AU2017235916A1 - A Climbing System Support Unit for Construction Site Safety Screens - Google Patents

Abstract

Abstract Apparatus for a climbing system screen support comprises a support unit by which an upwardly extending safety structure can be supported in relation to a multi-level building construction. The support unit includes: (a) an elongate ratchet bar to which a safety screen section is attachable, the ratchet bar having alongitudinal series of ratchet teeth over alength of the ratchet bar sufficient to span at least two successive floor levels of a multi-level building construction; (b) at least a first and a second mounting body, each having a respective guide section through which the ratchet bar is able to extend so as to be held adjustably at a selected holding position, or to be longitudinally adjustable, relative to the guide section; and (c) a respective latch mechanism in each guide section, with each latch mechanism operable to selectively engage at least a respective one of the ratchet teeth for holding the ratchet bar at a selected holding position relative to the guide section. _ CE I 7-Need I H and Ie "un T Plate 2-0

Description

A Climbing System Support Unit for Construction Site Safety Screens

Field of the Invention [001] This invention relates to a support unit for use in a climbing system by which a safety screen can be supported at a multi-level building construction site, and by which the screen can be elevated as successive levels of the building are constructed.

Background to the Invention [002] The construction of multi-level buildings is controlled by numerous governmental regulations. Include in the regulations are requirements for a safety screen to protect work-site personnel, and to protect against injury or damage resulting from equipment or materials falling from the construction, prior to the formation of outer walls of the building. There has been a wide variety of proposals for systems for supporting a safety screen and the like around a building as it is being erected, with many of these comprising climbing systems in that they enable the screen to be raised as successive levels of a building are constructed.

[003] The present invention seeks to provide a support unit for use in a climbing system by which a screen can be supported at a multi-level building construction site in a manner enabling elevation of the screen as successive levels of the building are constructed. At least in preferred forms, the invention seeks to provide a support unit enabling a climbing system that is more cost-effective, or more economically operable, or both more cost-effective and more economically operable than climbing systems currently in use.

Broad Outline of the Invention [004] In a first form, the present invention provides apparatus comprising a support unit intended to form part of a climbing system screen support by which an upwardly extending safety structure such as a safety screen (herein simply referred to as a safety screen, but intended to encompass other suitable safety structures) can be supported in relation to a multi-level building construction. The safety screen may comprise a plurality of screen sections each having a height enabling it to span at least two successive floor levels of the building, with each of a side-by-side series of

2017235916 26 Sep 2017 safety screen sections able to be supported by the system to form the overall safety screen adjacent at least one side of the building. At least a respective pair of the support units of the invention may enable each safety screen section to be supported, such as with each support unit of a pair engaged with the screen section adjacent to a respective upright side of the safety structure section.

[005] A support unit of the first form of the invention, able to form part of a climbing system by which a safety structure such as a safety screen can be supported in an upwardly extending disposition adjacent to a multi-level building construction, includes:

(a) an elongate ratchet bar to which a safety screen section is attachable, the ratchet bar having a longitudinal series of ratchet teeth over a length of the ratchet bar sufficient to span at least two successive floor levels of a multi-level building construction;

(b) at least a first and a second mounting body, each having a respective guide section through which the ratchet bar is able to extend so as to be held adjustably at a selected holding position, or to be longitudinally adjustable, relative to the guide section; and (c) a respective latch mechanism in each guide section, with each latch mechanism operable to selectively engage at least a respective one of the ratchet teeth for holding the ratchet bar at a selected holding position relative to the guide section. Each mounting body can be detachably secured in relation to the building, at a respective floor level, to position the respective guide section outwardly from an edge of the respective floor level. The arrangement is such that, with each mounting body secured at a respective one of successive floor levels to position one of the respective guide sections above the, or each, other guide section, the ratchet bar is able to extend upwardly through, and to be adjustably held in a first selected holding position relative to each of an upper or uppermost and a lower or lowest guide section or raised from the first holding position. Also, the arrangement is such that the ratchet bar can be raised longitudinally from the first holding position to a second holding position by the ratchet bar moving out of the lower or lowest guide section and extending into and through a guide section of a further mounting body detachably secured in relation to the building at a next uppermost floor level above

2017235916 26 Sep 2017 the successive floor levels, after which the ratchet bar can be similarly raised to at least a third selected position.

