AU2007100963A4 - Pit Covers - Google Patents

Description

P001 Section 29 Regulation 3.2(2)

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION INNOVATION PATENT Application Number: Lodged: Invention Title: Pit covers The following statement is a full description of this invention, including the best method of performing it known to us: 8 PIT COVERS The present invention relates to cover members adapted to cover a pit c structure, preferably in a manner whereby the cover member or members may be releasably latched and locked in a closed position covering an upwardly facing access opening of the pit structure.

Australian patent application no. 2003201290 discloses a cover member and pit structure arrangement whereby the cover member can be locked to a surround fixable in the pit structure. In this disclosure a fixed length cross member has opposed ends engageable in catch structures formed on opposed inwardly facing walls of the surround, the cross member having also an intermediate portion that is selectably lockable via a padlock or similar to the underside of the cover member. Access to the intermediate region of the crossbar and the padlock when used is via a small hatch or pivoted door in the cover member itself. The cross member is released from the catch structures by sliding movement in the transverse direction of the cross member when the padlock or similar is disengaged. Australian patent application no. 2004210514 shows a modification of the arrangements disclosed in Australian patent application no. 2003201290 where the cross member includes two extension pieces, each being threadingly engageable with a respective opposed end of the cross member whereby rotation of the extension pieces relative to the cross member will result in the overall length of the crossbar (including the extension pieces) increasing or decreasing.

The cover member may cover part or all of the access opening to the pit structure and may sit on or over the pit structure in a closed position or lifted bodily off the pit structure to provide an open position enabling access to same through the access opening. Often the cover member may be permanently connected to the pit structure by a hinge mechanism where the cover member pivots between the closed and open positions. It is recognized that when the cover member is hinged to the pit structure, it is desirable that the cover member be movable from the closed position to the open position and in the open position, the cover member should be capable of laying flat against the ground or pavement region adjacent the pit structure when installed. The hinge structure, however should desirably not provide any obstruction to traffic when the pit cover O member is closed and preferably should be fully hidden by the cover member in the closed position. Moreover, when the cover member is intended to be c selectably secured or locked to the surround, the hinge should not provide a point of attack where the securing of the cover member to the surround can be defeated.

The objective of the present invention is therefore to provide a cover Iarrangement for a pit structure that will provide a capability of securing in a 0lockable manner the cover arrangement in its closed position and/or a hingeable cover arrangement meeting the aforesaid capabilities.

According to a first aspect, the present invention provides a cover member for a pit structure having an upper surface plate which, when in a closed position, covers at least part of an upwardly facing access opening for said pit structure, said cover member including a first pivotable member mounted by a first pivot connection to said cover member whereby the first pivotable member is disposed beneath said upper surface plate and is pivotable in a plane generally parallel to the plane of said upper surface plate, a first arm member connected at one end by a second pivot connection to said first pivotable member, said second pivot connection being spaced from said first pivot connection, and a second arm member connected at one end by a third pivot connection to said first pivotable member, said third pivot connection being spaced from said first pivot connection and being located on an opposite side of said first pivot connection relative to said second pivot connection, said first and said second arms being restrained for movement generally parallel to said upper surface plate on an underside thereof, whereby swinging movement of said first pivotable member about said first pivot connection results in movement of said first and second arm members either in an outward direction to a latching position or are withdrawn in an inward direction to a delatching position, said first pivotable member being accessible from above said upper surface plate.

The cover member may be arranged simply to sit on or over the pit structure and be bodily moved from the pit structure when moved to an open position. Alternatively the cover member may be hingedly connected to the pit structure to be pivoted between the closed or open positions. The hinge structure O may be of any desired known type including the preferred hinge structure described hereafter.

c The pit structure may be made from metal, concrete or plastics materials 7and may be of single or multi piece construction for any desired purpose.

Preferably, in the latching position, a portion of said first pivotable member is positioned adjacent a fixed abutment on an underside of said cover member, Isaid portion of the first member and said fixed abutment including adjacent retainer means in said latching position permitting a padlock or similar to lock said first pivotable member and said fixed abutment together in said latching position.

The portion of said first pivotable member and said fixed abutment may both be located in planes substantially parallel or perpendicular to said upper surface plate. The first pivotable member may include a gripping tab formation formed in a plane generally perpendicular to said upper surface plate.

In a preferred embodiment, strengthening webs may be provided extending perpendicularly relative to the upper surface plate from an underneath surface thereof, said strengthening webs being located at spaced locations across said underneath surface. The first and second arm members being restrained for sliding movement in apertures formed in web plates secured to and extending downwardly from the underneath surface of the upper surface plate.

