Improvements in Closing Manholes and like Openings in Boilers, Tanks, and other Vessels.
Year: 1897

page_text: Date of Application, 25th May, 1897
Complete Specification Left, 16th Nov., 1897-Accepted, 29th Jan., 1898
PROVISIONAL SPECIFICATION.
Improvements in Closing Manholes and like Openings in Boilers,
Tanks, and other Vessels.
I, ALFRED HEWENS, of High Road, Hayes, in the County of Middlesex, Engineer,
do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in inside manhole and like covers and in
means for fixing the same whereby a tight joint is obtained in a simple and expe-
ditious manner without the necessity of employing bolts or screws.
In carrying out my invention I form the cover of the shape of the opening in
the boiler, tank or other vessel to be closed, and I provide the said cover with a
flange or rim of a channel shape and designed to receive the packing which may
be of any suitable material.
'
To fix the cover in position in the manhole or other opening, I provide the face
or top side of the cover with two projecting ribs forming between them an under-
cut keyway adapted to receive a key or wedge longer than the diameter of the
manhole or other opening and preferably having its inclined faces which fit into
the undercut faces of the ribs made concave in order to facilitate its withdrawal
from the cover when it has been in position for any length of time.
As the cover of the manhole or other opening is inside the vessel, it will be
obvious that suitable means must be provided for holding the cover in position in
the opening whilst my wedge is being driven in. To this end I form suitable holes
or recesses in the two projecting ribs upon the manhole cover and I advantage-
ously employ a tool consisting of a curved bar having inwardly bent ends adapted
to engage with the recesses or holes in the ribs upon the cover, the said tool being
operated by a screw winch, lever, or by other suitable means.
0
100%
Improvements in Closing Manholes and like Openings in Boilers,
Tanks, and other Vessels.
I, ALFRED HEWENS, of High Road, Hayes, in the County of 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:
This invention relates to improvements in inside manhole and like covers and in

page_text: means for fixing the same whereby a tight joint is obtained in a simple and
expeditious manner without the necessity of employing bolts or screws.
In carrying out my invention I form the cover of the shape of the opening in
the boiler, tank or other vessel to be closed, and I provide the said cover with a
flange or rim of a channel shape and designed to receive the packing which may
be of any suitable material.
To fix the cover in position in the manhole or other opening, I provide the face
or top side of the cover with two projecting ribs forming between them an undercut
keyway adapted to receive a key or, wedge longer than the diameter of the man-
hole or other opening and preferably having its inclined faces, which fit into the
undercut faces of the ribs, made concave in order to facilitate its withdrawal from
the cover when it has been in position for any, length of time.
In the case where the cover is to be used for closing circular manholes or open-
ings not having lateral recesses to permit of the insertion of the cover, I form the
cover in halves, which are hinged together at the top side thereof, and I provide
packing between the two inner edges of the half covers so that when the cover is
placed in position the wedge securely holds the two hinged parts together and the
packing forms a tight joint between them.
41.1.1
As the cover of the manhole or other opening is inside the vessel, it will be
obvious that 'suitable means must be provided for holding it in position in the
opening whilst my wedge is being driven in. To this end I provide the cover with
eyes, the said eyes being preferably cast in the cover. When the cover has been
passed through the manhole or opening to the inside of the boiler, tank or other
vessel, it is held in position against the inside of the said opening by means of
string, wire or the like passed through the eyes.
4
To enable my invention to be fully understood, I will describe it by reference
to the accompanying drawings, in which:
Figure 1 is a plan of a cover made according to my invention:
Figure 2 is a section on the line 2-2 Figure 1:
Figure 3 is a plan of a cover made to close a circular hole or opening:
Figure 4 is a sectional plan of a circular hinged cover made according to my
invention:
Figure 5 is a section on the line 5-5 Figure 4:
Figures 4 and 5 are drawn to a larger scale than Figures 1, 2 and 3.
A is a portion of a boiler, tank or other vessel, and B is a manhole formed
therein. a is my cover, the said cover being of the shape of the opening B. In
Figures 1 and 2 it is shewn oval or elongated, and in Figures 3 and 4, circular.
is the flange or rim of channel shape formed around the periphery of the
cover a, and c is the packing of any suitable material inserted in the said channel
shaped rim b. The cover made of such a size that when placed in position inside
the manhole or other opening, the channel shaped portion overlaps the edge of
the said hole or opening as clearly indicated in Figures 1 and 2.
d, are the ribs formed upon the top side of the cover, the said ribs being under-
cut so as to form an undercut keyway between them, and c is the wedge designed
to fit into the said keyway. The tapered edges of the wedge or key e are shewn
concave so as to facilitate the withdrawal of the wedge e when it is desired to
remove the cover.
The keys, to facilitate removal when covers are fixed in cramped positions, are
provided with a sunk. hole,at. the, driving end, into which is placed a small hand
set which renders it an easy matter to draw the key without burring or injuring it
in any way.
ff are the eyes which are of wire and are preferably cast in the cover, the said
eyes being as above described, designed to receive string or wire for holding the
cover in position against the edge of the manhole or other opening whilst the
wedge e is being driven home.
Where the manhole or other opening is circular in form, the said hole must be
provided with lateral recesses in order that the cover may be passed through the

page_text: opening from the outside to the inside of the boiler, tank or other vessel and the
said cover must in consequence be provided with lateral extensions a¹, a¹ as shewn
in Figure 3 to cover the said lateral recesses when the cover has been passed
through the manhole.
Or, as above described, the cover may be hinged so that it can be folded up when
being passed through the manhole. Figures 4 and 5 illustrate a cover of this
description, the said cover, being made in halves a, a which are hinged together
at the under side thereof by a pin g made of hard wood or other material. The
division of the cover is made along a line at right angles to the keyway so that
when the key is driven home, the halves are held tightly against one another as
long as the key or wedge remains in position. is the packing which is placed in
channels formed in the inner faces of the halves of the cover so as to ensure a
tight joint when the cover is in position. Figure 5 shews in dotted lines the
manner in which the cover is folded when it is being passed through the manhole.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
-
1. An inside cover for closing manholes and like openings in boilers, tanks and
other vessels having a peripheral flange or rim of a channel shape for receiving
packing and ribs upon its top side adapted to form a keyway for receiving a wedge
or key, substantially as, and for the purpose, herein before described.
2. Closing manholes and like openings in boilers, tanks and other vessels by an
inside cover a having a peripheral channel shaped flange or rim b for receiving
packing and undercut ribs d, d with a wedge or key e combined and arranged as
herein before described and illustrated in the several figures of the accompanying
drawings.
3. In a circular inside cover for closing manholes and like openings in boilers,
tanks and other vessels of the kind described in Claim 1, forming the said cover
in halves hinged together at the top side, substantially as, and for the purpose,
herein before described.
4. The improved covers for manholes and like openings in boilers, tanks and
other vessels, hereinbefore described and illustrated in Figures 1 and 2; 3; and
4 and 5 of the accompanying drawings.
.
1007
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.