GB2502563A

GB2502563A - Surface access closure with cover and frame linked together

Info

Publication number: GB2502563A
Application number: GB201209632A
Authority: GB
Inventors: Tim Elkin; John Neil Pickavance; Steven Peter Baldwin
Original assignee: Saint Gobain PAM UK Ltd
Current assignee: Saint Gobain PAM UK Ltd
Priority date: 2012-05-30
Filing date: 2012-05-30
Publication date: 2013-12-04
Anticipated expiration: 2032-05-30
Also published as: GB2502563B; GB201209632D0

Abstract

A surface access closure assembly (10) comprises a rigid frame (16) defining the periphery of an aperture; and a rigid cover (11, figure 1) with a closed position in which the cover occupies the aperture and is located so as to protrude no further than an edge of the frame; and an advanced position in which the cover protrudes beyond the edge. The cover in the advanced position also is displaceable to an open position in which it is outside the line of the periphery; and the frame and the cover are connected together by a linkage (28) permitting movement between the closed and open positions of the cover via the advanced position. The linkage may include a hinge member (29), (31) and a slide member (32) which may be captive relative to the frame.

Description

A SURFACE ACCESS CLOSURE ASSEMBLY

The invention relates to a surface access closure assembly, and in particular to a surface access closure assembly of the kind known as a "surface box' These are used to provide selective access to e.g. fire hydrants, water mains and similar sub-surface water or other utility supply features that are accessed from Street or road level.

A surface box typically consists of a rigid frame comprising four upstanding walls that are joined seriatim at their ends to define a rectangular frame that is closed on its upstanding sides and is open at its in-use upper and lower ends. A cover in the form of a rigid plate is receivable in the resulting aperture selectively to close it off. A series of features such as protuberances and recesses secured to or formed integrally with the walls of the frame inside the aperture provide supports on which the cover rests when inside the frame.

The surface boxes are provided by utility companies so that authorised persons may gain access for example to control elements (such as valves and taps) forming part of the subterranean water supply infrastructure that is commonplace in many countries.

The frame of the surface box therefore is mounted so as to define the periphery of an aperture in a roadway, pavement, hard standing or other ground surface. The aperture leads in to a chamber that contains the feature to which selective access is required.

The need to limit access to authorised persons derives from obvious requirements to ensure security of the supply of e.g. water to domestic and commercial users. To this end the covers and frames of such boxes often include mutually engageable, spring-loaded detent parts the purpose of which is to retain the cover in the aperture defined by the frame. An authorised user may insert a tool such as a shaped prising bar into a perforation formed in the cover for the purpose of permitting manipulation of the detent features in order to release the cover from the frame.

The frame and cover of a surface box typically are made from cast iron, one form of which (so-called "ductile iron", also referred to as "nodular iron" or "sphemidal graphite iron') is, for well-known reasons, particularly well suited to manufacture of the frame and cover of a surface box.

Such cast iron however has a comparatively high scrap value and therefore is frequently a target for thieves. The problem of theft of ductile iron has worsened during recent times of financial and economic hardship in many countries. In the case of surface boxes such theft manifests itself as removal of the covers following illicit prising of the detents.

Aside from the clear loss in asset value represented by surface box cover theft, such activity leaves the apertures defined by the frames in an open condition. This creates a risk of accidents in turn giving rise to personal injury claims; and also negates the purposes of the surface boxes, in preventing the ingress of contaminants (such as leaves, dirt and lifter) into the chambers defined below the apertures and in limiting unauthorised access to the engineering components in the chambers.

A solution to the theft of surface box covers might be to employ security devices such as padlocks to retain the covers permanently in place in the frames unless opened by an authorised person having possession of the correct key This solution however aside from increasing the cost and complexity of the surface box installations directly conflicts with requirements of fire services, for whose benefit many surface boxes are installed containing fire hydrants.

Fire and rescue workers require access to hydrants on an urgent basis during fire emergencies. Fire services therefore cannot accept surface box covers that require the time-consuming unlocking of security devices such as padlocks using uniquely encrypted keys. On the contrary, fire and rescue workers need to be sure that they can open all hydrant covers in surface boxes using the same (simple, prising bar) equipment that operates quickly and reliably to release the covers.

There is in addition a regulatory requirement for the cover of a surface box to lie flush with the upper edge of the frame when the cover is closed. A further requirement is that the aperture of the frame when the cover is in an open position must be substantially clear. In other words the cover should not encroach significantly inwardly of the edges of the frame when in an open position.

