WO2020193952A1

WO2020193952A1 - Safety net support assembly and method of installing safety net assembly

Info

Publication number: WO2020193952A1
Application number: PCT/GB2020/050719
Authority: WO
Inventors: Michael Clive Laurence MORLEY; William Michael OUGHTON
Original assignee: Morley Michael Clive Laurence
Priority date: 2019-03-28
Filing date: 2020-03-19
Publication date: 2020-10-01
Also published as: GB2582616B; GB201904309D0; GB2582616A

Abstract

Safety net assembly (2) including: a support arrangement (4) configured to be connected to a structure (20)and including a first form-fit engagement means (40); a suspended mechanism(6)including a suspended body (8) and a net support arm(10)rotatably coupled to a lower portion of the suspended body(8), the suspended body (8) including a second form-fit engagement means (118) configured to be releasably engageable with the first form-fit engagement means (40) in a form fitting manner in order to suspend the suspended mechanism (6) from the support arrangement (4); and a safety net (12) and first (14) and second (16) transverse safety net support members, the first safety net support member (14) arranged to be connected to a distal portion of the net support arm(10)and the second safety net support member (16) arranged to be connected to at least one of the suspended body (8) and the support arrangement (4). The invention also provides a method of installing the safety net assembly.

Description

SAFE TY NE T SUPPORT ASSEMBLY AND ME THOD OF

INSTALLING SAFE TY NE T ASSEMBLY

[0001] The present invention relates to a safety net support assembly of the type typically connected to the outside of a structure such as a building or scaffold structure during construction work. The invention also relates to a method of installing a safety net assembly.

[0002] Such nets are typically provided while construction work is in progress to catch any objects which have been dropped thereby preventing such objects being a hazard to anything below the net. A further purpose of such nets is to catch any person who accidentally falls from the building or scaffold structure.

[0003] Prior art safety net assemblies of the above type are generally constructed remotely from where they are to be installed and then lifted into place as a single assembly and secured. A typical construction site might have 30 or 40 safety net assemblies which may each need to be moved 3, 4 or more times in the course of construction work at that site. Since the safety net assemblies typically each weigh around 100 kg, a crane is needed each time a safety net assembly needs to be installed or moved. Tying up a crane for this purpose, crane access and windage problems all add to the undesirability of present safety net assemblies and the installation technique. Furthermore if the safety net assembly needs to be installed at a very high level it may not be practicable for a crane on the ground to be used.

Also there are other locations not reachable with a crane. [0004] Examples of prior art safety net assemblies are disclosed in patent WO 2011/116829, each of which is at least substantially constructed remotely from its finally installed location and then lifted into place, which gives rise to the problems referred to above. For the first assembly

disclosed, front and rear net support tubes are connected to a net and then two columns are connected to the rear tube.

The front tube is connected to two arms, each of which is pivotably connected to a lower end of a respective one of the columns. This whole assembly is then lifted into place and supported by means of the rear tube being engaged in a pre installed attachment arrangement connected to a structure.

For the second assembly disclosed in WO 2011/116829, front and rear net support tubes are connected to a net and then two attachment arrangements are connected to the rear tube.

A downwardly projecting part of each attachment arrangement is then slid into an upper end of a respective column and secured there with a bolt. The front tube is then connected to two arms, each of which is pivotably connected to a lower end of a respective one of the columns. This whole assembly, including the two attachment arrangements, as then lifted into place and the attachment arrangements are connected to a structure. Neither of the assemblies disclosed in WO

2011/116829 can be built in situ.

[0005] The object of the invention is to overcome at least one of the above problems.

