GB2188664A

GB2188664A - Grating and frame assembly

Info

Publication number: GB2188664A
Application number: GB08608132A
Authority: GB
Inventors: Anthony Charles Elmer; Dennis William Sains; Keith Stanley Thompson
Original assignee: BRICKHOUSE DUDLEY Manufacturing
Current assignee: BRICKHOUSE DUDLEY Manufacturing
Priority date: 1986-04-03
Filing date: 1986-04-03
Publication date: 1987-10-07
Also published as: GB8608132D0; GB2188664B

Abstract

A grating (12) and frame (10) assembly comprises a frame (10) adapted to be embedded in the ground over a manhole, sump, sewer, gulley or the like, the frame (10) affording an access opening (11) and the grating (12) adapted to be received in the frame (12), the grating providing drainage apertures. The grating (12) is captively mounted in the frame (10) for pivotal movement between an open condition in which access can be gained to the manhole, and a closed condition in which the access opening (11) is closed by the grating, the grating (12) comprising a pair of endmost grating bars (20,25) and intermediate grating bars (21,22,23,24), the endmost and intermediate grating bars extending in a generally common direction across the grating (12), each of the grating bars (20-25) being connected at or adjacent at least one of its ends, by a bridge bar (42,43,38,39,44,46), to an adjacent grating bar, and at least one of the intermediate grating bars (21-24) being connected at a position between its ends to an adjacent intermediate grating bar by a further bridge bar (40,41), the grating being deformable in a direction transverse to the grating bars (20-24) as the grating is moved to its closed condition, sufficient to permit a first co-operating means (69) of the grating (12) to engage with a second co-operating means (71,73) of the frame (10). <IMAGE>

Description

SPECIFICATION Improvements in or relating to grating and frame assemblies This invention relates to a grating and frame assembly of the kind, hereinafter referred to as of the kind specified, comprising a frame adapted to be embedded in the ground over a manhole, sump, sewer, gulley or the like, (hereinafter generically referred to as "a man hole") the frame affording an access opening, and a grating adapted to be received in the frame, the grating providing drainage apertures.

Assemblies of the kind specified are known wherein the grating is made in a ductile material, and the combination of this material and the configuration in which the grating is made, permits the grating to be deformed to permit it being received in the frame.

Such as assembly is described in our previous published Application No. GB 2119836, in which the grating is of a generally zig-zag configuration, but the grating for such as assembly has proved difficult to manufacture.

It is an object of the present invention to provide a new or improved grating and frame assembly of the kind specified which overcomes or reduces the above mentioned problem.

According to a first aspect of the invention we provide a grating and frame assembly of the kind specified, the grating being captively mounted in the frame for pivotal movement between an open condition in which access can be gained to the manhole, and a closed condition in which the access opening is closed by the grating, the grating comprising a pair of endmost grating bars, and intermediate grating bars, the endmost and intermediate grating bars extending in a generally common direction across the grating, each of the grating bars being connected at or adjacent at least one of its ends, by a bridge bar, to an adacent grating bar, and at least one of the intermediate grating bars being connected at a position between its ends to an adjacent intermediate grating bar by a further bridge bar, the grating being deformable in a direction transverse to the grating bars as the grating is moved to its closed condition, sufficient to permit a first co-operating means of the grating to engage with a second co-operating means of the frame.

It has been found that connecting at least one of the intermediate grating bars to an adjacent intermediate grating bar at a position between its ends, considerably facilitates the manufacturing casting process. Moreover, even though connecting at least one of the intermediate bars in this manner to another bar, reduces the ability of the ductile grating to deform, sufficient deformation can be achieved to permit locking of the grating in the frame as the first and second co-operating formations engage.

Preferably, the frame is generally rectangular, in which case the grating may be pivoted about an axis generally parallel with one pair of sides, nd the endmost grating bars may lie adjacent each side of the one pair of sides of the frame, and extend from one of the other pair of sides of the frame, to an opposite side.