According to the invention in a first aspect there is provided a surface access closure assembly comprising a rigid frame defining the periphery of an aperture; and a rigid as cover that is moveable between (a) a closed, relatively retracted position in which the cover occupies or substantially occupies the aperture and is located so as to protrude no further than an edge of the frame; and (b) an advanced position in which the cover protrudes beyond the said edge of the frame, the cover in the advanced position also being displaceable to (c) an open position in which it generally outside the line of the periphery of the aperture; and the frame and the cover being connected together by a linkage permitting movement between the closed and open positions of the cover via the advanced position.

The use of a linkage connecting the cover and the frame and that permits movement of the cover as aforesaid simultaneously satisfies the conflicting requirements set out above. In particular the linkage prevents complete separation of the cover from the ID frame while nonetheless (a) allowing the cover to lie flush with the frame when in the closed position and (b) allowing it to move to an open location in which the cover lies almost entirely outside the peripheral line of the upper edge of the frame. The assembly of the invention therefore successfully addresses the regulatory needs of surface boxes at the same time as providing an arrangement that is quick, reliable and easy to open without running the risk of complete removal of the cover.

Preferably the linkage comprises at least one hinge member that is pivotably secured to one of the frame and the cover; and a slide member that is (a) fixed to the hinge member and (b) slideably captive relative to the other of the frame and the cover, thereby permitting both advancing and displacement movement of the cover relative to the frame during movement between the closed and open positions.

In a preferred embodiment of the invention the slide member is slideably captive in a guide groove defined by or secured to the frame. This in turn means that the hinge member is pivotably attached to the cover. Such an arrangement permits advancing movement of the cover in an in-use vertical direction so that the cover protrudes vertically above the upper edge of the frame before rotational displacement of the cover to the open position may take place, by hinging of the cover about the hinge member.

More specifically the slide member preferably is slideably captive in a guide groove defined by or secured to the frame. The arrangement preferably is such that one of the guide groove and the slide member includes formed therein a closed-ended slot and the other of the guide groove and the slide member includes protruding therefrom a pin that is slideably receivable in the slot so as to permit sliding movement of the slide member 3s relative to the guide groove between limits defined by the ends of the slot.

In a particularly preferred arrangement the guide groove is defined by an L-shaped or U-shaped member defining at least one limb that is secured to the frame and a spine member that is spaced from the frame, the pin extending in the region between the spine member and the frame through the closed-ended slot so as slideably to retain the slide member relative to the frame.

The described guide groove and retention arrangements advantageously provide for good security, reliable operation and a simple, low-cost construction.

When the assembly of the invention is as defined in Claim 2 hereof preferably the slide member is or includes a generally laminar, rigid plate. This is simple and cheap to manufacture and easily may be bifurcated at one end so as to define a pair of hinge members in accordance with a preferred aspect of the invention.

Correspondingly the cover preferably includes a pair of hinge bosses each including a respective, open ended recess in each of which a respective said hinge member is rotatably captively received.

When the assembly is so arranged further preferably the open ends of the recesses face one another and are separated by a space, the recesses being of circular cross-section and the hinge members each including secured thereto a cylindrical hinge pin that by reason of the relative positions of the recesses and the hinge members is rotatably captive in a said recess.

This arrangement beneficially provides for simple, secure rotatable retention of the cover and the slide member (which latter as stated is slideably captive relative to the frame in preferred embodiments of the invention) together.

Regardless of the chosen linkage arrangement between the cover and the frame in preferred embodiments of the invention the frame and the cover are generally rectangular in plan view, the frame defining four serially connected walls that in use are upstanding and an in-use upper peripheral edge of which defines the said edge relative to which the cover protrudes in the open position.

In a further optional refinement the assembly of the invention may include a sealing plate secured to the in-use underside of the cover so as to seal the aperture against contaminant ingress when the cover is closed. In order to facilitate this arrangement preferably the cover includes a moulded protuberance that secures the sealing plate and the cover one to the other.

The sealing plate furthermore may include a flexible peripheral gasket that when the cover is closed sealingly engages the frame to prevent or limit the ingress of contaminants.

The foregoing features advantageously provide for improved sealing of the cover in the frame notwithstanding the presence of the components described above and elsewhere to herein that provide for improved cover security.