[0006] According to a first aspect of the invention there is provided a safety net support assembly including: first and second transverse safety net support members; a support arrangement configured to be connected to a structure and including a first form-fit engagement means; a suspended mechanism including a suspended body and a net support arm rotatably coupled to a lower portion of the suspended body, the suspended body including a second form-fit engagement means configured to be releasably engageable with the first form-fit engagement means in a form fitting manner in order to suspend the suspended mechanism from the support

arrangement independently of the net support members; and first connection means for connecting the first safety net support member to a distal portion of the net support arm and second connection means for connecting the second safety net support member to at least one of the suspended body and the support arrangement after engagement of the second form-fit engagement means of the suspended body with the first form- fit engagement means of the support arrangement. Such a safety net support assembly can be built in situ so there is no need for a crane to be used. The components can all be designed to be easily handleable and therefore easily carried to an installation location and assembled there in situ.

Downward force on the safety net itself will urge the suspended body towards the structure and can be resisted by the suspended body bearing against a lower portion of the structure .

[0007] Preferably the second form-fit engagement means is supportively engageable with the first form-fit engagement means by translation of the second form-fit engagement means in a single direction. This will provide a quick easy engagement of the form-fit engagement means.

[0008] Preferably the second form-fit engagement means is supportively engageable with the first form-fit engagement means by lowering of the second form-fit engagement means relative to the first form-fit engagement means. In view of the typical position in which such a safety net assembly is installed, i.e. at or slightly below the upper surface of a floor slab or similar structure, it is particularly

convenient to be able to lower the suspended mechanism into its final location. This will reduce the need for

installation personnel to lean outwardly over an edge of the floor slab during installation and assembly.

[0009] Preferably the first form-fit engagement means includes a pair of laterally spaced support surfaces and the second form-fit engagement means includes a pair of laterally protruding support shoulders each of which is engageable with a respective one of the support surfaces. This arrangement provides a stable support for the suspended mechanism as soon as the engagement means have been engaged with each other and prior to the installation of any locking or securing means.

It will provide a limited resistance against pendular motion of the suspended body pending installation of a locking member and completion of the safety net assembly.

[0010] Preferably the assembly further includes a locking member which is engageable with at least one of the first and second form-fit engagement means to lock them in engagement with each other. With such an arrangement it will not only be the weight of components of the assembly which holds the first and second form-fit engagement means in engagement with each other.

[0011] Preferably the second safety net support member is held in place by a securing member which is securable to at least one of the support arrangement and the suspended body. The connection of the support arrangement to the suspended body can be arranged to be easily reachable, so a securing member can be easily secured to the support arrangement and/or the suspended body to hold the second safety net support member in place.

[0012] Preferably the assembly is configured such that the first safety net support member is connectable to the distal portion of the net support arm and the second safety net support member is connectable to at least one of the

suspended body and the support arrangement after the

suspended mechanism has been suspended from the support arrangement by inter-engagement of the first and second form- fit engagement means. Such an arrangement reduces the weight of components which have to be supported by an installer at any one time as the assembly is built up.

[0013] Preferably the net support arm includes an arm main portion rotatably coupled to the lower portion of the

suspended body and an arm extension member releasably coupled to the arm main portion, the first safety net support member being connected to the arm extension member. Such an

arrangement reduces the overall length and weight of

components handled by an installer as the assembly is built up. Without the net support arm including a main arm portion and an arm extension member the weight of the suspended mechanism might exceed acceptable length and weight

restrictions on handleable components if the overall size of the safety net assembly is large.

[0014] Preferably the suspended body includes a lifting handle engagement means for releasably connecting a lifting handle to the suspended body. This will enable a handle to be used to lower the suspended mechanism into place which will in turn reduce the extent to which an installer needs to lean over the edge of a structure to which the safety net assembly is being connected. The handle can then be released from the suspended body once the first and second form-fit engagement means have been engaged with each other so that the handle will not impede further assembly steps.

[0015] Conveniently the suspended body comprises a column. Since the suspended body largely resists only axial tensile forces it is conveniently in the form of a column and might in practice be constituted by a metal tube of the type used as a scaffold pole.

