AU2012205189A1 - A Safety System - Google Patents

Abstract

A manhole safety system is described that provides an obstruction to objects falling into a manhole through its entrance. The manhole safety system has a manhole entrance frame to at least in part define the entrance of a manhole, the entrance frame including at least two anchor points. The system also has a grate to locate in said manhole entrance frame, the grate including at least two fixture points provided in locations complementary to the two anchor points. The fixture and anchor points allow the grate be secured in the manhole entrance frame. - 29 - 7'i0 q-1 k N

Description

Regulation 3.2 AUSTRALIA PATENTS ACT, 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT ORIGINAL Name of Applicant: KEVIN DOUGLAS MASKELL Actual Inventors: MASKELL, Kevin Douglas Address for service AJ PARK, Level 11, 60 Marcus Clarke Street, Canberra ACT in Australia: 2601, Australia Invention Title: A Safety System The following statement is a full description of this invention, including the best method of performing it known to us.

FIELD OF THE INVENTION The present invention relates to a safety grate system. More particularly but not exclusively it relates to a safety grate system for preventing the ingress of a person into a stormwater drain system via a stormwater access way that is normally covered by a removable cover. BACKGROUND Stormwater drainage systems are often required to handle increased volumes of fluids such as when it rains heavily. Increased fluid volume can lead to increased pressure within the drain pipes of the stormwater system. Stormwater drain pipes are known to be prone to blockages. These blockages are normally caused by roots from nearby trees entering the pipes and/or by debris entering the stormwater system via the catchment intakes. These blockages further add to the pressures that can build in a stormwater system. It is known that if the pressures become too great then damage can occur to the stormwater drain pipes due to them bursting or cracking. Replacing damaged pipes can be expensive and the damages caused by water that is not able to flow due to the damaged pipes can be significant. As such it is common to have pressure relief systems that allow the pressure generated in the pipes to be redirected thereby preventing damage to the pipes. Stormwater systems need to be accessible to allow them to be checked and maintained. As such stormwater systems have stormwater access ways located at periodical intervals throughout the system. One example of a pressure relief system uses the stormwater access ways as an alternative route for pressure to be released from. Standard stormwater access ways consist of an opening or manhole leading into a shaft that connects directly into the stormwater drain pipe system. To prevent any persons or debris accidentally falling into the manhole they are covered with a manhole cover. Subsequently the stormwater access way can only act as a pressure release system when the manhole covers are removed. It is known that most manhole covers are designed to be able to be popped out of the manhole when high pressures build in the stormwater systems. The covers are sufficiently light such that the pressure generated by blockages and additional fluids is sufficient to pop the covers of the manhole before damage occurs to the pipes. Whilst this solves the problem of preventing damage to the pipes it is undesirable to have an exposed stormwater access way. Exposed stormwater access ways are hazardous as a person could accidentally fall or enter the stormwater system and subsequently harm themselves. Fitting a known safety grate of the kind as described in my New Zealand registered design NZ412823 can be time consuming as existing manholes need to have - 2the grate retrofitted in situ. This involves drilling 3 accurately spaced holes into the manhole which are often made of cast iron and this can hence be hard. SUMMARY OF THE INVENTION It is an object of the present invention to provide a safety grate system that overcomes or at least ameliorates some of the abovementioned disadvantages or which at least provides the public with a useful choice. In a first aspect the present invention may be said to be a manhole safety system to present obstruction to objects falling into a manhole through its entrance, the system comprising a manhole entrance frame to at least in part define the entrance of a manhole, the entrance frame including at least two anchor points, a grate to locate in said manhole entrance frame, the grate including at least two fixture points provided in locations complementary to said two anchor points to allow said grate to thereat be secured in said manhole entrance frame. Preferably said grate is shaped and configured to extend across said entrance. Preferably the manhole entrance frame defines a main central round aperture and said grate is of a shape to extend across said aperture. Preferably said anchor points are equispaced. Preferably the fixture points are each defined by a hole (blind or through hole) or receptacle of said manhole entrance frame. Preferably a first of said fixture points is defined by a threaded fastener. Preferably a second of said fixture points is defined by a threaded fastener. Preferably there are at least three fixture points and the third of said fixture points is a threaded fastener. Preferably a first of said fixture points is defined by a lug or lip. Preferably a second of said fixture points is defined by a lug or lip. Preferably there are at least three fixture points and the third of said fixture points is a lug or lip. Preferably a first of said fixture points can receive one of a lug, pin, stud, padlock and treaded fastener. Preferably a second of said fixture points can receive one of a lug, pin, stud, padlock and treaded fastener. Preferably there are at least three fixture points and the third of said fixture points can receive one of a lug, pin, stud, padlock and treaded fastener. Preferably said lug, threaded fastener, padlock, pin, stud, lip, is able to be received by said hole or receptacle of a said anchor point. - 3- Preferably said lug, threaded fastener, padlock, pin, stud, lip, of the or each fixture points is able to be received by said hole or receptacle of each said anchor points. Preferably said grate comprises a frame. Preferably the threaded fastener(s) are threadingly engaged to said frame. Preferably the threaded fastener(s) can be moved between a hole or receptacle engaging condition and a hole or receptacle withdrawn condition. Preferably the frame is round and the threaded fastener(s) can be actuated to move in a radial manner relative said frame. Preferably the frame is cylindrical in shape. Preferably the frame includes lugs the fixture points being defined by an aperture through each said lug. Preferably the manhole entrance frame is cylindrical in shape. Preferably the apertures of the manhole entrance frame extend radially into said manhole entrance frame. Preferably the apertures of the manhole entrance frame extend parallel to the axial direction of and into said manhole entrance frame. Preferably the manhole entrance frame is made of cast metal. Preferably the manhole entrance frame is an annular ring that includes a first end at which a said manhole cover can nest to close the manhole. Preferably the anchor points are located such that the grate is able to locate below and immediately adjacent said manhole cover. Preferably the grate is to locate in said manhole adjacent and below where the manhole cover is to position to seal said manhole. Preferably said grate, when secured, is immovable secured to said entrance frame. In a second aspect the present invention may be said to be a manhole safety system to present obstruction to objects falling into a manhole through its entrance, the system comprising a manhole entrance frame to at least in part define the entrance of a manhole, having a central round hole and at least two radially extending apertures, a grate to locate in said manhole entrance frame, the grate presenting for receipt by a respective hole of said entrance frame, at least one of a pin and a threaded fastener, two threaded fasteners, provided in locations complementary to said two apertures to allow said grate to thereat and in cooperation be secured in