Boilers and other similar Purposes.
Year: 1885

page_text: Boilers and other similar Purposes.
We JOSEPH STEWART, Boiler Maker and FRANCIS HENRY HALLARD Engineer,
both of Leigh in the County of Lancaster do hereby declare the nature of our
invention for "IMPROVED MEANS FOR FASTENING TUBES IN METAL PLATES FOR
BOILERS AND OTHER SIMILAR PURPOSES and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement :-
"
This invention is designed principally for fastening stay tubes in Steam Boilers
but it is also applicable for fastening fire tubes in marine or locomotive boilers of
the multitubular class, and for fastening tubes in surface condensers, and for other
purposes where it is desirable to fasten tubes into metal plates and to afford
facility for removal and replacement thereof for inspection or for repairs or
otherwise..
The nature of our invention and the practical application of the same will
be readily understood on reference to the sheet of drawings annexed hereunto
and the following explanation thereof.
The principal feature of our invention consists of a ferrule or bush screwed both
internally and externally so that whilst the inner thread, screws onto the screwed
end of the tube, the outer thread screws into the screwed hole in the plate and thus
fastens the two firmly together.
The simplest form of our invention is shown in section at Fig. 1. and end
and side views at Fig. 2. on the annexed drawing. a, a is a portion of the plate
and b, b one end of the tube, c, c is the internally and externally screwed ferrule
or bush, the two screws of which must be cut with exactly the same thread.
It will be seen that the end of the tube b, b is screwed to fit the inner thread on
the ferrule or bush c, c, and the hole in the plate a, a is made sufficiently large and
screwed to fit the outer thread of the ferrule or bush c, c.
The external part of this ferrule or bush is made with a shoulder and of an
increased diameter, and is formed like a six sided nut as shown at Fig. 2. or
is otherwise formed or fitted to enable it to be turned by a spanner, key, or similar
instrument in order to screw it into its place or remove it therefrom. d, d is
metallic washer placed between the outside of the plate a, a and the inner
shoulder of the ferrule c, c.

page_text: In Fig. 3 the screwed end of the tube a, a is made rather longer and a lock
nut e, e is screwed thereon against the outer end of the double screwed ferrule or
bush c, c, and in the modification shown at Fig. 4 the screwed ferrule or bush c*, c*
is made without the external shouldered part and is screwed into its place by
means of a forked driver, the lock nut e*, e* being screwed onto the end of.
the tube outside. This does not require so long a tube as the modification shown
at Fig. 3.
Having now particularly described. and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is
'
Fastening the ends of tubes into metal plates by means of a ferrule or bush
which is made with a screw thread both externally and internally, the internal
thread screwing onto the threaded end of the tube and the external thread at the
same time fitting into the screwed hole in the plate which is made of a larger
diameter than the tube so as to allow of the ferrule or bush being screwed in
between the two either with or without a lock nut substantially in the manner
herein before described and illustrated by the drawings annexed.
GEORGE DAVIES,
Agent for the Applicant,
4, St. Ann's Square, Manchester.