[0016] According to a second aspect of the invention there is provided a method of deploying a safety net assembly on a structure including the steps of:

(i) connecting a support arrangement to the structure;

(ii) connecting a suspended mechanism to the support

arrangement with a releasable securing means, the suspended mechanism including a suspended body and a net support arm rotatably coupled to a lower portion of the suspended body;

(iii) connecting spaced portions of a safety net to first and second safety net support members;

(iv) with the net support arm positioned alongside the

suspended body, connecting the first safety net support member to a distal portion of the net support arm; (v) connecting the second safety net support member to at least one of the suspended body and the support arrangement; and

(vi) rotating the net support arm away from the suspended body so as to move the first safety net support member away from the second safety net support member with at least a portion of the safety net positioned therebetween, wherein steps (i) and (ii) are performed prior to steps (iv), (v) and (vi) .

[0017] Preferably the support arm includes a main arm portion rotatably coupled to the lower portion of the

suspended body and an arm extension member and the method includes the further step, after step ii and with the main arm portion adjacent to the suspended body, of connecting the arm extension member to the main arm portion so as to extend its length.

[0018] Preferably in step (ii), connecting the suspended mechanism to the support arrangement includes the step of engaging a second form-fit engagement means of the suspended body with a first form-fit engagement means of the support arrangement .

[0019] Preferably engaging the second form-fit engagement means with the first form-fit engagement means involves translating the second form-fit engagement means in a single direction relative to the first form-fit engagement means. [0020] Preferably the second form-fit engagement means is engaged with the first form-fit engagement means by

translating it downwardly into engagement therewith.

[0021] Preferably the method includes a step of connecting a temporary lifting handle to the suspended mechanism to facilitate manoeuvering the suspended mechanism as it is connected to the support arrangement and removing the handle after this operation has been completed.

[0022] The safety net support assembly and the method of deploying a safety net assembly on a structure will now be described by way of example only with reference to the accompanying drawings in which:

[0023] Figure 1 shows a perspective view of the safety net assembly including a safety net support assembly according to the invention;

[0024] Figure 2 shows a partly exploded view of the safety net assembly shown in Fig. 1;

[0025] Figure 3 shows the components of one of the support arrangements and the suspended mechanisms of the safety net assembly shown in Fig. 1 with other components omitted;

[0026] Figure 4 shows an exploded view of the components shown in Fig. 3;

[0027] Figures 5 to 9 show various stages in the

construction and deployment of the safety net assembly shown in Fig. 1; [0028] Figure 10 shows details of the support arrangement and components connected thereto of the safety net assembly shown in Fig. 1;

[0029] Figure 11 shows an exploded view of the components shown in Fig. 10;

[0030] Figure 12 shows a side view of the safety net

assembly shown in Fig. 1 connected to a structure and showing an under-slab reaction support;

[0031] Figure 13 shows a partially exploded side view of a modified version of the safety net assembly shown in Fig. 1 including a net extension arrangement; and

[0032] Figure 14 shows a non-exploded side view of the modified safety net assembly shown in Fig. 13.

[0033] The complete safety net assembly 2 including the safety net support assembly according to the invention is shown in Fig. 1. The assembly 2 includes two support

arrangements 4 each of which supports a suspended mechanism 6. As shown in Fig. 3 and 4, each suspended mechanism 6 includes a suspended column 8 or body and a net support arm 10. Referring again to Fig. 1 the assembly also includes a safety net 12. The safety net 12 is suspended between a first and second transverse safety net support members 14 and 16.