said manhole entrance frame. -4- In yet a further aspect the present invention may be said to be a manhole safety system to present obstruction to objects falling into a manhole through its entrance, the system comprising a manhole entrance frame to at least in part define the entrance of a manhole, having a central round hole and three equispaced radially extending apertures, a grate to locate in said manhole entrance frame, the grate presenting a pin that can be manoeuvred into a said aperture and presenting two threaded fasteners that can me moved to extend into and out of a respective aperture, the pin and the threaded fasteners acting in cooperation to allow a releasable securing of the grate to said entrance frame. In even a further aspect the present invention may be said to be a manhole safety system to present obstruction to objects falling into a manhole through its entrance, the system comprising a manhole entrance frame to at least in part define the entrance of a manhole, having a central round hole and one equispaced radially extending aperture and two receptacles, a grate to locate in said manhole entrance frame, the grate presenting a pin that can be manoeuvred into a said aperture and presenting two threaded fasteners that can me moved to extend into and out of operative engagement with a respective receptacle, the pin and the threaded fasteners acting in cooperation to allow a releasable securing of the grate to said entrance frame. In even a further aspect the present invention may be said to be a manhole safety system to present obstruction to objects falling into a manhole through its entrance, the system comprising a manhole entrance frame to at least in part define the entrance of a manhole, having a central round hole and three equispaced radially extending apertures, a grate to locate in said manhole entrance frame, the grate presenting a pin that can be manoeuvred into a said aperture and presenting two threaded fasteners that can me moved to extend into and out of a respective aperture, the pin and the threaded fasteners acting in cooperation to allow a releasable securing of the grate to said entrance frame. In yet a further aspect the present invention may be said to be a manhole safety system to prevent objects falling though the entrance of and into a manhole the system comprising: a manhole entrance frame to at least in part define the entrance of a manhole, the entrance frame including at least two anchor points, -5a grate to locate in said manhole entrance frame, the grate including at least two fixture points provided in locations complementary to said two anchor points to allow said grate to thereat be secured in said manhole entrance frame. Preferably said grate is shaped and configured to extend across said entrance. Preferably the manhole entrance frame defines a main central round aperture and said grate is of a shape to extend across said aperture. Preferably said anchor points are equispaced. Preferably the fixture points are each defined by a hole (blind or through hole) or receptacle of said manhole entrance frame. Preferably a first of said fixture points is defined by a threaded fastener. Preferably a second of said fixture points is defined by a threaded fastener. Preferably there are at least three fixture points and the third of said fixture points is a threaded fastener. Preferably a first of said fixture points is defined by a lug or lip. Preferably a second of said fixture points is defined by a lug or lip. Preferably there are at least three fixture points and the third of said fixture points is a lug or lip. Preferably a first of said fixture points can receive one of a lug, pin, stud, padlock and treaded fastener. Preferably a second of said fixture points can receive one of a lug, pin, stud, padlock and treaded fastener. Preferably there are at least three fixture points and the third of said fixture points can receive one of a lug, pin, stud, padlock and treaded fastener. Preferably said lug, threaded fastener, padlock, pin, stud, lip, is able to be received by said hole or receptacle of a said anchor point. Preferably said lug, threaded fastener, padlock, pin, stud, lip, of the or each fixture points is able to be received by said hole or receptacle of each said anchor points. Preferably said grate comprises a frame. Preferably the threaded fastener(s) are threadingly engaged to said frame. Preferably the threaded fastener(s) can be moved between a hole or receptacle engaging condition and a hole or receptacle withdrawn condition. Preferably the frame is round and the threaded fastener(s) can be actuated to move in a radial manner relative said frame. Preferably the frame is cylindrical in shape. Preferably the frame includes lugs the fixture points being defined by an aperture through each said lug. Preferably the manhole entrance frame is cylindrical in shape. - 6- Preferably the apertures of the manhole entrance frame extend radially into said manhole entrance frame. Preferably the apertures of the manhole entrance frame extend parallel to the axial direction of and into said manhole entrance frame. Preferably the manhole entrance frame is made of cast metal. Preferably the manhole entrance frame is an annular ring that includes a first end at which a said manhole cover can nest to close the manhole. Preferably the anchor points are located such that the grate is able to locate below and immediately adjacent said manhole cover. Preferably said grate, when secured, is immovable secured to said entrance frame. In yet a further aspect the present invention may be said to be the combination of (i) a manhole entrance frame to be installed at and define the entrance of a manhole and (ii) a safety grate that can extend across the entrance frame to present an obstacle to objects falling down the manhole, the entrance frame including means to secure the safety grate to said manhole entrance frame. Preferably the safety grate includes means complementary to said means to secure to facilitate the securing of said grate to said manhole entrance frame. Preferably said grate, when secured, is immovable secured to said entrance frame. Preferably one of said means to secure and said means complementary allows the releasable securing of said grate to said entrance frame. In yet a further aspect the present invention may be said to be a kitset comprising of (i) a manhole entrance frame to be installed at and define the entrance of a manhole and (ii) a safety grate that can extend across the entrance frame to present an obstacle to objects falling down the manhole, the entrance frame including means to secure the safety grate to said manhole entrance frame. Preferably the safety grate includes means complementary to said means to secure to facilitate the securing of said grate to said manhole entrance frame. Preferably said grate, when secured, is immovable secured to said entrance frame. Preferably one of said means to secure and said means complementary allows the releasable securing of said grate to said entrance frame. In a further aspect the present invention may be said to be a kitset to present obstruction to objects falling into a manhole through its entrance, the kitset comprising a manhole entrance frame to at least in part define the entrance of a manhole, the entrance frame including at least two anchor points, - 7a grate to locate in said manhole entrance frame, the grate including at least two fixture points provided in locations complementary to said two anchor points to allow said grate to thereat be secured in said manhole entrance frame. Preferably said grate is shaped and configured to extend across said entrance. Preferably the manhole entrance frame defines a main central round aperture and said grate is of a shape to extend across said aperture. Preferably said anchor points are equispaced. Preferably the fixture points are each defined by a hole (blind or through hole) or receptacle of said manhole entrance frame. Preferably a first of said fixture points is defined by a threaded fastener. Preferably a second of said fixture points is defined by a threaded fastener. Preferably there are at least three fixture points and the third of said fixture points is a threaded fastener. Preferably a first of said fixture points is defined by a lug or lip. Preferably a second of said fixture