IMPROVEMENTS IN THE FITTING OR CONNECTING OF TUBES TO TUBE PLATES OR HOLDERS, AND IN APPARATUS EMPLOYED THEREFOR OR IN CONNECTION THEREWITH
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by John Henry Johnson at the
Office of the Commissioners of Patents, with his Petition, on the
26th January 1875.-A communication from abroad by Joseph
Constant, of Paris, in the Republic of France.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE FITTING OR CONNECTING OF TUBES TO TUBE
PLATES OR HOLDERS, AND IN APPARATUS EMPLOYED THEREFOR OR IN CONNECTION
THEREWITH," a communication to me from abroad by Joseph Constant, of
Paris, in the Republic of France, to be as follows:
-
This Invention relates to an improved mode of fitting or connecting
tubes to tube plates or tube holders, which is more particularly
applicable to the tubes of tubular boilers, but may also be employed for
other purposes where tubes are required to be secured to plates or
holders, and it consists essentially in the employment of tubes or
washers composed of an asbestos fabric or similar fire resisting material;
and by preference slightly conical or tapering, placed around the
extremity of the tube, which is to be connected to the plate or holder

page_text: in combination with conical or tapering tubes or washers composed of
iron or other suitable rigid material, and placed outside of the asbestos
tubes or washers, the taper of the two being by preference arranged in
reverse directions, so that when the metal tube or washer is driven in
around the asbestos tube or washer, and between it and the sides of the
aperture in the tube plate provided for the reception of the tube, the
latter will be firmly secured in its place.
The metal tubes or washers may be made slightly larger in external
diameter than the diameter of the apertures in the tube plate, and the
asbestos if found too spongy may be sprinkled with a small quantity of
powdered silica before inserting it in its place.
In fitting or securing a tube to the tube plates one of the asbestos
tubes or washers is placed over its end, and the tube is inserted into the
apertures in the two plates. The metal tubes or washers are then intro-
duced around the ends of the tubes so covered, and are driven into their
place by the aid of rods or bars, one end of which, made of a shape
corresponding to that of the interior of the tube, is inserted therein to the
extent allowed by a flange or shoulder formed on cach rod or bar, and
which then comes into contact with the end of the metal tube or washer,
so that by striking the opposite end of the rod or bar with a hammer or
other tool, the metal tubes or washers become wedged in their place,
thereby compressing the asbestos tube or washer and forming a tight joint
between the tubes and the plates. If the tube then projects in either
direction it may be driven into its place by the aid of a similar rod or
bar made of suitable dimensions. When it is required to drive in the
metal tubes or washers without at the same time forcing in the tube,
this may be effected by the aid of the rod or bar firstly herein-before
mentioned by fitting a short tube over its flanged end.
In order to effect the disconnection or removal of the tubes from their
plates, it is proposed to employ apparatus constructed in the following
manner: In one end of a rod or bar of suitable dimensions there is
formed a socket for the reception of a short tube, which is secured
therein in such a manner as to protrude from the end of the rod or bar,
and at the same time leave a space between its exterior and the interior
of the socket, with which space the interior of the short tube may be
made to communicate.
The end of the rod or bar at which the short tube before mentioned is
Sammad it hath

page_text: with a handle for the facility of turning such rod or bar. The extremity
of the tool thus formed is inserted into the end of the tube which is
required to be disconnected or removed from the plate, and the rod or
bar being turned round the teeth or claws scize the asbestos tube or
washer which is by this means removed, the end of the tube which is in
process of being disconnected then occupying the space left between the
exterior of the protruding tube and the interior of the rod or bar. The
tube having thus been liberated it is then required to effect the with-
drawal of the metal tubes or washers from the tube plates, for which.
purpose the following apparatus may be employed. AU shaped frame
is provided having an aperture in its centre through which passes a rod
or bar fitted with hinged expanding arms or semi-tubes at one extremity,
and at the opposite extremity formed with a screw thread, over which
works a nut for adjusting the position of the rod or bar in its frame.
The rod or bar is made hollow throughout its length for the reception of
an internal rod, which is also formed and fitted with a screw thread and
nut at one end for traversing it along in the interior of the outer rod or
bar, and is at its opposite end made tapering or wedge shaped, so that by
the longitudinal motion of the internal.rod, its extremity will be caused
to act upon the expanding portions of the outer rod or bar and forco
them outwards. In operating with this apparatus the end of the rod or
bar is first passed through the metal tubes or washers to be withdrawn,
after which the internal rod is acted upon so as to cause the expanding
portions of the outer rod or bar to open, when a flange or shoulder with
which they are provided will be brought behind the end of the metal
tube or washer to be removed. The rod or bar is then adjusted longi-
tudinally so as to bring the ends of the U'frame into contact with the
tube plate, and by continuing the motion the metal tubes or washers are
readily withdrawn, the operation being performed without injury to the
tubes or washers, or to the plate in which they were inserted.