[0034] Figs 4 and 11 show detailed partly exploded views of the support arrangement 4. The support arrangement 4 includes a fixing plate 18 which can be secured to a floor slab 20 by any suitable means such as by fasteners (not shown) which pass through holes 22 in the fixing plate 18. The fixing plate 18 has four upwardly extending lugs 24 with holes for receiving bolts 26 which pass through holes 58 in a lower end of an off-stand bracket 28 which is substantial in the form of an inverted L-shape, including a horizontal arm 30. An outer end of the arm 30 receives a vertical support 32 which is vertically movable relative to the horizontal arm 30 and fixed in position thereto with two bolts 34 and associated nuts 36. The vertical support includes a series of holes 38 which are selectively engageable by the bolts 34 so as to adjust the height of the vertical support 32

relative to the horizontal arm 30. Connected to a lower end of the vertical support 32 by bolts 42 is a first form-fit engagement means or member 40. The first form-fit engagement member 40 includes a back-plate 50 and two outwardly

projecting flank walls 43 which project therefrom. Each flank wall 43 has a horizontal support surface 44 extending therefrom. The support surfaces are horizontally aligned with each other, extend towards each other, and have a gap 46 therebetween. The outer edges of each flank wall 43 is provided with a retaining wall 48. The two retaining walls 48 extend towards each other and are separated by the gap 46. The back-plate 50, the flank walls 43 and the retaining walls 48 define a receiving space 52 which is downwardly bounded by the support surfaces 44. The receiving space 52 is upwardly open and partially open at gap 46 at its surface which is opposite to that defined by the back-plate 50. The flank walls 43 have aligned holes 54 for receiving a locking member or bolt 56.

[0035] All parts of the support arrangement could

appropriately be made of steel and more preferably stainless steel. Other materials such as aluminium or aluminium alloy could also be suitable for components thereof other than the nuts and bolts.

[0036] The suspended mechanism 6 will now be described with particular reference to Figs. 3, 4 and 11.

[0037] The suspended mechanism 6 includes a suspended column 8 or body to a lower portion of which an arm bracket 62 is bolted with bolts 64 which pass through two side walls 66 and corresponding holes 68 in the suspended column 8. Outer ends of the side walls 66 each have a pivot hole 69 through which a pivot bolt 70 passes. A proximal or first end 78 of the net support arm 10 is positioned between the outer ends of the side walls 66 and includes a pivot hole 72 through which the pivot bolt 70 extends.

[0038] The net support arm 10 may be a unitary member or may comprise plural members permanently connected together.

Preferably however the net support arm 10 includes a main arm portion 74, which includes the pivot hole 72 at the first end 78 and an arm extension member 76. The arm extension member 76 is connected to an opposite second end 80 of the main arm portion 74 by a connection arrangement 82. The connection arrangement 82 includes a stub connection member 84 which is inserted into the second end 80 of the main arm portion 74 and extends therefrom to form a spigot 86, shown in Fig. 5. The stub connection member 84 is secured in the second end 80 of the main arm portion 74 by bolts 88 and associated nuts 90. A first end 92 of the arm extension member 76 receives the spigot 86 which is secured therein by further bolts 88 and nuts 90. [0039] At an upper end 116 of the suspended column 8, the second form-fit engagement means 118 is provided. The second form-fit engagement means 118 comprises a pair of support shoulders 120 which project in opposite directions from opposed sides of the suspended column 8. The support

shoulders 120 are configured to seat on the support surfaces 44 of the first form-fit engagement means 40 in its receiving space 52, as shown in Figs. 3 and 6. A hole 122 is formed in the upper end of the suspended column 8 just above the support shoulders 120, which hole 122 receives the locking member bolt 56 which passes through the holes 54 of the first form-fit engagement means 40 to secure the first and second form-fit engagement means 40 and 118 in engagement with each other. The retaining walls 48 of the first form-fit

engagement means also act to restrain the second form-fit engagement means from becoming disengaged from the first form-fit engagement means prior to insertion of the locking member bolt 56.

[0040] All parts of the suspended mechanism could

appropriately be made of steel and more preferably stainless steel. Other materials such as aluminium or aluminium alloy could also be suitable for components thereof other than the nuts and bolts. The net support arm 10, main arm portion 74 and arm extension member 76 could all be fabricated from standard scaffold tubing and the connection arrangement 82 could also be a proprietary scaffold tube connection

arrangement .

