IMPROVEMENTS IN DEVICES FOR SECURING TUBES IN Steam-boilers, AND IN THE CONSTRUCTION OF TUBES FOR USE IN SUCH BOILERS, AND FOR OTHER PURPOSES.
Year: 1881

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for an Invention
of "IMPROVEMENTS IN DEVICES FOR SECURING TUBES IN Steam-boilers,
AND IN THE CONSTRUCTION OF TUBES FOR USE IN SUCH BOILERS, AND FOR
OTHER PURPOSES.". A cominunication from abroad by John Andrew Reed,
of the City and State of New York, United States of America, Mechanical
Engineer.
COMPLETE SPECIFICATION filed by the said William Robert Lake at the
Office of the Commissioners of Patents on the 15th November 1881.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent
Agents, Southampton Buildings, London. "IMPROVEMENTS IN DEVICES FOR
SECURING TUBES IN STEAM-BOILERS, AND IN THE CONSTRUCTION OF TUBES FOR
USE IN SUCH BOILERS, AND FOR OTHER PURPOSES." A communication from
abroad by John Andrew Reed, of the City and State of New York, United States
of America, Mechanical Engineer.
This Invention relates to an improved joint for uniting wrought iron boiler-tubes
to the tube sheet or plate, and to a cast metal tube of peculiar form, as hereinafter
described.
In the accompanying Drawing
Figure 1 represents a longitudinal section of my improved cast metal tube, and
Figure 2 is an end view of the same.
Figure 3 is a transverse section of the said tube on the line X, X, Figure 1.
Figure 4 is a longitudinal section of a wrought metal tube and the devices for
securing the same in the tube sheet or plate.
Figure 5 represents in longitudinal section and plan one end of the said tube,
and
Figure 6 represents in longitudinal section and plan a portion of the tube sheet
or plate.
I will first proceed to describe my improved joint for uniting wrought iron tubes
to tube sheets or plates.

page_text: A, Figures 4 and 5, represents a wrought metal tube, each end of which is
turned up true and provided with a narrow circular recess a, as shown; B, B,
represent the tube sheets or plates which may form part of the water box or case
of a boiler, as shown; b, b, represent annular bosses or projections having a central
recess corresponding in area with the end of the boiler-tube, and a central V-shaped
rib b, as shown. When the parts are in the position shown in Figure 4 the
V-shaped ribs b' will project into the circular recesses a of the tube-ends.
this
C represents a tube extending through the water-box and the tube A;
tube C is secured at one end either by being screwed into the outer plate of the
water-box, or by being provided with a nut or head c, as shown, and at the other
end by means of a nut c¹, as shown.
The operation is substantially as follows:-The tubes A and C and the tube-
sheets B having been properly prepared and placed in position as above described,
all the joints between the ends of the tubes and the tube-sheets may be made
perfectly tight simultaneously by simply screwing up the nuts on the tubes C.
In consequence of this action the projecting ribs 6 of the tube-sheets will be forced
into the recesses a of the tube ends and consequently spread the sides of the same
apart. The bearing parts of the sheet and tube are thus brought into such close
contact that the steam cannot pass between them.
By the above described construction the parts of the boiler may be properly
prepared at a small cost, and when prepared may be quickly set up with the
certainty that all the joints will be tight. The above described joint may be used
in heaters and other analogous apparatus.
This tube has
I will now proceed to describe my improved cast metal tube.
the form of an ogee helix, or spiral with circular ends, and is especially adapted
for use as flues or water tubes in furnaces; the said tube may however be placed
at intervals in steam, gas, or water pipes, or mains, to allow for expansion and
contraction without injury to the tubes or joints.
D, Figure 1, represents my improved cast metal tube, which, in longitudinal
section, has the form of an undulating line, or series of ogee curves as shewn.
The convex curves are shewn at d and the concave curves at d', and they are of
equal or nearly equal radius. The tube has a configuration that would result
from the revolution of the convex and concave curves d, d', around the axis of the
tube at the same time that an endwise motion is given to the said tube sufficient
to produce a screw form.
In order to obtain a pipe that is reliable under various changes of temperature
and compression I make the pitch-line of the screw about two thirds the diameter
of the tube, and I make the depth of the depression (forming tho helical groove
around the pipe) about one eighth of the diameter of the pipe so as to obtain the
requisite strength and lightness.
This tube can be compressed end wise to a considerable extent without injury
although made of cast iron, and the ordinary expansion and contraction can take
place without injury to the tube or to the joints by which the said tube is
connected to others, hence the said tube may be used as a flue for boilers, to
contain water with the heat outside the tube, or in water, gas, or steam mains
or pipes to allow of expansion or contraction, and for other purposes for which a
compressible cast iron tube can be employed.
At the ends of the tube the spiral terminates in a partial cylinder at that
forms a circular end to the tube, and has the axis of the tube for its centre; other-
wise the end of the said tube would open at one side; to strengthen the end of
the tube it is formed with either an outer or an inner flange d³.
I am aware that screw-shaped tubes have been made, but the convex and concave
curves are not equal, and hence the strain resulting from compression is not equal
on all parts of the metal. Flanges have also been employed at the ends of the
tubes, and cylindrical ends to the screw shaped tubes have also been proposed.
In my improved tube the cylindrical ends are contracted so as to be smaller
than the screw-shaped portiou of the tube, and the extreme ends are flanged or

page_text: thickened, the object of this being to allow of the necessary strength of metal
between one opening and the next in the tube-sheets, against which the ends of
the screw-shaped tubes are received; at the same time the screw-shaped tubes can
be arranged moderately closely together so as to obtain the maximum number of
tubes in a given space.
Having thus fully described the said Invention, as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim,
First. The herein described joint between the end of the tube A and the tube-
plate B consisting essentially of the recess a and the V-shaped projection b', as
above set forth.
Second. The cast metal tube whose body is of the form of an ogee helix with
equal or nearly equal convex and concave curves, and which has circular ends
flanged or thickened and smaller in diameter than but having the same axis as
the helical portion, all substantially as above set forth and for the purposes
specified.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Fifteenth day of November, in the year of our Lord
One thousand eight hundred and eighty one.
W. RUB'. LAKE. (L.S.)