[006] With the support unit installed in relation to a multi-level building being constructed, the ratchet bar can be raised to successive selected holding positions by being pulled upwardly from above in successive stages. In each position the respective latch mechanisms are operable to the ratchet bar by engaging with at least one tooth of the ratchet bar, and to disengage from the at least one tooth as a force is applied to pull the ratchet bar upwardly. In use for supporting a safety screen in relation to the building, at least a pair of laterally successive support units, of a plurality of support units installed in relation to the building, will support a respective screen section of a plurality of screen section comprising the safety screen, and the force applied to raise a ratchet bar can be applied directly to the ratchet bar or to a screen section supported by the ratchet bar.

[007] In a second form, the present invention provides apparatus comprising a multilevel building construction site at which a safety screen is supported by a climbing system in an upwardly extending disposition adjacent to a building under construction at the site, wherein:

(1) the screen comprises a plurality of screen sections each having a height spanning at least two successive floor levels of building being constructed at the site, with each of a side-by-side series of screen sections supported by the climbing system to form the safety screen at one side, or at least adjacent sides, of the building;

(2) the climbing system comprises a plurality of support units, with each screen section supported by at least a respective pair of the support units, such as with a respective support unit engaged with the respective screen section adjacent to each of opposite upright sides of the screen section;

(3) each support unit includes:

(a) an elongate ratchet bar to which a respective screen section is attached, the ratchet bar having a longitudinal series of ratchet teeth over a length of the ratchet bar sufficient to span at least two successive floor levels of the building;

(b) at least a first and a second mounting body, each having a respective guide section through which the ratchet bar is able to extend so as to be held adjustably at

2017235916 26 Sep 2017 a selected holding position, or to be longitudinally adjustable, relative to the guide section; and (c) a respective latch mechanism in each guide section, with each latch mechanism operable to selectively engage at least a respective one of the ratchet teeth for holding the ratchet bar at a selected holding position relative to the guide section; and wherein each mounting body is detachably secured in relation to the building, at a respective floor level, to position the respective guide section outwardly from an edge of the respective floor level with each mounting body secured at a respective floor level to position one of the respective guide sections above the, or each, other guide section, with the ratchet bar extending upwardly through, and adjustably held in a selected holding position relative to each guide section, or moved longitudinally to another selected holding position.

[008] In a third form, the present invention provides apparatus comprising a climbing system by which a safety screen can be supported in an upwardly extending disposition adjacent to a multi-level building construction, wherein the climbing system comprises a plurality of support units, with each of a plurality screen sections comprising the safety screen supportable in the upwardly extending disposition by at least a respective pair of the support units, such as with a respective support unit engaged with the respective screen section adjacent to each of opposite upright sides of the screen section; wherein each support unit includes:

(a) an elongate ratchet bar to which a screen section is attachable, the ratchet bar having a longitudinal series of ratchet teeth over a length of the ratchet bar sufficient to span at least two successive floor levels of a multi-level building construction;

(b) at least a first and a second mounting body, each having a respective guide section through which the ratchet bar is able to extend so as to be held adjustably at a selected holding position, or to be longitudinally adjustable, relative to the guide section; and (c) a respective latch mechanism in each guide section, with each latch mechanism operable to selectively engage at least a respective one of the ratchet teeth for holding the ratchet bar at a selected holding position relative to the guide section. Each mounting body can be detachably secured in relation to the building, at a respective floor level, to position the respective guide section outwardly from an edge of the respective floor level. The arrangement is such that, with each mounting

2017235916 26 Sep 2017 body secured at a respective floor level to position one of the respective guide sections above the, or each, other guide section, the ratchet bar is able to extend upwardly through, and to be adjustably held in a selected holding position relative to each guide section or moved longitudinally to another selected holding position.

[009] In each of the second and third form of the invention, each ratchet bar is able to be raised to and held at successive selected positions in the manner described for the first form of the invention. Thus, a force applied to pull ratchet bars upwardly can be applied to a screen section, or at least two laterally successive screen sections, or directly to at least one ratchet bar for each screen section. The force can be provided by a number of arrangements, such as an overhead pulley or hoist arrangement or by a crane operable at the construction site.

[010] In each of the first, second and third form of the present invention, the ratchet bar, the mounting body and its guide section, and the latch mechanism of the or each support unit is made of a suitable high strength ferrous material, or a suitable alternative metal having appropriate physical properties for the load carrying requirements evident from a consideration of the present overall disclosure. These parts of the support unit preferably are made of a suitable grade of high strength steel.

