AN IMPROVED POST CLAMP TECHNOLOGICAL FIELD [001] This invention relates to post clamps, the kinds of which one generally associates with fencing arrangements which use main support posts to which 5 post clamps are attached thereto, to which these post clamps include along their peripheral edges collars or skirts to which rail clamps, adjustable or otherwise, that can be then connected thereto in order to construct the overall fence arrangement. BACKGROUND ART DISCUSSION 10 [002] Conventionally these post clamps in such fence arrangements using rail clamps were hingedly joined at one end between two separable substantially semi-circular fastening members wherein each of these semi-circular fastening members also included a tab extension which had a hole therethrough so that when the post clamp had to be fastened to the post the respective semi-circular 15 fastening members would be hingedly joined to each other clamped about the post by bringing together the tab extensions through conventional nut and bolt type configurations. [003] With respect to these kinds of post clamps the prior art included the hinging arrangement through the use of tongue extensions that ended in a 20 raised lip, wherein these raised lips were able to fit within corresponding holes of an adjacent semi-circular fastening member. [004] Accordingly the only real locking mechanism in order to secure one semi circular fastening member to the other at the hinge joint was through the raised lip at the end of the tongue which extended into the corresponding hole. 1 [005] While at first instance this may seem adequate enough to initially fasten the post clamp to the post, problems arise when slippage of the clamp occurs and/or re-tensioning is required [006] Often the post clamp needs to be re-tightened which once the post clamp 5 is fastened to the post this is achieved by bringing further together the two tab extensions of the semi-circular fastening members with the tightening of the bolt arrangement which is at the opposite end of the post clamp to the hinged arrangement. [007] As the person skilled in the art will appreciate, the tightening at one end 10 of the post clamp is placing significant stress on the hinge joint and as the hinge joint between the semi-circular fastening members is simply relying on just a raised lip at the end of the tongue that protrudes into the corresponding aperture on the adjacent semi-circular fastening member, can legitimately lead to a case where the post clamp is loosing its integrity to remain as a true 15 continued fastenable support for the connected rail clamps as there is a real possibility that when the post clamp is re-tightened it is at the same time arguably tearing apart the hinged arrangement between the semi-circular fastening members which will reduce the overall effectiveness of the re tightening of the post clamp. 20 [008] Therefore there remains a need in the field associated with post clamps used to support rail clamps that will overcome this weakness in the hinge joint when re-tightening and tensioning is required when slippage and so forth is happening on the post and where there will always be the requirement to re tension and tighten the post clamp and this needs to be achieved without 25 disintegration of the hinge joint which will ultimately lead to a damaged post clamp that will not be able to adequately support in future the rail clamps for the overall fence construction. [009] It is therefore an object of this invention to provide an improved post clamp that will allow continued tensioning, stressing and re-tightening of a 2 conventional type post clamp without the destruction of the integrity of the hinged joining of the semi-circular fastening members. SUMMARY OF THE INVENTION [010] Accordingly in one form of the invention there is provided a post clamp 5 fastenable to a post wherein the fastened clamp is adapted to support one or more rail clamps in a fence construction, said post clamp including: [011] a pair of lockable hingeable joinable substantially semi-circular fastening members each having a terminating tab extension, wherein a collar extension along the peripheral upper and lower edges of at least the semi-circular portion 10 of the fastening members provides a clampable support for rail clamps; [012] such that when the clamp is to be fastened to the post, the pair of fastenable members is hingedly locked in a pivot support of one fastening member with the other, said hinge including; [013] a pair of tongue extensions on each of the semi-circular fastening 15 members, each tongue including a raised portion adapted to be positioned into or out through a corresponding aperture on an adjacent fastening member to hingedly secure one fastening member with the other wherein the alignment of the raised tab within the aperture occurs wherein slots configured on each respective tongue of the fastening members allow a vertical displacement of 20 one tongue partly within the other for a lateral engagement between said fastening members that becomes lockable once the raised tabs are positioned or protrude from the apertures. [014] Advantageously in this arrangement rather than simply relying, as was the case with the prior art of a raised lip of the tongue extension being slotted 25 into an aperture on a corresponding fastening member, the introduction of the slot within each of the respective tongues of the fastening member means that there is the ability for vertical displacement such that not only is there a locking 3 engagement between a raised portion of the tongue within an aperture of a corresponding fastening member, there is also further secured engagement between the respective fastening members within the hinge through the vertical displacement