AU658751B2

AU658751B2 - Manhole cover

Info

Publication number: AU658751B2
Application number: AU41593/93A
Authority: AU
Inventors: Ananda Gunasekera
Original assignee: TRELOAR GROUP Ltd
Current assignee: Treloar Manufacturing Pty Ltd
Priority date: 1992-07-28
Filing date: 1993-06-29
Publication date: 1995-04-27
Anticipated expiration: 2013-06-29
Also published as: AU4159393A

Description

1. 658751 p00011 Regulation 3.2

AUSTRALIA

Patents Act, 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Original 4a 44 *r 4* 4. 4r i TO BE COMPLETED BY THE APPLICANT a 4 o 4* S* NAME OF APPLICANT: 4 ACTUAL INVENTOR(S): ADDRESS FOR SERVICE: ADDRESS FOR SERVICE: TRELOAR GROUP LIMITED, 000 364 465), ANANDA GUNASEKERA Peter Maxwell Associates Blaxland House, Suite 10, 5 Ross Street, NORTH PARRAMATTA NSW 2151 INVENTION TITLE: DETAILS OF ASSOCIATED PROVISIONAL APPLICATION NO(S): MANHOLE COVER PL 3781 The following statement is a full description of this invention, including the best method of performing it know to me:- This invention relates to manhole covers and for the sake of brevity it will be described in relation to covers for manholes leading to underground liquid storage tanks.

However, it is to be understood that the invention is not limited thereto.

One of the problems associated with the design of manhole covers for underground liquid storage tanks is that the cover must be capable of withstanding loads in excess of 7,500 kg. Manhole covers capable of withstanding such loads cannot be opened and closed without the aid of lifting equipment.

It is an object of this invention to provide a two part manhole cover which lends itself to manual operation without the use of lifting equipment.

According to the invention there is provided a manhole cover adapted to be seated in the opening of a manhole, said manhole cover comprising first and second complementary cover portions, the first cover portion having a lip along a face adjacent the second cover portion, the second cover portion 20 having a rib along a face adjacent the first covii gortion which underlies the lip, and a seal between the lip and the rib to form a rainproof connection between the cover portions, the lip, the rib and the seal being engageable together whereby the first and second cover portions form the manhole cover.

Preferably, the opening of the manhole is circular and the cover portions are semicircular in plan with the adjacent faces being along a diameter of the circular opening.

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o 0 *e 0 Or 9 n 0 o 0 49 404CC Ce.0 0C 0* i -3- In a preferred form of the invention at least one cover portion has an access opening therethrough and there is provided an inspection lid to close the opening.

In order that the invention may be more readily understood and put into practical effect, reference will now be macle to the accompanying drawings in which:- Fig. 1 is a plan view of a manhole cover according to one embodiment of the invention, Fig. 2 is an exploded view of an installed manhole cover of the kind shown in Fig. 1, Fig. 3 is a plan view of the manhole cover shown in Fig. 1 with the inspection lids removed and the half covers separated, Fig. 4 is a view taken along lines A-A of Fig. 3, Fig. 5 is an enlarged view of the locking lip of the left hand half cover of Fig. 4, Fig. 6 is a partly cut away perspective view of the right hand half cover of Fig. 4, Fig. 6A is an enlarged view of the sealing gasket arrangement in the seat ring, Fig. 6B is an enlarged view of the sealing gasket arrangement between the half covers, Fig. 7 is a plan view of the right hand inspection lid shown in Fig. 1, Fig. 8 is a broken away cross-sectional view of the Dc rr

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j (j S. -4inspection lid shown in Fig. 7 mounted in the right hand halt cover shown in Fig. 3, Fig. 9 is a plan view of a manhole cover according to a second embodiment of the invention, and, Fig. 10 is a plan view of a manhole cover according to a third embodiment of the invention.

The manhole cover 10 shown in Figs. 1 to 8 of the drawings comprises first and second complementary cover S. portions 11, 12. In this instance, the manhole cover 10 is 10 adapted to close the circular opening 13 of the manhole 14 shown in Fig. 2. Thus, the manhole cover portions 11 and 12 are semi-circular in plan as can be seen in Fig. 1 with the join line 15 being along a diameter of the circular opening o 13.

The manhole 14 has a riser 16 which provides access to a liquid storage tank 17. Within the access riser 16 there is a vapour pipe 18 and a dip/fill point 19 disposed on opposite sides of the centre line 20 of the access riser 16.

Around the opening 13 of the manhole 14 there is seat ring 21 I 20 that is secured to the concrete surround 22 by eight concrete anchors 23 spaced around the seat ring 21. Depending downwardly from the seat ring 21 there is a shirt 24 which overlies the upper end of the access riser 16. At the bottom face of the seat ring 21 there is a main sealing gasket 26 which is shown in greater detail in Fig. 6A.

The cover portions 11 end 12 are shown in greater i detail in Fig. 4. The left hand cover portion 11 has an access opening 27 therethrough to provide access to the vapour recovery pipe 18 without the need to remove cover portion 11. A similar access opening 28 is provided in the cover portion 12 to provide access to the dip/fill point 19.