There now follows a description of preferred embodiments of the invention, by way of non-limiting example, with reference being made to the accompanying drawings in which: is Figure 1 is a perspective view from above and to one side of a surface access closure assembly, according to the invention, in the form of a surface box in which the cover is in a closed position; Figure 2 is a perspective view of the Figure 1 surface box from underneath; Figure 3 is a perspective view of the Figure 1 surface box showing its cover having been moved initially to an advanced position and then part-way to an open position through a sideways rotational displacement movement; Figure 4 is a view that is similar to Figure 3 and illustrates the cover when displaced further towards the open position; and Figure 5 is a further perspective view of the Figure 1 surface box, showing the cover in its fully open position.

Referring to the drawings, a surface access closure assembly in the preferred embodiment of the invention is a surface box 10.

ao Figure 1 shows the surface box 10 with its cover 11 in a closed position. Thus cover 11, which is essentially rectangular in plan view as shown except for two truncated corners 12, 13 at one end, substantially occupies an aperture 14 the periphery of which is defined by a generally rectangular, rigid frame 16.

Frame 16 is in many respects similar to conventional surface box frames. Therefore frame 16 includes an in-use lowermost, rectangular, horizontal flange 17 having upstanding therefrom four rigid walls 18, 19, 21, 22. The walls 18, 19, 21, 22 are connected seriatim at their ends to define the four-sided box-like shape illustrated.

The frame 16 is chamfered at inner corners 24, 26 corresponding to the truncated corners 12, 13 of the cover 11 when the latter is in its closed position shown in Figure 1.

This accommodates the truncations 12, 13 of the frame 11, such truncations being formed primarily to avoid presenting sharp corners of the cover 11 when it occupies an upright position as shown in Figure 4.

The flange 16 includes perforations 23 that in the example illustrated are elongate, through-going slots spaced at intervals along two sides of the flange 17. The purpose of the slots is to assist in keying the flange 17, and hence the frame 16, in a bedding medium such as mortar in an excavated recess a short distance below the e.g. pavement surface in which in use the surface box 10 is received. The arrangement of the perforations 23 therefore may vary widely within the scope of the invention while achieving this aim.

When so mounted the upper edges of the walls 18, 19, 21, 22 lie flush with the pavement (or other) surface, with bedding medium surrounding and supporting the frame 16 in a per so known manner As best shown in Figure 1 when in the closed position the cover 11 protrudes no higher than, and preferably lies flush with, the upper edges of the walls 18, 19, 21, 22, and hence also the pavement etc surface.

The cover 11 may be retained in this closed position by a resiliently deformable detent acting between the cover 11 and the frame 16. The detent is not visible in the drawings but may take any of a range of forms known in the relevant art. In preferred embodiments of the invention the cover 11 and/or the frame 16 may be cast from ductile iron. The detent parts may make use of the resilient deformability of this material to provide e.g. an engageable tongue and mortise combination that may be released through operation of a prising bar or similar tool. The latter is insertable via a passage 27 extending downwardly through the cover 11 at one end as illustrated.

In this regard the nature of ductile iron is that to e.g. manual pressure it appears entirely rigid, but when acted on by a tool (and when the dimensions of the part being acted on are consistent with such action) it may be caused resiliently to bend without fracturing.

This is in contrast with many other cast iron alloys, the brittleness of which is considerably greater than that of ductile iron.

Subject to satisfactory installation of any detent arrangement should this be required the parts of the invention could be manufactured from rigid materials other than ductile iron.

Such materials do not necessarily need to be metals or metal alloys, although metal materials are commonplace in the manufacture of surface boxes.

By reason of a linkage 28 described in more detail below the cover 11, following release of the detent if present, is capable of advancing upwardly relative to the frame so that following initial advancement the cover 11 is raised so as to protrude above the upper edges of the walls 18, 19, 21, 22 without substantially changing its orientation from that represented in Figure 1.

is From this position the linkage 28 permits displacement of the cover 11 sideways relative to the frame 16, such that the cover eventually lies largely outside the line of the periphery of the aperture defined by the upper edges of the walls 18, 19. 21, 22.

Throughout such movement the linkage 28 maintains connection of the cover 11 and frame 16 to one another such that the cover 11 cannot be removed entirely from the frame 16.