Where the frame has a pair of longer sides and a pair of shorter sides, preferably the axis of pivot of the grating is parallel to and adjacent one of the shorter sides of the frame.

Preferably the first co-operating means of the grating comprises a plurality of formations, each of which co-operates with a corresponding formation comprising the second co-operating means of the frame. In a preferred arrangement, a formation is provided at or adjacent each corner of the grating, and a corresponding formation is provided at an appropriate position in or on the frame.

The endmost grating bars may each comprise a loop of material over part of the length of the grating bar only. The loop may comprise a pair of grating bar parts which extend generally alongside one another and are connected at their ends. Each of the endmost grating bars may be connected to adjacent intermediate grating bar at the end remote from the loop, via a bridge bar.

It has been found that this loop arrangement also considerably facilitates the manufacturing casting process.

Each of the grating bars may have projections which extend into the spaces between the grating bars. Further, each grating bar may comprise an end region at each end which is generally parallel with one pair of sides of the rectangle, and a mid region connecting the end regions, which is transverse to each of the sides of the rectangle.

The projections which extend into the spaces between the grating bars, are preferably provided at the junctions of the parallel and transverse grating bar regions.

It has been found that such a configuration reduces the risk of small wheels such as perambulator wheels for example, passing between the grating bars and thereby becoming wedged between the grating bars.

The endmost grating bars may have projections which extend into the spaces between the endmost grating bars and the adjacent sides of the frame. Preferably the frame provides seatings which may engage the underside of the grating, for example the undersides of the bridge bars, to support the grating in the frame.

The seatings may be provided by projections which extend inwardly of the access opening afforded by the frame, from at least the other pair of sides of the frame between which the grating bars extend.

The frame may provide lands along the side thereof adjacent the pivotal axis of the grating, which lands may extend into the access opening afforded by the frame, and may be aligned with the projections of the adjacent endmost grating bar and co-operate with projections of the adjacent endmost grating bar at least as the grating is deformed during closing.

Preferably the grating is retained in the frame in both its open and closed conditions, by hinge pins which are received within aligned passages of the grating and the frame.

For example, the pins may comprise Bissell pins or other pins which may be driven into position and then resist withdrawal, whilst permitting relative rotation i.e. pivotal movement of the grating relative to the frame.

As the grating is deformed as the grating is closed in the frame, the lands of the frame and corresponding projections of the endmost grating bar may engage so that no stress is applied to the hinge pins, but any stress is taken by the engaging lands and projections.

The frame may have passages for hinge pins at each end of the other pair of sides of the frame, e.g. the longer sides, and a second co-operating means may be provided at each side of the one pair of sides of the frame e.g.

each short side, so that the grating may be selectively orientated in the frame for pivoting about an axis parallel to and adjacent one or other of the sides of the one pair of sides i.e.

in one of two alternative opposite orientations.

Thus the assembly is double handed in that the pivotal axis of the grating can be arranged to be at either end of the frame.

It will be appreciated that gratings are usually arranged to be pivoted to the open condition towards the direction from which traffic passes over the assembly. This is so that in the event of an open grating being struck by traffic, the grating merely slams shut.

The frame may have lands which extend into the access opening from both sides of the one pair of sides e.g. from both the short sides of the rectangle. The lands at the side opposite to the side parallel and adjacent to which the grating is pivoted, would not therefore be used.

The frame may comprise an outwardly extending flange along at least three sides thereof, which flange may in use, be embedded in the ground.

The frame may be not provided with such a flange along the side which in use lies adjacent a kerb, for example one or other of the sides of the other, longer, pair of sides of the frame.

The or each formation of the first co-operating means may comprise a rabbet formation provided in a projection from the endmost grating bar at the side of the frame opposite to the pivotal axis. The or each formation of the second co-operating means of the frame may comprise a shoulder beneath which the rabbet formation of the corresponding formation of the grating, may engage. The or each projection of the grating may have an inclined surface which tapers upwardly beneath the rabbet formation. Thus as the grating is closed, the inclined surface of the or each projection of the endmost grating bar will engage the frame, and as a downwards force is imposed on the grating, the grating will be deformed until the or each rabbet formation of the grating snap interengages beneath the corresponding shoulder of the formation of the frame.