[011] The mounting body and its guide section may be cast, such as in two or three parts to provide at least one separable side of the guide section to facilitate location of the ratchet bar to extend through the guide section. However, as is evident from an embodiment described later herein with reference to the drawings, both of the mounting body and the guide section can be fabricated from plate metal of a suitable gauge.

[012] The mounting body can take a variety of forms consistent with its primary function of enabling it to be detachably secured at a respective floor level so as to position its guide section as required. In one form, the mounting body is of elongate form, with the guide section provided at one of opposite ends of the mounting body. In that form, the mounting body is adapted to be detachably secured on or in relation to a respective floor level. The mounting body may be secured down onto floor

2017235916 26 Sep 2017 structure at the floor level by at least one bolt or other suitable fastener applied through the body, into the floor structure, or by at least one bolt, fastener or pin applied laterally through the body and through a bracket or the like secured to the floor structure. Alternatively, the body may be secured by a strap or bracket that is fitted over the body and that is attached to the structure by bolts or other suitable fasteners.

[013] In one arrangement, the guide section comprises a pair of side members that are spaced from each other to define a recess through which the ratchet bar extends. The recess preferably opens away from the mounting body to facilitate attachment of a screen section to the ratchet bar. For such attachment, there may be at least two connectors secured to the ratchet bar at longitudinally spaced locations along the ratchet bar, with the screen section able to be attached to the ratchet bar by the connectors. The connectors may project from the recess for the attachment. Alternatively, the connectors may be located outside the recess as a consequence of the ratchet bar having a first longitudinal portion that extends through the recess and by which the ratchet bar is adjustably held in the guide section, and a second longitudinal portion the extends laterally from the first portion so as to project from the recess. In that alternative, the connectors are secured to the second longitudinal portion of the ratchet bar, outside the recess.

[014] Each side member of the guide section may be provided by a respective extension of the mounting body or be integrally attached to the mounting body, such as by welding. However, one or each side member may be detachably connected to the mounting body to facilitate separation of at least one side member for positioning of the ratchet bar so as to extend through the guide section, prior to the or each side member being repositioned in relation to the mounting body.

[015] The ratchet bar may be engaged in guide section by at least one engagement member that acts to hold the ratchet bar against lateral forces acting to rotate an upper longitudinal extent of the ratchet bar outwardly away from the building. In a preferred form, the engagement member comprises a roller that bears against a longitudinal surface defined by the ratchet bar. The roller may bear against a surface of a flange defined by the ratchet bar, such as of a flange having a width

2017235916 26 Sep 2017 dimension that extends across the recess defined between the side members of the guide section. In a preferred form, at least two engagement members are provided, with each comprising a roller spaced along a line substantially parallel to the length of the ratchet bar when extending through the guide section. In the case of two rollers, each roller preferably bears against a respective one of two oppositely facing flange surfaces, such as with an upper roller bearing against a flange surface facing outwardly with respect to the recess defined between the side members of the guide section and a lower roller facing inwardly with respect to that recess.

[016] The ratchet bar may have a main body that includes an elongate web that is disposed edgewise in the recess defined between the side members of the guide section so that a respective main surface of the web faces each side member. The ratchet bar may have a main body of l-shape in transverse cross-sections, formed by the elongate web joining a parallel pair of flanges along a centerline for each flange. With a main body of such cross-sections, the ratchet bar extends through the guide section with each flange of the parallel pair extending across the recess defined between the side members of the guide section, such that first flange of the parallel pair is nearer to the mounting body than the other flange of the pair. The longitudinal series of ratchet teeth preferably disposed along a surface defined by the first flange that faces away from the other flange, such as with the ratchet teeth projecting from the centerline of the first flange. The ratchet teeth preferably are inclined with respect to the longitudinal extent of the ratchet bar so as to incline with respect to the longitudinal extent of the ratchet bar such that, with the ratchet bar disposed in its intended upwardly extended position, the ratchet teeth are inclined downwardly.

[017] The latch mechanism in each guide section may comprise a pivotally mounted pawl or rack latch operable to engage with a selected ratchet tooth for holding the ratchet bar against the influence of gravity, at a selected holding position relative to the guide section, but operable to release the ratchet bar in response to a force applied to raise the ratchet bar to an upper holding position. The pawl or rack latch preferably is movable to an engagement position by a bias force, but able to pivot to a release position against the bias force. The bias force may be the force of gravity or provided by a spring. In the engagement position the pawl or rack latch may bear

2017235916 26 Sep 2017 against an abutment member that extends across the recess and is integral with one or each of the side members.