[0041] The safety net 12 may be made from high tenacity knotless polypropylene and of the type supplied by Leon De Oro or may be made from any other suitable material. As shown in Fig. 1 the safety net 12 includes an inner side 100 and an opposed outer side 102. An inner pocket 104 extends along substantially all of the inner side 100 and an outer pocket 106 extends along substantially all of the outer side 102. Gaps 108 are formed in the inner pocket 104 and gaps 110 are formed in the outer pocket 106.

[0042] The first transverse safety net support member 14 is situated in and extends at least the majority of the length of the outer pocket 106. The first safety net support member 14 is exposed at the locations of the gaps 110 in the outer pocket 106. At each of these gaps 110 in the outer pocket 106 a first connection means 112 is provided which connects an exposed portion of the first safety net support member 14 to a distal portion of a respective net support arm 10 as shown in detail B in Fig. 8. The distal portion will be a part of the respective arm extension member 76, where such an arm extension member 76 forms part of the net support arm 10. The connection means 112 may comprise a proprietary scaffold clamp for clamping together two scaffold tubes which are perpendicular to each other. Other connection means are possible such as a bolt which passes through the first safety net support member 14 and the net support arm 10.

[0043] The second transverse safety net support member 16 is situated in and extends at least the majority of the length of the inner pocket 104. The second safety net support member 16 is exposed at the locations of the gaps 108 in the inner pocket 104. At each of these gaps 108 in the inner pocket 104 the second safety net support member 16 is

connected to at least one of the respective suspended column 8 and the support arrangement 4. In the particular

embodiment shown in the accompanying Figs, this connection or second connection means is effected as described below. [0044] The first and second safety net support members 14 and 16 can conveniently be proprietary scaffold tubes and may comprise a single tube or two tubes joined end-to-end as shown in Fig. 2 or possibly more than two tubes so joined.

[0045] The connection of the second safety net support member 16 at the gaps 108 in the inner pocket 104 to the respective suspended column 8 and/or support arrangement 4 will be described with particular reference to insert A of Fig. 8 and Figs. 10 and 11.

[0046] When the second form-fit engagement means 118 of the suspended mechanism 6 has been engaged with the first form- fit engagement means 40 of the support arrangement 4, as described above, a support member insertion gap 126 exists above the second form-fit engagement means 118, as shown in insert A of Fig. 8. This insertion gap 126 is immediately above the flank walls 43 and the receiving space 52. This insertion gap 126 is bounded on three sides and is open at an opening 144 at its fourth side, which is opposed to the side defined by the back-plate 50. At each support arrangement 4, a portion of the second safety net support member 16 which is exposed at one of the gaps 108 in the inner pocket 104, is inserted through the opening 144 and into a respective one of the insertion gaps 126.

[0047] On an outer surface (i.e. that facing away from the structure 20) of the suspended column 8, adjacent to the second form-fit engagement means 118, there is provided a securing member socket 128. A slot 140, is provided between the securing member socket 128 and the suspended column 8 on each side of the securing member socket 128 each of which is configured to receive a respective one of the retaining walls 48 of the first form-fit engagement means 40. A securing member 130 is provided which is engageable with the securing member socket 128. The securing member 130 is configured to close the opening 144. The securing member 130 includes a spigot portion 132 and a projecting portion 134 which is connected to the top of and projects from the spigot portion 132 towards the first form-fit engagement means 40. The securing member 130 is retained in the securing member socket 128 by a bolt 124 which passes through a hole 136 in each side of the securing member socket 128 and complementary holes 138 in the securing member 130 once the securing member 130 has been inserted into the securing member socket 128, as shown in insert A of Fig. 8. The securing member 130 at least substantially closes the opening 144 thereby retaining the second safety net support member 16 in the support member insertion gap 126. In the embodiment shown, this is achieved by an upper portion of the spigot portion 132 and the

projecting portion 134 of the securing member 130.