points is defined by a lug or lip. Preferably there are at least three fixture points and the third of said fixture points is a lug or lip. Preferably a first of said fixture points can receive one of a lug, pin, stud, padlock and treaded fastener. Preferably a second of said fixture points can receive one of a lug, pin, stud, padlock and treaded fastener. Preferably there are at least three fixture points and the third of said fixture points can receive one of a lug, pin, stud, padlock and treaded fastener. Preferably said lug, threaded fastener, padlock, pin, stud, lip, is able to be received by said hole or receptacle of a said anchor point. Preferably said lug, threaded fastener, padlock, pin, stud, lip, of the or each fixture points is able to be received by said hole or receptacle of each said anchor points. Preferably said grate comprises a frame. Preferably the threaded fastener(s) are threadingly engaged to said frame. Preferably the threaded fastener(s) can be moved between a hole or receptacle engaging condition and a hole or receptacle withdrawn condition. Preferably the frame is round and the threaded fastener(s) can be actuated to move in a radial manner relative said frame. Preferably the frame is cylindrical in shape. Preferably the frame includes lugs the fixture points being defined by an aperture through each said lug. Preferably the manhole entrance frame is cylindrical in shape. -8- Preferably the apertures of the manhole entrance frame extend radially into said manhole entrance frame. Preferably the apertures of the manhole entrance frame extend parallel to the axial direction of and into said manhole entrance frame. Preferably the manhole entrance frame is made of cast metal. Preferably the manhole entrance frame is an annular ring that includes a first end at which a said manhole cover can nest to close the manhole. Preferably the anchor points are located such that the grate is able to locate below and immediately adjacent said manhole cover. Preferably the grate is to locate in said manhole adjacent and below where the manhole cover is to position to seal said manhole. Preferably said grate, when secured, is immovable secured to said entrance frame. In a further aspect the present invention may be said to be a kitset to present obstruction to objects falling into a manhole through its entrance, the kitset comprising a manhole entrance frame to at least in part define the entrance of a manhole, having a central round hole and at least two radially extending apertures, a grate to locate in said manhole entrance frame, the grate presenting for receipt by a respective hole of said entrance frame, at least one of a pin and a threaded fastener, two threaded fasteners, provided in locations complementary to said two apertures to allow said grate to thereat and in cooperation be secured in said manhole entrance frame. In yet a further aspect the present invention may be said to be a kitset to present obstruction to objects falling into a manhole through its entrance, the kitset comprising a manhole entrance frame to at least in part define the entrance of a manhole, having a central round hole and three equispaced radially extending apertures, a grate to locate in said manhole entrance frame, the grate presenting a pin that can be manoeuvred into a said aperture and presenting two threaded fasteners that can me moved to extend into and out of a respective aperture, the pin and the threaded fasteners acting in cooperation to allow a releasable securing of the grate to said entrance frame. In even a further aspect the present invention may be said to be a kitset to present obstruction to objects falling into a manhole through its entrance, the kitset comprising -9a manhole entrance frame to at least in part define the entrance of a manhole, having a central round hole and one equispaced radially extending aperture and two receptacles, a grate to locate in said manhole entrance frame, the grate presenting a pin that can be manoeuvred into a said aperture and presenting two threaded fasteners that can me moved to extend into and out of operative engagement with a respective receptacle, the pin and the threaded fasteners acting in cooperation to allow a releasable securing of the grate to said entrance frame. In even a further aspect the present invention may be said to be a kitset to present obstruction to objects falling into a manhole through its entrance, the kitset comprising a manhole entrance frame to at least in part define the entrance of a manhole, having a central round hole and three equispaced radially extending apertures, a grate to locate in said manhole entrance frame, the grate presenting a pin that can be manoeuvred into a said aperture and presenting two threaded fasteners that can me moved to extend into and out of a respective aperture, the pin and the threaded fasteners acting in cooperation to allow a releasable securing of the grate to said entrance frame. In yet a further aspect the present invention may be said to be a kitset to prevent objects falling though the entrance of and into a manhole the kitset comprising: a manhole entrance frame to at least in part define the entrance of a manhole, the entrance frame including at least two anchor points, a grate to locate in said manhole entrance frame, the grate including at least two fixture points provided in locations complementary to said two anchor points to allow said grate to thereat be secured in said manhole entrance frame. In a further aspect the present invention may be said to be a manhole grate to present obstruction to objects falling into a manhole through its entrance frame the entrance frame including at least two anchor points, the manhole grate comprising: a grate to locate in said manhole entrance frame, the grate including at least two fixture points provided in locations complementary to said two anchor points to allow said grate to thereat be secured in said manhole entrance frame. Preferably said grate is shaped and configured to extend across said entrance. Preferably the manhole entrance frame defines a main central round aperture and said grate is of a shape to extend across said aperture. Preferably said anchor points are equispaced. Preferably the fixture points are each defined by a hole (blind or through hole) or receptacle of said manhole entrance frame. - 10 - Preferably a first of said fixture points is defined by a threaded fastener. Preferably a second of said fixture points is defined by a threaded fastener. Preferably there are at least three fixture points and the third of said fixture points is a threaded fastener. Preferably a first of said fixture points is defined by a lug or lip. Preferably a second of said fixture points is defined by a lug or lip. Preferably there are at least three fixture points and the third of said fixture points is a lug or lip. Preferably a first of said fixture points can receive one of a lug, pin, stud, padlock and treaded fastener. Preferably a second of said fixture points can receive one of a lug, pin, stud, padlock and treaded fastener. Preferably there are at least three fixture points and the third of said fixture points can receive one of a lug, pin, stud, padlock and treaded fastener. Preferably said lug, threaded fastener, padlock, pin, stud, lip, is able to be received by said hole or receptacle of a said anchor point. Preferably said lug, threaded fastener, padlock, pin, stud, lip, of the or each fixture points is able to be received by said hole or receptacle of each said anchor points. Preferably said grate comprises a frame. Preferably the threaded fastener(s) are threadingly engaged to said frame. Preferably the threaded fastener(s) can be moved between a hole or receptacle engaging condition and a hole or receptacle withdrawn condition. Preferably the frame is round and the threaded fastener(s) can be actuated to move in a radial manner relative said frame. Preferably the frame is cylindrical in shape. Preferably the frame includes lugs the fixture points being defined by an aperture through each said lug. Preferably the manhole entrance frame is cylindrical in shape. Preferably the apertures of the manhole entrance frame extend radially into said manhole entrance frame. Preferably the apertures of the manhole entrance frame extend parallel to the axial direction of and into said