AU2015100413A4 - Adjustable access stairway - Google Patents

Abstract

The present invention provides an apparatus for facilitating the ascent and/or descent of a 5 worker or other user between two levels, the adjustable access stairway comprising a step having an upper face configured to receive a foot of a user, and an elongate step support member, wherein the step is connected to the elongate step support member such that the angle made by the step upper face with the longitudinal axis of the elongate step support member is alterable. The step may be is connected to the elongate support by means of an .0 adjustable step bracket, such that the angle made by the upper surface of the step with the longitudinal axis of the elongate member is alterable. The apparatus may be utilized as an adjustable access stairway capable of being configured within a range of angles of maximum and minimum degrees, the steps remaining horizontal for safety purposes by virtue of being adjustable. The present invention is useful alone, or in combination with auxiliary features .5 which may be fitted such as a protective handrailing system, and/or other apparatus such as an elevated service or maintenance platform system of adjustable height, to which the apparatus may be attached by means of additional components. oc

Description

ADJUSTABLE ACCESS STAIRWAY FIELD OF THE INVENTION 5 The present invention is directed toward adjustable access stairways, and particularly those required to be installed in industrial and commercial premises and facilities, for utilisation by workers and other users in the course of executing routine service and maintenance, inspection and related duties and tasks. 0 BACKGROUND TO THE INVENTION Stairways are commonly used in industrial and commercial environments to provide access for workers and other users, to service and maintenance platforms situated in both elevated and sunken areas. Typically, the access stairway comprises a number of treads fixed to a 15 pair of parallel angled stringers, the treads being arranged in a horizontal plane and ascending or descending pattern. For personnel access safety, it is generally the case that auxiliary protective handrailings are fixed to each of the parallel stringers. In many cases, an access stairway may be utilised as a temporary measure, for example 20 installation of a step bridge over an obstacle on a construction site. A step bridge typically comprises a central structure and an elevated platform, with an access stairway disposed at each end. Thus a worker or other user ascends the access stairway at one end of the step bridge, traverses the platform, and then descends the access stairway at the other end. 25 It is an acknowledged problem in the art that access stairways of varying heights, lengths and gradients may need to be installed to suit the particular setting. For example, access to a lower service or maintenance platform may require a relatively shorter stairway having a lesser number of treads, while a higher platform may require a relatively longer stairway having a greater number of treads. In the light of that variability, it is necessary to have 30 available a customised range of access stairways of variable height, length and gradient. Alternatively, it is necessary to design and construct an adjustable access stairway de novo, in order to accommodate these variables for both practical and economical considerations. Similar and somewhat more complex problems arise where an access stairway is to be 35 designed and installed as a permanent or semi-permanent structure. The access stairway typically requires a lesser or greater number of treads to suit the varying height, length and gradient parameters applicable to any particular setting. 1 Further problems arise where an access stairway may need to be installed to provide worker or user access to a service or maintenance platform specially designed to be raised or lowered. Such problems may arise in modular stairway and platform systems which are typically adapted to suit varying access requirements or circumstances. 5 It is an aspect of the present invention to overcome or alleviate a problem or a disadvantage associated with the prior art, by providing an adjustable access stairway configured to accommodate varying heights, lengths and gradients in a range of settings. It is a further aspect to provide a modular access stairway, that is economical to manufacture and supply, 1o handle and package, transport to site, assemble and install. It is again a further aspect to provide a user-friendly, adjustable and versatile alternative to the prior art, to overcome an inherent limitation of conventional fixed access stairways, or to provide an alternative to conventional fixed access stairways 15 The discussion of documents and acts, materials and devices, articles and the like is included in this Adjustable Access Stairway Specification, solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base, or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this 20 Application. SUMMARY OF THE INVENTION In a first aspect, but not necessarily the broadest aspect, the present invention provides an 25 apparatus for facilitating the conveyance of a user from a first level to a second level, the apparatus comprising: a step having an upper face configured to receive a foot of a user, and an elongate step support member wherein the step is connected to the elongate step support member such that the angle 30 made by the step upper face with the longitudinal axis of the elongate step support member is alterable. In one embodiment, the step is a stairway tread and the elongate step support member is a stairway stringer. 35 In one embodiment, the step is lockable (and optionally unlockable) in position with respect to the elongate step support member. 2 In one embodiment, the angle made by the step upper face with the longitudinal axis of the elongate step support member is alterable between about 25 degrees and about 45 degrees. 