Thus the grating may only be removed from the frame by levering the endmost grating bar remote from the hinge to cause the grating to become deformed sufficiently to allow the rabbet formation or formations of the grating to clear the shoulder or shoulders of the frame.

The grating may conveniently be made by casting in ductile iron, although may be made by other methods, and in other materials as required.

According to a second aspect of the invention we provide an assembly of the kind specificed in which the frame is generally rectangular when the frame has at or adjacent each corner thereof, a passage which extends generally parallel to one pair of sides of the frame, the passages at each end of the frame being generally aligned, the grating also having a passage or passages which may be selectively aligned with the pair of passages at one or other end of the frame, a hinge pin being provided in each of the adjacent passages to provide a pivotal connection between the grating and the frame to permit the grating to be moved between an open condition in which access may be gained to the manhole beneath, and a closed condition, and to maintain the grating captive in the frame in both the open and closed conditions.

The assembly according to the second aspect of the invention may be any of the features of the assembly according to the first aspect of the invention.

The invention will now be described with the aid of the accompanying drawings in which: Figure 1 is a plan view of a grating and frame assembly in accordance with the invention.

Figure 2 is a cross section through the grating of Fig. 1, along the lines ll-ll but showing only part of the frame.

Referring to the drawings, a grating and frame assembly comprises a frame 10 which in use is located above a manhole, and affords an access opening 1 in which a grating 12 is received.

The frame 10 is gnerally rectangular, having four sides, one pair of sides 12 and 14, being shorter than the other pair of sides 15, 16.

One longer side 15, and each of the shorter sides 13, 14, have an outwardly extending flange 17 which in use is embedded in the ground around the manhole, apertures 18 being provided in the flange 17 to facilitate keying in the ground.

The frame 10 also includes an upstanding wall 19 which extends around all four sides 13, 14, 15, 16.

The grating 12 comprises, in the present example, six grating bars 20-25.

The grating bars 20-25 each extend generally from one longer side 16 of the rectangular frame 10 towards the other longer side 15.

The endmost grating bar 20 lies generally alongside the shorter side 13 of the frame 10, and defines a loop 26 comprising two grating bar parts 30 and 31, which extend generally alongside one another and are connected together at their ends in the regions indicated at 32 and 33. The endmost grating bar 25 at the opposite end of the grating which lies generally alongside the shorter side 14 of the frame 10 similarly defines a loop 34 comprising a pair of grating bar parts 35 and 36 which extend generally alongside one another and are connected together at their ends at regions indicated at 37 and 38.

The intermediate grating bars 22 and 23 are connected together by bridge bars 38 and 39 at both their opposite ends, and by further bridge bars 40 and 41 at positions between their ends.

The endmost grating bar 20 is connected to adjacent intermediate grating bar 21 by a bridge bar 42 whilst grating bar 21 is connected at its other end to the pair of grating bars 22, 23, by a further bridge bar 43. The grating bars 22 and 23 are connected at their other ends by a further bridge bar 44 to the next adjacent intermediate grating bar 24, which in turn is connected at its opposite end via a bridge bar 38' to the other endmost bridge bar 25.

Each of the grating bars 20-25 have end regions indicated at 20a-25a which extend generally parallel to the shorter sides 13 and 14 of the rectangular frame 10, and opposite end regions, indicated at 20ti25b which are again generally parallel to the shorter sides 13 and 14 of the rectangular frame 10.

Connecting the end regions, 20a-25a, 20ti25b are respective mid regions indicated at 20c-25c which regions are each inclined both to the shorter sides 13 and 14 of the rectangular frame 10, and to the longer sides 15 and 16 of the rectangular frame 10. At the junctions where the end parts 20a-25b and 201 > -25b interconnect the mid regions 20c-25c, each grating bar 20, 22, 23, 25, has at least one projection 50-57 which projections extend into the spaces between the grating bars 20-25.