manhole entrance frame. Preferably the manhole entrance frame is made of cast metal. Preferably the manhole entrance frame is an annular ring that includes a first end at which a said manhole cover can nest to close the manhole. Preferably the anchor points are located such that the grate is able to locate below and immediately adjacent said manhole cover. - 11 - Preferably the grate is to locate in said manhole adjacent and below where the manhole cover is to position to seal said manhole. Preferably said grate, when secured, is immovable secured to said entrance frame. In a further aspect the present invention may be said to be a safety grate to present obstruction to objects falling into a manhole through its manhole entrance frame the entrance frame having a central round hole and at least two radially extending apertures, said safety grate comprising: a grate to locate in said manhole entrance frame, the grate presenting for receipt by a respective hole of said entrance frame, at least one of a pin and a threaded fastener, two threaded fasteners, provided in locations complementary to said two apertures to allow said grate to thereat and in cooperation be secured in said manhole entrance frame. In yet a further aspect the present invention may be said to be a manhole safety grate to present obstruction to objects falling into a manhole through its entrance frame to at least in part define the entrance of a manhole, having a central round hole and three equispaced radially extending apertures, said safety grate comprising: a grate to locate in said manhole entrance frame, the grate presenting a pin that can be manoeuvred into a said aperture and presenting two threaded fasteners that can me moved to extend into and out of a respective aperture, the pin and the threaded fasteners acting in cooperation to allow a releasable securing of the grate to said entrance frame. In even a further aspect the present invention may be said to be a safety grate to present obstruction to objects falling into a manhole through its entrance frame, said entrance frame having a central round hole and one equispaced radially extending aperture and two receptacles, said safety grate comprising: a grate to locate in said manhole entrance frame, the grate presenting a pin that can be manoeuvred into a said aperture and presenting two threaded fasteners that can me moved to extend into and out of operative engagement with a respective receptacle, the pin and the threaded fasteners acting in cooperation to allow a releasable securing of the grate to said entrance frame. In even a further aspect the present invention may be said to be a manhole safety grate to present obstruction to objects falling into a manhole through its entrance frame said entrance frame defining a central round hole and three equispaced radially extending apertures, said safety grate comprising: - 12 a grate to locate in said manhole entrance frame, the grate presenting a pin that can be manoeuvred into a said aperture and presenting two threaded fasteners that can me moved to extend into and out of a respective aperture, the pin and the threaded fasteners acting in cooperation to allow a releasable securing of the grate to said entrance frame. In yet a further aspect the present invention may be said to be a manhole safety grate to prevent objects falling though the entrance of and into a manhole entrance frame, the entrance frame including at least two pre-defined anchor points, said safety grate comprising: a grate to locate in said manhole entrance frame, the grate including at least two fixture points provided in locations complementary to said two anchor points to allow said grate to thereat be secured in said manhole entrance frame. Preferably the entrance frame is retrofitted or retrofittable to an existing manhole. Preferably the anchor points are defined by lugs. Preferably the anchor points are defined by discreet lugs. In a first aspect the present invention may be said to be a manhole safety system to present obstruction to objects falling into a manhole through its entrance, the system comprising a manhole entrance frame to at least in part define the entrance of a manhole, the entrance frame including a ledge, and at least one anchor point a grate to locate in said manhole entrance frame, the grate including at least one fixture point provided in a location to complementary to said anchor point points to allow said grate to thereat be secured in said manhole entrance frame, the grate being of a shape and configuration to, when so secured to also be supported by said ledge, Preferably the grate is of a shape and configuration to not be able to pass through the entrance frame. Preferably the object that the grate can present obstruction to is a mobile person, e.g. from a child that can crawl and upwards in age. Preferably the system prevents the ingress of a person into a stormwater drain system via a stormwater access way that is normally covered by a removable cover. Preferably the system is configured such that a cover for covering the entrance can be used in conjunction with the grate. In yet a further aspect the present invention may be said to be a grate and manhole entrance frame that in combination that can securely yet releasably be fastened together by a 3 point fastening system that comprises 3 spaced apart mounts of said - 13 grate and complementary mounts of said manhole entrance frame, said grate being configured so as to prevent, in use, the ingress of a person into an underground pipe. Preferably at least one of the 3 spaced apart mounts comprised a threaded fastener. Preferably at least one of the mounts includes of is engagable by a removable fastening means such as bolts, screws, hooks, padlocks, clips or their like. Preferably the mounts are an integral part of the mounts. In an alternatively aspect the present invention consist in a system as herein described with reference to any one or more of the accompanying drawings. Other aspects of the invention may become apparent from the following description which is given by way of example only and with reference to the accompanying drawings. As used herein the term "and/or" means "and" or "or", or both. The term "comprising" as used in this specification means "consisting at least in part of". When interpreting statements in this specification which include that term, the features, prefaced by that term in each statement, all need to be present but other features can also be present. Related terms such as "comprise" and "comprised" are to be interpreted in the same manner. To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting. BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described by way of example only and with reference to the following drawings. Figure la is a perspective view of a preferred embodiment of the grate mounted in a manhole entrance frame. Figure lb is a perspective view of a preferred embodiment of the cover mounted on a manhole entrance frame. Figure 2a is a plan view of a preferred embodiment of the grate. Figures 2b is an elevation view of a preferred embodiment of the grate. Figure 3a is a plan view of a preferred embodiment of a manhole entrance frame. Figures 3b is an elevation view of a preferred embodiment of a manhole entrance frame. - 14 - Figure 4a is a plan view of a preferred embodiment of the grate mounted in a manhole entrance frame. Figures 4b is an elevation view of a preferred embodiment of the grate mounted in a manhole entrance frame. Figure 5 is a sectional view through line A-A of figure 4a of a preferred embodiment of the grate mounted in a manhole entrance frame. Figure 6 is a plan view of an alternative embodiment of the grate with a support. Figure 7 is a sectional view of an alternative arrangement of a manhole entrance frame and grate engaged therewith. Figure 8 is a perspective view of the grate of Figure 6. Figure 9 is a perspective view of the manhole entrance frame and grate of Figure 7. Figure 10 is a perspective view from below of the manhole entrance frame and grate of Figure 9. Figure 11 is a perspective view of yet another alternative arrangement of the grate of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Figure la shows a preferred embodiment the present invention being a system of a grate 100 and a manhole entrance frame 200 designed to cooperate