General Description of the Drawings [018] In order that the invention may more readily be understood, reference now is directed to the accompanying drawings, in which:

[019] Figure 1 is a schematic perspective view of part of a climbing system according to the invention supporting part of a safety screen in an upwardly extending disposition adjacent to a building under construction;

[020] Figure 2 is an enlarged perspective of the respective parts of the system and screen of Figure 1;

[021] Figure 3 is a partial perspective view of a support unit of the invention, able to form part of a climbing system by which a safety structure such as a safety screen can be supported in an upwardly extending disposition adjacent to a multi-level building construction;

[022] Figure 4 shows a partially sectioned side elevation of the support unit shown in Figure 3;

[023] Figure 5 is a perspective view of a component of the support unit of Figure 3;

[024] Figure 6 corresponds to Figure 5, but shows the component partially broken away to reveal internal detail; and [025] Figure 7 is a perspective view of a part of the component shown in Figure 5.

Detailed Description of the Drawings [026] With reference to Figures 1 and 2, there is shown a schematic perspective view of a safety unit U comprising a climbing system part 10 of a climbing system (not otherwise shown) according to the invention. The climbing system part 10 is shown as supporting a screen section 12 comprising part of a safety screen (not

2017235916 26 Sep 2017 otherwise shown) in an upwardly extending disposition adjacent to a multi-storey building (not shown) that is under construction. The building has progressed to the stage of construction of five successive floor levels, each partially depicted only by flooring areas A1 to A5. The climbing system part 10 is shown as spanning the five levels, although the part 10 need only span two levels and preferably spans three levels. The screen section 12 is shown as attached to the climbing system part 10 to provide a safety cover above each of the five levels. However, screen sections 12 more usually are made in rectangular areas having a height of about 15 meters, sufficient to span four levels to provide safety cover between successive levels from A1 to A4.

[027] In Figures 1 and 2, the climbing system part 10 comprises two laterally spaced support units 16 on each of which the screen sections 12 are supported. A complete screen over at least a side of the building is formed by a laterally extending series of safety units U in a closely positioned side-by-side relationship.

[028] Referring now to Figures 3 and 4, there is shown a section of a single support unit 16 that has (a) an elongate ratchet bar 18 to which a safety screen section (not shown) is attachable, (b) at least a first mounting body 20 and a second mounting body (not shown but spaced from mounting body along ratchet bar 18), with each mounting body 20 having a respective guide section 22 through which the ratchet bar 18 extends, and (c) a respective latch mechanism 24 in each guide section 22. The support unit 16 is able to form part of a climbing system by which a safety structure such as a safety screen can be supported in an upwardly extending disposition adjacent to a multi-level building construction. The ratchet bar 18 has a longitudinal series of ratchet teeth 26 over a length of the ratchet bar 18 sufficient to span at least two successive floor levels of a multi-level building construction. The ratchet bar 18 extends through each guide section 22 so as to be held adjustably at a selected holding position by the latch mechanism 24, or to be longitudinally adjustable relative to the guide sections 22. To enable this, each latch mechanism 24 is operable to selectively engage at least a respective one of the ratchet teeth 26 for holding the ratchet bar 18 at a selected holding position relative to the guide sections 22.

2017235916 26 Sep 2017 [029] In use of support member 16, each mounting body 20 is detachably secured in relation to the building, at a respective floor level, to position the respective guide section 22 outwardly from an edge of the respective floor level. As is apparent from Figures 1 and 2 in which each support member 16 its ratchet bar 18 extending through three mounting bodies 20, with a respective body 20 secured at a respective one of levels A2, A3 and A4. The arrangement is such that, with each mounting body 20 so secured, the respective guide section 22 at level A4 is directly above each of the respective guide section 22 at each of levels A3 and A2. Thus, the ratchet bar 18 extends upwardly through the guide sections 22, and is adjustably held in a first selected holding position relative to each of the guide sections 22, such as shown in Figures 1 and 2 or, after a mounting body 20 is secured at level A5, raised from the first holding position to a second position in which the ratchet bar 18 extends through guide section 22 at levels A3, A4 and A5. The arrangement is such that the ratchet bar 18 can be raised longitudinally from the first to the second holding position by the ratchet bar 18 moving out of the lower or lowest guide section 22 and extending into and through a guide section 22 of the further mounting body 20 detachably secured in relation to the building at a next uppermost floor level above the successive floor levels, after which the ratchet bar 18 can be similarly raised to at least a third selected position.

