Improvements in Covers for Inspection-chambers, Man-holes, and the like.
Year: 1896

page_text: Date of Application, 23rd Oct., 1896-Accepted, 23rd Jan., 1897
COMPLETE SPECIFICATION.
Improvements in Covers for Inspection-chambers, Man-holes, and
the like.
I, JOHN YOUNG, trading as J. Young & Co. at Kennington Cross, London S.E.,
Glass, Lead and Iron Merchants, 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 :-
My invention relates to improvements in covers for inspection chambers as
provided at certain intervals in sewers, and the conduits for electric-light,
telegraphy and other mains, and the inlets of coal-cellars and the like, and has
for its object to provide such a cover that may be easily placed in position and
locked after use, and as easily unlocked and removed when necessary, and which
shall operate for the exclusion of wet and dirt more effectually than by the
methods of constructing such covers hitherto employed, and it is my intention that
the said cover shall be commercially known as "Youngs screw cover."
To facilitate a clear and perfect knowledge of my invention, and the manner of
its application and use, as hereinafter described, I have hereunto appended a sheet
of drawings in which
Fig. 1 is a plan view of the frame for receiving and holding the said cover,
Fig. 2 being a central section of the same upon the line A. B.
Fig. 3 is a plan of the said cover while Fig. 4 is a central section of the same
taken upon the line C, D.
Fig. 5 is a ground section shewing my improved cover in position, enclosing a
coal-cellar, sewer-manhole, inspection-chamber or the like, and in which the frame
is shewn in cross section similar to Fig. 2, while the cover is shewn in section
taken upon the line E. F. of Fig. 3, the object of the latter section being to show
morely clearly the locking arrangement.
For the purposes of my invention I cast or otherwise produce of iron or other
suitable metal a circular frame A, of any dimensions, according to the purpose for
which it is intended, upon the upper or top face of which is formed an annular race
or groove B, while upon its inner periphery is formed one or more (preferably two)
projecting ridges or tonques C and C, each of a length equal to that of a third of
the circumferential dimensions of the said inner periphery, or thereabouts, and
diametrically opposite to each other, both of which are out of parallel with the
upper and lower surfaces of A, with their initial ends a slightly higher than their
opposite ends b, as shewn in Figs. 2 and 5. The said frame may be built into the
mouth D of the inspection chamber or the like in the usual way as shewn in
Fig. 5.
A circular cast iron or other metallic disc or plate E forms a cover or lid for the
said frame, and has upon its under surface an annular ridge o arranged to fit into,
and occupy the annular groove B in A, and a pair of lugs or ears d and d¹, arranged
to engage with the ridges or tonques C and C. The said plate may be provided
upon its outer face with any well known form of tapered projection such as G, for
the reception of a like shaped key or spanner in the usual way for the partial
rotation of the said plate, but I do not claim the said projection nor the key or
spanner therefor as forming part of my invention.
In first placing the cover upon the frame the lugs d and d' would be dropped
between the ends and clear of the ridges C and C, when, if a key or spanner be

page_text: applied to the tonque or projection G, and the said cover be rotated in the direction
of the arrow Fig. 3, the said lugs d and d¹ thereon, would first pass idly under the
ends a of the said ridges C and C', but by reason of the opposite ends of these b
being lower than a, a continuation of the rotation of the said cover E would cause
the said lugs d d¹ to engage with and grip the under surfaces of C and C¹ and so
draw down and lock the said cover firmly upon A with its annular ridge C in the
groove B.
The outer end of the under surface of E would be arranged to fit closely down
upon the upper surface of A, but for the inspection covers of electric light,
telegraphy, telephony and other mains, the usual plastic substance employed for
sealing these may be deposited in the groove B before placing the cover in position,
but for the inspection chambers of sewers, and the inlets of coal cellars where such
cement is not used, water may be placed in the said groove and so form a water seal
for preventing the escape of sewer gas, and such rain as may percolate between the
edges of E and A. would have the same effect.
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 :-
In an improved cover for inspection chambers, manholes, coal cellars inlets and the
like the combination of a frame A, having upon its upper surface an annular groove B,
and upon its inner periphery one or more ridges such as C and C¹, with
plate E, having upon its under surface an annular ridge c for engaging with the
groove B, and lugs such as d d for engaging with the ridges C C upon A with
means for partially rotating the said plate substantially as and for the purposes
herein described and shewn by the accompanying drawings.
Dated this 23rd day of October 1896.
GEO. THOS. HYDE,
1 Broad Street Buildings, Liverpool Street, London, E.C.,
Agent for Applicant.