Improvements in Drain or Sewer Gratings with Lock-up Covers
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Drain or Sewer Gratings with Lock-up Covers,
EDWARD MAY MUNRO, HENRY BRECKNELL and HUGH INNES ROGERS, of Edin-
burgh Chambers, Baldwin Street, Bristol, Electrical and Mechanical Engineers,
do hereby declare the nature of this invention to be as follows:-
Our invention relates to improvements in gratings having a hinged cover or
top provided with a locking device for the purpose of preventing the tops or
covers from being removed or opened excepting only with the tools or appliances
for that purpose, an arrangement which is found advisable when gulley gratings
or the like are placed in public highways and particularly in connection with
gratings which form manholes or handholes which provide access to the drainage
of points &c. used in tramway road construction.
Our invention, consists of improved means of forming locking device in a
grating which consists of a frame and cover.
The cover is fitted with a screw tapped into its side or end, and the frame has
a hole or recess formed in it for the purpose of receiving the end of screw which
may be revolved so as to advance and enter the hole or recess before mentioned in
side or end of frame.
We carry out our invention in the following manner. The screw is formed
having a head conveniently shaped to receive a spanner or key or the like for
the purpose of revolving it. The screw has its other end turned down or otherwise
conveniently shaped so as to readily engage in the hole or recess in grating
frame. A recess is cored or otherwise formed in the grating end or side, the
said recess being somewhat larger than the diameter of the screw before named.
The screw is placed in position in the recess in grating and a metal or alloy
in a molten or plastic state is poured or otherwise introduced into the recess
in grating from an opening suitably arranged for that purpose, and the said
metal or alloy upon cooling or hardening in its position in the recess and
around the screw thread forms the nut or female screw. The screw used for the
forming of the nut may be a dummy screw and used only to form a core when
running the metal or alloy into the recess and the screw itself as used in the
grating and forming a part of the locking device may be produced in quantity
by any improved means and inserted after the core or dummy screw has been
withdrawn.
If preferred the grating may be cored or drilled a size smaller than the diameter
of the screw and afterwards tapped out or screwed by any approved means to
receive the screw before mentioned. One or more screws may be employed
and the device is applicable to gratings whether hinged or otherwise.
Having now particularly described the construction of our invention we show
its manipulation as follows:-When the grating is free to be lifted out of its
frame, the screw is revolved so as to withdraw within the face or faces bounding
its edges or extreme dimensions and forms no obstruction to its being lifted
out of its frame.
When the grating is closed and it is desired to lock it in that position the

page_text: screw is revolved by means of the spanner key or tommybar or other appliance
provided for that purpose & the screw advances until its end enters the hole or
recess in frame and is then partly in the grating' and partly into the frame which
prevents the grating being removed or withdrawn from the frame.
E. M. MUNRO.
H. I. ROGERS.
H. BRECKNELL.
We, EDWARD MAY MUNRO, HENRY BRECKNELL and HUGH INNES ROGERS, of
Edinburgh Chambers, Baldwin Street, Bristol, Engineers, 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;-
-
Our invention relates to improvements in gratings or gulley traps for sewers
and drains, having for its object to provide a locking device which will prevent
the gratings or tops from being lifted or removed except by the use of the special
fool or appliance provided for unlocking them; this locking arrangement is
specially useful in connection with gratings which cover manholes or handholes
to provide access to points and the like in tramway road construction.
This invention consists essentially in the addition of a screw locking device
engaging in the end or side of the grating with a hole or recess in the outer
frame to receive the end of the screw.
Our invention will be more fully described in connection with the accompany-
ing sheet of drawings, in which Figure 1 is a section, and Fig. 2 a plan, of a
grating and frame complete, and Fig. 3 is a section, on an enlarged scale, show-
ing a suitable method of forming the nut in the end of the grating to receive the
screw.
A is an ordinary sewer grating, hinged at a to the sides of the frame B, and C
is the line of contact of the frame with the brickwork or pipe of the sewer; a
screwthreaded bolt D) engages in a nut F or tapped hole in the end or side of the
grating furthest from the hinge, a hole E, conveniently larger than the diameter
of the bolt, is made in the frame, in which the head of the bolt enters when it
has been advanced by turning the head of the bolt by a spanner or other
appliance prepared therefor; a suitable opening or recess G is made in the
grating to permit the insertion of the spanner to operate the bolt head; the end
of the bolt may be turned down, coned, or rounded, as shown in Fig. 3, that; it
may enter the hole E more readily.
A suitable method of making a nut or female screw for the bolt is shown in
Fig. 3 a recess F is cored or otherwise formed in the end of the grating which
is considerably larger than the screw; a screwthreaded mandril of the exact size
and thread of the screw bolts to be used, is placed in position in the centre of
the recess, and through an opening f suitably arranged above the core, a metal
er alloy in a molten or plastic state, is poured or otherwise introduced into the
recess, and as the metal cools or hardens, a nut or female screw is formed around
the mandril; when the mandril is removed, a screwthreaded hole is provided,
ready for the insertion of the bolt D when required.
The bolts when required to be produced in large quantities, are cast with the
threads and heads complete, from any suitable metal, such as brass, gun-metal
and the like, and these engaging in nuts made as described from white metal, will
make effective screws, unaffected by damp or changes of temperature,

page_text: If preferred, two or more bolts may be used for locking the grating, and the
may also be used effectively with gratings that are lifted bodily from their
frames.
The grating, frame, and screwing arrangement being provided as described,
the operation of the same is as follows:-the grating being in position in the
frame, the bolt-head is turned by the spanner or other appliance, and the screw-
thread advances the end of the bolt until it engages in the hole in the frame
provided as shown in the drawings; the grating is thus locked in its place, and
can only be opened by the operation of the spanner on the head of the bolt with-
drawing it until the end is out of contact with the frame.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is :-
In the construction of sewer gratings and the like, the provision of screw-
threaded bolts with heads and keys to operate them, which will advance the ends
of the bolts until they are within recesses in the frame, and the bolts he thus
retained and the gratings locked by the action of the key, substantially as and
for the purpose herein described and set forth in the drawings.
Dated this 12th day of June.
J. G. WESTLAKE,
Applicants' Agent,
2, John Street, Bristol.
J. G. WESTLAKE,
Applicants' Agent,
2, John Street, Bristol.