AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant(s): SULO MGB Australia Pty Ltd Invention Title: BARRIER SYSTEM FOR UNDERGROUND COLLECTION SYSTEM The following statement is a full description of this invention, including the best method of performing it known to me/us: -2 BARRIER SYSTEM FOR UNDERGROUND COLLECTION SYSTEM Field of the Invention 5 The present invention broadly relates to underground collection systems and more specifically to a safety barrier system for use in an underground refuse collection system. 10 Background of the Invention Underground refuse collection systems are utilised to contain and store refuse (such as waste, recyclables, reusable items such as clothing, organics including garden 15 clippings and food scraps and the like) until the refuse is removed to another location. Generally the system comprises a vessel set into a cavity lined with a watertight steel, concrete or plastic shaft. Refuse can be disposed into the underground vessel by means of a 20 disposal column set above the vessel and open to the vessel. A platform is set across the top of the underground vessel to allow traffic to proceed over the underground vessel. This platform typically forms the top surface of the vessel and vessel is accessible for removal 25 of the refuse therein. Typically the vessel is lifted from the cavity by a lifting assembly and is moved over a refuse collection vehicle where the contents are emptied into the vehicle via an opening in the vessel base. 30 An underground collection system is more aesthetically attractive than an ordinary garbage bin as the disposal column (which is the primary visible part of the system) can be smaller. The small size of the column 61966 -3 does not impede traffic significantly in high traffic areas and produces the psychological advantage of dissuading people from dropping litter around the outside of the column. Further, the noise of throwing refuse into 5 the vessel is reduced. Most importantly the underground vessel has a large storage volume and allows for less frequent removal of the refuse. This decreases waste management costs and means 10 that the vessels are unlikely to overflow, causing waste management problems. When the vessel of the collection system is removed from the underground cavity in which it is disposed, a 15 hazard for pedestrians and vehicles is produced. A lift assembly, such as a crane is typically utilised to remove the vessel from the cavity and this too, can cause dangers for pedestrians and other traffic. 20 Summary of the Invention Disclosed is a safety barrier for an underground collection system, the underground collection system including a vessel being removably disposed in use in an 25 underground cavity and including an upper surface that allows thoroughfare thereover, the safety barrier comprising a safety fence movable between a retracted and an active position; wherein when the vessel is disposed in the 30 underground cavity, the safety fence is positioned in its retracted position so to not impede thoroughfare over the upper surface, and when the vessel is removed from the underground cavity, the underground cavity is exposed, and 61966 -4 the safety fence is positioned in its active position to prevent thoroughfare into the cavity. In a second embodiment, disclosed is a safety system for an underground collection system that includes a 5 vessel that is removably disposed in an underground cavity and operative to be removed from, and disposed in, the cavity by a refuse collection vehicle during collection of the refuse, the safety system comprising a safety barrier operative in an active mode to extend about at least a 10 portion of the underground cavity, wherein the system is associated with the refuse collection vehicle and the barrier is able to adopt its active mode when a refuse collection vehicle is positioned to remove the vessel from the underground cavity. 15 In one form, the safety system further comprises at least one security station, and wherein the security barrier extends between the or each security station and the refuse collection vehicle, when the vehicle is 20 positioned to remove the vessel from the underground cavity. In another form, the security barrier is arranged to operate in its active mode in response to a controller 25 disposed in the refuse collection vehicle. In a particular form, the security barrier comprises electromagnetic radiation. In that form, the safety barrier may be in the form of a light beam either in the 30 visible or invisible spectrums. In another form, the barrier comprises a physical barrier such as a cable, strap or cord. Typically in the 61966 -5 latter arrangement, the barrier is retractable to enable easy operation between its active mode and its inactive mode. 5 In a particular form, the safety system further comprises an alarm which is activated in response to breaching of the security barrier. In one form, this alarm is an audible alarm. In another embodiment, the refuse collection vehicle includes a lifting assembly and 10 wherein the safety system includes a controller operative to interrupt operation of the lifting assembly in response to the presence of a breach of the security barrier. In a third embodiment, disclosed is a safety system 15 for underground collection system that includes a vessel that is removably disposed in an underground cavity and operative to be removed from, and disposed in, the cavity by a lifting assembly, the safety system comprising a safety barrier operative in an active mode to extend about 20 at least a portion of the underground cavity, and a controller operative to interrupt operation of the lifting assembly in response to the presence of a breach of the security barrier. 25 In yet a further embodiment, disclosed is a method of safe removal of a vessel from an underground cavity by a lifting assembly the method comprising: providing a security barrier which extends around at least a portion of the underground cavity; and 30 interrupting operation of the lifting assembly in response to the presence of a breach of the security barrier. 61966 -6 Brief Description of the Drawings Notwithstanding any other forms that may fall within 5 the scope of the barrier system as defined in the summary, specific embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings in which: 10 Fig. 1 is a sectional view of a refuse collection system including a barrier system; Fig. 2 is the collection system of Fig. 1 with the vessel 2 partially removed and barrier system in a 15 partially active position; Fig. 3 is the collection system of Fig. 1 with the vessel removed and the barrier system in its fully active position; and 20 Fig. 4 is a schematic plan view of an alternative safety system for an underground collection system. Detailed Description of the Preferred Embodiments 25 Fig. 1 shows an underground refuse collection system 100 that includes a vessel 10 which is removably disposed underground. The vessel 10 is of sufficiently rigid structure to be able to accommodate refuse therein and in 30 the illustrated form is composed of galvanised steel panels 11 which are mounted within a frame 12. The system 100 further comprises a shaft 13 which is disposed in the ground to form a cavity 14 in which the vessel 10 locates. 