[0048] A special lifting handle 142, which does not form part of the safety net assembly 2 itself, but is used during its installation and in-situ assembly, is shown in Fig. 5. A lower end of the lifting handle 142 is configured to engage the securing member socket 128 of the suspended mechanism 6. The lifting handle 142 has a hole at its lower end, which end is configured to be received in the securing member socket 128. The bolt 124 can be inserted through the holes 136 in the securing member socket and the hole at the lower end of the lifting handle 142 to temporarily secure it in place.

[0049] The method of installing the safety net assembly 2 according to the invention will be described below. In the description of the method, the installation of one support arrangement 4 and suspended mechanism 6 and the connection of the first and second safety net support members 14 and 16 thereto will be described. It will be appreciated however that the safety net assembly includes two such support arrangements 4 and suspended mechanisms 6.

[0050] The fixing plate 18 is fixed to a floor slab or other structure 20 by means of bolts (not shown) which pass through holes 22 in the fixing plate 18. The off-stand bracket 28 is bolted to the fixing plate by means of bolts 26 which pass through the lugs 24 of the fixing plate 18. The first form- fit engagement means 40 is bolted to a lower end of the vertical support 32 by means of the bolts 42. The vertical support 32 is engaged with the off-stand bracket 28 and adjusted to a suitable vertical position and then bolted to the off-stand bracket 28 by means of the bolts 34, which pass through the off-stand bracket 28 and appropriate holes 38 in the vertical support 32. The lifting handle 142 is connected to the securing member socket 128 of the suspended mechanism 6 by means of the bolt 124 as shown in Fig. 5. With the main arm portion 74 rotated so that it is adjacent to the

suspended column 8, and possibly retained there by means of a temporary lashing (not shown) , the suspended mechanism 6 is lowered so as to bring the second form-fit engagement means 118 of the suspended mechanism 6 into engagement with the first form-fit engagement means 40 of the support arrangement 4. This is achieved by positioning the support shoulders 120 above the receiving space 52 and then lowering it into the receiving space 52. As this occurs the support shoulders 120 of the second form-fit engagement means 118 are lowered into engagement with the support surfaces 44 of the first form-fit engagement means 40. Once this has occurred, the retaining walls 48 will be accommodated in the slots 140 of the suspended mechanism 6 and will prevent lateral disengagement (away from the structure 20) of the second form-fit

engagement means 118 from the first form-fit engagement means 40. The locking member bolt 56 is then passed through the flank walls 43 of the first form-fit engagement means 40 and the hole 122 in the second form-fit engagement means 118 to secure the suspended mechanism 6 in engagement with the support arrangement 4. The lifting handle 142 is then disengaged from the securing member socket 128 and removed. This leaves the safety net assembly in the configuration shown in Fig. 6.

[0051] The arm extension member 76 is then connected to the main arm portion 74 by positioning its first end 92 over the spigot 86 and then passing two of the bolts 88 through the arm extension member 76 and the spigot 86 as shown in Fig. 7. At this stage the first safety net support member 14 is not connected to the arm extension member 76.

[0052] The first and second safety net support members 14 and 16 are then respectively threaded into the outer pocket 106 and the inner pocket 104 of the safety net 12. Two portions of the second safety net support member 16 which are exposed at the gaps 108 in the inner pocket 104 are then inserted into respective support member insertion gaps 126 immediately above the flank walls 43 of a respective one of the first form-fit engagement means 40. At each support arrangement 4, the spigot portion 132 of a respective

securing member 130 is inserted into the securing member socket 128 which is retained there by the bolt 124 which is passed through the securing member socket 128 and the hole 138 in the securing member 130. As shown in detail A in Fig. 8, once the securing member 130 has been fixed in the securing member socket 128, an upper portion of the securing member 130 and the projecting portion 134 thereof at least substantially close the opening 144 of the support member insertion gap 126. This prevents the second safety net support member 16 from coming out of the support member insertion gap 126. Each support member insertion gap 126 and its associated securing member 130 constitutes a second connection means for the second safety net support member 16.