In a particularly preferred embodiment, the remote or outer ends of the first and second arm members are spaced inwardly from a peripheral edge of the upper surface plate when in said latching position. Conveniently the cover member is adapted, in closed position at least partially covering the upwardly facing access opening for the pit structure, to sit on a ledge surrounding said access opening, the outer ends of the first and second arm members being cooperable with retaining means of said pit structure located below said ledge. In this manner, in the latching position, the first and second arm members cannot be accessed through any gap existing between the peripheral edge of the upper surface plate and the surrounding pit structure.

Conveniently, a pivotal access door may be formed in the upper surface plate permitting access to the first pivotable member at least when the cover member is in said closed position. This access door may be spring loaded towards a closed position providing a generally continuous upper surface of the O upper surface plate. In addition or alternatively a releasable closure catch means C may be provided to releasably hold the pivotal access door in the closed position.

C.)

th Preferably, the cover member may include a first hinge structure permitting the cover member to be hingedly mounted to a surround, in use, forming part of the pit structure, the first hinge structure being disposed below the peripheral edge region of said upper surface plate. Preferably the first hinge structure is Ialso located inwardly of said peripheral edge. In one possible arrangement a cover member as described above may, in a closed position, cover all of the access opening to said pit structure. In another possible preferred embodiment, a cover structure might be provided comprised of a first cover member as defined in the preceding cooperable with a second cover member having a second upper surface plate, the second cover member further including a second hinge structure disposed below a peripheral edge region of said second upper surface plate whereby in a closed position said first and said second cover members together cover all of the upwardly facing access opening of the pit structure.

In accordance with a second aspect of this invention, there is provided a hinge structure for a panel having a defined perimeter edge region, said hinge structure having a pivot structural means including a first pivot connection means enabling pivot connection of said pivot structural means to said perimeter edge region of the panel, said hinge structure including a second pivot connection means enabling pivot connection of said pivot structural means to a stationary surround of said panel whereby in a first part of pivoting movement of said panel relative to said stationary surround, pivoting action occurs about said first pivot connection means and during a subsequent second part of pivoting movement of said panel relative to said stationary panel, pivoting action occurs about said second pivot connection means.

Conveniently the first pivot connection means defines a first pivot axis disposed parallel to and transversely spaced from a panel surface of said panel adjacent said perimeter edge region of the panel. Preferably the second pivot connection means defines a second pivot axis disposed parallel to and spaced from said first pivot axis, said second pivot axis being disposed outwardly of the perimeter edge region of said panel relative said panel surface.

In a preferred arrangement, the perimeter edge region of the panel is adapted to engage the pivot structural means to commence pivoting movement c about said second pivot connection means.

Preferably the pivot structural means may include at least two and possibly more spaced hinge plate means, each carrying aligned first pivot elements forming part of said first pivot connection means and aligned second pivot IN elements forming said second pivot connection means, and a torsion bar interconnecting said hinge plate means whereby the hinge plate means pivot together about said first and said second pivot connection means. The respective first and second pivot elements may in fact be pivot shafts connecting the respective hinge plate means.

Conveniently a recessed zone may be formed in said hinge plate means between said first and said second pivot elements, the perimeter edge region of said panel being adapted to engage with a portion of said recessed zones part way through a pivoting motion of said panel. Preferably, the panel surface is adapted, in use, to pivot through at least 1800 when pivoting from a closed position to an open position. When the panel is a cover member for a pit structure or the like, the closed position effectively closes the top access opening of the pit structure and in the open position, the cover member has pivoted to a position where the cover member lays flat against the ground surface adjacent the upper rim region of the pit structure.

In one preferred embodiment the pivot structural means includes at least two spaced hinge plate means, each carrying aligned second pivot elements forming part of said first pivot connection means and aligned second pivot elements forming said second pivot connection means, and a torsion bar interconnecting said hinge plate means whereby the hinge plate means pivot together about said first and said second pivot connection means, said stationary surround including spaced stationary hinge plates each including a recess in an edge region to locate and partially surround said torsion bar in a closed position of the cover member, said cover member further including an edge plate aligned with each said spaced stationary hinge plate, the edge plates also including a recess in an edge region thereof to locate and partially surround said torsion bar in the closed position of the cover member.