[030] Each of the mounting bodies 20 can take a variety of forms consistent with its primary function of enabling it to be detachably secured at a respective floor level so as to position its guide section as required. In form illustrated in Figures 3 and 4, and also in Figures 5 to 7, the mounting body 20 is of elongate form, with the guide section 22 provided at one of opposite ends of the mounting body 20. In that form, the mounting body 20 is adapted to be detachably secured on or in relation to a respective floor level such as level A1, A2 and A3. The mounting body may be secured down onto floor structure at the floor level by at least one bolt or other suitable fastener applied through the body, into the floor structure, or by at least one bolt, fastener or pin applied laterally through the body and through a bracket or the like secured to the floor structure, or the body 20 may be secured by a strap or bracket that is fitted over the body and attached to the structure by bolts or other suitable fasteners. In the arrangement of Figures 1 and 2, each body 20 is secured by being received between a pair of brackets 28 that are attached to the floor

2017235916 26 Sep 2017 structure, and then retained by at least one fastener or pin 30 inserted through each bracket and the body 20. For safety, a further fastener or pin 32 can be inserted through the brackets, above the body 20.

[031] In the arrangement of Figures 3 and 4, and also Figures 5 to 7, the guide section 22 comprises a pair of side members 34 that are spaced from each other to define a recess 36 through which the ratchet bar 18 extends. The recess 36 opens away from the mounting body 20 to facilitate attachment of a screen section 12 to the ratchet bar 18. For such attachment, there may be at least two connectors 38 secured to the ratchet bar at longitudinally spaced locations along the ratchet bar 18, with the screen section 12 able to be attached to the ratchet bar by the connectors 38 in any convenient manner (not illustrated). The arrangement could be such that the connectors 38 project out of the recess 36, laterally away from the ratchet bar 18. However, in the arrangement shown in Figures 3 and 4, the connectors 38 are located outside the recess 36 as a consequence of the ratchet bar 18 having a first longitudinal portion 18a that extends through the recess 36 and by which the ratchet bar is adjustably held in the guide section 22, and a second longitudinal portion 18b that extends laterally from the first portion 18a so as to project from the recess 36. In that alternative, the connectors 38 are secured to the second longitudinal portion 18b of the ratchet bar 18, outside the recess 36.

[032] Each side member 34 of the guide section 22 may be provided by a respective extension of, or be integrally attached such as by welding to, the mounting body 20. However, one or each side member 34 may be detachably connected to the mounting body 20 to facilitate separation of at least one side member 34 for positioning of the ratchet bar 18 so as to extend through the guide section 22, prior to the or each side member 34 being repositioned in relation to the mounting body 20. The latter arrangement, of each side member being detachable, is shown by Figures 3 and 4, and also by Figures 5 to 7, as is evident form the showing of fasteners 40 and holes 42 in the side member 34 shown in Figure 7.

[032] In the illustrated arrangement of Figures 3 to 6, the ratchet bar 18 is engaged in guide section 22 by at least one engagement member that acts to hold the ratchet bar 18 against lateral forces acting to rotate an upper longitudinal extent of the

2017235916 26 Sep 2017 ratchet bar 18 outwardly away from the building. In arrangement of Figures 3 to 6, the engagement member comprises roller 44 that bears against a respective longitudinal surface defined by the ratchet bar 18. Each roller 44 bear against a surface 46a or 48b of a flange 46 defined by the ratchet bar 18, with the flange 46 having a width dimension that extends across the recess 36 defined between the side members 34 of the guide section 22. In the preferred form illustrated, at least two rollers 44 are provided, the rollers spaced along a line substantially parallel to the length of the ratchet bar 18 when extending through the guide section 22. Each of the two rollers 44 bears against a respective one of two oppositely facing flange surfaces 46a and 46b, with an upper roller 46 bearing against a flange surface 46a facing outwardly with respect to the recess 36 defined between the side members 34 of the guide section 22 and a lower roller 44 bearing against a flange surface 46b facing inwardly with respect to recess 36.