together so as to allow for easy installation in a manhole. The grate 100 is configured to be used in conjunction with a manhole entrance frame 200 and a manhole cover 300. The grate is configured to be securely mounted in the manhole entrance frame 200 such that a person cannot ingress into, for example, a stormwater system. Yet the grate can be removed therefrom as and when desired. The grate preferably is installed such that it is removably secured in the manhole entrance frame and suspended immediately below the manhole entrance frame 200 and cover 300. The grate 100 in the preferred embodiment is configured to fit into a manhole entrance frame 200 with a substantially round opening (for example, an annular ring) or aperture 210, as shown in figures 3a and 3b. Alternatively, the opening 210 to the manhole entrance frame 200 could be a rectangle, square or any other shaped opening. Thus a grate that fits such a shaped frame would also have a complimentary shape to that frame. Referring to Figures 2a and 2b, the grate comprises a frame 110 which in a preferred embodiment is a hoop or circle. The grate frame 110 also preferably cylindrical in shape. The grate also includes a mesh 120. In a preferred embodiment the mesh extends across the opening formed by the frame 110. The mesh 120 could be fine or - 15 coarse mesh of any orientation or configuration but that has openings that are suitably shaped to prevent the smallest of children from falling through. In the preferred embodiment the perimeter of the grate frame 110 is the substantially the same as the narrowest part of the manhole entrance frame. Alternatively, the mesh 120 may be a series of cross-hatched round rods, making up a grill, where, for example, the grill is made from steel or other appropriate materials. The rods may be of a steel material or any other appropriate rigid material. Preferably the grate frame and manhole entrance frame are made of cast metal; however, they may be made from other appropriate materials, particularly other appropriate metals. The grate also includes fixture points 140 for mounting the grate 100 to anchor points 130 of the manhole entrance frame 200. In a preferred embodiment the fixture points are mounts 140 that are attached to the frame 110 of the grate 100. In a preferred embodiment the mounts 140 are threaded fasteners or pins. However, the fixture points or mounts may be a bolt or bolts or pin or lip or merely an aperture that can receive a pin or padlock, threaded fastener or similar that can in cooperation with the anchor points of the manhole entrance frame to secure the grate thereto. In the preferred form of the present invention the fixture points 140 include a fastener, such as a threaded fastener, that can be actuated to move in a radial manner relative to the grate 100 and grate frame 110. The anchor points 130 are preferably integrally formed with the manhole entrance frame. However, in other forms the anchor points may be retrofitted to existing manhole entrance frames. The anchor point 130 preferably extend downwardly so as not to project into the opening of the manhole entrance frame. The anchor points are preferably equispaced from each other. There are preferably three anchor points. The anchor points 130 are preferably defined by an aperture or a hole (blind or through hole), receptacle, lug or lip at the manhole entrance frame 200. The grate 100 is securely mounted by the anchor points 130 of the manhole entrance frame 200. In a preferred embodiment the grate 100 is mounted to the manhole entrance frame 200 at the anchor points 130 using a bolt(s), screw(s) or similar retaining means 150. Alternatively the mounts 140 could be attached to the manhole entrance frame 200 using any removable attachment means such as screws, padlocks or hooks. Figure 5 shows a preferred embodiment of how the mount 140 can securely fasten the grate 100 (via the frame 110) to the manhole entrance frame 200. In an alternative embodiment the grate 100 includes at least one mount that is a pin 160 ("mounting pin") as seen in Figures 6 and 8. The at least one pin 160 in the - 16 preferred embodiment extends outwardly from the outer edge of the frame 110 of the grate 100. The mounting pin is configured to at least in part support the grate within the manhole entrance frame 200 by engaging with an anchor point 130 of the manhole entrance frame 200 (see Figure 10). In the preferred embodiment the manhole entrance frame 200 is adapted to at least in part receive the mounting pin 160 thereby providing a support surface to at least in part support the grate 100. In this alternative form as shown in Figure 6, the grate has one mounting pin 160 and two other mounts 140 that are threaded fasteners. The threaded fasteners 140 are used for securing the grate 100 to corresponding anchor points 130 on the manhole entrance frame 200. Thus in use, a person could locate the mounting pin 160 into an anchor point 130 of the manhole entrance frame to help partially support the grate to the manhole entrance frame. Then the other mounts (threaded fasteners) can be used to secure the frame in place. For example, bolts can be used to fix the grate to the anchor points 130 and hence the manhole entrance frame 200. When the anchor points of the manhole entrance frame are equispaced, the orientation of the grate may not matter to the extent that any of the mounts could be lined up to engage with any of the anchor points of the manhole entrance frame. This can make installation quick and convenient. In a preferred embodiment the opening 210 of the manhole entrance frame 200 is or can be covered by a cover 300. In a preferred embodiment the cover covers substantially all of the opening 210. In a preferred embodiment the cover is configured to substantially seal the opening of the manhole entrance frame 200 such that in the event that the pressure within the stormwater system significantly increases then the cover will be forced upwards exposing the opening. The cover 300 is configured to be mounted at a point above the grate 100 and to be used in conjunction with a grate 100 mounted at the same time. In Figures 7 and 9 an alternative arrangement is shown wherein the manhole entrance frame defines a ledge 260 on which the frame or other part of the grate can rest. In this arrangement, it is preferred that the grate is of a size to not be able to fall down the manhole entrance but still needs to be secured in place by at least one mount 140. This mount may include a bolt that can be engaged into a threaded hole of the manhole entrance frame. The hole may present for engagement by a bolt in a vertical direction making it easy for the frame to be secured in place. A further alternative embodiment of a grate of the present invention is shown in Figure 11. This grate 400 is similar to that described above, in that it has a frame 410 and mesh or cross-hatched bars 420 fixed thereto. However, the at least one fixture point or mount is disposed above the frame 410 of the grate. - 17 - In this embodiment, the grate 400 has three fixture points or mounts, one being a mounting pin 460, similar to that described above. The other two mounts are lugs 440 to which threaded fasteners 441 may attach the lugs 440 to the anchor points 130 (for example, those shown in Figure 3b or 10). The grate 400 may be mounted to a manhole entrance frame in a similar manner to that described above. That is, the pin 460 fits into an anchor point of the manhole entrance frame 200, the lugs 440 then being fixed to the other two anchor points 130, with the threaded fasteners securing the lugs to the anchor points. In this embodiment, the pin 460 is offset from the frame 410 of the grate 400 and the lugs 440 are mounted above the frame 410. This means there is more room for a user to manoeuvre and operate tools used to secure and tighten the mounts/fasteners to the anchor points 130. As the frame is more offset from the manhole entrance frame 200 and cover 300 in use, there is more of a clearance from the mesh or bars 420, meaning they are less of a hindrance during installation of the grate 400 into the manhole entrance frame. The result in this embodiment is that the grate 400 (frame and mesh/bars) in use will be further suspended below the manhole entrance frame compared to the other embodiments described above. - 18 -