5 In one embodiment, the step is connected indirectly to the elongate step support member. In one embodiment, the apparatus comprises an adjustable step support bracket disposed between the step and the elongate support member, the bracket configured to indirectly 1o connect the step to the elongate support member. In one embodiment, the step or the step support bracket comprises a fixing region having one or more apertures, each aperture configured to receive a fastener. 15 In one embodiment, the fixing region is connected to the elongate step support member via a first fastener disposed toward the leading edge of the step, and a second fastener disposed toward the trailing edge of the step respectively. In one embodiment, one of the one or more apertures is an elongate slot. 20 In one embodiment, the apparatus comprising two apertures, wherein the first aperture is an elongate slot, and the second aperture is a hole. In one embodiment, the elongate slot is configured to accept a fastener such that 25 substantially no free play in the fastener traversing the slot is permitted, while the fastener is permitted to slide along the slot when the stair is not locked. In one embodiment, the hole is configured to accept a T-head fastener. 30 In one embodiment, an end of the elongate step support member is fitted with a hinged fixing region, the hinged fixing region configured to engage with a substantially vertical surface. In one embodiment, the hinged fixing region is a hinged plate configured to engage with a substantially vertical surface. 35 In one embodiment, the hinged plate is configured to rest horizontally on the ground. 3 In a second aspect the present invention provides a system for facilitating the conveyance and support of a user, the system comprising the apparatus as described herein, and a platform having an adjustable height, wherein the apparatus and/or platform are interconnected such that, in use, a user is able to ascend or descend the apparatus to or 5 from the platform. In one embodiment, the system comprising hinging means interconnecting an end of the elongate step support member and the platform. 10 In one embodiment, the apparatus and/or platform are configured to form a step bridge or a part thereof. In a third aspect the present invention provides a kit of parts comprising two elongate step support members, steps configured to be disposed between the two elongate step support 15 members, the elongate step support members and/or the steps configured such that the angle of the upper surfaces of the steps with the longitudinal axes of the two elongate support members are alterable. In a fourth aspect, the present invention comprises a kit of parts comprising the apparatus as 20 described herein, and a platform having an adjustable height. BRIEF DESCRIPTION OF THE FIGURES 25 Fig. 1 shows a perspective cut-away arrangement (Fig. 1A) of an adjustable access stairway of the present invention, attached to a typical elevated service or maintenance platform. Fig. 2 and Fig. 3 show perspective views of the various modular system components of an 30 adjustable access stairway system, interconnected with a service or maintenance platform system having an adjustable height, according to a first and second aspect of the present invention. Fig. 3 shows an embodiment having fixing and positioning apertures to receive identical sets 35 of purpose designed special mating fasteners, shown as: an adjustable tread bracket (Fig. 3A), having horizontal and vertical legs at right angles; an adjustable upper connector plate (Fig. 3B), comprising two parts assembled with standard captive fasteners; and an 4 adjustable lower base plate (Fig. 3C), having a horizontal leg to receive standard anchor bolts. Fig. 4 shows cut-away portions of an adjustable access stairway of the present invention, 5 whereby a tread is shown mounted on an adjustable tread bracket, and in turn assembled to a stringer by means of identical sets of purpose designed special mating fasteners, comprising tee-head setscrews and serrated locknuts, as depicted in the typical annotated cross-sectionals (Figs. 4B and 4D). The annotated cut-away lateral views show the stringers disposed at the maximum and minimum angles of 45 degrees (Fig. 4A) or 25 degrees (Fig. 1o 4C) respectively, to a horizontal plane of the ground or bearing surface. Fig. 5 shows cut-away perspective interconnection views of an adjustable access stairway of the present invention, attached to a typical elevated service or maintenance platform. The annotated cut-away assembly details show the respective adjustable upper connector plate 15 (Fig. 5A) and the adjustable lower base plate (Fig. 5D), both demonstrating in particular the use of hinged plates. All the modular components are assembled by means of identical sets of purpose designed special mating fasteners, comprising tee-head setscrews and serrated locknuts to connect and secure the system and structure, as depicted in the respective typical annotated cross-sectionals (Figs. 5B & 5C & 5E). 20 Fig. 6 shows a typical step bridge, comprising a central structure and elevated platform with adjustable access stairways disposed at each end, and fitted with auxiliary protective handrailings, according to an example of the present invention. 