[033] As can be appreciated from Figures 3 and 4, the ratchet bar 18 has an elongate web 18c that is disposed edgewise in the recess 36 defined between the side members 34 of the guide section 22 so that a respective main surface of the web 18c faces each side member 34. The ratchet bar 18 has a main body that is Ishaped in transverse cross-sections, formed by the elongate web 18c joining a parallel pair of flanges 18d and 18 e along a centerline for each flange 18d, 18e. The ratchet bar 18 extends through the guide section 22 with each flange 18d and 18e extending across the recess 36, such that first flange 18d of the parallel pair is nearer to the mounting body 20 than the other flange of 18e. The longitudinal series of ratchet teeth 26 is disposed along a surface defined by the flange 18d that faces away from flange 18e, with the ratchet teeth 26 projecting from the centerline of the flange 18d. The ratchet teeth 26 are inclined with respect to the longitudinal extent of the ratchet bar 18 so as to incline with respect to the longitudinal extent of the ratchet bar 18 such that, with the ratchet bar 18 disposed in its intended upwardly extended position, the ratchet teeth 26 are inclined downwardly.

[034] The latch mechanism 24 in each guide section 22 comprises a pivotally mounted pawl or rack latch 50 mounted on bracket 51 and operable to engage with a selected ratchet tooth 26 for holding the ratchet bar 18 against the influence of gravity, at a selected holding position relative to the respective guide section 22, but

2017235916 26 Sep 2017 operable to release the ratchet bar 18 in response to a force applied to raise the ratchet bar 18 to an upper holding position. The pawl or rack latch 50 is movable to an engagement position by a bias force, but able to pivot to a release position against the bias force. The bias force is force of gravity assisted by a spring 52. In the engagement position the pawl or rack latch 50 bear against an abutment member 54 that extends across the recess 36 and is integral with one or each of the side members 34.

[035] In use of the apparatus, the ratchet bars of successive units are raised by being pulled from above, with the screen units mounted on the ratchet bars similarly raised. As the screen is elevated above successive floor units, external walls can be completed, with the screen raised to provide safety protection at a higher completed floor level in which construction workers are to operate. As the ratchet bars are raised, the lower end of each ratchet bar moves out of the guide section of the lowest mounting body and that mounting body can be detached from the floor level at which it was installed, and moved to a higher floor level at which it is able to be used in guiding the ratchet bar as it rises to higher levels. As the lower end of the ratchet bar moves from the lowermost mounting body, the upper end of the ratchet bar is raised to extend through the guide section of a mounting body already put into position at the next higher floor level. In positioning successive mounting bodies at progressively higher floor levels, care is required to ensure the positioning of the mounting body to ensure appropriate engagement of the latch mechanism with the teeth of the ratchet bar, to offset slight differences in the height between successive floor levels and, for this purpose, wedge devices or the like can be used to fine-tune the positioning of each mounting body.

Claims (3)

1. Apparatus for a climbing system screen support, wherein the apparatus comprises a support unit intended to form part of a climbing system screen support by which an upwardly extending safety structure such as a safety screen (herein simply referred to as a safety screen, but intended to encompass other suitable safety structures) can be supported in relation to a multi-level building construction, the safety screen comprising a plurality of screen sections each having a height enabling it to span at least two successive floor levels of the building, with each of a side-by-side series of safety screen sections able to be supported by the system to form the overall safety screen adjacent at least one side of the building, with at least a respective pair of the support units of the invention may enable each safety screen section to be supported, such as with each support unit of a pair engaged with the screen section adjacent to a respective upright side of the safety structure section; wherein the support unit includes:

(a) an elongate ratchet bar to which a safety screen section is attachable, the ratchet bar having a longitudinal series of ratchet teeth over a length of the ratchet bar sufficient to span at least two successive floor levels of a multi-level building construction;

2017235916 26 Sep 2017 (b) at least a first and a second mounting body, each having a respective guide section through which the ratchet bar is able to extend so as to be held adjustably at a selected holding position, or to be longitudinally adjustable, relative to the guide section; and (c) a respective latch mechanism in each guide section, with each latch mechanism operable to selectively engage at least a respective one of the ratchet teeth for holding the ratchet bar at a selected holding position relative to the guide section.

2. The apparatus of claim 1, wherein each mounting body can be detachably secured in relation to the building, at a respective floor level, to position the respective guide section outwardly from an edge of the respective floor level.

3. The apparatus of claim 1 or claim 2, wherein with each mounting body secured at a respective one of successive floor levels to position one of the respective guide sections above the, or each, other guide section, the ratchet bar is able to extend upwardly through, and to be adjustably held in a first selected holding position relative to each of an upper or uppermost and a lower or lowest guide section or raised from the first holding position.