O The invention will now be described with reference to the accompanying Sdrawings showing preferred embodiments of the invention. In the drawings: Fig 1 is a perspective view of a pit structure with a security pit cover member in a closed position; Fig 2 is a perspective view similar to Fig 1 where the access door to the Msecurity structure of the cover member is open; IFig 3 is a detailed perspective view of the access door region shown in Fig 2; Fig 4 is a perspective view similar to Figs 1 and 2 showing the security pit cover member partially open; Fig 5 is a perspective view similar to Fig 1 showing the security pit cover member in a fully open position; Fig 6 is a perspective view similar to Fig 5 showing the second cover member in a partially open position; Fig 7 is a perspective view similar to Figs 1 and 5 showing the security pit cover member and the second cover member in fully open positions; Fig 8 is an underneath perspective view where the pit structure is partially broken away to illustrate the underneath regions of the security pit cover member; Fig 9 is a detailed view of the circled area of Fig 8; Fig 10 is a transverse section view of the security pit cover member in a closed position sealed on a ledge in the upper regions of the pit structure with the access door in an open position; Fig 11 is a longitudinal sectional view through the security pit cover member in the position illustrated in Fig Fig 12 is an underneath perspective view of the security pit cover member shown in earlier drawings with the arms of the security latch in a detached position; Fig 13 is a longitudinal sectional view similar to Fig 11 but with the access door in a closed position; Fig 14 is an underneath perspective view of the security pit cover member similar to Fig 12 but with the arms of the security latch in a latching position; Fig 15 is a perspective view of one preferred hinge structure according to the present invention; O Figs 16 to 20 show the hinge structure of Fig 15 in various positions N progressively from a fully closed to a fully open position.

c Referring initially to Figs 1 to 8 of the annexed drawings, there is shown a

O

Ssecurity pit cover structure 10 for a pit structure 11 having a security cover member 18 and a second cover member 51, each comprised of an upper plate M member 12 having an upper surface plate 13 with appropriate anti-slip Iprotrusions on its tread surface 20 formed thereon. The underside surface 14 of the plate member 12 has a plurality of downwardly depending strengthening webs in a criss-cross lattice type configuration. The cover members 18, 51 may be assembled from suitable steel plate when fabricated but it will be appreciated by those skilled in this art that the cover members 18, 51 could also be at least partially formed by a casting technique from a suitable cast iron or similar. The security pit cover member 18 has a mounting structure 16 at one end adapted to be fixed to the upper regions of the pit structure 11 and a suitable hinge formation 17 pivotally connecting the cover member 18 to the mounting structure 16. As can be seen in the drawings, the hinge formations 17 are mounted fully below and are completely hidden by the upper surface plates 12 of the cover members 18, 51 including the mounting structures 16. The upper surface plate 12 of the security pit cover member 18 may include a pivoting access door 21 enabling an access opening 22 in the upper plate member 12 to be opened (as illustrated) or closed. The hinges for the access door 21 may or may not be spring loaded towards a closure position. In a possible alternative releasable catches or releasable fasteners might be provided to hold the access door in the closure position. As best seen in Fig 3, opposed side edges 24, 25 and the free end edge 26 of the access door 21 may rest on support ledges 27 adjacent the access opening 22 in the closure position to provide a substantially continuous upper tread surface in this condition.

As can be seen in Figs 1 to 8, when the two cover members 18, 51 are closed, the security pit cover member 18 prevents the second cover member 51 from being pivoted upwardly towards an open position. This is possible, however when the cover member 18 has been at least partially opened. In the open positions, the cover members 18, 51 can be laid flat on the ground surrounding the pit structure 11. While two cover members 18, 51 are illustrated in the drawings, it will be appreciated that one security pit cover member 18 might cover the complete pit access opening 23 defined within the upper rim of the pit structure 11.

The security pit cover member 18 has, between strengthening webs 15, a compartment 28 housing the latch actuating mechanism 29. The mechanism 29 includes a support plate 30 (Figs 12, 14) pivotally mounting a first pivot member 31 thereto by a first central pivot connection 32 such that the first pivot member 31 is capable of pivoting movement in a plane parallel to the upper plate member 12 and spaced there below. The first pivot member 31 has second and third pivot connections 33 and 34 (Figs 8a, 9a) on opposite sides of the first pivot connection 31 pivotally connecting oppositely directed latch arms 35, 36 thereto. The first pivot member 31 has an end portion 37 extending beyond the second pivot connection 33 through an aperture 38 in an adjacent one of the webs 15, the end portion 37 having a first part 39 bent perpendicularly to the plane of the plate member 12 adapted to be gripped and through the access opening 22 and moved to selectably position the first pivot member 31 as described hereafter. The end portion 37 has a second part 40 also bent perpendicularly to the plane of the plate member 12 which, in one position of the first pivot member 31 (Fig 3) comes to rest against a fixed abutment 41. The abutment 41 includes an aperture 42 which is aligned, in the position shown in Fig 14, with a similar aperture 80 in the part to allow a padlock 43 to secure the first pivot member 31 in this position which is the latching position.