Claims (105)

1. A manhole safety system to present obstruction to objects failing into a manhole through its entrance, the system comprising: a manhole entrance frame to at least in part define the entrance of a manhole, the entrance frame including at least two anchor points, a grate to locate in said manhole entrance frame, the grate including at least two fixture points provided in locations complementary to said two anchor points to allow said grate to thereat be secured in said manhole entrance frame.

2. A manhole safety system as claimed in claim 1 wherein said grate is shaped and configured to extend across said manhole entrance frame.

3. A manhole safety system as claimed in any one of claims 1 or 2, wherein said grate is of a shape to extend across said entrance.

4. A manhole safety system as claimed in any one of claims 1 to 3 wherein said anchor points are equispaced.

5. A manhole safety system as claimed in any of claims 1 to 4 wherein the anchor points are each defined by an aperture (blind or through hole), receptacle, lug or lip at said manhole entrance frame.

6. A manhole safety system as claimed in any one of claims 1 to 5 wherein a first of said fixture points is defined by a threaded fastener.

7. A manhole safety system as claimed in any one of claims 1 to 6 wherein a second of said fixture points is defined by a threaded fastener.

8. A manhole safety system as claimed in any one of claims 1 to 7 wherein there are at least three fixture points and the third of said fixture points is a threaded fastener.

9. A manhole safety system as claimed in any one of claims 1 to 7 wherein there are at least three fixture points and the third of said fixture point is a lug, pin or lip.

10. A manhole safety system as claimed in any one of claims 1 to 5 wherein a first of said fixture points is defined by a lug, pin or lip.

11. A manhole safety system as claimed in any one of claims 1 to 5 and 10 wherein a second of said fixture points is defined by a lug, pin or lip.

12. A manhole safety system as claimed in any one of claims 1 to 5, 10 and 11 wherein there are at least three fixture points and the third of said fixture points is defined by a lug, pin or lip.

13. A manhole safety system as claimed in any one of claims 1 to 12 wherein a first of said anchor points can receive one of a lug, pin, lip, stud, padlock and threaded fastener. - 19 -

14. A manhole safety system as claimed in any one of claims 1 to 13 wherein a second of said anchor points can receive one of a lug, pin, lip, stud, padlock and threaded fastener.

15. A manhole safety system as claimed in any one of claims 1 to 14 wherein there are at least three anchor and the third of said anchor points can receive one of a lug, pin, lip, stud, padlock and threaded fastener.

16. A manhole safety system as claimed in any one of claims 1 to 15 wherein said lug, threaded fastener, padlock, pin, stud, lip, is able to be received by said hole, receptacle, lug or lip of a said anchor point.

17. A manhole safety system as claimed in any one of claims 1 to 16 wherein said lug, threaded fastener, padlock, pin, stud, lip, of the or each fixture points is able to be received by said hole, receptacle, lug or lip of each said anchor points.

18. A manhole safety system as claimed in any one of claims 1 to 17 wherein said grate comprises a frame.

19. A manhole safety system as claimed in any one of claims 6 to 8 and 18 wherein the threaded fastener(s) are threadingly engaged to said frame.

20. A manhole safety system as claimed in any one of claims 6 to 8, 18 and 19 wherein the threaded fastener(s) can be moved between a hole or receptacle engaging condition and a hole or receptacle withdrawn condition.

21. A manhole safety system as claimed in any one of claims 18 to 20 wherein the frame is round and the threaded fastener(s) can be actuated to move in a radial manner relative said frame.

22. A manhole safety system as claimed in any one of claims 18 to 21 wherein the frame is cylindrical in shape.

23. A manhole safety system as claimed in any one of claims 18 to 22 wherein the frame includes lugs, the fixture points being defined by an aperture through each said lug.

24. A manhole safety system as claimed in any one of claims 1 to 23 wherein the manhole entrance frame is cylindrical in shape.

25. A manhole safety system as claimed in any one of claims 1 to 24 wherein the anchor points are holes in the manhole entrance frame that extend radially into said manhole entrance frame.

26. A manhole safety system as claimed in any one of claims 1 to 24 wherein the anchor points are holes in the manhole entrance frame extend parallel to the axial direction of and into said manhole entrance frame.

27. A manhole safety system as claimed in any one of claims 1 to 26 wherein the manhole entrance frame is made of cast metal. - 20 -

28. A manhole safety system as claimed in any one of claims 1 to 27 wherein the manhole entrance frame is an annular ring that includes a first end at which a said manhole cover can nest to close the manhole.

29. A manhole safety system as claimed in any one of claims 1 to 28 wherein the anchor points are located such that the grate is able to locate below and immediately adjacent said manhole cover.

30. A manhole safety system as claimed in any one of claims 18 to 29 wherein the fixture points are disposed above but connected to said frame of said grate, such that when installed to said manhole entrance frame said grate locates below said manhole entrance frame.

31. A manhole safety system as claimed in any one of claims 1 to 30 wherein the grate is to locate in said manhole adjacent and below where the manhole cover is to position to seal said manhole.

32. A manhole safety system as claimed in any one of claims 1 to 30 wherein said grate, when secured, is immovably secured to said manhole entrance frame.

33. A manhole safety system as claimed in claim 1 wherein said anchor points are retrofittable to a manhole entrance frame that exist already on a manhole.

34. A manhole safety system as claimed in any one of claims 1 to 32 wherein said manhole entrance frame is retrofitted or retrofittable to an existing manhole.

35. A manhole safety system as claimed in any one of claims 1 to 34 wherein said grate frame has a perimeter that is the substantially the same as the narrowest part of the manhole entrance frame.

