Patent Publication Number: US-10774496-B2

Title: Cover

Description:
This invention relates to a cover intended for use in covering a trench or the like formed in a road surface or footpath surface to allow the continued passage of vehicles or pedestrians along the road or footpath surface. 
     The use of covers in covering trenches or the like formed in road surfaces is well known. Traditionally, the covers have taken the form of steel sheets positioned over trenches and anchored to the road surface using suitable pins, in use. Whilst such covers function adequately, they have the disadvantage that the covers are relatively heavy and so are inconvenient to handle and transport, for example requiring the use of lifting equipment to position the covers over the trench. Clearly, this is inconvenient. Furthermore, as vehicles ride up onto and pass over such covers a significant level of noise is typically generated. 
     An alternative form of cover takes the form of a metal reinforced moulded plastics panel, often formed with rubber or rubber like material flexible end sections. Such covers are of lighter weight than the traditional metallic covers and so are easier to handle and transport. Furthermore, the design of the covers and choice of materials used can result is the generation of less noise as vehicles pass over the covers. 
     Where a number of such covers are arranged side-by-side to cover a trench or the like, it is desirable to be able to link the covers to one another to avoid the formation of gaps therebetween and enhance the stability of the covers. Where reinforced moulded plastics material covers of the type outlined hereinbefore are used, linking of adjacent covers has been achieved by providing linking arrangements comprising interengaging projections receivable within sockets provided in the covers. The presence of the metal reinforcing members in the covers has typically meant that the fitting of the linking arrangements has had to be undertaken after moulding of the cover, and requires the formation of openings in the side walls of the cover above the positions of the reinforcing members, which cannot conveniently be moulded into the cover. As a consequence, manufacture of the cover is undesirably complex. 
     It is an object of the invention to provide a cover in which at least some of the disadvantages associated with known covers are overcome or are of reduced effect. 
     According to the present invention there is provided a cover comprising main section provided with link means to allow linking of the cover to an adjacent cover, wherein the main section is shaped to include opposing side walls and defines a reinforced plastics material central region in which elongate reinforcement members are provided extending within the side walls, and end regions located to opposite ends of and integrally formed with the central region, the elongate reinforcement members provided in the side walls stopping short of the end regions, and wherein the link means are provided at the end regions. 
     It will be appreciated that as the link means are provided at the end regions into which the reinforcement members do not extend, the reinforcement members do not impede the installation or formation of the link means. 
     Conveniently, the side walls are formed with recesses opening to the underside of the cover, the recesses being located in the end regions. Recesses of this type are relatively easy to mould into the main section, and so the manufacturing process used in the formation of the cover may be simplified compared to arrangements in which openings have to be machined into the side walls of the main section after moulding thereof. 
     The link means conveniently comprise a connector plate fitted to the main section and projecting from one of the recesses thereof, and a connector pin fitted to the main section adjacent another of the recesses thereof. In use, the connector pin of one cover is received within an opening provided in the connector plate of an adjacent cover to link the covers to one another. The underside of the recess with which the connector pin is associated is preferably closed by a cover plate, the recess and cover plate together defining an opening into which the connector plate of the adjacent cover is fitted for cooperation with the connector pin. In such an arrangement, separation of the covers simply by lifting one of the covers relative to the adjacent cover is resisted. 
     The connector plate is preferably arranged such that a part thereof in which the opening is provided is angled upwardly, in use. Conveniently, this is achieved by forming the connector plate in such a manner as to include a mounting part secured, in use, to the main section, and an upwardly angled part in which the opening is formed. 
     The cover preferably further comprises additional reinforcement members, the reinforcement members and additional reinforcement members together forming a grid-like arrangement. The main section preferably defines a series of downwardly depending ribs, the reinforcement members and additional reinforcement members being located within respective ones of the ribs. 
     Flexible end ramps are preferably fitted to the end sections. 
     The main section is preferably provided with an opening whereby a probe associated with a gas sensor can be introduced into a trench over which the cover extends to allow tests to be undertaken without first removing the cover from the trench. 
     A retainer arrangement may be provided to resist longitudinal movement of the cover, in use. The retainer arrangement conveniently comprises a housing with which a plurality of moveable pins are associated, the pins being movable under the action of gravity between raised and lowered positions, the pins projecting from the underside of the main section when in their lowered positions. Preferably, the main section is formed with mounting formations to allow the housing to be secured thereto such that the housing extends in a substantially horizontal orientation, in use. Such an arrangement is advantageous in that even where the profile of the main section is curved along its length, the same length pins may be used throughout the retainer arrangement. 
    