[0053] Two portions of the first safety net support member 14 which are exposed at the gaps 110 in the outer pocket 106 are then connected to a respective upper end 94 of a

respective arm extension member 76. This connection is effected using one of the first connection means 112 and results in the arrangement shown in Fig. 8.

[0054] The safety net 12 is then deployed by allowing the net support arm 10 rotate about the pivot bolt 70 from the position shown in Fig. 8 to the position shown in Figs. 1, 9 and 12.

[0055] Any downward force on the safety net 12, and the weight of the safety net assembly itself, will urge the suspended column 8 inwardly towards the structure 20 on which it is supported by rotation (anticlockwise as viewed in Fig. 12) about the first form-fit engagement means 40. This inward force is resisted by one or both of: (i) a lower portion 148 of the suspended column 8 bearing against an underlying portion 150 of the structure 20; and (ii) a cantilevered assembly 152, connected to an intermediate portion 154 of the suspended column 8 bearing against an underside 156 of the floor slab to which the support

arrangement 4 is connected. [0056] With the safety net 12 deployed in the manner shown in Figs 1, 9 and 12 it will catch and retain any person or object which falls onto it, thereby preventing such person or object from falling further and causing a hazard.

[0057] It should be noted that the precise order of the deployment steps could be different from the order set out above. For example the arm extension member 76 could be connected to the main arm portion 74 before the suspended mechanism 6 is connected to the support arrangement 4. Also the support arrangement 4 could be put together prior to its connection to the structure or floor slab 20. An important part of the sequence however is that the support arrangement 4 and the suspended mechanism 6 are installed prior to connection thereto of the safety net 12 and the first and second safety net support members 14 and 16.

[0058] Uninstalling of the safety net assembly will comprise a reversal of the deployment sequence described above.

[0059] Fig 13 shows a partially exploded view of a modified safety net assembly 160 in which parts which correspond to the safety net assembly 2 shown in Fig. 1 have been

designated with the same reference numerals and will not be described in detail. The safety net assembly 160 includes a net extension arrangement 161 including an additional arm extension member 162 connected to the end of each net support arm 10 by an angled double ended spigot 164. An extension net 166 is supported by the two additional arm extension members 162 so as to project outwardly and upwardly relative to the safety net 12. The extension net 166 may be connected to the additional arm extension members 162 by any suitable means. For example an upper edge 168 of the extension net 166 may be provided with a pocket 172 which accommodates an extension net support member 176 or tube in a similar manner to that in which the main safety net outer pocket 106

accommodates the first safety net support member 14. The support member 176 may be constituted by a proprietary scaffold tube and may be connected to the additional arm extension members 162 by clamping means such as proprietary scaffold clamps 180, only one of which is shown in Fig. 13.

A lower end 174 of the extension net 166 is connected to the first safety net support member and/or an outer edge of the safety net 12 by any suitable restraining means such as rope, cord, straps or cable ties. The extension net is preferably arranged to overlap the main safety net 12 so as to avoid any gaps between these nets from being present. When the

modified safety net assembly 160 is deployed, the additional arm extension members 162, extension net 166 and support member 176 will preferably be added to the safety net

assembly 2 when it is in the configuration shown in Fig. 8.

In this way the extension net can be added by a person standing on the structure 20.

[0060] While a particular configuration of first and second form-fit engagement means have been described, other

configurations would be possible. For example, the first form-fit engagement means could comprise one or more V-shaped slots and the second form-fit engagement means could comprise one or more complementary V-shaped projections which engage the one or more V-shaped slots.

[0061] As a consequence of the in-situ assembly of the safety net assembly, which is made possible by the

construction thereof, the safety net assembly can be

installed and uninstalled without the use of a crane, which provides a very significant advantage over existing safety net assemblies which need to be lifted as completed

assemblies into place with a crane, as a result of the weight of a typical complete safety net assembly.

[0062] The first and second safety net support members 14 and 16 may conveniently be tubes such as proprietary scaffold tubes .