36. A manhole safety system to present obstruction to objects falling into a manhole through its entrance, the system comprising: a manhole entrance frame to at least in part define the entrance of a manhole, having a central round hole and at least two radially extending apertures, a grate to locate in said manhole entrance frame, the grate presenting for receipt by a respective hole of said entrance frame, at least one of: a pin and a threaded fastener, or two threaded fasteners, provided in locations complementary to said two apertures to allow said grate to thereat and in cooperation be secured in said manhole entrance frame.

37. A manhole safety system to present obstruction to objects falling into a manhole through its entrance, the system comprising: a manhole entrance frame to at least in part define the entrance of a manhole, having a central round hole and three equispaced radially extending apertures, - 21 - a grate to locate in said manhole entrance frame, the grate presenting a pin that can be manoeuvred into one of said apertures and presenting two threaded fasteners that can be moved to extend into and out of a respective aperture, the pin and the threaded fasteners acting in cooperation to allow a releasable securing of the grate to said entrance frame.

38. A manhole safety system to present obstruction to objects falling into a manhole through its entrance, the system comprising: a manhole entrance frame to at least in part define the entrance of a manhole, having a central round hole and one equispaced radially extending aperture and two receptacles, a grate to locate in said manhole entrance frame, the grate presenting a pin that can be manoeuvred into said aperture and presenting two threaded fasteners that can be moved to extend into and out of operative engagement with a respective receptacle, the pin and the threaded fasteners acting in cooperation to allow a releasable securing of the grate to said manhole entrance frame.

39. A manhole safety system as claimed in any one of claims 36 to 38 wherein said grate is shaped and configured to extend across said entrance.

40. A manhole safety system as claimed in any one of claims 36 to 39 wherein said grate is of a shape to extend across said aperture.

41. A manhole safety system as claimed in any one of claims 36 to 40 wherein said grate comprises a frame.

42. A manhole safety system as claimed in any one of claims 36 to 41 wherein the threaded fastener(s) are threadingly engaged to said frame.

43. A manhole safety system as claimed in any one of claims 36 to 42 wherein the threaded fastener(s) can be moved between an aperture or receptacle engaging condition and a hole or receptacle withdrawn condition.

44. A manhole safety system as claimed in any one of claims 36 to 41 wherein the frame is round and the threaded fastener(s) can be actuated to move in a radial manner relative said frame.

45. A manhole safety system as claimed in any one of claims 36 to 44, wherein the frame is cylindrical in shape.

46. A manhole safety system as claimed in any one of claims 36 to 45 wherein the frame includes lugs, the fixture points being defined by an aperture through each said lug.

47. A manhole safety system as claimed in any one of claims 36 to 46 wherein the manhole entrance frame is cylindrical in shape. - 22 -

48. A manhole safety system as claimed in any one of claims 36 to 47 wherein the apertures of the manhole entrance frame extend radially into said manhole entrance frame.

49. A manhole safety system as claimed in any one of claims 36 to 47 wherein the apertures of the manhole entrance frame extend parallel to the axial direction of and into said manhole entrance frame.

50. A manhole safety system as claimed in any one of claims 36 to 49 wherein the manhole entrance frame is made of cast metal.

51. A manhole safety system as claimed in any one of claims 36 to 50 wherein the manhole entrance frame is an annular ring that includes a first end at which a manhole cover can nest to close the manhole.

52. A manhole safety system as claimed in any one of claims 36 to 51 wherein the anchor points are located such that the grate is able to locate below and immediately adjacent said manhole cover.

53. A manhole safety system as claimed in any one of claims 63 to 52 wherein said grate, when secured, is immovably secured to said entrance frame.

54. The combination of (i) a manhole entrance frame to be installed at and define the entrance of a manhole and (ii) a safety grate that can extend across the entrance frame to present an obstacle to objects falling down the manhole, the entrance frame including means to secure the safety grate to said manhole entrance frame.

55. The combination of claim 54 wherein the safety grate includes means complementary to said means to secure to facilitate the securing of said grate to said manhole entrance frame.

56. The combination of claim 54 or 55 wherein said grate, when secured, is immovably secured to said manhole entrance frame.

57. The combination of any one of claims 54 to 56 wherein one of said means to secure and said means complementary allows the releasable securing of said grate to said entrance frame.

59. A kitset comprising of (i) a manhole entrance frame to be installed at and define the entrance of a manhole and (ii) a safety grate that can extend across the entrance frame to present an obstacle to objects falling down the manhole, the entrance frame including means to secure the safety grate to said manhole entrance frame.

60. A kitset as claimed in claim 59 wherein the safety grate includes means complementary to said means to secure to facilitate the securing of said grate to said manhole entrance frame.

61. A kitset as claimed in claim 59 or 60 wherein said grate, when secured, is immovably secured to said entrance frame. - 23 -

62. A kitset as claimed in any one of claims 59 to 61 wherein one of said means to secure and said means complementary allows the releasable securing of said grate to said entrance frame.

63. A kitset to present obstruction to objects falling into a manhole through its entrance, the kitset comprising a manhole entrance frame to at least in part define the entrance of a manhole, the entrance frame including at least two anchor points, a grate to locate in said manhole entrance frame, the grate including at least two fixture points provided in locations complementary to said two anchor points to allow said grate to thereat be secured in said manhole entrance frame.

64. A kitset as claimed in claim 63 wherein said grate is shaped and configured to extend across said entrance.

65. A kitset as claimed in any one of claims 63 to 64 wherein the manhole entrance frame defines a main central round aperture and said grate is of a shape to extend across said aperture.

66. A kitset as claimed in any one of claims 63 to 65 wherein said anchor points are equispaced.

67. A kitset as claimed in any one of claims 63 to 66 wherein the anchor points are each defined by a hole (blind or through hole), receptacle, lug or lip of said manhole entrance frame.

68. A kitset as claimed in any one of claims 63 to 67 wherein said grate comprises a frame.

69. A kitset as claimed in any one of claims 63 to 68 wherein the frame is cylindrical in shape.

70. A kitset as claimed in claim 68 or 69 wherein the frame includes lugs, the fixture points being defined by an aperture through each said lug.

71. A kitset as claimed in any one of claims 63 to 70 wherein the manhole entrance frame is cylindrical in shape.

72. A kitset as claimed in any one of claims 67 to 71 wherein the hole or receptacle of the manhole entrance frame extend radially into said manhole entrance frame.

73. A kitset as claimed in any one of claims 67 to 71 wherein the hole or the receptacle of the manhole entrance frame extend parallel to the axial direction of and into said manhole entrance frame.