    
     
       The invention will further be described, by way of example, with reference to the accompanying drawings, in which: 
         FIG. 1  is a plan view of a cover in accordance with an embodiment of the invention; 
         FIG. 2  is a side view of the cover of  FIG. 1 ; 
         FIG. 3  is a view of the cover from beneath; 
         FIG. 4  is an exploded view illustrating the cover; 
         FIG. 5  is a sectional view illustrating the linking of adjacent covers; 
         FIG. 6  is a view to an enlarged scale illustrating part of the cover; and 
         FIGS. 7 a  to 7 h    illustrate alternative designs of link means that may be used with the cover of  FIGS. 1 to 6 . 
     
    
    
     Referring to  FIGS. 1 to 6  of the accompanying drawings, a cover  10  is illustrated that is intended for use, in conjunction with other similar covers, in covering a trench, opening or cavity or the like formed in a road surface or footpath surface to allow the continued use of the road or footpath by vehicles or pedestrians. The primary purpose of the cover  10  is in covering trenches formed in road surface to allow vehicles to pass over the trench. Accordingly, the cover  10  is designed to be of sufficient strength to carry vehicles over the trench. 
     The cover  10  is comprises a main section  12  to the ends of which are fitted end ramps  14 . The main section  12  is of moulded plastics material form shaped to define an upper surface  16  and integral side walls  18 . The underside of the main section  12  is formed with a series of ribs  20 , some of which extend along the length of the main section  12 , and some of which extend across the width of the main section  12 . 
     The main section  12  defines a central, metal reinforced region  22 , and integral end regions  24  located to opposite ends of the central region  22 . In the central region  22 , the side walls  18  and ribs  20  each contain respective elongate reinforcing members  26 , each of which takes the form of a length of steel rod or bar. The rods or bars are conveniently welded or otherwise secured to one another in a grid-like configuration before being introduced into a mould and having the plastics material of the main section over moulded onto the reinforcing members  26 . It will be appreciated, however, that this represents just one technique by which the main section  12  may be formed, and that other techniques may be used without departing from the scope of the invention. 
     The elongate reinforcing members  26  located within the side walls  18  stop short of the end regions  24 . Likewise, the reinforcing members  26  located within the ribs  20  stop short of the end regions  24 , and so the end regions  24  are not of metal reinforced form. However, it will be appreciated that arrangements are possible within the scope of the invention in which the reinforcing members  26  located within the ribs  20  (but not those located within the side walls  18 ) extend into the end regions  24 . 
     The parts of the sides walls  18  located in the end regions  24  are formed with recesses  28  which open to the underside of the cover. The recesses  28  could be machined into the side walls  18  after completion of the moulding process, but are conveniently formed as part of the moulding operation, the mould being shaped in such a manner as to result in the formation of the recesses  28 . 
     One of the recesses  28  located on each side of the cover  10  has a connector plate  30  associated therewith, the connector plate  30  extending through the recess  28  and including a mounting part  30   a  located beneath and bolted to (or otherwise secured to) the underside of the main section  12 . The connector plate  30  further includes a projecting part  30   b , angled upwardly relative to the plane of the mounting part  30   a  and provided with an opening  32 . 
     The other of the recesses  28  located on each side of the cover  10  has a cover plate  34  mounted adjacent thereto so as to define a closed opening through which a connector pin  36  mounted to the underside of the main section  12  can be accessed. 
     The connector plate  30  and connector pin  36  together serve as link means whereby adjacent covers  10  can be connected or linked to one another. To link adjacent covers  10  to one another, as shown in  FIG. 5 , one of the covers  10  is laid in the desired position and the other is held in an angled configuration to allow the connector plates  30  to be partially inserted into the respective openings defined between the recesses  28  and cover plates  34  to align the openings  32  with the respective connector pins  36 . The angled one of the covers  10  is then laid down with the result that the connector pins  36  become located within the openings  32 , linking the adjacent covers  10  to one another. It will be appreciated that the presence of the cover plates  34  resists lifting of one of the covers  10  relative to the other. It will be appreciated that in this manner, a number of covers  10  can be linked to one another to form an assembly of sufficient width to cover the full length of a trench formed in a road (or other) surface. 
     The end ramps  14  are conveniently of a flexible rubber like material which flexes to accommodate bumps, dips or other non-uniformities in the road surface. The ramps  14  reduce noise generated as vehicles ride onto and leave the covers  10  and the nature of the materials used in the cover  10  serve to further reduce noise generation and reverberation in use. 
