AU657370B2 - A concealed releasable hinge means - Google Patents

Description

657370, P/00/011 Regulation 3.2

AUSTRALIA

e Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT r a *c a.

Name of Applicant: Actual Inventor: Address for Service: Invention Title: Details of Associated Provisional Application No: PHILIP GRAHAM BREENE Philip Graham Breene TREVOR DREDGE ASSOCIATES Patent Trade Mark Attorneys 13th Floor, 379 Queen Street BRISBANE, QLD, 4000 (GPO Bix 1339, BRISBANE, 4001) "A Concealed Releasable Hinge Means" Australian Patent Application No.

PK9520 filed 15 November, 1991.

The following statement is a full description of this invention, including the best method of performing it known to me: tt 2 THIS INVENTION relates to a grating assembly employing a concealed releasable hinge means suitable for eleasably coupling two parts of the grating assembly together and in particular but not limited to a grating assembly for a roadway drainage grating suitable for use in conjunction with, and adjacent to, a roadway kerb or raised median for collection of water flowing along the roadway.

The applicant's Australian Patent No. 471,361 teaches a roadway drainage grating having a plurality of spaced water flow through slots which in use extend in the direction of water flow across the grating and in most cases, this is also o the direction of traffic flow along the roadway. The grating is of a "drop in" type in that it drops in to the frame and is removed completely to open and give access to the gully pit. A problem with the aforementioned gratings of a drop in type is that because they are usually employed over a gully pit, from time to time, access to the gully pit is required and such gratings do not provide ease of access to the gully 0 pit. A further problem is that prior gratings are frequently 20 stolen and it would be desirable to inhibit theft.

It is an object of the present invention to alleviate at least to some degree the aforementioned problems associated with the prior art. The following description refers to application of the invention to a roadway grating but it will be appreciated the invention has general application wherever a hinge may be employed.

In one aspect, the invention resides in a grating assembly employing a concealed releasable hinge means, the assembly 3 including a grating, a grating support frame and the concealed hinge means coupling the grating to the grating support frame so that the grating can be pivoted through an angular range of movement between a closed position against the frame and an open position swung away from the frame, the grating being separable from the frame by manipulating the grating to release the hinge means and separate the grating from the frame, said hinge means preventing separation of the frame from the grating unless the hinge means is arranged in a predetermined release position, said hinge means having separation resistance means operative when said hinge means is in the release position to resist separation.

The hinge means preferably comprises decouplable cooperating hinge members on the frame and on the grating such that the grating and frame can be separated.

Advantageously, the hinge members remain mutually captive at all but a selectable release angle within the range of movement of the grating. Preferably, the hinge means comprises opposed pairs of stubs and co-operating open necked recesses so that the stubs can pass through the necks of the recesses when the stubs and necks are aligned at the release angle.

Typically, the stubs are on the frame and the recesses on the grating so that the stubs and recesses are at least partially concealed by an upper surface portion of the grating when the grating is closed. The recesses and the stubs typically include alignable narrow regions which 4 align or partially align at the release angle. The stub preferably includes an eccentrically positioned surface defining the narrow region of the stub, the surface being an undersurface of the stub when the grating is closed and being inclined to the horizontal. Advantageously, the undersurface is inclined slightly to the horizontal and the recess is preferably configured so that it bears on and has to ride over an upper surface of the stub as the grating is removed. This resistance is in order to inhibit separation and thereby enhance the difficulty encountered by a person attempting to pilfer the grating.

In order that the present invention can be more readily understood and be put into practical effect, reference will now be made to the accompanying drawings which illustrate preferred embodiments of the invention and wherein:- Figure 1 is a plan view illustrating a grating having a hinge means according to a preferred embodiment of the "S present invention; Figure 2 is a section drawn to enlarged scale taken through 2-2 of Figure 1; •Figure 3 is a plan view of a grating support frame suitable for use ,with the grating of Figure 1; Figures 4 and 5 are respective longitudinal and transverse sectional views illustrating a grating assembly having a hinge means according to the present invention, the grating assembly is shown in situ and employing the grating of Figure 1 and the grating support frame of Figure 3; Figures 6 and 7 are sectional views illustrating in detail a typical hinge means according to the invention and in this case, as is illustrated in the grating assembly depicted in Figures 4 and Figure 8 is an end view of the grating of Figure 1.