4. The apparatus of any one of claims 1 to 3, wherein the arrangement is such that the ratchet bar can be raised longitudinally from the first holding position to a second holding position by the ratchet bar moving out of the lower or lowest guide section and extending into and through a guide section of a further mounting body detachably secured in relation to the building at a next uppermost floor level above the successive floor levels, after which the ratchet bar can be similarly raised to at least a third selected position.

5. The apparatus of any one of claims 1 to 4, wherein with the support unit installed in relation to a multi-level building being constructed, the ratchet bar can be raised to successive selected holding positions by being pulled upwardly from above in successive stages; and wherein in each position the respective latch mechanisms are operable to the ratchet bar by engaging with at least one tooth of the ratchet bar, and to disengage from the at least one tooth as a force is applied to pull the ratchet bar upwardly; whereby, in use for supporting a safety screen in relation to the

2017235916 26 Sep 2017 building, at least a pair of laterally successive support units, of a plurality of support units installed in relation to the building, will support a respective screen section of a plurality of screen section comprising the safety screen, and the force applied to raise a ratchet bar can be applied directly to the ratchet bar or to a screen section supported by the ratchet bar.

6. Apparatus for a climbing system screen support, wherein the apparatus comprises a multi-level building construction site at which a safety screen is supported by a climbing system in an upwardly extending disposition adjacent to a building under construction at the site, wherein:

(1) the screen comprises a plurality of screen sections each having a height spanning at least two successive floor levels of building being constructed at the site, with each of a side-by-side series of screen sections supported by the climbing system to form the safety screen at one side, or at least adjacent sides, of the building;

(2) the climbing system comprises a plurality of support units, with each screen section supported by at least a respective pair of the support units, such as with a respective support unit engaged with the respective screen section adjacent to each of opposite upright sides of the screen section;

(3) each support unit includes:

(a) an elongate ratchet bar to which a respective screen section is attached, the ratchet bar having a longitudinal series of ratchet teeth over a length of the ratchet bar sufficient to span at least two successive floor levels of the building;

(b) at least a first and a second mounting body, each having a respective guide section through which the ratchet bar is able to extend so as to be held adjustably at a selected holding position, or to be longitudinally adjustable, relative to the guide section; and (c) a respective latch mechanism in each guide section, with each latch mechanism operable to selectively engage at least a respective one of the ratchet teeth for holding the ratchet bar at a selected holding position relative to the guide section; and wherein each mounting body is detachably secured in relation to the building, at a respective floor level, to position the respective guide section outwardly from an edge of the respective floor level with each mounting body secured at a respective floor level to position one of the respective guide sections above the, or each, other

2017235916 26 Sep 2017 guide section, with the ratchet bar extending upwardly through, and adjustably held in a selected holding position relative to each guide section, or moved longitudinally to another selected holding position.

6. Apparatus for a climbing system screen support, wherein apparatus comprises a climbing system by which a safety screen can be supported in an upwardly extending disposition adjacent to a multi-level building construction, wherein the climbing system comprises a plurality of support units, with each of a plurality screen sections comprising the safety screen supportable in the upwardly extending disposition by at least a respective pair of the support units, such as with a respective support unit engaged with the respective screen section adjacent to each of opposite upright sides of the screen section; wherein each support unit includes:

(a) an elongate ratchet bar to which a screen section is attachable, the ratchet bar having a longitudinal series of ratchet teeth over a length of the ratchet bar sufficient to span at least two successive floor levels of a multi-level building construction;

(b) at least a first and a second mounting body, each having a respective guide section through which the ratchet bar is able to extend so as to be held adjustably at a selected holding position, or to be longitudinally adjustable, relative to the guide section; and (c) a respective latch mechanism in each guide section, with each latch mechanism operable to selectively engage at least a respective one of the ratchet teeth for holding the ratchet bar at a selected holding position relative to the guide section.

8. The apparatus of claim 7, wherein each mounting body is adapted to be detachably secured in relation to the building, at a respective floor level, to position the respective guide section outwardly from an edge of the respective floor level.

9. The apparatus of claim 8, wherein with each mounting body secured at a respective floor level to position one of the respective guide sections above the, or each, other guide section, the ratchet bar is able to extend upwardly through, and to be adjustably held in a selected holding position relative to each guide section or moved longitudinally to another selected holding position.

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10. The apparatus according to any one of claims 1 to 9, wherein the or each ratchet bar is able to be raised to and held at successive selected positions by a force applied to pull ratchet bars upwardly can be applied to a screen section, or at least two laterally successive screen sections, or directly to at least one ratchet bar for each screen section.

