*Improvements in Manhole, Inspection, and like Coverings.
Year: 1898

page_text: PROVISIONAL SPECIFICATION..
*Improvements in Manhole, Inspection, and like Coverings.
I, GEORGE WILLIAM BELDAM (M.A. Cantab), Engineer and Ironfounder, of
Boston Lodge, Brentford, in the County of Middlesex, do hereby declare the
nature of this invention to be as follows:-
This invention has reference to covers or gratings for street or road manholes,
inspection boxes, air gratings, and the like, and, more particularly, to the type
of such covers, which consist of a metallic body, with blocks of wood or suitable
material in it, the blocks projecting above the surface of the metal, and forming
the "tread" of the cover; and the invention has for its object, amongst other
things, to provide certain improvements, hereinafter described, by which these
covers are rendered more serviceable, and are generally improved in the respects
as hereafter specified.
According to one part of this invention, the blocks of wood, or other suitable
material, of covers of the characters described, are made tapered or conical, the
inclination of the sides towards each other being from below; and they are
introduced into their sockets or apertures from below; the sockets themselves
being also tapered or coned. The blocks project through or above the covers
to the usual degree; and they are held up in position in the special supporting
means.
According to one construction, the blocks are held up in position in the cover
by a plate below their inner ends, the two parts being screwed together or fastened
by suitable means.
In another construction, the blocks are provided with heads or flanges below
the cover plate, which prevent their being pulled or knocked out, and the lower
holding plate supports the blocks by these heads.
The blocks, or plugs, according to one special form, are circular; whilst the
ordinary forms are rectangular, or other suitable shape.
By these constructions, it will be seen, the blocks cannot become loose, or
knocked or drawn out of place, or the cover become dangerous to traffic."
According to a modification under this invention, the blocks of manhole and
like covers, are tapered inwards from the outside, and fit in corresponding tapered
sockets, and are held therein, that is prevented from becoming loose or pulled
[out, (which they are very liable to, as ordinarily arranged) by means of a coach
screw or screws, or other suitable screw, bolt, or nail, or the like, which are
passed through a hole in a bottom plate below the blocks on the cover.
the case of round or circular wood blocks, these are prevented from being with-
drawn, by being unscrewed from the outside of the cover, by providing the hole
in the bottom of the cover, out of the centre of the wood block, and introducing
the fastening screw or the like, excentrically into the block.
And in
In some cases, instead of the blocks being tapered, they may be parallel, and
fastened as described; or they may be of any other suitable shape or form, and
fitted to any manhole, air grating, or other cover.
In the case of air tight manhole covers, according to this invention, there is.

page_text: employed, between the cover or upper part, and the frame, a packing, the cover
and frame being provided with grooves or recesses, or the like, forming a seating
or rest for the packing. In one case, the packing is introduced between a lower
plate, supporting "tread" blocks, in the cover, and an internal flange in the
frame; whilst the fastening mean between the cover and lower plate consists
of a central stud or bolt with suitable washers between them, and a gun metal
cap on the end of same, by which the cover is screwed down to a cross bar held
on the frame; the bar being let into, and fastened or locked to the inner side
of the frame, by means of projections or slots or the like, and a central bolt
fastened to the above bar by a square head. Thus the whole is screwed down by
the cap nut on the outside."
In lieu of the cross bar referred to, for fastening the cover, this is effected
under a modification, by projections and slots, either on the frame, or on the
plates; that is, if slots are provided in the frame, then projections are formed in
the plate, and vice versa. By this construction, the cross bar would be dispensed
with.
According to another form, the plate or cover itself is made air tight with its
frame, by providing a packing between its own outer edge, and an internal flange
on the frame; or, by introducing the packing on the upper edge of the frame,
or, again, by introducing it (the packing) in a groove on the inside of the frame,
on which the outer edge of the cover bears; the cover, in any case, being screwed
down by an internal fixed bar or plate, to make the air tight joint.
In some cases, especially in the case of cast iron covers, they may be made in
sections and by the above construction, the parts, that is the whole plate and
parts, are made air tight; and they can be removed together or separately in
a very little time.
