AU612279B2

AU612279B2 - Grate fastening means

Info

Publication number: AU612279B2
Application number: AU40029/89A
Authority: AU
Inventors: Michael Graham Richards
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-08-31
Filing date: 1989-08-18
Publication date: 1991-07-04
Anticipated expiration: 2009-08-18
Also published as: AU4002989A

Description

612279 COMMONWEALTH OF AUSTRALIA The Patents Act 1952 Name of Applicant(s): MICHAEL GRAHAM RICHARDS 0040 0 0 0 0O 0 a 4 0 O0 e Address of Applicant(s): 6 FREDERICK STREET NORTHGATE, QUEENSLAND, 4013

AUSTRALIA

Actual Inventor(s): Address for Service: MICHAEL GRAHAM RICHARDS G.R. CULLEN COMPANY, Patent Trade Mark Attorneys, Dalgety House, 79 Eagle Street, Brisbane, Qld. 4000, Australia. 00e4 a 0 a0 ou a *i t a COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED: 0 04 0 0u GRATE FASTENING MEANS The following statement is a full description of the invention including the best method of performing it known to me: Ik -I -1

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2 THIS INVENTION relates to drainage grates and, in particular, to fittings for securely fastening such drainage grates to pre-formed drain openings.

Grates are conventionally held in place over a drain opening by reason solely of their weight. Because no fixing means is used to secure the grates in place, they are subject to theft or displacement from the drain which they or*t o cover. This can give rise to personal injury as well as 0 t danger and damage to vehicular traffic in the case of drains O 0 located in carriageways. Furthermore, ill-fitting grates in 4 carriageways tend to clatter and move about as vehicles pass 000o over them, giving rise to wear in the drain seating surface and noise pollution which can be particularly disconcerting in residential locations.

.Ia It is therefore an object of the present invention 0 0 to obviate or at least minimise these problems by providing o00 0 °0 4 suitable fittings for fastening grates to drains.

According to the present invention, there is 0 provided fittings for fastening a grate to a drain comprising "2t> the combination of an arcuate-shaped wedge adapted to span the opposite walls of a drain and to be frictionally retained thereby, and a connector element adapted to connect to the wedge and be retained against a seating surface associated with the grate, the arrangement being such that when the connector element is retained against the seating surface, tightening of the connector element to the wedge tends to S* 2*1 3 straighten the wedge and increase the frictional engagement of the wedge with the walls of the drain.

The arcuate-shaped wedge may have any crosssectional profile such as circular, elliptical, square or rectangular, but it is preferably rectangular as this profile enables the best frictional engagement with the walls of most drains. Any rigid material may be used to manufacture the Qo o* arcuate-shaped wedge but particularly suitable materials are o metals such as tin plate, caste-iron, aluminium and steel, as °1U' well as high density plastics materials such as polypropylene and polybutylene. The preferred material is steel because of its inherent strength and its ability to bend to a very small degree to permit it to produce a very good frictional engagement with the drain walls, which are generally 11.5 concrete.

The connector element may be any rigid, semi-rigid Sa or flexible component which is either formed integrally with, or separate from, the arcuate-shaped wedge. When it is I o° formed integrally with the arcuate-shaped wedge, it will 2*o preferably comprise a single element extending from the concave side of the wedge at a location which is approximately mid-point between the ends of the wedge. The single element will extend to a sufficient height to enable it to protrude through the grills of the grate for connection, by way of a screw-threaded end piece or the like, to a suitable retainer such as a nut, on or adjacent to the f1~ ii i 4 upper surface of the grate, or to be at least manipulable from the top side of the grate.

Preferably however, the connector element is a separate component to the arcuate-shaped wedge. It may accordingly be adapted for connection to the wedge by clamping or by threading, or other common frictional engagement. The most preferred form of connection is by

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S means of a screw thread. Such a thread may be formed on the o exterior end of the connector element with a complimentary o tr internal thread formed in the arcuate-shaped wedge. However, 1 r the threads could also be reversed, that is, an internal thread formed on the end of the connector element which mates with an external thread formed on a nub or like projection extending outwardly from the concave face of the wedge. The

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ih former of these constructions is, nevertheless, preferred.

o; It is preferred that the connector element be iO formed of a rigid materials this generally aids in the location and placement of the wedge. Any rigid material which oo is not brittle or otherwise subject to wear, or destruction, o0 1 may be utilized. It will generally be the same material as the wedge itself and is thus preferably metallic or a high density plastics material as previously described.

~ttA particularly preferred connector element is a metal bolt having an enlarged diameter head to bridge any adjacent two grills of the grate. However, other very useful connector elements have smaller more conventional heads, and to enable retention with the grills of the grate, a bridging member comprising a flat plate or U-shaped plate may be employed. Such a plate is adapted to extend between adjacent grills and includes an opening through which the shank of the connector bolt may extend but through which the bolt head cannot extend. In a further arrangement, the bridging plate is formed integrally with the grate and is a preferably formed on the bottom surface of the grate so that 00 o" the head of the connector bolt is recessed.

In use, the arcuate-shaped wedge is frictionally engaged between the opposite walls of a drain at a spaced location from the drain inlet. It is frictionally engaged in such a manner that the concave side of the wedge faces the drain inlet. The grate is then placed over the drain in the usual manner and a connecting element, if not integral with I o0 the wedge, is inserted between the adjacent grills of the 0* 0 0 grate, preferably somewhere about its midpoint, and connected to the wedge, such as by screwing in the case of a bolt. As the connecting element is tightened, the arcuate-shape wedge °o2o tends to straighten thereby increasing the frictional force against the walls of the drain and simultaneously securing the grate to the drain.