74. A kitset as claimed in any one of claims 63 to 73 wherein the manhole entrance frame is made of cast metal. - 24 -

75. A kitset as claimed in any one of claims 63 to 74 wherein the manhole entrance frame is an annular ring that includes a first end at which a said manhole cover can nest to close the manhole.

76. A kitset as claimed in any one of claims 63 to 75 wherein the anchor points are located such that the grate is able to locate below and immediately adjacent said manhole cover.

77. A kitset as claimed in any one of claims 63 to 76 wherein the grate is to locate in said manhole adjacent and below where the manhole cover is to position to seal said manhole.

78. A kitset as claimed in any one of claims 63 to 77 wherein said grate, when secured, is immovably secured to said entrance frame.

79. A kitset to present obstruction to objects falling into a manhole through its entrance, the kitset comprising: a manhole entrance frame to at least in part define the entrance of a manhole, having a central round hole and at least two radially extending apertures, a grate to locate in said manhole entrance frame, the grate presenting for receipt by a respective hole of said entrance frame, at least one of a pin and a threaded fastener, two threaded fasteners, provided in locations complementary to said two apertures to allow said grate to thereat and in cooperation be secured in said manhole entrance frame.

80. A kitset to present obstruction to objects falling into a manhole through its entrance, the kitset comprising: a manhole entrance frame to at least in part define the entrance of a manhole, having a central round hole and three equispaced radially extending apertures, a grate to locate in said manhole entrance frame, the grate presenting a pin that can be manoeuvred into a said aperture and presenting two threaded fasteners that can me moved to extend into and out of a respective aperture, the pin and the threaded fasteners acting in cooperation to allow a releasable securing of the grate to said entrance frame. 80. A kitset to present obstruction to objects falling into a manhole through its entrance, the kitset comprising: a manhole entrance frame to at least in part define the entrance of a manhole, having a central round hole and one equispaced radially extending aperture and two receptacles, a grate to locate in said manhole entrance frame, the grate presenting a pin that can be manoeuvred into a said aperture and presenting two threaded fasteners that can - 25 - me moved to extend into and out of operative engagement with a respective receptacle, the pin and the threaded fasteners acting in cooperation to allow a releasable securing of the grate to said entrance frame.

81. A manhole grate to present obstruction to objects falling into a manhole through its entrance frame the entrance frame including at least two anchor points, the manhole grate comprising: a grate to locate in said manhole entrance frame, the grate including at least two fixture points provided in locations complementary to said two anchor points to allow said grate to thereat be secured in said manhole entrance frame.

82. A manhole grate as claimed in claim 81 wherein said grate is shaped and configured to extend across said entrance.

83. A manhole grate as claimed in claim 81 or 82 wherein said grate is of a shape to extend across said aperture.

84. A manhole grate as claimed in any one of claims 81 to 83 wherein said anchor points are equispaced.

85. A manhole grate as claimed in any one of claims 81 to 84 wherein the fixture points are each defined by a hole (blind or through hole) or receptacle of said manhole entrance frame.

86. A manhole grate as claimed in any one of claims 81 to 85 wherein at least one of said fixture points is a threaded fastener.

87. A manhole grate as claimed in any one of claims 81 to 86 wherein at least one of said fixture points is a pin.

88. A manhole grate as claimed in any one of claims 81 to 87 wherein there are three fixture points, one being a pin and the other two being threaded fasteners.

89. A manhole grate as claimed in any one of claims 81 to 88 wherein said grate comprises a frame.

90. A manhole grate as claimed in any one of claims 86 to 89 wherein the threaded fastener(s) are threadingly engaged to said frame.

91. A manhole grate as claimed in any one of claims 86 to 90 wherein the threaded fastener(s) can be moved between a hole or receptacle engaging condition and a hole or receptacle withdrawn condition.

92. A manhole grate as claimed in any one of claims 86 to 91 wherein the frame is round and the threaded fastener(s) can be actuated to move in a radial manner relative said frame.

93. A manhole grate as claimed in any one of claims 89 to 92 wherein the frame is cylindrical in shape. - 26 -

94. A manhole grate as claimed in any one of claims 89 to 93 wherein the frame includes lugs the fixture points being defined by an aperture through each said lug.

95. A manhole grate as claimed in any one of claims 81 to 94 wherein the grate is to locate in said manhole adjacent and below where a manhole cover is to position to seal said manhole.

96. A manhole grate as claimed in any one of claims 81 to 91 wherein said grate, when secured, is immovably secured to said manhole entrance frame.

97. A manhole safety system to present obstruction to objects falling into a manhole through its entrance, the system comprising: a manhole entrance frame to at least in part define the entrance of a manhole, the entrance frame including a ledge, and at least one anchor point. a grate to locate in said manhole entrance frame, the grate including at least one fixture point provided in a location to and complementary to said at least one anchor point to allow said grate to thereat be secured in said manhole entrance frame, the grate being of a shape and configuration to, when so secured to also be supported by said ledge.

98. A manhole safety system as claimed in claim 97 wherein the grate is of a shape and configuration to not be able to pass through the entrance frame.

99. A manhole safety system as claimed in claim 97 or 98, wherein the object that the grate can present obstruction to is a mobile person, e.g. a child that can crawl and upwards in age.

100. A manhole safety system as claimed in any one of claims 97 to 99 wherein the system prevents the ingress of a person into a stormwater drain system via a stormwater access way that is normally covered by a removable cover.

101. A manhole safety system as claimed in any one of claims 97 to 100 wherein the system is configured such that a cover for covering the entrance can be used in conjunction with the grate.

102. A grate and manhole entrance frame that in combination that can securely yet releasably be fastened together by a three point fastening system that comprises three spaced apart mounts of said grate and complementary mounts of said manhole entrance frame, said grate being configured so as to prevent, in use, the ingress of a person into an underground pipe.

103. A grate and manhole entrance frame as claimed in claim 102 wherein at least one of the three spaced apart mounts comprised a threaded fastener.

104. A grate and manhole entrance frame as claimed in claim 102 or 103 wherein at least one of the mounts includes of is engagable by a removable fastening means such as bolts, screws, hooks, padlocks, clips or their like. - 27 -

105. A manhole safety system as herein described with reference to any one or more of the accompanying drawings.

106. A grate and manhole entrance frame as herein described with reference to any one or more of the accompanying drawings. - 28 -