Endmost grating bar 25 also has projections 26, 27 which extend into the space between bar 25 and the wall 19 of frame side 14. The endmost grating bar 20 also has a pair of further projections 66 which extend into the space between bar 20 and the adjacent side 13 of the frame 10, and have a further purpose which will be explained hereinafter.

By this configuration, cycle wheels for example are prevented from entering the spaces between the grating bars 20-25.

The endmost grating bar 20 also has further projections adjacent the corner of the frame 10, as indicated at 60 and 61. Each projection 60, 61 has a passage 62, 63 respectively, which is aligned with a corresponding passage 64, 65, provided in the adjacent part of the upstanding wall 19 of the longer sides 15, 16 of the frame 10.

Hinge pins H are provided in the passages 62, 64 and 63, 65 to provide a pivotal connection between the grating 12 and the frame 10, to enable the grating 12 to be pivoted between open and closed conditions, about a pivotal axis indicated at A. When the grating 12 is in its open condition, access can be gained to the manhole beneath; when the grating 12 is in its closed condition as shown, the access opening 11 afforded by the frame 10 is closed by the grating 12.

The other endmost grating bar 25 also has projections 67, 68 adjacent the corners of the frame 10. Each projection 67, 68 has a rabbet formation 69 at its end, and beneath the rabbet formation 69, an inclined surface 70. The upstanding wall 19 of the side 14 of the frame 10 adjacent the projections 67, 68 has a shoulder 71 and a rebate 72 beneath the shoulder 71.

The grating 12 is made of a ductile material, namely ductile iron, and thus it will be appreciated that when the grating 12 is closed in the frame, the inclined surfaces 70 will engage upper surfaces 73 of the shoulders 7 1 If a sufficient downwards force is imposed upon the grating 12, the grating 12 will be deformed because of both the material from which the grating is made, and the serpentlike configuration of the grating bars 20-25.

Of course, grating bar 25 will move more than grating bar 24, which in turn will move more than grating bars 22 and 23, which will in their turn move more than grating bars 21 and 20. However, particularly because the grating 12 is pivoted about axis A which is adjacent the shorter side 13 of the rectangular frame 10, the grating will deform sufficiently to permit the rabbet formations 69 of the grating 12 to be received beneath the shoulders 71 of the frame with a snap inter-engagement.

Such snap inter-engagement occurs at two positions i.e. each side 15, 16, of the frame 10 enabling the grating 12 to be firmly locked within the frame 10.

When it is desired to remove the grating 12 from the frame 10, it is necessary to apply a levering force to at least grating bar 25 sufficient to enable the shoulders 71 and rabbet formation 69 of each of the projections 67 and 68, to disengage.

It can be seen that the upstanding wall 19 of the frame 10 has lands 75 adjacent each projection 66 of the end grating bar 20 which extend into the space between the upstanding wall 19 and the grating bar 20.

At least as the grating 12 is deformed, as the grating is closed, the projections 66 and lands 75 are brought into engagement. Thus little or no force is imposed upon the hinge pins H received in the passages 61, 64; 63, 65, which permit of pivotal movement of the grating 12 relative to the frame 10.

It has been found, surprisingly, that even where two or more of the grating bars are rigidly connected together as described, the grating 12 may still be deformed sufficiently to enable the snap inter-engagement of the grating 12 in the frame as described.

As shown, it is intended that traffic passes over the grating 12 in the direction shown by the arrows B. Thus if for example, the grating 12 is left inadvertently in an open position and is struck by traffic, the grating 12 will simply be slammed shut. Where it is intended that traffic passes in an opposite direction to the direction indicated by arrow B, it would be desirable for the grating to be hinged about a pivotal axis at the opposite side of the frame in order to provide the same advantage.

Thus the frame 10 is substantially symmetrical in that passages like passages 64, 65, are also provided at the opposite in wall 19 adjacent short side 14 of the frame 10, as indicated at 64', 65'.