Referring to the drawings and initially to Figures 1 and 2, there is illustrated a grating 10 suitable for use adjacent to a kerb or raised median of a roadway to intercept water flowing along the roadway in the direction of arrow 11 (or in the opposite direction), the grating has a plurality of apertures 12 defined by longitudinal frame members 13 and transverse frame members 14 which define a 0. grid-pattern of apertures, the apertures define water flow .0 through passages having wall portions which in this case are in the form of undersurfaces 15 which recede in the downstream direction according to flow across the grating.

Each of the transverse members 14 also include upstanding steps 16 which intercept flow of water along the longitudinal members 13 (see Figure 4) while the receding surfaces 15 reduce turbulence thereby reducing the tendency of water to "skip" across the top of the grating and assist in improving the hydraulic efficiency of the grating. As can be seen in Figure 2, each transverse grating member is of modified triangular section in which the apices are truncated to form the steps 16. Surfaces 15 may be made flat or concave in shape as indicated in phantom to facilitate easy removal of a pattern from a mould to simplify manufacture by casting.

In Figure 2:t width of a member 14 s width of opening between members 14 w width of lower truncation dl depth of step 16 on the sides of members 14 d2 depth of members 14 below the step 16 The preferred relations between these measurements are as follows:dl lies between 2mm and (dl d2) lies between 0.5 and 2.0 times t; and s lies between 1.0 and 6.0 times t.

In an example generally effective for a kerbside o.

grating, the dimensions are:t dl o t d2 w 6mm s 955*9 It will be seen from the preferred ratios of t and s that the ratio of the open area of the grating to its total area may range from 0.16 to 0.50.

While the direction of flow is normally at 90 degrees to transverse grating members 14, it may be at an angle as low at 30 degrees to these members.

This grating 10 fits in the frame 23 shown in Figure 3, the grating being supported on end rebates 17 and an optional seating 18 to lie flush with the road or gutter 7 surface (see Figures 4 and The frame includes a frame edge 19 which extends round three sides of the frame, the fourth being a relatively thin bar 20. Extensions 21 on the level of rebate 17 are provided to support bar 22 (see Figure 1) during insertion of the grating and prevent the grating from dropping through the frame 23 as it is moved into position.

The grating 10 is hinged within the frame using concealed hinge means by way of a recess 24 in support bars 22, which match respective stubs 25 cast in a corresponding position on the frame 23. The hinge means would permit the roadway edge 26 of the grating to be raised and rotated up and towards the kerb 27 while pivoting on the stubs 25. A more detailed description of the hinge means is given below in relation to Figures 6 and 7.

Figure 5 shows a grating 10 in its frame 23 adjacent 0 a kerb 27 and feeding to a gully pit 28 adjacent a gutter.

0S S The grating 10 and frame 23 combination, are sloped towards S' kerb 27 to conform with the slope of the gutter. Bar 20 of the frame is spaced from the projecting kerb face 30 to give a kerb inlet 29 not appreciably impeded by the thin bar 20. Bar 20 is beneath the projecting face 30 of the kerb inlet 29 and so cannot be subjected to traffic loads.

The overall hydraulic efficiency of the grating as described is increased by at least two factors:- Once the restricted area of opening at the surface has been passed by the flow, the water enters a wider area for free fall into pit 28.

8 The receding undersurfaces of members 14 which face the flow cause the flow to be defli cted into the pit using the energy of the flowing water to improve the capture of water into the pit.

The small height of the steps given by vertical section having measurement dl in proportion to measurement d2 minimises the tendency of the flow to dam up against the members 14 and so minimises the tendency of flow to skip from bar to bar across the grating.

It will be apparent that in certain circumstances only some instead of all of the transverse bars need to have the aforedescribed deflecting means and not all need be of modified triangular section but many other mechanically equivalent arrangements will be apparent to those skilled 15 in the art.

Referring to Figures 6 and 7, there is illustrated in more detail the hinge means by which the grating 10 and frame 23 of the preferred embodiment are coupled together.

