Improvements in or relating to Manhole Covers for Drains and the like.
Year: 1894

page_text: Date of Application, 5th Apr., 1894
Complete Specification Left, 31st Jan., 1895-Accepted, 9th Mar., 1995
PROVISIONAL SPECIFICATION.
Improvements in or relating to Manhole Covers for Drains
and the like.
I, JOHN JONES of 40 Sydney Street, Chelsea, in the County of Middlesex,
Builder, do hereby declare the nature of this invention to be as follows :-
:―
One of the principal objects of this invention is to hermetically seal the manhole,
and this I effect in the following manner :-
I form the frame or edging which surrounds the top of the manhole preferably
of cast iron and with two channels adapted to serve as water seals if required.
Into the lower of these channels fits a cover consisting substantially of a flat or
dished plate or cover with a downwardly projecting ridge or flange adapted to rest
in the lower of the two channels and upon any suitable packing say for example
asbestos. Above this cover is a plate or skeleton cover which obtains a bearing
upon the frame as under suitable lugs or entering a recess or recesses therein and
carries a central screw adapted to bear upon the centre of the cover; by turning
this screw the cover can be forced down upon the packing in the channel while
the plate or frame is forced upwards and if made in the form of a complete plate
taking a bearing entirely around the inside of the frame may also make a tight
joint therewith.
In the upper of the channels a rim or flange upon a top cover intended to be
level with the roadway or ground surface rests so as if desired to form a water or
other liquid seal while the inner edge of the chanuel is preferably carried up
sufficiently high to engage with the under face of the cover which lying snugly
upon it would make another nearly gas-tight joint.
Dated this 5th day of April 1894.
W. P. THOMPSON & BOULT,
Agents for the Applicant.
Improvements in or relating to Manhole Covers for Drains
and the like.
I, JOHN JONES, of 40 Sydney Street, Chelsea, in the County of Middlesex,
Builder, 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 :-
One of the principal objects of this invention is to hermetically seal the manhole,
and this I effect in the manner hereinafter described with reference to the
accompanying drawings in which
Fig. 1 is a perspective view and Fig. 2 a transverse section of one form of
manhole constructed according to this invention; in Fig. 2 all the parts are shown
but in Fig. 1 the upper cover is omitted.
Like letters indicate like parts in both figures.
In carrying the invention into practice I form the frame or edging A which

page_text: surrounds the top of the manhole preferably of cast iron and with two
channels A' A' adapted to serve as water seals if required. Into the channel A'
fits a cover B consisting substantially of a flat or dished plate with a downwardly
projecting rim or flange B' adapted to rest in this channel and upon any suitable
packing C say for example asbestos, cork or equivalent at the bottom thereof.
Above the cover BI provide a purchase device D consisting of preferably two
bars each of which obtains a bearing against shoulders A³ constituting the upper
walls or surfaces of recesses A' formed in the frame A, and at its centre carries a
screw D adapted to bear upon and if desired, as shown, slightly enter a boss B
provided at the central part of the cover B. By turning the screws D' which may
be done by a suitable key or spanner the cover B can be forced down upon the
packing C in the channel A¹ while the bars D are forced upwards against the
shoulders A thus securing the cover B against being raised by the pressure of
gas within the drain which sometimes happens with manhole covers as hitherto
applied.
In the channel A2 a rin or flange E¹ upon a top cover E intended as shown in
Fig. 2 to be level with the roadway or ground surface F rests so as, if desired, to
form a seal by submersion in water or other liquid or as also shown in this figure
by bearing upon asbestos, cork or equivalent packing G, while the inner edge A³
of the channel A2 is preferably carried up sufficiently high to engage with the
underface of the cover E which, lying snugly upon it would make another nearly
gas-tight joint.
B' are two handles which I prefer to provide on the cover B to facilitate its
removal after the bars D have been disengaged from the recesses A to open the
manhole and its replacement when the manhole is to be closed.
The cover B is preferably dished in the manner shown so as to allow the water
formed by condensation upon it to run into the trough or channel A¹ and form in
conjunction with the rim B' a liquid seal.
The before described device may be modified without departing from the spirit
of the invention for example instead of the purchase device D comprising two bars
as shown it may consist of only one the screw of this bar being arranged to bear
on the centre of the lid or cover B, or it may comprise or consist of a skeleton
cover or frame or a complete plate adapted to take a bearing upon the frame A,
as for example under suitable lugs or entering a recess or recesses therein, and
carrying one or more screws D'. If a complete plate be used as last mentioned it
may be arranged to take a bearing entirely around the inside of the frame A and
make a tight joint therewith.
Instead of the foregoing arrangements I may incline the shoulders A³ or their
equivalent so that they may act as cams upon the ends of the bars I) when
these latter are placed in position, the bar. D in this arrangement being adapted to
bear upon the losses B either directly or through the screws D',
Having now particularly described and ascertaincl the nature of this inven
tion, and in what manner the same is to be performed, I declare that what I
claim is
1. A frame and cover for a drain or similar manhole arranged substantially as
described so that they may readily be either hermetically sealed together when the
hole is to be closed or separated when the hole is to be opened.
2. The combination with a frame and cover for a drain or similar manhole of
means for securing the cover against being raised by pressure within the drain and
maintaining a hermetically tight joint between the cover and frame substantially as
described.
3. The combination with a channelled frame such as A A' for a drain or similar
manhole and a cover such as B therefor of a purchase device such as DD'
substantially as described and illustrated in the accompanying drawings.
+. The combination with a frame for a drain or similar manhole having two
channels such as A³ A² and two covers each having a rim fitting into one of the

page_text: channels of a purchase device such as D D' for holding down the lower cover and
maintaining it hermetically sealed against the frame substantially as and for the
purpose described and illustrated in the accompanying drawings.
5. The combination and arrangement of parts constituting the complete frame
and covers for a drain manhole substantially as described and illustrated in the
accompanying drawings.