Further, the upstanding wall 19 along the short side 14 of the frame 10 also has lands 75' in similar positions to lands 75 of short side 13.

Further, the upstanding wall 19 at the shorter side 13 of the frame 12 also has shoulder formations indicated at 71', at each corner.

Thus if desired, instead of receiving the grating 12 in the frame 10 so that grating 12 pivots about a pivot axis A adjacent the shorter side 13 of the frame, if desired, the grating 12 may be received in the frame 10 in an opposite orientation with the hinge pins received in passages 63, 65' and 62, 64' to provide the pivotal connection, in which case the rabbet formations 69 of the projections 67 and 68 may engage with the formations 71' along the shorter side 13 of the frame 10.

Thus the grating and frame assembly described is double handed although it will be appreciated that the grating 12 is normally made captive with the frame 10 in both its open and closed conditions by insertion of the hinge pins within the passages 62 and 63 and one or other pair 64, 65, or 65', 64' respectively, of the passages in the upstanding wall 19, during manufacture.

The grating 12 is supported on seatings S which extend inwardly of the access opening 11 on the longer sides 15, 16 of the frame, and engage the undersides of the bridge bars 38/44, 43/39.

Various modifications may be made to the assembly described without departing from the scope of the invention.

For example, instead of the grating bars 22 and 23 being rigidly connected by the bridge bars 38, 39, 40 and 41, if desired, others of the intermediate grating bars 21 to 24 may be rigidly connected together.

It is not essential for the end grating bars 20 and 25 to provide loops of material as described, although in an alternative arrangement it may be necessary to provide further projections to extend into the spaces between the endmost grating bars 20 and 25 and the next adjacent bars 21, 24, or for the endmost grating bars 20 and 25 to be of an alternative configuration to minimise the gap between the endmost grating bars 20, 25, and the adjacent intermediate grating bar 21 or 24 and/or between the adjacent upstanding wall 11 of the frame 10.

Although the assembly described has a rectangular frame 10 having two short sides 13, 14, and two longer sides 15, 16, if desired, the sides may be of equal lengths. Further, the frame and grating may be of entirely different configurations such as triangular, or polygonal of more than four sides.

The features disclosed in the foregoing description, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, or a class or group of substances or compositions, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. A grating and frame assembly of the kind specified, the grating being captively mounted in the frame for pivotal movement between an open condition in which access can be gained to the manhole, and a closed condition in which the access opening is closed by the grating, the grating comprising a pair of endmost grating bars, and intermediate grating bars, the endmost and intermediate grating bars extending in a generally common direction across the grating, each of the greating bars being connected at or adjacent at least one of its ends, by a bridge bar, to an adjacent grating bar, and at least one of the intermediate grating bars being connected at a position between its ends to an adjacent intermediate grating bar by a further bridge bar, the grating being deformable in a direction transverse to the grating bars as the grating is moved to its closed condition, sufficient to permit a first co-operating means of the grating to engage with a second co-operating means of the frame.

2. An assembly according to claim 1 wherein the frame is generally rectangular and is pivoted about an axis generally parallel with one pair of sides.

3. An assembly according to claim 2 wherein the endmost grating bars lie adjacent each side of the one pair of sides of the frame, and extend from one of the other pair of sides of the frame, to an opposite side.

4. An assembly according to claim 2 or claim 3 wherein the frame has a pair of longer sides and a pair of shorter sides, the axis of pivot of the grating being parallel to and adjacent one of the shorter sides of the frame.

5. An assembly according to any one of the preceding claims wherein the first co-operating means of the grating comprises a plurality of formations, each of which co-operates with a corresponding formation comprising the second co-operating means of the frame.

6. An assembly according to claim 5 wherein a formation is provided at or adjacent each corner of the grating, and a corresponding formation is provided at an appropriate position in or on the frame.

7. An assembly according to any one of the preceding claims wherein the endmost grating bars each comprise a loop of material over part of the length of the grating bar only.