As can be seen, each stub 25 protrudes into the respective 20 recesses 24 and in Figure 5, the grating 10 is shown in its •closed position. As can be seen, the stub 25 is generally cylindrical but has a segment removed from its undersurface to provide a flattened side portion 31 while the recess includes a narrow neck shown generally at 32. It will be appreciated that by manipulating the grating and on rotation of the recess 24 relative to the stationary stub and at a suitable angle, the release angle, the minimum width of the stub 25 will be partially aligned with the 9 neck 32. The stub will be able to slide through the neck of the recess as the recess rides over the stub so that the grating can be separated from the frame. The effect of the recess having to slide over the stub is to make a prospective thief think he has the wrong angle due to the resistance he feels. Under this arrangement, two people will usually be required to remove the grating.

As can be seen in Figure 6 and Figure 7, as the stub is located on the frame, the upper surface 35 of the closed grating conceals the stub and recess thus concealing operation of the hinge and coupled with the complexity of the removal process, this provides a relatively secure arrangement to discourage vandalism or theft of the grating 15 Concerning another feature of th hinge means, as can be seen in Figure 5, in use, the recess and stub will be spaced from the projecting face 30 of the kerb 27 so that when the grating is pivoted to its fully open position, it will be positioned beyond the vertical and will rest at a 20 relatively safe angle to prevent inadvertent closure on any •workmen working in thm pit 28.

Other features illustrated in the drawings include the generally tapered form of the longitudinal and transverse members 13 and 14 which serves to assist in removing the cast grating from a mould. Likewise, in the illustrated embodiment as shown in Figure 4 and also in Figure 8, the longitudinal frame members 13 are tapered adjacent their respective opposed ends so that they are strengthened in the middle but the quantity of cast material employed is minimised by this feature.

The illustration of Figure 8 is an end view of the grating of Figure 1 showing that portion of the grating remote from the kerb and as can be seen, the two central transverse frame members include support extensions 33 and 34 which seat on the rebate 18 of the frame illustrated in Figure 3 to provide additional support to the grating.

Whilst the above has been given by way of illustrative example of the present invention, many variations and modifications thereto will be apparent to those skilled in the art without departing from the broad ambit and scope of V o the invention as set forth in the appended c.aims.

o

Claims (6)

1. A grating assembly employing a concealed releasable hinge means, the assembly including a grating, a grating support frame and the concealed hinge means coupling the grating to the grating support frame so that the grating can be pivoted through an angular range of movement between a closed position against the frame and an open position swung away from the frame, the grating being separable from the frame by manipulating the grating to release the hinge means and separate the grating from the frame, sa'ld hinge means preventing separation of the frame from the grating unless the hinge means is arranged in a predetermined release position, said hinge means having separation resistance means operative when said hinge means is in the release position to resist separation.

2. A grating assembly according to claim 1 wherein the hinge means comprises decouplable co-operating hinge members on the frame and on the grating, the hinge members remaining mutually captive at all but a selectable release angle within the range of movement of the grating.

3. A grating assembly according to any one of the preceding claims wherein the hinge means comprises opposed pairs of stubs and co-operating open necked recesses so that the stubs can pass through the necks of the recesses when the scuhs and necks are aligned at the release angle.

4. A grating assembly according to claim 3 wherein the stubs and recesses are at least partially concealed by an upper surface portion of the grating whe:. the grating is closed. 12 A grating assembly according to claim 3 or claim 4 wherein the recesses and the stubs include alignable narrow regions which align or partially align at the release angle.

6. A grating assembly according to any one of the preceding claims wherein when the grating is operatively positioned in a gully pit and the release angle is close to the horizontal, the hinge means preventing release at higher angles.

7. A grating assembly substantially as described with reference to the accompanying drawings. 0 SDATED this 16th day of November, 1992. PHILIP GRAHAM BREENE By his Patent Attorneys *0 e INTELLPRO o S-: o• t ABSTRACT A hinge means by which a grating 10 and frame 23 are coupled together inc Jes a pair of stubs 25 which protrude into respective recesses 24. Stub 25 is generally cylindrical but has a segment removed from its undersurface to provide a flattened side portion 31 while the recess includes a narrow neck 32. By manipulating the grating and on rotation of the recess 24 relative to the stationary stub 25 and at a suitable angle, the release angle, the minimum width of the stub 25 will be partially aligned with the neck 32. The stub will be able to slide throuqh the neck of the recess as the recess rides over the stub so that the grating can be separated from the frame. The effect of the recess having to slide over the stub is to make a prospective thief think he has the wrong angle due to the resistance he feels. Under this arrangement, two people will usually be required to remove the grating as the preferred release angle is close to the horizontal. C o* 0•ee o*«o* *ooo