By the above characteristics, the blocks or covers can be renewed very quickly,
and at little cost, when required; while, normally, they cannot become loose,
or be taken out from outside; and, by the constructions described, covers of
manholes, and the like, can be made perfectly air and gas tight; and, at the
same time, access can be had to them, very easily and quickly.
Dated this 12th day of March 1900
CHEESBROUGH & ROYSTON,
plicant's Patent Agents, 15, Water Street, Liverpool.
Improvements in Manhole, Inspection, and like Coverings.
,
I, GEORGE WILLIAM BELDAM (M.A. Cantab), Engineer and Ironfounder, of
Boston Lodge, Brentford, in the County of Middlesex, 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:-
-
This invention has reference to covers or gratings for street or road manholes,
inspection boxes, air gratings, and the like; and, more particularly, to the type
of such covers, which consist of a metallic body, with blocks of wood or suitable
material in it, the blocks projecting above the surface of the metal, and forming
the "tread" of the cover; and the invention has for its object, amongst other
things, to provide certain improvements, hereinafter described, by which these
covers are rendered more serviceable, and are generally improved in the respects
as hereafter specified.

page_text: The invention will be described with the aid of the accompanying drawings,
which illustrate various modifications or constructions thereunder, and these
modifications or constructions are hereafter described in the order of the number
of the figures by which they are marked.
According to one part of this invention, the blocks of wood, or other suitable
material, of covers of the characters described, are made tapered or conical, the
inclination of the sides towards each other being from below; and they are
introduced into their sockets or apertures from below; the sockets themselves
being also tapered or coned. The blocks project through or above the covers
to the usual degree; and they are held up in position by special supporting
means.
:
Figure 1 and Figure are, respectively, cross elevation, and plan, of a cover
illustrating the construction, in which the blocks are held up in position in the
cover by a plate below their inner ends, the two parts being screwed together,
or fastened by suitable means. In the drawings, is the frame of the manhole
or other street or road chamber, and bis the metal body of the cover are the
tapered wood blocks, which are introduced into their sockets-also correspond-
ingly tapered from below, and d is a plate below the inner or lower ends of the
blocks, by which they are supported and held up in position in the cover plate
or body b; the plate d being screwed up to 6 by the screw stud or bolt e. f
denotes holes through the plate d for ventilation:
Figure 3 is a sectional elevation shewing another or modified means of sup
porting the blocks in the body b, or plate. This consists of wedges g, which
are driven up into or in between the blocks and the sockets in the frame. These
wedges may take any suitable form, such for example, as those illustrated in
Figure 3. Figures: 4, 4, 4", 4°, 4" and 4" are cross sections and elevations
showing castings containing different forms and sizes of holes, into which the
tapered wood blocks are inserted, as shewn.
In the modifications shewn in Figures 5 and 6; and Figures 7 and 8-which
are respectively sectional elevations and plans-the blocks c are provided with
heads or flanges; e below the cover plate b, for preventing their being pulled
or knocked out from the road surface, in lieu of the inverted tapered form shewn
in Figures 1 and 3. The lower holding plated on which the heads c¹ of the
blocks rest, holds them in position in the covers, similarly as in the former case.
The blocks or plugs c are shewn of circular form they may, however, be of
the ordinary rectangular form, or of other suitable shape.
By these constructions, it will be seen the blocks cannot become loose, or
knocked or drawn out of place, or the cover become dangerous to traffic.
According to a modification under this invention, the blocks of manhole, and
like covers, are round or circular in form, and are tapered inwards from the
outside, and fit in corresponding tapered sockets, and are held therein, that is
prevented from becoming loose or pulled out, (which they are very liable to, as
ordinarily arranged) by means of a coach screw or screws, or other suitable
screw, bolt, or mail, or the like, which is or are introduced through a hole or
holes disposed out of the centre of the socket in a bottom plate below the blocks
on the cover; and by this eccentric arrangement, these circular blocks are
prevented from being unscrewed from the outside of the cover, and withdrawn:
This modification is shewn in Figures 9 and 10 in cross section, and in plan
of the underside, respectively.
The wood blocks c. as shewn in Figure 9, are tapered inwards from the outside,
and are introduced into their sockets in the cover b. h are the coach screws
which are screwed up into the block e from the underside, and pass through
holes in the bottom plate of the block sockets.
