AN IMPROVED AIR-TIGHT MANHOLE FLAP AND FRAME FOR COVERING OVER SHAFTS TO TO DRAINS, SYPHONS, AND GREASE-RECEIVERS
Year: 1880

page_text: LETTERS PATENT to Arthur Torrington Angell, of 144, Fulham Road, South
Kensington, in the County of Middlesex, for an Invention of "AN IMPROVED
AIR-TIGHT MANHOLE FLAP AND FRAME FOR COVERING OVER SHAFTS TO
PROVISIONAL SPECIFICATION left by the said Arthur Torrington Angell at
the Office of the Commissioners of Patents on the 30th April 1880.
ARTHUR TORRINGTON ANGELL, of 144, Fulham Road, South Kensington, in the
County of Middlesex. "AN IMPROVED AIR-TIGHT MANDOLE FLAP AND FRAME
FOR COVERING OVER SHAFTS TO DRAINS, SYPHONS, AND GREASE-RECEIVERS."
An improved airtight man-hole-flap and frame for covering over shafts to sewers,
syphons, traps to drains, or for any other purpose whatsoever where flaps and
frames are necessary for the purpose of getting access to works of any description
situated under ground, and by their situation liable to get injured by water, damp,
or dust, and where it is necessary from time to time to examine, inspect, or repair
such works. This flap and frame is particularly adapted for covering over syphons,
grease-receivers, and inspection pipes to the drains of domestic houses, where in
confined vaults and areas it is necessary that the shafts built round such syphons,
grease-receivers, and inspection pipos should be kept airtight.
The frame of the manhole consists of two parts, namely, an outer or a principal
frame, to which the flap or lid is hinged and fastened, and an inner frame or rim
running parallel with the inner sides of the main frame upon which the flap or lid
rests when closed. This rim is V shaped on its upper ledge, and presses tightly
upon a strip or tube of indiarubber, felt, or other pliable and airtight substance,
fixed in a groove formed by two projecting flanges running parallel with each other
round the inner side of the flap. The same effect is also produced by fixing the
indiarubber or other substance as aforesaid in a groove formed in the frame, and
a V shaped flange projecting from the underside of the flap or lid. These flaps and
frames can be made of cast-iron, wrought-iron, steel, gun-metal, or various other
metals suitable for the purpose.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Arthur Torrington Angell in the Great Seal Patent Office on the
29th October 1880.
ARTHUR TORRINgton Angell, of 144, Fulham Road, South Kensington, in the
County of Middlesex. "AN IMPROVED AIR-TIGHT MANHOLE FLAP FOR COVERING
OVER SHAFTS TO DRAINS, SYPHONS, AND GREASE-RECEIVERS."
An improved airtight manholo flap and frame for covering over shafts to sewers,
syphons, traps to drains, or for any other purpose whatsoever where flaps and frames
are necessary for getting access to works of any description situated under ground,
and thereby liable to get injured by water, damp, or dust, and where it is necessary
from time to time to examine, inspect, or repair such works. This Invention is
particularly adapted for covering over syphons, traps, grease-receivers, and inspection
pipes to the drains of domestic houses, where in confined vaults and areas it is
necessary that the shafts built around such syphons, grease-receivers, and inspection
pipes should be kept airtight.
The frame of the manhole consists of two parts, namely, an outer or principal
frame to which the flap or lid is hinged, and an inner frame running parallel to the
inner side of the main frame upon which the flap or lid rests when closed. The
rim of this inner frame is V shaped on its upper edge, and presses tightly upon a
strip or tube of india-rubber, felt, or any other pliable and airtight substance fixed
in a groove formed by two projecting flanges running parallel to each other around
the under side of the flap. The same effect is also produced by fixing the india-
rubber, felt, or other pliable substance in a groove formed in the frame, and
a V shaped flange projecting from the under side of the flap or lid. These flaps
and frames are mado of cast-iron by preference, but can also be made of wrought-
iron, gun-metal, or other metal.
For the better explanation and illustration of my said Invention I refer to the
accompanying Drawings, corresponding parts in which are marked by the same
letter.
Figure 2 is a plan of the frame.
Figure 3 is a section taken at the line m, n, on Figure 2.
Figure 4 is a cross-section taken at the line o, p, on Figure 2. Referring to
Figures 3 & 4, the flap closed and locked is shown by dotted lines in the two last
Figures.
Figure 5 is a plan of the underside of the flap.
Figuro 6 is a cross-section of the flap taken at the line q, ?, on Figure 5.
Figure 7 is a longitudinal section of the flap taken at the line s, t, on Figure 5.
The outer frame is shown cast in one piece with the inner frame c, although I
may, when I chose, form the two frames separately and bolt them together.
Corners b³ can be added to the frame for supporting a safety grate as with the
ordinary sewer frame. The flap a is hinged to the frame by means of a rod a³ passing
through two knuckles a', at, cast with the flap and passing through the sides of the
frame. The groove a filled with felt or its equivalent elastic material is shown in
the Drawings as formed on the underside of the flap by incans of projecting and
parallel ribs a³, although I may, when I chose, form this groove on the top face of
the inner frame, in which case the V shaped rim c² would be formed on the underside
of the flap. is a bar hinged or bolted to the side of the inner frame; it is used
for holding up the flap a by catching in the hollow stud bt, as shown in Figure 1,
when it is required to gain access to the drain, etc. At other times it rests upon
the bracket b³, as shown in Figure 2. For holding the felt or its equivalent firmly

page_text: and permanently in the groove I use a solution of india-rubber or its equivalent.
For locking the flap I use a turn-buckle a mounted on a box as which is part and
parcel of the flap a. The distance of the turn-buckle from the under face of the
flap is such that when the latter is down the buckle cannot readily be turned into the
slot a' because of the rim bearing up the weight of the flap, but I insert the wrench,
Figure 8, in the turn-buckle, and pressing upon the flap so as to make the felt
yield I turn the buckle a into the slot a' and so secure a perfectly air-and gas-
tight joint. For opening and raising the flap I use the wrench on the turn-buckle
in the ordinary way. Having turned the buckle round, I pull the end of the
wrench out of the buckle and raise the flap by the web of the wrench d which
catches against the under side of the flap. The slot in the side of the flap giving
access to the turn-buckle, and shown in part in Figure 5, is formed of such a size
as to allow the pin and web of the wrench to pass through with ease, and yet to
present sufficient gripping edge to the web of the wrench when it is desired to
raise the flap. A small cover a³, Figuro 3, is cast or formed on the outer frame
to keep dirt from plugging the slot a³, and so interfering with the action of the
turn-buckle.
Having now fully described my Invention, and the manner in which the same is
to be carried into effect, I wish it to be understood that what I consider new, and
therefore protected by the above in part recited Letters Patent is as follows, viz. :-
In a flap and frame for any of the purposes named the juxta-position of a V shaped
flange and groove filled with india-rubber or its equivalent material, as and for
the purpose hereinbefore described and illustrated in the accompanying Drawings.
In witness whereof, I, the said Arthur Torrington Angell, have hereunto set
my hand and seal, this Twenty sixth day of October, in the year of our
Lord One thousand eight hundred and eighty.
Signed and sealed
in presence of
A. L. DUNNING.
A. T. ANGELL. (L.S.)