The access openings 27 and 28 are closed by inspection lids 29 and 30 respectively.

The left hand cover portion 11 has a semi-circular periphery 31 and a straight slightly inclined face 32, which o a faces the straight face 33 of the right hand cover portion l 12. The cover portion 12 has a semi-circular periphery 34 S 10 that has an aperture 35 at or adjacent its mid point for receiving a fastener described below. The left hand cover portion 11 has three apertures 36, 37 and 38 for receiving fasteners. Aperture 36 is at or adjacent the mid point of periphery 31 and apertures 37 and 38 are adjacent to the opposite ends of straight face 32.

As can be seen in Fig. 4, the upper part of straight face 32 of the cover portion 11 has an outwardly projecting lip 39 which defines a downwardly facing sealing surface.

The straight upper part of straight face 33 of the cover portion 12 has an upwardly facing rib 41 which defines an upwardly facing sealing surface. The lip 39 is shown enlarged in Figs. 5 and 6B and the rib 41 is shown enlarged in Fig. 6B.

As can be seen in Fig. 6B, there is a sealing gasket 43 on the sealing surface of rib 41 against which the lower sealing surface of lip 39 seals. The outer ends of rib 41 are trended downwardly although only one end is shown in h Fig. 6.

The seat ring 21 and gasket 26 are shown enlarged in Figs. 6 and 6A. It will also be seen that the outer lower face of the rib 41 has a step 44 which seats against the gasket 26. A similar step is provided at the other end of rib 41.

The manner of connection of the inspection lid 30 to the cover portion 12 is shown in Fig. 8. The lid 31 has a downwardly depending annular flange 45 that fits within the o o upper end of access opening 28. A second annular flange 46 o 10 depending downwardly from the periphery of the lid 30 seats in upwardly open groove 47 in the top face of cover portion 12. The inspection lid 29 is mounted on cover portion 11 in a similar way. Drainage lugs 48 are provided around the o* •periphery of access openings 27 and 28.

The monhole cover 10 is mounted on the seat ring 21 by first seating the cover portion 12 which may be secured to the seat ring 21 by fasteners 48 and washers 49 with the washer engaging the periphery of aperture 35 and the fastener 48 engaging lug 50 on the seat ring 21.

The other cover portion 11 is then positioned over the opening with the lip 39 seated in the groove 42. The cover portion 11 is then secured to the seat ring 21 by further fasteners 48 and washers 49 which engage lugs 50 and apertures 36, 37 and 38 respectively.

The manhole coN Br of one embodiment of the invention provides a means of cess to an underground tank through a manhole having a 900 mm opening. The cover is designed to ii -7withstand loads in excess of 7,500 kg. The use of two half covers instead of a single cover plate allows one operator to open and close the manhole without the aid of any lifting equipment. The two smaller inspection lids prevent regular access to the manhole without the need to remove either or both of the half covers.

The manhole cover 100 shown in Fig. 9 has first and second complementary cover nortions 101 and 102. The left hand cover portion 101 has an access opening similar to 10 access opening 27 of the first embodiment of the invention which is closed by inspection lid 103. The right cover o0 portion 102 does not have an inspection lid.

The manhole cover 110 shown in Fig. 10 has first and second complementary cover portions 111 and 112. Neither 15 cover portion 111, 112 has an inspection lid. The left hand o cover portion 111 has an access opening 113 for receiving a lifting handle.

Although the invention has been described in relation to a cover for a manhole leading to an underground liquid storage tank, it is to be understood that the two-part manhole cover could be used in a variety of situations.

Various modifications may be made in details of design and construction without departing from the scope and arabit of the invention the nature of which is set forth in the preceding description.

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Claims

2. A manhole cover as claimed in claim 1 wherein the opening of the manhole is circular and the cover portions are semicircular in plan with the adjacent faces being along a diameter of the circular opening.
3. A manhole cover as claimed in claim 1 or claim 2 wherein at least one cover portion has an access opening therethrough and there is provided an inspection lid to close the opening.
4. A manhole cover as claimed in claim 3 wherein each cover portion has an access opening therethrongh and there is t provided an inspection lid to close each opening. *t 1* 4*:is 1 0:4 4 -9- A manhole cover substantially as hereinbefore described with reference to the accompanying drawings. Dated this 23rd day of January, 1995. TRELOAR GROUP LIMITED Patent Attorneys for the Applicant: PETER MAXW'ELL ASSOCIATES *4 44 4 4 S 4 4 4,4, 44 4 44 44 4 4* 454 4 444444 4 4 '4,4 445 4 44 4 4 4* 4 44 44 44 04 ABSTRACT A manhole cover to be seated in the opening of a manhole of an underground petrol tank has first and second complementary cover portions (11, 12), the first cover portion (11) having connection means (39) along a face adjacent the second cover portion the second cover portion (12) having connection means (41) along a face o adjacent the first cover portion the connection means (39, 41) being engageable together whereby the first and 0 0 a a second cover portions (11, 12) form the manhole cover. 000. O 0 00