Claims

1. Safety net support assembly including:

first and second transverse safety net support members ;

a support arrangement configured to be connected to a structure and including a first form-fit engagement means;

a suspended mechanism including a suspended body and a net support arm rotatably coupled to a lower portion of the suspended body, the suspended body including a second form-fit engagement means configured to be releasably

engageable with the first form-fit engagement means in a form fitting manner in order to suspend the suspended mechanism from the support arrangement independently of the net support members; and

first connection means for connecting the first safety net support member to a distal portion of the net support arm and second connection means for connecting the second safety net support member to at least one of the suspended body and the support arrangement after engagement of the second form-fit engagement means of the suspended body with the first form-fit engagement means of the support arrangement .

2. The assembly of claim 1, wherein the second form-fit engagement means is supportively engageable with the first form-fit engagement means by translation of the second form- fit engagement means in a single direction.

3. The assembly of claim 2 wherein the second form-fit engagement means is supportively engageable with the first form-fit engagement means by lowering of the second form-fit engagement means relative to the first form-fit engagement means .

4. The assembly of claim 2 or 3 wherein the first form-fit engagement means includes a pair of laterally spaced support surfaces and the second form-fit engagement means includes a pair of laterally protruding support shoulders each of which is engageable with a respective one of the support surfaces.

5. The assembly of any preceding claim further including a locking member which is engageable with at least one of the first and second form-fit engagement means to lock them in engagement with each other.

6. The assembly of any preceding claim wherein the second connection means includes a safety net support member insertion gap and a securing member which is securable to at least one of the support arrangement and the suspended body.

7. The assembly of any preceding claim configured such that the first safety net support member is connectable to the distal portion of the net support arm and the second safety net support member is connectable to at least one of the suspended body and the support arrangement after the

suspended mechanism has been suspended from the support arrangement by interengagement of the first and second form- fit engagement means.

8. The assembly of any preceding claim wherein the net support arm includes an arm main portion rotatably coupled to the lower portion of the suspended body and an arm extension member releasably coupled to the arm main portion, the first safety net support member being connected to the arm

extension member.

9. The assembly of any preceding claim wherein the suspended body includes a lifting handle engagement means for

releasably connecting a lifting handle to the suspended body.

10. The assembly of any preceding claim wherein the suspended body comprises a column.

11. A method of deploying a safety net assembly on a

structure including the steps of:

(i) connecting a support arrangement to the structure;

(ii) connecting a suspended mechanism to the support

(iv) with the net support arm positioned alongside the

suspended body, connecting the first safety net support member to a distal portion of the net support arm;

(v) connecting the second safety net support member to at least one of the suspended body and the support arrangement; and (vi) rotating the net support arm away from the suspended body so as to move the first safety net support member away from the second safety net support member with at least a portion of the safety net positioned therebetween, wherein steps (i) and (ii) are performed prior to steps (iv), (v) and (vi) .

12. The method of claim 11 wherein the net support arm includes a main arm portion rotatably coupled to the lower portion of the suspended body and an arm extension member and the method includes the further step, after step ii and with the main arm portion adjacent to the suspended body, of connecting the arm extension member to the main arm portion so as to extend its length.

13. The method of claim 11 or 12 wherein, in step (ii) connecting the suspended mechanism to the support arrangement includes the step of engaging a second form-fit engagement means of the suspended body with a first form-fit engagement means of the support arrangement.

14. The method of claim 13 wherein engaging the second form- fit engagement means with the first form-fit engagement means involves translating the second form-fit engagement means in a single direction relative to the first form-fit engagement means .

15. The method of claim 14 wherein the second form-fit engagement means is engaged with the first form-fit

engagement means by translating it downwardly into engagement therewith .

16. The method of any of claims 11 to 15 including a step of connecting a temporary lifting handle to the suspended mechanism to facilitate manoeuvering the suspended mechanism as it is connected to the support arrangement and removing the handle after this operation has been completed.