As is shown in the drawings, the screws are eccentric to the axes of the blocks,
and consequently they cannot be rotated in their sockets and removed from
outside accidentally, or otherwise, without first removing the coach screws h.
In some cases, instead of the blocks being tapered, they may be parallel, and

page_text: fastened as described; or they may be of any other suitable shape or form, and
fitted to any manhole, air grating, or other cover.
I will now describe the construction of air. tight manhole covers for roads
and streets, according to this invention. In this case, the cover and frame are
provided with grooves or recesses, or like provisions, forming a seating or rest,
one for the other; and also, between the cover or upper part, and the frame,
there is employed a packing.
Various forms and modifications of these constructions, according to this part
of the invention, are given in the drawings, and will now be described
One of these modifications is shewn in Figure 11. In this case, the frame a
has an inwardly projecting flange a', on the upper surface of which there is a
groove or recess extending all round it; and in this groove there is a ring k of
comparatively soft material constituting a packing, on the upper edge of which
the outer edge of the plate rests, this edge being also provided with a groove
or recess, as shewn..
The cover band plate d are fastened together by a central stud or bolt e, the
lower end of this stud being cast, or otherwise secured, to the cross bar 1, held
at its ends in suitable slots or grooves, similar to those in Figure 13, in the
flange a A gun metal cap e¹ or nut, is fitted over the upper end of e; and
washers ee, of suitable material, are fitted respectively under the cap e¹, or
nut, and between the body b and plate d. It will be seen that when the cap e¹
is screwed up, the whole cover is forced down into its seat and held in position,
and all the parts are held in place.
A modified means of. holding the covers down in their frames is illustrated
in Figures 12 and 13, which are respectively cross section, and inside face view.
In this case, projections m are provided on the edge of the body of the cover
or plate, as the case may be, and corresponding recesses m¹ are provided on the
inside face of the frame a. A vertical slot m³ leads from the upper edge of the
frame to the horizontal slot; and the upper surface of these slots m¹ are inclined
as shewn in Figure 13, in order that when the cover is slipped into position and
turned, the slot m will force the stud and cover downwards on to the packing.
The converse of this mode of fastening consists in providing projections on
the underside of the frame, and slots or openings in the edge of the cover, equiva-
lently to those first described.
In these cases, by these constructions, the cross bars 7, referred to, are dispensed
with.
Another modification, in section, is shewn in Figure 14. In this case, there
is shewn a simple cast iron or cast metal cover b, while the flange a¹ of the frame
is near the upper part of it, and is provided with a groove all round it, and the
outer edge of the cover b (which has also a recess) rests on the packing k.
This cover is held down in position by a central screw bolt e, and is held in
the frame a similarly to that shewn in Figure 11.
Further modifications of air tight manhole and similar covers are shewn in
Figures 15, 16, 17 and 18, in which the packing is introduced and held on the
upper edge of the frame, a. In this upper edge, a groove or recess is formed,
in which the packing ring k is received, and on which the outer edge 6 of the
cover b rests, and presses. The covers b, in these cases, are held down in position
by fastening bars, or by the projection and slot mode of fastening above described;
or, if they are sufficiently heavy, the weight-of the metal cover may serve alone
to keep the covers in place, and make them air tight.
In Figure 15, the groove or recess in the frame a is towards the outside of
the upper edge; whilst in Figure 16 it is in the centre, and the outer edge b¹ of
the cover b fits into this recess, and rests on the packing k in the bottom of it.
In Figure 17, the groove or recess in which the packing & rests lies considerably
below the upper edge of the frame a inside; whilst the outer edge 61 of the groove
fits over these upwardly projecting parts of the frame, as shewn, and rests on
the packing k

page_text: The modification in Figure 18 is the same as that shewn in Figure.17; except
the form of body of the cover.
Figures 19 to 25 shew modifications of the construction shewn in Figures 15
to 18, in which the frames are provided with grooves or recesses at their upper
edges, and the covers with corresponding provisions on their outer edges, and
forming seats; but in lieu of the packing in the grooves or recesses in the upper
edge of the frame, the outer edge of the cover itself. takes the place of the packing,
and enters into, and rests in such grooves or recesses.