through the introduction of the slot arrangement within the tongue 5 which allows in a sense each of these tongues of the fastening member to be nested one within the other so that they cannot be laterally pulled apart. [015] This lateral securing due to the vertical displacement allowed for by these slots in each of the respective tongues of the fastening members is then further secured in place by having the raised tabs of the tongues then being 10 positioned within the aperture or protruding therefrom on the adjacent fastening member. [016] In preference the raised tab on each of the respective tongues of the fastening member includes a raised hump. [017] In preference the raised hump is generally centrally positioned within the 15 tongue of the substantially semi-circular fastening member. [018] In preference this raised hump includes a frontal shoulder of similar height and configuration to that part of the aperture which abuts up against when the respective fastening members hingedly joined. [019] In preference the raised hump is of a dimension comparable with the 20 aperture to which it is positioned therein such that when the raised tab is located within the aperture it does not protrude therefrom thereby removing any risks of catching outside engagement but also as the frontal shoulder of the raised hump is of the same dimensions of its abutting edge of the aperture means that all the aperture is being used in appropriate fixed engagement to 25 minimise release of one fastening member from the other during times of re tensioning of the clamp to the post. 4 [020] An advantage of such an arrangement is that rather than having the simple raised lip on the end of the tongue which was the case of the prior art, during times of fastening and re-tensioning of the post clamp about the post all those stresses are then not simply placed upon a raised lip which is likely to 5 draw itself out and free itself from its capture withinside the aperture. [021] Advantageously in this invention by having the raised hump and its frontal shoulder more central to the tongue it is unlikely that there will be a peeling away or levelling out of the raised lip as one would expect from the conventional arrangements referred to above. 10 [022] By having the raised hump of comparable dimensions to the aperture in which it rests means that there are no protruding lips and so forth from the aperture to which things could get caught or scratched upon. [023] BRIEF DESCRIPTION OF THE DRAWINGS [024] In order now to describe the invention in greater detail a preferred 15 embodiment will be shown with the assistance of the following illustrations. [025] Figures 1a to 1e show various perspective views of the preferred embodiment of the invention. [026] Figure 2 is a frontal view of the hinged side of the post clamp. [027] DETAILED DESCRIPTION OF THE INVENTION 20 [028] Referring to the drawings now in greater detail where there is provided a post clamp shown generally as (10) that includes a pair of substantially semi circular fastening members (12) and (14) which each include on its respective upper and lower peripheral edges, collars (16), (18) that are adapted to have rail clamps fastenable thereon such that when the rail clamps are attached to 25 the post clamp there is a general movement towards the construction of a fence configuration. 5 [029] Each semi-circular fastening member (12), (14) includes terminating tab extensions (20), (22) wherein holes (24), (26) will allow a means in which the post clamp can be fastened onto a post. Bolt (25) and nut (27) are shown in figure b. 5 [030] In order to have the post clamp fastenable to the post the semi-circular fastening members (12), (14) need to be hingedly joined and this is achieved through the use of the tongues (28) and (30) which include slots (32) and (34) whereby these slots (32), (34) as part of the respective tongues (28), (30) on each of the semi-circular fastening members (12), (14) allows for a vertical 10 displacement so that the tongues (28) and (30) can be locked in place through the resting or nesting brought about by the slots (32), (34) in each of the tongues (28), (30). [031] Each tongue (28) and (30) also includes a raised hump (40) and (42) which is able then to be positioned within the aperture (36) and (34) of the semi 15 circular fastening members (12) and (14). [032] By having the raised hump (40) and (42) with its frontal shoulder configured to be of similar dimensions to the edge (45) and (47) of the apertures (36) and (38) means that there is solid firm engagement and unlike in a conventional lip of a tongue there can be no pulling away or flattening of such a 20 lip thereby loosening the engagement between one fastening member to that of another. [033] As introduced above the hinged arrangement between one fastening member (12) and (14) to the other is achieved not only through the raised tabs (40) and (42) of each of the tongues (28) and (30) but also because of that 25 vertical alignment or initial adjustment that requires the respective tongues (28) and (30) to be nested and fixed one within the other which has been established through the slots (32) and (34). 6 [034] With the improved overall engagement of the hinge side of the joining of each of these semi-circular fastening members (12) and (14) are improved upon by this invention, means that during the initial fastening of the post clamp to the post and also any subsequent re-tensioning of the post clamp using 5 conventional means will not be able to place a stress upon the hinge which will be working counter-productively with the actual conventional fastening of the post clamp through those terminating tabs (20) and (22) and the bolt that passes through holes (24) and (26). 7