Improvements in Covers for Man, Hand, and other Holes in Vessels Subject to internal Pressure,
Year: 1899

page_text: Date of Application, 12th July,
1000
Complete Specification Left, 26th Sept., 1399 -Accepted, 28th Oct.,
1899
Date of Application, 16411 July, 1000
Complete Specification Left, 26th Sept., 1399-Accepted, 28th Oct., 1899
PROVISIONAL SPECIFICATION.
Improvements in Covers for Man, Hand, and other Holes in Vessels
Subject to internal Pressure,
I, JOHN CHARLES RAYMOND OKES, The Limes, Brondesbury Park, Middlesex,
Engineer, do hereby declare the nature of this invention to be as follows: -
The improvements herein specified have reference principally to the form and
mode of attachment of covers in steam boilers and other vessels subject to internal
pressures, such as covers of openings or apertures necessary for the insertion and
fixing of steam or other tubes or for man and mud hole covers and also for any
similar class of work.
For the purpose of closing the apertures used for the insertion of generating
tubes of boilers-especially in the water-tube class-it is customary to fix the
outside cover by a single central bolt and nut, the bolt being held on the inside
by a cross bar; hence the bolt has to sustain or carry the entire strain due to the
steam pressure upon the area of the inside of the cover which is, with high
It is evident that in case of a fracture
pressures of steam, very considerable.
of this bolt the steam and water would escape into the stokehole or boiler house.
In some cases, to avoid this danger, covers are made oval or oblong and corre-
sponding holes are made in the boiler plate but of smaller area so as to allow
of an internal lap, thus, the joint being on the inside, no danger exists—but
this formation necessitates a larger opening in the boiler plate than is sometimes
convenient or even possible on account of the stays and various other reasons.
To obviate this difficulty and yet make a perfectly safe joint is the object of
the present invention.
:
I propose making the openings in the boiler or other plate circular in form and
of different diameters as regards the inside and outside of the plate, the internal
diameter being the larger of the two. The cover of the opening is also tapered
to fit the opening in the plate, and in order that the said cover may be passed
through the opening, two flat surfaces, cutting away about one half of the taper,
are formed upon the peripheries of the cover and two corresponding or similar
flats are made in the opening in the boiler plate. By this device the cover can
be passed through the opening from the front by being placed upon its side and
when it is through the opening in the boiler front can be turned half round so
that the smaller diameter comes to the front, also by rotating the cover in its
place, the flats or parts cut away in the cover and the boiler plate can be brought
into contact with those parts not cut away and hence the escape of steam or
water be avoided and danger prevented in the event of a fracture of the main
central bolt.
It is evident that the principle embodied in this invention may be carried out
in various ways though obtaining the same desired end or effect.
Dated this 12th day of July 1899.

page_text: Improvements in Covers for Man, Hand, and other Holes in Vessels
Subject to Internal Pressure.
I, JOHN CHARLES RAYMOND OKES, The Limes, Brondesbury Park, Middlesex,
Engineer, do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement:-
The improvements herein specified have reference principally to the form and
mode of attachment of covers in steam boilers and other vessels subject to internal
pressures, such as covers of openings or apertures necessary for the insertion and
fixing of steam or other tubes or for man or mud hole covers and also for any
similar class of work.
For the purpose of closing the apertures used for the insertion of generating
tubes of boilers especially in the water-tube class-it is customary to fix the
outside cover by a single central bolt and nut, the bolt being held on the inside
by a cross bar, hence the bolt has to sustain or carry the entire strain due to the
steam pressure upon the area of the inside of the cover which is, with high
pressures of steam, very considerable. It is evident that in case of a fracture
of this bolt, the steam and water would escape into the stokehole or boiler house.
In some cases, to avoid this danger, covers are made oval or oblong and corre
sponding holes are made in the boiler plates but of smaller area so as to allow
of an internal lap, thus, the joint being on the inside, no danger exists—but
this formation necessitates a larger opening in the boiler plate than is sometimes
convenient or even possible on account of the stays and various other reasons.
To obviate this difficulty and yet make a perfectly safe joint is the object of
the present invention.
I propose making the openings in the boiler or other plate circular in form and
of different diameters as regards the inside and outside of the plate, the internal
diameter being the larger of the two. The cover of the opening is also tapered
to fit the opening in the plate; in order that the said cover may be passed
through the opening two flat surfaces, cutting away about one half of the taper,
are formed upon the peripheries of the covers and two corresponding or similar
flats are made in the opening in the boiler plate. By this device the cover can
be passed through the opening from the front by being placed upon its side and
when it is through the opening in the boiler front it can be turned half round so
that the smaller diameter comes to the front, also by rotating the cover in its
place, the flats or parts cut away in the cover and the boiler plate can be brought
into contact with those parts not cut away and hence the escape of steam or
water be avoided and danger prevented in the event of a fracture of the main
central bolt.
In order to enable my invention to be clearly understood I now proceed to describe
the same by aid of the accompanying sheet of drawings in which
Fig. I represents in plan a portion of an outer shell of a boiler with the cover
in position.
Fig. II is a sectional side elevation of a portion of boiler shell showing opening,
and
Fig. III is a plan of ditto.
Fig. IV is a sectional side elevation showing a portion of boiler shell with
cover in position.
Fig. Vis a plan of cover showing taper and flats.
Figs. VI and VII represent a cover and opening made with "steps" in place
of taper.

page_text: Similar letters refer to similar parts_throughout.
Referring more particularly to Figs. I II III IV and VA is a portion of
the shell of boiler or other vessel in which is cut a circular opening, the edge
being tapered, the larger diameter being on the inside of plate. B B are two
flats or recesses cutting away about half the taper. C is the cover plate which
is also tapered to fit the opening and on its periphery two flats D D are formed.
Attached to this plate or forming part thereof is a stud or bolt E which is
screwed at the end and being passed through the tripod F is held firmly in
position by the nut G. In place of the tripod F a hollow hemisphere may be
used thus forming a joint on the outside of boiler shell.
Figs. VI and VII show another way of making the opening and cover-
iz. in place of a taper "steps" are formed, the flats or recesses in the circum-
ference of the opening and the flats on the periphery of the cover being
substantially as already described.
Where the projection of the cover inside the boiler or other vessel is not
objectionable, it is unnecessary for the opening and the periphery of the cover
to be tapered or stepped, the flats or recesses in the circumference of the open-
ing and the flats on the periphery of the cover only being formed.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. Openings or orifices and their covers in the shells or walls of vessels
subjected to internal pressure, the said openings being circular in
form and tapered, the larger diameter, being on the inside of the
vessel the covers being tapered to fit and having two parallel flats upon them,
and in the seat two corresponding recesses or flats whereby the cover may be
passed through the opening-all as shown in the accompanying drawings and
described herein.
2. In the outer shell of a boiler or other vessel the formation of circular open-
ings of different diameters as regards the front and back of the plate with
corresponding covers fitting them--such covers being passed through the open-
ings from the outside by means of flats on the larger diameter of cover and
recesses in the smaller diameter of the opening in the plate as described and shown
in the accompanying drawing for the purpose stated."
3. In the outer shell of a boiler or other vessel, the formation of circular
openings and covers (the joint being on the inside)-the forming of two parallel
flats on the periphery of the cover (which is of larger diameter than the opening)
and two corresponding recesses in the circumference of the opening, thus allow-
ing the cover to be passed through from the outside, substantially as described
and for the purpose set forth..