The modification or construction, of the man-hole covers with grooves or recesses
in the upper edge of the frame in Figures 19 and 20, are the equivalents of
those shewn in Figures 15 and 16 with the packings in the grooves or recesses;
the outer edges 61 being extended as shewn, and filling, more or less, the grooves
or recesses of the frame, and resting upon them. And, again, the constructions
in Figures 21 and 22 are the equivalents of those shewn in Figures 17 and 18.
In Figures 23 and 24, the edge of the cover b rests on the upper: face of the
frame a, while the groove or recess is provided in the underside of the outer edge
of the cover, and a projecting ledge a³ is formed upon the upper edge of the
frame, and normally stands inside this recess. By this groove and construction
of frame, it will be seen, that wet and dirt cannot get down into the cover or
manhole.
The construction in Figure 24 is the same as that shewn in Figure 23, except
that there is no bearing part between the cover and frame flange; within the
ledge a³.
Then again, as regards the modification shewn in Figure 25, it is similar in
construction to that shewn in Figure 24, except that the bearing surface of the.
outer edge of the cover, and the upper edge of the frame, are inclined down-
wards and outwards, instead of being horizontal.
In covers resting on frame edges such as described, it is not necessary-to have
a long flange extending inwards at the bottom as indicated in dotted lines at
in Figure 25, but in any case it is preferred to leave a small flange y, as indicated
in this and other-figures; so as to catch and hold the cover in
breaking at its outer edge.
case of its
In view of making the edges 1, and the grooves in the frame rounded, or as
shewn, they may be wedged or V shaped, and of any depth. As to the means
of holding these covers in position, this may be any of those described, or of
other suitable kinds; and in other respects than those specified, the bodies of
the covers may be of different forms.
Figures 26 and 27 shew two other modified constructions, in which the packing
is employed to make the air tight joint. In Figure 26, the packing is placed
in a groove on the inner face of an inclined upper edge of the frame; whilst the
outer edge of the cover is also inclined, and at the angle rests on the top of the
packing. In Figure 27, the packing lies in a groove in the angle of the flange a
on the frame and a groove is formed in the lower outer corner of the cover b,
and rests upon it.
It is to be stated that the several improvements herein described may be used
separately as well as conjointly, in different combinations and arrangements,
as may be deemed desirable or advantageous, under different conditions of the
application of the invention.
Having now particularly described and ascertained the nature of this inven-"
tion and in what manner the same is to be performed, I declare that what I
claim is:-
1. The improvement in manhole, inspection hole, and similar street or road
chamber coverings, consisting of wood or equivalent blocks, fitted and introduced
in position in the covers thereof, and held in position from the inside; sub-
stantially as set forth.
'
2. In manhole, inspection hole, and similar street or road chamber coverings

page_text: having wood or equivalent blocks, fitted and held in position from within, the
constructions and arrangements thereof, substantially as set forth with reference
to Figures 1 and 2; 5 and 6; 7 and 8; and Figures 3 and 4 of the drawings,
respectively.
3. In manhole, inspection hole, and similar street or road chamber coverings,
the improvement consisting of circular wood or equivalent blocks introduced
into sockets in the cover thereof from outside, and held therein by coach screws,
or similar fastenings, introduced eccentrically into the blocks through the
socket from the inside; substantially as set forth.
4. The herein described improved manhole, inspection hole, or similar street
or road chamber coverings, having a joint between the cover, and its frame;
substantially as set forth with reference to Figures 1 to 27.
5. The manhole, inspection hole, and similar street or road chamber covering,
having parts arranged, constructed, and adapted to operate as shewn in and set
forth with reference to Figures 11, 12, 13, 14, 15, 16, 17, 18, 26, and 27, of the
drawings.
.
6. In manhole, inspection hole, or similar street or road chamber coverings
of the character herein described and claimed in the claiming clauses 4 and 5,
the constructions of frames and covers as shewn in and set forth with reference
to Figures 19 to 25 of the drawings.
'
1
1000
CHEESBROUGH & ROYSTON,
Applicant's Patent Agents, 15, Water Street, Liverpool.