Preferred embodiments of the invention will now be described with reference to the accompanying drawings, in which:- Fig. 1 is a cross-sectional elevation of a wedge Ij_ and connector element; Fig. 2 is a partial cross-sectional view of a connector element and a separate bridging element in situ; Fig. 3 is a partial cross-sectional view of a connector element and an integral bridging element; and Fig. 4 is an end-on perspective of a grate in position on a drain fastened with fastening means according 0r0o 0g to the present invention.

4 o Referring firstly to Fig. I, the fastening means O 0 comprises an arcuate shaped metal plate 10 having a central 0000 °#oG orifice 11 which is internally threaded, and a connector *act 0010 element 12 in the form of a bolt with a flattened rectangular head-piece 13 and a cylindrical shank 14 which is externally threaded at end 15. The head piece 13 is dimensioned so as 4 a,1, to bridge adjacent grills of a grate to thereby pull the grate hard against its seating which the connector element 12 0 is tightened and the arcuate shaped metal plate 10 engages the opposite side walls of a concrete drain.

0 00 Fig. 2 illustrates a connector element 20 which is similar to a conventional hexagonal headed elongated bolt.

The connector element tensions against the grills 21, 22 of a grate through a separate bridging element 23. The bridging element comprises a U-shaped plate which extends across adjacent grills and is retained in position by its down-bent arms 24, 25 which lie adjacent the sides of the respective grills 21, 22. A central opening 26 permits the shank 27 of 1 j -L 7 the connector element to pass therethrough, the is not large enough to allow the head ot pass through. This arrangement is useful in that it is very simple to use, but will generally only be used in situations where a smooth grate surface is not necessary or desirable.

Fig. 3 illustrates a connector element 30 which is the same as the one depicted in Fig. 2. the means by which the connector element is associated with the grate is, S however, different. In this case, a bridging member 31 is Q o formed integrally with the grate and extends from between o o adjacent grills 32, 33 on the lower surface thereof.

0 0000 By the term "integral" is meant that the bridging member is either formed with the grill during its casting or manufacture, or is immovably fixed to the grill afterwards by oi. welding or the like.

0o 0 This particular embodiment is the most preferred o~o o 0 0° one as the connector element does not project above the grate surface, it is out of sight, and it is difficult to undo 0 o. without the proper tool, making theft of the grill more o0 ~difficult and less likely to happen.

Referring finally to Fig. 4, there is depicted a fastening means comprising a connector element 44 and bridging member 45 similar to that shown in Fig. 3, and an arcuate shaped wedge 40 similar to that shown in Fig. 1. The wedge is shown straddling the opposite walls 41, 42 of a drain 43. It comprises a steel plate with a centrally

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8 threaded hole 47. The connector element 44 is a bolt which threadingly engages with the wedge. The bolt is retained by the bridging member 45 formed integrally with the grill 46.

In use, the steel plate 40 is arcuately bent and frictionally engaged between the walls 41, 42 of the drain, directly beneath the location which the bridging plate 45 of the grate will take up when the grate is positioned. The r o steel plate is arranged so that it is downwardly convex. The 0 o o grate 46 is then positioned over the drain in the usual 9 9 "TO manner and the connector element 44 is inserted through the a o bridging plate 45 and tightened into the hole 47 of the steel plate 40. Upon tightening, the steel plate tends to straighten against the walls 41, 42 of the drain and thereby increase its frictional engagement therewith so as to tension a 6 o 15 the grate against the seating surface of the drain.

By this method a secure grill is provided which 0 09 0 meets the aforestated objects of the invention.

Whilst the above has been given by way of 9 o illustrative example of the invention, many modifications and variations maybe made thereto by persons skilled in the art without departing from the broad scope and ambit of the invention as herein set forth.

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Claims

1. Fittings for fastening a grate to a drain comprising the combination of an arcuate-shaped wedge adapted to span the opposite walls of a drain and to be frictionally retained thereby, and a connector element adapted to connect to the wedge and be retained against a seating surface associated with the grate, the arrangement being such that o when the connector element is retained against the seating surface, tightening of the connector element to the wedge tends to straighten the wedge and increase the frictional engagement of the wedge with the walls of the drain. *4.

2. Fittings for fastening a grate to a drain as claimed in claim 1, wherein said arcuate-shaped wedge is substantially rectangular in profile.

3. Fittings for fastening a grate to a drain as claimed in claim 1 or claim 2, wherein said arcuate-shaped wedge has an opening in its mid-section for connection to the connector element.

4. Fittings for fastening a grate to a drain as claimed in claim 3, wherein said opening has an internal screw thread for connection to a complimentary screw-thread portion of the connector element.

Fittings for fastening a grate to a drain as claimed in any one of the preceding claims, wherein said connector element is a bolt having an enlarged diameter head to bridge two adjacent grills of the grate. i fC

6. Fittings for fastening a grate to a drain as claimed in any one of claims 1 4, wherein said connector element is a bolt with a small diameter head which is adapted for retention within the adjacent grills of the grate.

7. Fittings for fastening a grate to a drain as claimed in any one of claims 1 4, and including a bridging member to enable the connector element to be retained on or l t within the grills of the grate. o o Do

8. Fittings for fastening a grate to a drain as t claimed in claim 7, wherein the bridging member is a U-shaped a 0 plate which is either formed integrally with the grate or separately therefrom, in which later instance it is adapted to extend over adjacent grills.

9. Fittings for fastening a grate to a drain as Ssa o 4 e claimed in any one of the preceding claims, which are pre- formed steel components. 0

10. Fittings for fastening a grate to a drain substantially as herein described with reference to any one 0o: of the accompanying drawings. 0 6J DATED this 18th day of August 1989 MICHAEL GRAHAM RICHARDS By his Patent Attorneys G.R. CULLEN CO.