8. An assembly according to claim 7 wherein the loop comprises a pair of grating bars which extend generally alongside one another and are connected at their ends.

9. An assembly according to claim 7 or claim 8 wherein each of the endmost grating bars are connected to adjacent intermediate grating bars at the end remote from the loop, via a bridge bar.

10. An assembly according to any one of the preceding claims wherein each of the grating bars have projections which extend into the spaces between the grating bars.

11. An assembly according to any one of claims 2 to 10 where appendant to claim 2 wherein each grating bar comprises an end region at each end which is generally parallel with the one pair of sides of the rectangle, and a mid region connecting the end regions, which is transverse to each of the sides of the rectangle.

12. An assembly according to claim 11 where appendant to claim 10 wherein the projections which extend into the spaces between the grating bars, are provided at the junctions of the parallel and transverse grating bar regions.

13. An assembly according to any one of claims 1 to 12 wherein the endmost grating bars have projections which extend into the spaces between the endmost grating bars and the adjacent sides of the frame.

14. An assembly according to any one of the preceding claims wherein the frame provides seatings which engage the uinderside of the grating to support the grating in the frame.

15. An assembly according to claim 14 wherein the seatings are provided by projections which extend inwardly of the access opening afforded by the frame, from at least the pair of sides of the frame between which the grating bars extend.

16. An assembly according to any one of claims 13 to 15 where appendant to claim 2 wherein the frame provides lands along the side thereof adjacent the pivotal axis of the grating, which lands may extend into the access opening afforded by the frame, and are aligned with the projections of the adjacent endmost grating bar and co-operate with projections of the adjacent endmost grating bar at least as the grating is deformed during closing.

17. An assembly according to any one of the preceding claims wherein the grating is retained in the frame in both its open and closed conditions, by hinge pins which are received within aligned passages of the grating and the frame.

18. An assembly according to claim 17 wherein the pins comprise pins which are driven into position and then resist with drawai, whilst permitting relative pivotal movement of the grating relative to the frame.

19. An assembly according to claim 17 or claim 18 where appendant to claim 2, wherein the frame has passages for hinge pins at each end of the other pair of sides of the frame, and a second co-operating means is provided at each side of the one pair of sides of the frame so that the grating may be selectively orientated in the frame for pivoting about an axis parallel to and adjacent one or other of the sides of the one pair of sides in one of two alternative opposite orientations.

20. An assembly according to claim 19 wherein the frame has lands which extend into the access opening from both sides of the one pair of sides.

21. An assembly according to any one of the preceding claims wherein the frame comprises an outwardly extending flange along at least three sides thereof, which flange is, in use, embedded in the ground.

22. An assembly according to any one of the preceding claims wherein the or each formation of the first co-operating means comprises a rabbet formation provided in a projection from the endmost grating bar at the side of the frame opposite to the pivotal axis.

23. An assembly according to claim 22 wherein the or each formation of the second co-operating means of the frame comprises a shoulder beneath which the rabbet formation of the corresponding formation of the grating engages.

24. An assembly according to claim 22 or claim 23 wherein an inclined surface which tapers upwardly beneath the rabbet formation has an inclined surface which tapers upwardly beneath the rabbet formation.

25. An assembly according to any one- of the preceding claims wherein the grating is made by casting in ductile iron.

26. An assembly of the kind specified in which the frame is generally rectangular when the frame has at or adjacent each corner thereof, a passage which extends generally parallel to one pair of sides of the frame, the passages at each end of the frame being generally aligned, the grating also having a passage or passages which may be selectively aligned with the pair of passages at one or other end of the frame, a hinge pin being provided in each of the adjacent passages to provide a pivotal connection between the grating and the frame to permit the grating to be moved between an open condition in which access may be gained to the manhole beneath, and a closed condition, and to maintain the grating captive in the frame in both the open and closed conditions.

27. An assembly according to claim 26 which has any of the features of the assembly according to any one of claims 1 to 25.

28. An assembly substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

29. Any novel feature or novel combination of features disclosed herein and/or shown in the accompanying drawings.