The preferred form of linkage 28 achieves such sideways displacement through rotation of the cover 11 about a hinge forming part of the linkage 27 and connecting the cover 11 and frame 16 together at the end of cover 11 lying remote from the truncated corners 12, 13. The process of rotating the cover 11 to the open position after advancing of the cover in an upward direction as described is shown in a sequence in Figures 3 to 5, with Figure 5 illustrating the cover 11 in its completely open position. As is apparent from Figure 5, save for a very small amount of overlap of the cover 11 and the wall 22 in the vicinity of linkage 28 the opening defined by the frame 16 is completely clear when the cover 11 adopts this position.

The linkage 28 in the preferred embodiment illustrated comprises a pair of hinge members 29, 31 formed as bifurcations at the in-use upper end of a flat, rigid (eg iron) slide member 32 in the form of a plate that is retained slideably captive relative to wall 22, inside the frame 16. The hinge members 29, 31 are rigidly secured to the slide member preferably by reason of being formed (e.g. by casting) integrally with the slide member 32. Other means of securing the hinge members and slide member together however lie within the scope of the invention and would occur to the worker of skill in the art The slide member 32 is retained slideably captive relative to the wall 22 of frame 16 by reason of the presence of a guide groove 33 defined adjacent wall 22.

Guide groove 33 is formed as an essentially U-shaped member in the preferred embodiment. The limbs 33a, 33b of the U-shape are secured rigidly at their ends to the wall 22 such that the spine member 33c of the U-shape is fixed spaced a short distance from the inner, vertical face of wall 22 extending parallel to it.

This arrangement defines the guide groove 33 having dimensions that support the slide member 32 and guide its sliding movement in a vertical dimension when the assembly is installed conventionally.

The slide member 32 is retained captive relative to the guide groove 33 by reason of a pin and slot combination that is not visible in the drawings.

In this combination an elongate, closed-ended slot extends part-way along the length of the slide member 32 in a direction that is essentially parallel to the extent of the spine member 33c as illustrated. A pin rigidly secured to one or both of the spine member 33c and wall 22 extends between opposed sides of the guide groove 33 and is received in the slot The sizes of the pin and slot are such that the slide member may slide vertically, constrained by the guide groove 33, between limits defined by contact of the pin with the ends of the slot. The position of the pin and slot are such that following manufacture of the assembly 10 the slide member 32 cannot be removed from the guide groove 33 but the pin is capable of sliding in the slot.

This in turn means that it is necessary to fix the components of the guide groove 33. e.g. by welding, after the frame 16 has been formed; but this represents a minor increase in complexity compared with the benefits of the invention.

The cover 11 includes formed (e.g. by reason of being integrally cast with it) on its in-use underside a pair of hinge bosses 34, 36 each including a respective, open ended recess in each of which a respective said hinge member is rotatably captively received.

The open ends of the recesses, which are not visible in the drawings, face one another and are separated by a space, the recesses being of circular cross-section and the hinge members 31, 32 each including secured thereto a cylindrical hinge pin that by reason of the relative positions of the recesses and the hinge members is rotatably captive in a said recess.

The inclusion of opposed hinge recesses in the bosses 34, 36 means that following manufacture of the assembly 10 it is impossible, or at least extremely difficult, to disconnect the cover 11 from the frame 16. This deters theft notwithstanding that the io cover 11 may be opened quickly and easily, when required, by e.g. fire service personnel equipped with a prising bar of appropriate dimension& As outlined therefore movement of the cover 11 from the closed position shown in Figure I to the fully open position shown in Figure 5 involves, firstly, releasing any detent present that secures the cover 11 in the closed position, followed by raising of the cover 11.

This can be achieved by hooking the prising bar or another tool into the recess defined by the passage 27 and pulling upwardly This causes the cover 11 to rise in the frame essentially without changing orientation, as the slide member 32 slides upwardly in the guide groove 33 until further upward movement is prevented by engagement of the pin described above in the lowermost end of the slot formed in the slide member 32. At the end of this stage of the opening process the cover 11 lies parallel to the orientation shown in Figure 1, raised proud of the upper edges of the frame walls 18, 19, 21, 22.

From this position the cover 11 may then be rotated as illustrated in Figures 3 to 5, with the hinge members and the recesses in which they are received undergoing rotation relative to one another, until the cover 11 occupies the fully open position represented in Figure 5 Thereafter the user of the assembly 10 has unimpeded access to the equipment in the chamber beneath the frame 16.

Closure of the cover 11 from the position shown in Figure 5 essentially is a reverse of the steps described above. It is not however usually necessary to use a tool to re-engage the detent, this instead occurring automatically as the cover is pushed from above (e.g. under foot pressure, by stamping) towards the position of Figure 1. The processes of opening and closing the cover 11 may be completed extremely rapidly.