     The main section  12  is conveniently formed with one or more openings  38  through which a probe of a gas detector can be inserted, with the cover  10  in position over a trench, to allow gas measurements or tests to be undertaken without the need to first remove the cover  10 . 
     It is desired to provide a means whereby movement of the cover  10  relative to the road surface is resisted to reduce the risk of the cover  10  moving to a position in which it is unstable or unable to safely bear the weight of vehicles or pedestrians passing over the cover  10 . Conveniently, the retainer means takes the form of a housing  40  secured to the underside of the main section  12 , the housing  40  having a series of pins  42  associated therewith. Each pin  42  is held captive to the housing  40  and is movable under the action of gravity between a raised position and a lowered position. In use, prior to lowering the cover into position over a trench, all of the pins  42  will adopt their extended, lowered positions, extending beneath the level of the lower edges of the side walls  18 . As the cover  10  is lowered into position, the ones of the pins  42  located above the road surface to each side of the trench will be pushed into the housing  40 , the remaining pins  42  remaining in their lowered positions. It will be appreciated that the pins  42  in their lowered positions may bear against the side walls of the trench, upon movement of the cover  10  relative to the road surface, limiting or resisting further movement. 
     The pins  42  are all of the same length, and in order to function properly, the housing  40  is preferably arranged horizontally, in use. In order to achieve this despite the curved profile of the cover  10  as illustrated, the underside of the main section  12  is conveniently provided with formations  44  upon which the housing  40  is located to hold the housing  40  in a substantially horizontal configuration, in use. 
     It will be appreciated that the cover  10  is advantageous in that the installation of the link means does not require the formation of openings in the side walls of the main section after completion of the moulding thereof, instead the link means being fitted in recesses that can be formed as part of the moulding process. The formation of the recesses as part of the moulding process is permitted through arranging for the reinforcing members to stop short of the end sections. In known cover designs, the presence of reinforcing members in these locations prevents the formation of recesses in these locations, and instead openings are cut above the level of the reinforcing members as a subsequent, time consuming manufacturing step. The arrangement of the invention is thus advantageous in that manufacture of the cover is simplified. 
     As the end sections  24  are not reinforced, it is desirable that in use these sections of the cover overlie the ground surface rather than being located above the trench, the trench preferably being spanned by the reinforced section  22 . To assist in ensuring that this is the case, the upper surface  16  is preferably provided with markings identifying which parts of the cover are permitted to safely extend over the trench, in use. 
     Although the arrangement described hereinbefore includes a specific type of link means, it will be appreciated that the invention is not restricted in this regard and that a number of other designs of link means may be employed without departing from the scope of the invention. By way of example,  FIGS. 7 a  to 7 h    illustrate several alternative forms of link means. In the arrangements of  FIGS. 7 a  and 7 b   , the link means take the form of projections  50  receivable within correspondingly shaped re-entrant recesses  52 , the projections  50  and recesses  52  being located at the end sections  24 .  FIG. 7 c    illustrates an arrangement in which, along one side of the cover is formed a lip  54  which can rest upon a ledge  56  projecting from the adjacent cover, bolts  58  or other fasteners being used to secure the lip  54  to the ledge  56 . The lips  54  and ledges  56  are located at the end sections  24 .  FIG. 7 d    illustrates an alternative configuration in which the lips  54  and ledges  56  includes side walls  54   a ,  56   a  which interact to resist separation of the covers.  FIG. 7 e    illustrates an arrangement in which the link arrangement takes the form of connector plates  60  which can be bolted to the covers, recesses  62  being formed in the end sections  24  to accommodate the connector plates  60 . 
       FIGS. 7 f  to 7 h    illustrate an arrangement that, in many respects, is similar to that of  FIGS. 1 to 6  but in which the connection plate  62  is located to the top of the cover and is fitted through a slot  64  formed in the end section  24  of the cover. The plate  62  is of stepped form rather than being of angled form.  FIG. 7 f    illustrates part of the cover,  FIG. 7 g    illustrating two covers linked to one another, and  FIG. 7 h    illustrating the method used to link the covers to one another. 
     It will be appreciated that the options shown in  FIGS. 7 a  to 7 h    represent examples of alternative link means, and that other arrangements are possible without departing from the scope of the invention. 
     Whilst a specific embodiment of the invention is described herein, it will be appreciated that a wide range of modifications and alterations may be made thereto without departing from the scope of the invention as defined by the appended claims.