Improvements in the Covers and Frames of Manholes used for Drainage Work, Electric Light, and other purposes.
Year: 1893

page_text: Date of Application, 18th Aug., 1893
Complete Specification Left, 14th June, 1894-Accepted, 11th Aug., 1894
PROVISIONAL DIECIFICATION.
Improvements in the Covers and Frames of Manholes used for
Drainage Work, Electric Light, and other purposes.
FREDERICK CHARLES LYNDE 25 Cross Street, Manchester, Civil and Sanitary
Engineer, do hereby declare the nature of this invention to be as follows:-
The object of my invention is to facilitate the releasing and raising of manhole
and other covers from their beds or frames and for locking the same. I accomplish
this in the following manner. The cover is provided with one or more holes tapped
with a screw thread. Below each hole and fixed to the frame or forming part of
it is a block. A screw or screws is or are inserted into the hole or holes in the
cover and upon turning these screws round they reach the blocks which form
resistance or in certain designs of frame the frame itself may form resistance. By
continuing to turn the screws the cover is thereby lifted out of its frame or bed
and can then easily be removed. Under ordinary conditions I provide each hole
with a plug so as to prevent dirt, obstruction or damage taking place within the
screwed holes of the cover. I obtain a similar result by arranging the lifting
screws so as to pass into the block upon the frame and providing each screw with a
collar and square head or other equivalent arrangement for turning it round. The
collar or its equivalent causes pressure through turning round the screw on the
underside of the plate and thus the plate is lifted thereby.
I may provide the holes with screwed bushes, plugs or plates of brass or other
material so as to avoid rust, or I may make the screws of similar material or both.
In some cases, I may have loose screwed blocks so as to be self adjusting with
the screw fitted into them. These blocks may rest on suitably formed brackets or
supports, or I may form the resistance pieces by a bar or bars across the frame.
I may also cause the locking down of the cover into its frame by securing it with
the screws described above, in which case, a double collar under the screw head to
embrace the portion of the cover through which the screw passes might be formed
by a loose washer subsequently fastened upon the screw.
The head of the screw
may be protected with a cover fixed over it.
Dated this 17th day of August 1893.
COMPLETE SPECIFICATION.
Improvements in the Covers and Frames of Manholes used for
Drainage Work, Electric Light, and other purposes.
FREDERICK CHARLES LYNDE 25 Cross Street Manchester, Civil and Sanitary
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 object of my invention is to facilitate the releasing and raising of manhole
and other covers from their beds or frames or for locking the same. I accomplish
this in the following manner. The manhole cover A is provided with one or more
holes tapped with a screw thread see B. B. Below each hole and fixed to the
frame C. is a block D. D. which may form part of the frame. A screw E is
inserted into the hole B in the cover and upon turning it round the screw reaches
the block D which forms a resistance or in certain designs of frames the frame
[Price 8d1

page_text: itself may form the resistance. By continuing to turn the screw the cover is
thereby lifted out of the frame and can be easily removed. Under ordinary con-
ditions I provide each hole with a plug F so as to prevent dirt obstruction or damage
In order to lock the cover
taking place within the screwed holes of the cover.
plate into the frame I may form upon the end of the screw plug F a screw of
reduced diameter, which may screw into the block D when prepared to receive it.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is-
The use and manufacture of manhole frames and covers substantially as described
and illustrated by the annexed drawing.
FRED. C. LYNDE.