', in: do.
Strength of joint equal to 82-2. per cent of solid plate.
To construct this joint in a similar method but with a greater number of rows of
rivets the plates are lapped in the usual manner.
The pitch of rivets in line furthest from "landing edge" determines the plate
strength of joint. The line of rivets next "landing edge" is closed spaced to secure
tight caulking and another line of rivets with an intermediate pitch is arranged
between these two lines.
To prevent rupture through line corresponding with caulking seam of the
underlying plate a strap is fitted taking all the rivets of the overlying plate, and
the additional lines of rivets through the underlying plate and strap only. There
are here 3 rows of rivets which pass through both plates and through strap and
two rows which take the underlying plate and the strap only.
In order to shew the resulting strength of this system, I herewith. append
particulars of a joint so constructed.

page_text: Steel rivets 1" dia:
Caulking seam rivets
2nd (or intermediate) seam rivets through both plates and strap
3rd Beam rivets through both plates and strap
-
-O
-
4th (next "landing edge") seam through underlying plate and
strap only
•
5th seam through underlying plate and strap only
K
Steel shell plate "/".
Steel straps
Strength of joint 90 per cent solid plate.
3³/in: pitch.
71 in: pitch.
15"
do.
7"
do.
-
15"
do.
-
gg
Instead of all the rows of rivets through the shell plates passing also through the
strap it may in some cases be sufficient for one row only or for two rows only to
take the strap as well as the two plates.
By this system I claim to be able to save about 20 per cent of the metal now
employed to construct structures where rivetting can be employed, such for instance
as steam boilers-domes superheaters, Receivers of compressed air, or gases, fluids,
or liquids exerting pressure on the apparatus containing them. And in addition to
this great saving of material the rivets are so arranged as to provide one very
much closer caulking pitch than is now known and this will produce a tighter
structure and one not so likely to become leaky and therefore costly to keep in
order. It may with advantage be employed in the construction of sailing ships,
steamers, or similar vessels.

page_text: In Figure 3, two plates are lapped in the usual way-The rivets in line A are
closer spaced than rivets in lines B. A strap is fitted to take the rivets of the
lapping plates and is extended so far beyond the lapped joint as to take the third
row of rivets which is pitched wider apart than the centre row.
Figure 4-Illustrates another joint constructed on the same principle-The three
centre lines of rivets aro close spaced and the centre one of the three by com-
manding the landing edge affords an excellent means of obtaining a tight joint
without excessive caulking-The rivets of the three centre lines are larger than
the rivets of the two outer rows which determine the plate strength or section
The pitch of rivets of outer rows is one and a half times the pitch of the
other rows.
Although the covering strap should by preference take every row of rivets, it is
not absolutely necessary it should take more than the centre line of rivets in
addition to the rivets which pass through the shell plates beyond the lap joint.
On the drawing I have given at side of each Figure the proportion of plate
thickness and of butt straps diameters and position of rivets which I consider are
the best for realizing the principle of my invention but I do not restrict myself
to those precise proportions.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I desire it to be clearly
understood that I do not restrict myself to the precise proportions which I have-
given, as the diameter, pitch and disposition of the rivets may be varied to meet
varying conditions without affecting the principle of my invention and I declare
that what I claim is
1st The construction of butted joints in which a wide and a narrow "butt "
strap are employed; the landings of the narrow strap forming the caulking edges
and receiving closely pitched rivets, by preference large ones, in two or more rows
so disposed as to give a minimum pitch next caulking edge to ensure a tight
joint; the rivetting in wider strap being so disposed as to secure a large per centage
of plate strength substantially as described and illustrated.
2nd The construction of lapped joints in which a single butt strap is employed
which by preference takes all the rivets of the lapped plates and an additional row
or rows of rivets of the underlying or overlying plato beyond the lap joint, the .
landing edge of the overlying or underlying plate forming the caulking edge with
closely pitched rivets so disposed as so ensure a tight joint, the other rivets being
Bo disposed as to secure a large per centage of plate strength substantially as
described and shewn,