IMPROVE- MENTS IN JOINTS AND CONNECTING CAPS FOR WATER TUBE BOILERS
Year: 1884

page_text: I CONRAD CHRISTIAN SEVERIN KNAP of Queen Victoria Street, in the city of
London, Engineer do hereby declare the nature of said invention for "IMPROVE-
MENTS IN JOINTS AND CONNECTING CAPS FOR WATER TUBE BOILERS," to be as
follows:-
It is the general practice to join the tubes of water tube boilers to each other or
to their connections; and further, to join the said connections to each other by
means of jointrings made from an elastic but perishable material; such joint rings
are interposed in order to allow or to admit of the unequal expansion and
contraction that takes place in the boiler; such expansion and contraction it is
essential to provide for by interposing a yielding material as described.
When metallic connection and other joints not allowing for such expansion
herein before described are constantly a source of danger and create undue strains
within the boiler or system of tubular connections, which is highly desirable to
avoid.
My invention consists of a metallic joint, which admits or allows for unequal
expansion and contraction, in a most positive and efficient manner. The metallic
joint last described is easily made or connected and disconnected, and sure to be
tight or sound under heavy pressures; that is, the joint is far more secure and
efficient than the joint rings in common use as first described; and further, the
metallic joints constructed according to my invention last as long as the boiler, and
should they be accidentally broken, they can be replaced any number of times
without damage; whereas the cost of renewal of an ordinary joint ring, is a most
serious item, to say nothing of the risk of their blowing out, and the general
unreliability.
The difficulty of obtaining a good joint has been one of the great objections
raised against water tube boilers.
In carrying out my invention in connecting tubes to each other, the joint
consists essentially of a double cone ended ferrule expanded about its middle so as
to admit of its change of figure, on expansion or contraction; that is, the joint
consists of a short tube with contracted or inclined ends with a bulbous like
middle, The conical or inclined ends are inserted within bulged socket' like conical
ends or seats preferably formed from the tubes. The joint may be made spherical

page_text: or ball like, or a combination of the two joints described. The ball like joint
consists essentially of the middle portion of a sphere, the ends as before seating
themselves within like sockets or seats formed within the ends of the tubes to be
joined together.
By constructing joints as last described, it matters not in which direction strain
takes place, the joints accommodate themselves accordingly.
The joints or connections may be made separate as described, or they may be
part of either the tube or the connection.
I prefer to make the joints of a metal which expands more under heat than
tubes of the connections; that is, the joint is made of a metal which expands with
a greater ratio than the tubes or connections to which it is applied; so that
increasing heat and steam pressure only tightens or seals the joint, from the fact
that the ends of the said joint are seated inside the ends of the tubes or connections
joined together.
The joints are provided with usual bolts and lugs for attaching the connections
and tubes to each other.
Although I have described the expansion joint, arranged between two bodies
with bulged ends, yet I do not limit myself to this exact form, as the joint may be
connected in various ways.
In applying my invention to a connecting cap, it is so shaped, that it will readily
take up expansion; that is, the cap is made in one piece with its corical or other
ends turned in the same direction; the middle of the connecting cap being swelled
or bulbous like, the cap turned ends being connected or fitted into the socket ends
of two parallel tubes in the way or ways as already described.
1001.
COMPLETE
SPECIFICATION.
I, CONRAD CHRISTIAN SEVERIN KNAP of Queen Victoria Street, London, in the
City of London, Engineer, do hereby. declare the nature of said invention for
"IMPROVEMENTS IN JOINTS AND CONNECTING CAPS FOR WATER TUBE BOILERS,"
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:―
It is the general practice to join the tubes of water tube boilers to each other
or to their connections, and further to join the said connections to each other
by means of joint rings made from an elastic but perishable material; such joint
+

