Improvements in Manhole, Sludge, Mudhole, and like Doors and the Method of Manufacturing same
Year: 1898

page_text: Date of Application, 28th July, 1898
Complete Specification Left, 28th Apr., 1899-Accepted; 10th June, 1899.
PROVISIONAL SPECIFICATION..
Improvements in Manhole, Sludge, Mudhole, and like Doors and the
Method of Manufacturing same.
I, WILLIAM MUIRHEAD, of The Mount Vernon Iron and Steel Company,
Shettleston, Lanarkshire, Manufacturer, do hereby declare the nature of my
invention to be as follows:
This invention has reference to and comprises improvements in manhole,
sludge, mudhole, and like doors for boilers, tanks, or other vessels, and the
method of manufacturing same, by which the liability of the joints to be blown
out is minimised and the manhole doors can be made lighter without decrease
of effective strength.
Hitherto manhole or other like doors of the class arranged to bear on the
inside edge of a turned in flange around the manhole when formed with a groove
to receive the edge of the flange, have had this groove turned out of the metal
thus necessitating the use of heavier doors than are otherwise required.
By the improvements of this invention the groove is formed in the manhole or
like door by pressing or stamping and the metal displaced is caused to form a
projection opposite the groove which allows the use of lighter doors, and still
maintains the thickness and strength of the metal.
To effect this the manhole door is pressed while hot between a die formed with a
flat surface having a projecting ring on same corresponding to the groove
desired, and a matrix formed with a flat surface and a groove therein, corresponding
to the shape of the projection desired.
Such doors formed with a check all round instead of a groove may also be
treated in the same way, as also all forms of embossed manhole or other doors
used in connection with inwardly turned flanges on the manholes, suitable forms
of dies and matrices being used.
By this method of manufacture any shape of manhole door desired may
formed with equal facility.
be
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Improvements in Manhole, Sludge, Mudhole, and like Doors and the
Method of Manufacturing same.
I, WILLIAM MUIRHEAD, of The Mount Vernon Iron and Steel Company,
Shettleston, Lanarkshire, Manufacturer, do hereby declare the nature of my
077

page_text: invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement in writing, reference
being made to the accompanying drawings:-
This invention has reference to and comprises improvements in manhole,
sludge, mudhole, and like doors for boilers, tanks, or other vessels, and the
method of manufacturing same, by which the liability of the joints to be blown
out is minimised and the manhole doors can be made lighter without decreases
of effective strength.
And in order that my said invention may be properly understood I have here-
unto appended one sheet of explanatory drawings in which Figure 1 shows a
longitudinal section and Figure 2 a plan of one form of manhole door manu-
factured according to my improvements while Figures 3 and 4 show cross
sections of other forms.
Hitherto manhole or other like doors of the class arranged to bear on the
inside edge of a turned in flange around the manhole when formed with a groove
to receive the edge of the flange, have had this groove turned out of the metal
thus necessitating the use of heavier doors than are otherwise required.
By the improvements of this invention the groove A¹ as shown in Figures 1, 2,
and 3, is formed in the manhole or like door A by pressing or stamping and
the metal displaced is caused to form a projection A opposite the groove which
allows the use of lighter doors, and still maintains the thickness and strength
of the metal.
To effect this in the case of a flat manhole door it is pressed while hot between
a die formed with a flat surface having a projecting ring on same corresponding
to the groove desired, and a matrix formed with a flat surface and a groove
therein, corresponding to the shape of the projection desired. For the production
of doors of the forms shown in Figures 1, 2, and 3,. correspondingly shaped dies
and matrices are used.
Such doors B as illustrated by Figure 4 formed with a check B₁ all round
instead of a groove may also be treated in the same way, as also all forms of
embossed manhole or other doors used in connection with inwardly turned
flanges on the manholes, suitable forms of dies and matrices being used.
By this method of manufacture any shape of manhole door desired may be
formed with equal facility.
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
First. The improved method of manufacturing manhole, sludge, mudhole, and
like doors substantially as herein described and as examples illustrated by the
accompanying drawings.
Second. Manhole, sludge, mudhole, and like doors formed with a groove or
check all round the edge and corresponding projection manufactured by stamping
or pressing while hot substantially as herein described and as examples illustrated
by the accompanying drawings.
Third. The manufacture of manhole, sludge, mudhole, and like doors sub-
stantially in the manner and by the process herein described.
Dated the 25th dox of Anril 1800
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.