11. The apparatus of claim 10, wherein the force can be provided by an overhead pulley or hoist arrangement or by a crane operable at the construction site.

12. The apparatus of any one of claims 1 to 11, wherein the ratchet bar, the mounting body and its guide section, and the latch mechanism of the or each support unit is made of a suitable high strength ferrous such as a suitable grade of high strength steel, or a suitable alternative metal having appropriate physical properties for the load carrying requirements.

13. The apparatus of claim 12, wherein each mounting body and its guide section is fabricated from plate metal of a suitable gauge.

14. The apparatus of any one of claims 1 to 13, wherein each mounting body is of elongate form, with the guide section provided at one of opposite ends of the mounting body, with the mounting body is adapted to be detachably secured on or in relation to a respective floor level.

15. The apparatus of any one of claims 1 to 14, wherein the guide section comprises a pair of side members that are spaced from each other to define a recess through which the ratchet bar extends.

16. The apparatus of claim 15, wherein the recess opens away from the mounting body to facilitate attachment of a screen section to the ratchet bar.

17. The apparatus of claim 15 or claim 16, wherein each side member of the guide section is provided by a respective extension of the mounting body or is integrally attached such as by welding to the mounting body.

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18. The apparatus of claim 15 or claim 16, wherein one or each side member is detachably connected to the mounting body to facilitate separation of at least one side member for positioning of the ratchet bar so as to extend through the guide section, prior to the or each side member being repositioned in relation to the mounting body.

19. The apparatus of any one of claims 1 to 18, wherein the ratchet bar is engaged in guide section by at least one engagement member that acts to hold the ratchet bar against lateral forces acting to rotate an upper longitudinal extent of the ratchet bar outwardly away from the building.

20. The apparatus of claim 19, wherein the engagement member comprises a roller that bears against a longitudinal surface defined by the ratchet bar, such as against a surface of a flange defined by the ratchet bar and having a width dimension that extends across the recess defined between the side members of the guide section.

21. The apparatus of claim 19 or claim 20, wherein at least two engagement members are provided, with each of the at least two engagement members comprising one of at least two rollers spaced along a line substantially parallel to the length of the ratchet bar when extending through the guide section.

22. The apparatus of claim 21, wherein there are two rollers with each roller bearing against a respective one of two oppositely facing flange surfaces, such as with an upper roller bearing against a flange surface facing outwardly with respect to the recess defined between the side members of the guide section and a lower roller facing inwardly with respect to that recess.

23. The apparatus of any one of claims 1 to 22, wherein the ratchet bar has a main body that includes an elongate web that is disposed edgewise in the recess defined between the side members of the guide section so that a respective main surface of the web faces each side member.

24. The apparatus of claim 23, wherein the ratchet bar has a main body of l-shape in transverse cross-sections, formed by the elongate web joining a parallel pair of

2017235916 26 Sep 2017 flanges along a centerline for each flange, with the ratchet bar extending through the guide section with each flange of the parallel pair extending across the recess defined between the side members of the guide section, whereby a first flange of the parallel pair is nearer to the mounting body than the other flange of the pair.

25. The apparatus of claim 24, wherein the longitudinal series of ratchet teeth is disposed along a surface defined by the first flange that faces away from the other flange, such as with the ratchet teeth projecting from the centerline of the first flange.

26. The apparatus of any one of claims 1 to 25, wherein the ratchet teeth are inclined with respect to the longitudinal extent of the ratchet bar such that, with the ratchet bar disposed in its intended upwardly extended position, the ratchet teeth are inclined downwardly.

27. The apparatus of any one of claims 1 to 26, wherein the latch mechanism in each guide section comprises a pivotally mounted pawl or rack latch operable to engage with a selected ratchet tooth for holding the ratchet bar against the influence of gravity, at a selected holding position relative to the guide section, but operable to release the ratchet bar in response to a force applied to raise the ratchet bar to an upper holding position.

28. The apparatus of claim 27, wherein the pawl or rack latch is movable to an engagement position by a bias force, but able to pivot to a release position against the bias force.

29. The apparatus of claim 28, wherein the bias force is the force of gravity or provided by a spring.

30. The apparatus of any one of claims 27 to 29, wherein the pawl or rack latch in the engagement position bears against an abutment member that extends across the recess and is integral with one or each of the side members.