page_text: rings are interpösed in order to allow or to admit of the unequal expansion and
contraction that takes place in the boiler" such expansion and contraction it is
essential to provide for by interposing a yielding material as described.
When metallic connection and other joints not allowing for such expansion as
herein before described are constantly a source of danger and create undue strains
within the boiler or system of tubular connections, which is highly desirable to
avoid.
My invention consists of a metallic joint, which admits or allows for unequal
expansion and contraction, in a most positive and efficient manner. The metallio
joint last described is easily made or connected and disconnected, and sure to be
tight or sound under heavy pressures; that is, the joint is far more secure and
efficient than the joint rings in common use as first described; and further, the
metallic joints constructed according to my invention last as long as the boiler, and
should they be accidentally broken, they can be replaced any number of times
without damage; whereas the cost of renewal of an ordinary joint ring, is a most
serious item, to say nothing of the risk of their blowing out, and their general
unreliability.
The difficulty of obtaining a good joint has been one of the great objections
raised against water tube boilers. .
In carrying out my invention in connecting tubes to each other the joint consists
essentially of a double cone euded ferrule expanded about its middle so as to admit
of its change of figure, on expansion or contraction; that is, the joint consists of a
short tube with contracted or inclined ends with a bulbous like middle. . The
conical or inclined ends are inserted within bulged socket like conical ends or seats
preferably formed from the tubes. The joint may be made spherical or ball like, or a
combination of the two joints described. The ball like joint consists essentially of
the middle portion of a sphere, the ends as before seating themselves within the
ends of the tubes to be joined together.
By constructing as last described, it matters not in which direction strain takes
place, the joints accommodate themselves accordingly.
The joints or connections may be made separate as described or they may be part
of either the tube or the connection.
I prefer to make the joint of a metal which expands more under heat than the
tubes of the connections; that is, the joint is made of a metal which expands with
a greater ratio than the tubes or connections to which it is applied, so that
increasing heat and steam pressure only tightens or seals the joint, from the fact
that the ends of the said joint are seated inside the ends of the tubes or connections
joined together.
The joints are provided with usual bolts and lugs for attaching the connections
and tubes to each other,
Although I have described the expansion joint, arranged between two bodies
with bulged ends, yet I do not limit myself to this exact form, as the joint may be
connected in various ways.
In applying my invention to a connecting cap, it is so shaped, that it will readily
take up expansion; that is, the cap is made in one piece with its conical or other
ends turned in the same direction; the middle of the connecting cap being swelled
or bulbous like, the cap turned ends being connected or fitted into the socket ends
of two parallel tubes in the way or ways as already described.
I will now proceed with reference to the accompanying Drawings, the manner
in which the same is to be performed.
Figure 1 is a front elevation, figure 2 is a longitudinal section and figure 3 is an
end elevation of a metallic joint constructed according to my invention, which
expands preferably more under heat than the connections or tubes to which it is
applied-Figure 4 is a complete section of a portion of the end of a Root or multi-
ubular boiler fitted with the said metallic joints and having connections suitably
formed to receive them; that is, the sockets or passages in the connections are

page_text: coned or tapered to fit the coned ends of the joints-Figure 5 shews the cap
connection in back elevation, with the connecting portion broken off-Figure 6
represents the joint applied for connecting together metallic tubes with expanded
ends wherein the coned ends of the joint ferrule seat themselves-Figure 7 is a
modification wherein the joint is made spherical or ball like-This joint consists
.essentially of the middle portion of a sphere, with the terminal ends seating
themselves within sockets or seats formed within the ends of tubes to be joined
together.
The same letters of reference indicate corresponding parts in the several figures
.of the Drawing.
a is the bulbous or middle part of the double coned ferrule joint figure 1, a² a³ are
.the inclined conical ends, which are inserted in the similarly coned or contracted
entrances b³ ³ as seen in figure 4-62 62 are the entrances to the end cast framing b
of the water tubes d d, and c² c² are the entrances or the entrance or exit to the
cap c-So that by constructing and connecting together the caps, tubes and other
parts of water tube boilers, by the conical or spherical ended joints or ferrules as
described, any increasing pressure of heat or steam only tightens or tends to tighten
the joints; that is to say, the greater the pressure, the more sound the joint becomes
in consequence of the formation of the joints and the shape of the parts or entrances
wherein the ends seat themselves.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, declare that what
I claim is
Making the joints of water tube boilers of a ferrule or ring, double coned or con-
tracted at its ends, and preferably expanded or bulged about its middle to admit of
its change of form on expansion; also making the said joints spherical, and the
sockets or seats of the connections or tubes to take the joints, coned or spherical,
substantially as and for the purpose herein before described and set forth.