Each of the latch arms 35, 36 extend laterally in opposite directions passing through apertures 44 in the strengthening or location webs 15 which retain and guide the latch arms for lateral outward and inward movement in response to pivoting movement of the first pivot member 31. The distal end regions 45, 46 of the latch arms 35, 36 may thereby extend outwardly to a latching position (Fig 14) or inwardly to a delatching position (Fig 12). In the outward latching position the ends 45, 46 of the latching arms engage in retainer members 82 positioned on and below the ledge 83 on which the cover members 18, 51 rest in the closed position of same. In this position the ends 45, 46 are spaced inwardly of the perimeter edge 84 of the plate member 12 and cannot therefore be accessed from above the cover member 18 when it is closed, O latched and locked. The pit structure 11 may be of any configuration but N conveniently includes a rim region 14 having the aforesaid support ledge 83 O surrounding the access opening 23 to the pit structure 11 on which the cover 0 member rests when closing the upper opening 50. The cover structure 10 may include a security cover member 18 or may include a pair of pivoting members 18, 51. In this latter option, the latching arms 35, 36 are mounted as described Iabove only in the pivoting cover member 18 and a suitable interengaging lip structure between the members 18, 51 is provided to prevent the member 51 being pivoted to an open position until the latching arms 35, 36 are moved to a delatched position and the cover member 18 is at least partially moved towards the open position.

Fig 15 illustrates a preferred hinge structure 17 for mounting either the cover member 18 or 51 in a pivoting relation to a fixed part 16 mountable to the rim region 14 of the pit structure 11. The hinge structure 17 comprises a plurality of hinge plate members 61 located in spaced location and retained in relative position to one another by a torsion bar 62 such that the hinge plate members 61 will all move together as a single unit. The plate members 61 are all shaped essentially the same with a recessed zone 63 located between arms 64, mounting a first pivot shaft 66 and a second pivot shaft 67. The pivot shafts 66, 67 enable pivot mounting to hinge plates 68 carried by the stationary mounting structure 16. While the drawings illustrate continuous pivot shafts 66, 67, it will be appreciated that it may be preferable to provide individual pivot connections between respective hinge plates 61, 68. Figs 16 to 20 illustrate operation of the hinge structure 17. The cover member 18 or 51 is initially pivoted about the pivot shaft 66 during the first part of the pivoting motion. At a certain stage (Fig 18), the perimeter edge region 69 of the plate member 12 engages with a portion of the recessed zone 63 and when this occurs, the hinge plates 61 commence to pivot about the second pivot shaft 67 (Figs 14, 15, 16). The double action of the hinge structure 17 allows the upper surface of the plate member 12 to pivot through at least 1800 from the fully closed position (Fig 16) to the fully open position (Fig 20), while still permitting the hinge structure 17 to be completely hidden and thereby protected below the plate member 12 and the adjacent stationary mounting structure 16. Moreover, the hinge plates 68 of the fixed O mounting structure have part circular recesses 85 formed therein into which the Storsion bar 62 engages in the closed position of the cover members 18 or 51.

o Each of the cover members 18 or 51 also include web or plates 15 with a similar 0 recess 86 formed therein that also engages on the other side of the torsion bar 62 in the closed position. The plates 68 and 15 with these recesses are aligned and the structure prevents unauthorized lifting of the cover members by any attempt IDto incorrectly manipulate the hinge structure 17.

Claims (3)

1. 2. A cover member according to claim 1 wherein, in said latching position, a portion of said first pivotable member is positioned adjacent a fixed abutment on an underside of said cover member, said portion of the first pivotable member and said fixed abutment including adjacent retainer means in said latching position permitting a padlock or similar to lock said first pivotable member and said fixed abutment together.
2. 3. A cover member according to claim 1 or claim 2 wherein in said latching position distal ends of said first and second arm members are spaced inwardly from a peripheral edge of said upper surface plate.
3. 4. A cover member according to any one of claims 1 to 3 further including a first hinge structure permitting the cover member to be hingedly mounted to a surround, in use, forming part of the pit structure, said first hinge structure being _disposed below a peripheral edge region of said upper surface plate, said first o hinge structure having a pivot structural means including a first pivot connection ,means enabling pivot connection of said pivot structural means to said perimeter edge region of the panel, said first hinge structure including a second pivot connection means enabling pivot connection of said pivot structural means to a IN stationary surround of said panel whereby in a first part of pivoting movement of Csaid panel relative to said stationary surround, pivoting action occurs about said first pivot connection means and during a subsequent second part of pivoting S 10 movement of said panel relative to said stationary panel, pivoting action occurs about said second pivot connection means. A cover member according to claim 4 wherein the pivot structure means includes at least two spaced hinge plate means, each carrying aligned second pivot elements forming part of said first pivot connection means and aligned second pivot elements forming said second pivot connection means, and a torsion bar interconnecting said hinge plate means whereby the hinge plate means pivot together about said first and said second pivot connection means, said stationary surround including spaced stationary hinge plates each including a recess in an edge region to locate and partially surround said torsion bar in a closed position of the cover member, said cover member further including an edge plate aligned with each said spaced stationary hinge plate, the edge plates also including a recess in an edge region thereof to locate and partially surround said torsion bar in the closed position of the cover member. BVCI PTY LTD WATERMARK PATENT TRADE MARK ATTORNEYS UIP1162AU00