An optional refinement of the arrangement of the invention involves the incorporation of co-operating anti-ingress features on the underside of the cover 11 and the inside faces of the frame 16.

Such features (that are not shown in the drawings) may include a sealing plate secured to the in-use underside of the cover so as to seal the aperture against contaminant ingress when the cover is closed. Such a sealing plate may include a flexible peripheral gasket that when the cover is closed sealingly engages the frame to prevent or limit the ingress of contaminants. The cover optionally may include a moulded protuberance that io secures the sealing plate and the cover one to the other.

The sealing features described may be present in the assembly 10 even in the absence of the features constituting the linkage 28. The invention therefore is considered to reside in the sealing I anti-ingress features in combination with e.g. a conventional surface box frame and cover.

The listing or discussion of an apparently prior-published document in this specification should not necessarily be taken as an acknowledgement that the document is part of the state of the art or is common general knowledge.

Claims

CLAIMS1. A surface access closure assembly comprising a rigid frame defining the periphery of an aperture; and a rigid cover that is moveable between (a) a closed, relatively retracted position in which the cover occupies or substantially occupies the aperture and is located so as to protrude no further than an edge of the frame; and (b) an advanced position in which the cover protrudes beyond the said edge of the frame, the cover in the advanced position also being displaceable to (c) an open position in which it generally outside the line of the periphery of the aperture; and the frame and the cover being connected together by a linkage permitting movement between the closed and open positions of the cover via the advanced position.
2. A surface access closure assembly according to Claim 1 wherein the linkage comprises at least one hinge member that is pivotably secured to one of the frame and the cover; and a slide member that is (a) fixed to the hinge member and (b) slideably captive relative to the other of the frame and the cover, thereby permitting both advancing and displacement movement of the cover relative to the frame during movement between the closed and open positions.
3. A surface access closure assembly according to Claim 2 wherein the at least one hinge member is pivotably secured to the cover and the slide member is slideably captive relative to the frame.
4. A surface access closure assembly according to Claim 3 wherein the slide member is slideably captive in a guide groove defined by or secured to the frame
5. A surface access closure assembly according to Claim 4 wherein one of the guide groove and the slide member includes formed therein a closed-ended slot and the other of the guide groove and the slide member includes protruding therefrom a pin that is slideably receivable in the slot so as to permit sliding movement of the slide member relative to the guide groove between limits defined by the ends of the slot.
6. A surface access closure assembly according to Claim 5 wherein the guide groove is defined by an L-shaped or U-shaped member defining at least one limb that is secured to the frame and a spine member that is spaced from the frame, the pin extending in the region between the spine member and the frame through the closed-ended slot so as slideably to retain the slide member relative to the frame.
7. A surface access closure assembly according to Claim 2 or any preceding claim depending therefrom wherein the slide member is or includes a generally laminar, rigid plate.
8. A surface access closure assembly according to Claim 2 or any preceding claim depending therefrom wherein the slide member is bifurcated at one end so as to define a pair of hinge members.
9. A surface access closure assembly according to Claim 8 wherein the cover includes a pair of hinge bosses each including a respective, open ended recess in each of which a respective said hinge member is rotatably captively received.
10. A surface access closure assembly according to Claim 9 wherein the open ends of the recesses face one another and are separated by a space, the recesses being of circular cross-section and the hinge members each including secured thereto a cylindrical hinge pin that by reason of the relative positions of the recesses and the hinge members is rotatably captive in a said recess.
11. A surface access closure assembly according to any preceding ctaim wherein the frame and the cover are generally rectangular in plan view, the frame defining four serially connected walls that in use are upstanding and an in-use upper peripheral edge of which defines the said edge relative to which the cover protrudes in the open position.
12. A surface access closure assembly according to any preceding claim including a sealing plate secured to the in-use underside of the cover so as to seal the aperture against contaminant ingress when the cover is closed.
13. A surface access closure assembly according to Claim 12 wherein the cover includes a moulded protuberance that secures the sealing plate and the cover one to the other.
14. A surface access closure assembly according to Claim 12 or Claim 13 wherein the sealing plate includes a flexible peripheral gasket that when the cover is closed sealingly engages the frame to prevent or limit the ingress of contaminants.
15. A surface access closure assembly generally as herein described, with reference to and/or as illustrated in the accompanying drawings.