61966 -7 The shaft 13 may be permanently disposed in ground. The shaft is preferably made of concrete, steel reinforced, concrete or any other watertight substance which can be adapted to be fitted in the ground and to contain the 5 vessel 2. A ground pump (not illustrated) may be disposed in the cavity 14. The vessel 10 may be any appropriate shape for containing refuse, and the shaft 13 being adapted to receive the vessel 10. 10 The vessel 10 may be any size but is preferably between and 2m 3 and 1Om 3 . The frame 12 of vessel 10 incorporates a base 15 to which movable flaps 16 are connected to form an opening to allow refuse (not illustrated) to be removed from the vessel 10 on removal 15 of the vessel from the shaft. An actuator assembly 17 is provided to operate the removable flaps. The operation of such an actuator assembly and the construction of the vessel 10 is disclosed in more detail in the applicant's corresponding application entitled "Improved Vessel for 20 Underground Collection System" the contents of which are herein incorporated by cross reference. The vessel 10 further includes an upper surface 18. The upper surface 18 allows thoroughfare thereover, such 25 as pedestrian and vehicle traffic. The upper surface 18 is therefore adapted to be load bearing. The rim 19 of the upper surface 18 is adapted to fit over the cavity 14 and leave no gap between the cavity 14 and the rim 8. 30 A disposal column 20 is mounted on the upper surface 18 of the vessel 10 to allow refuse to be deposited into the vessel 10. 61966 -8 The system 100 incorporates safety barrier system 21. The safety barrier system is disposed as a subframe 23 between the vessel 10 and the shaft 13 and incorporates a safety fence 24. The safety fence 24 is disposed adjacent 5 the inner wall of the shaft 4 and is movable between a fully retracted position (shown in Fig. 1) to a fully active position (shown in Fig. 3). When the vessel 10 is disposed in the underground 10 cavity 4, the upper surface 18 is in position for thoroughfare thereover and the safety fence 24 is positioned in its retracted position so as not to impede thoroughfare over the upper surface 18. In this position, the vessel 10 can be utilised by people wishing to throw 15 refuse through the disposal column 20 into the vessel 10. However, when the underground refuse receptacle 10 is removed from the underground cavity 14 for collection of the refuse by a lifting assembly, such as that fitted on a refuse collection vehicle, the underground cavity 14 is 20 exposed creating a danger for pedestrians and other traffic. At this time the safety fence 24 is positioned in its active position as shown in Fig. 3 to prevent thoroughfare into the cavity 14. 25 The safety system 21 includes a counterweight system 25 incorporated in the subframe 23. The counterweight system 25 enables movement of the safety fence 24 between the retracted and the active position on removal of the vessel 10 from the cavity 14 by biasing the safety fence 30 10 into its active position. Location of the vessel 10 in the cavity 14 acts to hold the safety fence 24 in its retracted position. Removal of the vessel 10 from the cavity 14 allows the safety fence 24 to move into its 61966 -9 biased active position. The safety fence 24 may be otherwise mechanised to move between the retracted and active positions. For 5 example, the fence may be spring biased, or may operate by a piston cylinder or strut arrangement. Alternatively the safety fence 24 may be manually moved by an operator between the retracted position and the active position. 10 A second embodiment of a safety system 50 of the present invention is shown in Fig. 4. The safety system 50 is used in conjunction with the vessel 10 of an underground refuse collection system 100 such as that disclosed above. 15 The safety system 50 comprises a safety barrier 51 adapted to extend about at least a portion of the collection system 100. In the illustrated form, the safety system 50 comprises two security stations 52 20 (typically in the form of bollards) and the barrier extends between the security stations 52 and a refuse collection vehicle 110, when the refuse collection vehicle 110 is positioned to remove the vessel 10 from the underground cavity 14 in which it is disposed. However, 25 it is to be appreciated that the barrier may extend solely about the stations 52, particularly if additional stations are employed about the collection system 100. The security stations 52 may be positioned by the 30 vehicle operator or may be permanently positioned on buildings 200 or other fixtures in the vicinity of the collection system 100. 61966 - 10 The safety barrier 51 may comprise a physical safety barrier such as an extendible belt in a signal colour. Alternatively the security barrier could comprise an electronic system with a light or other electromagnetic 5 signal emanating from the station 52 and/or refuse collection vehicle 110. The security stations 52 may include their own power supply and the electronic barrier could emanate from one 10 of the security stations. Attenuating the stations may be passive and all power is provided from the refuse collection vehicle 110. In use, the refuse collection vehicle 110 may 15 incorporate a controller to activate the safety barrier. In another form, the lifting assembly 111 of the refuse collection vehicle incorporates a controller whereby on response to the presence of a breach of the security barrier, the operation of the lifting assembly is 20 interrupted. In another form, breaching of the barrier may activate an audible alarm to signal the presence of a danger. It can be seen that both embodiments of the safety 25 barrier system allow for removal of the vessel of an underground collection system in which it is disposed without endangering vehicle or pedestrian traffic. Although the present invention has been described 30 with reference to the specific embodiments shown in the accompanying drawings, it will be understood that numerous modifications and variations are possible without departing from the scope of the invention. 61966 - 10a The above references to the background art do not constitute an admission that the art forms a part of the common general knowledge of a person of ordinary skill in the art. The above references are also not intended to limit the application of the method and system as disclosed herein. In the claims which follow and in the preceding description, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the method and apparatus.