25 Fig. 7 shows details of the purpose designed tee-head setscrews and standard serrated locknuts (Fig. 7A). The typical diagrams depicting insertion, twisting and locking in position into the intermediate recess of an elongate platform attachment extrusion (Fig. 7B), serve to illustrate the design features of the special mating fasteners. Particularly the novel step over the prior art, in being ideally adapted for assembling all modular components of the present 30 invention, thereby avoiding utilisation of diverse sizes of standard fasteners. DETAILED DESCRIPTION OF THE INVENTION After consideration of this Detailed Description, it will be apparent to one skilled in the art 35 how the present invention is implemented in various alternative embodiments and alternative applications. However, although these various embodiments and applications of the present invention will be described herein, it is to be understood that they are presented by way of 5 example only, and not limitation. As such, this description of the various alternative embodiments and alternative applications, should not be construed as limiting the scope or breadth of the present invention. Furthermore, statements relating to novelty or innovation, advantages or other aspects apply to specific exemplary embodiments, and not necessarily 5 to all embodiments covered by the Claims. Throughout both this Detailed Description and the Claims of the Specification, the word "comprise" and variations of the word, such as "comprises" and "comprising" are not intended to exclude other additives or components, integers or steps. 0 Reference throughout this Specification to "one embodiment" or "an embodiment" means that a particular component or structure, feature or characteristic described in connection with the embodiment, is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places 15 throughout the Specification, may or may not necessarily all be referring to the same embodiment. The present invention is predicated at least in part on Applicant's discovery, that an access stairway may be adapted to service platforms of various heights, by configuring the tread 20 angle to be alterable relative to the ground or bearing surface. Accordingly, the stairway may be disposed at either a shallow or a steep angle, with the treads adjustable such that their upper surfaces remain substantially horizontal and parallel, and are thus easily traversed by a worker or other user irrespective of the angle at which the stairway stringers are disposed. 25 Accordingly in a first aspect, the present invention provides an apparatus for facilitating the conveyance of a user from a first level to a second level, the apparatus comprising: a step having an upper face configured to receive a foot of a user, and an elongate step support member wherein the step is connected to the elongate step support member such that the angle 30 made by the step upper face with the longitudinal axis of the elongate step support member is alterable. The apparatus may obviate the need to design and construct customised fixed access stairways for servicing a number of different elevated or sunken areas above or below 35 ground level. For example, the apparatus may be part of a temporary or semi-permanent installation that may be configured to service one particular level, and then removed and re 6 configured to service another different level by simply altering the angular disposition of the components. The apparatus is particularly useful in industrial environments, such as the installation of a 5 step bridge over an obstacle on a construction site, typically comprising a central structure and an elevated platform with an access stairway disposed at each end. Thus a worker or other user ascends the access stairway at one end of the step bridge, safely traverses the elevated platform and then descends the access stairway at the other end. 1o A single adjustable access stairway may be incorporated into several step bridges over obstacles of differing heights, given that the stairway may be disposed at varying angles to the ground or bearing surface. According to the prior art, a specific stairway of fixed height and angular inclination is required to be designed and constructed to suit one particular step bridge application. Alternatively in the light of that variability it is necessary to have available 15 for selection, a customised range of access stairways of variable height, length and gradient. The present invention overcomes the problems inherent to the prior art, by providing an adjustable access stairway de novo having angle-alterable treads, such that the stringers may be disposed at a shallow angle (e.g. 25 degrees to service a platform of a lesser 20 height), or a steep angle (e.g. 45 degrees to service a platform of a greater height), while the treads remain substantially level thereby allowing a worker or other user to safely ascend or descend the stairway. The requirement for the treads to be in a horizontal plane parallel to the ground or bearing surface, is mandatory for eliminating or substantially reducing the safety hazard to such personnel of slipping or tripping, losing balance or falling. 25 Prior art access stairways of fixed height and angular inclination, cannot simply or conveniently be disposed at varying angles of greater or lesser degree to the ground or bearing surface, in order to reach or service platforms of varying heights, given that in the case of most installations the treads will deviate from a horizontal or level plane, as a 30 consequence of the configuration of the particular fixed stairway relative to the platform. Catwalks are another example of service or maintenance structures that can be installed in industrial and commercial environments for temporary or permanent applications, to provide or facilitate access to elevated or sunken areas above or below ground level. Again, the 35 adaptability and versatility of the present invention makes an adjustable access stairway ideally suited to reach or service typical catwalks at different heights and depths. 7 While the apparatus may generally be more amenable and suited to temporary or semi permanent applications, distinct advantage is also gained for use in permanent installations. The design and construction of an access stairway for any particular environment or predetermined purpose is not a straightforward or trivial task, but requires precise calculation 5 and/or accurate measurement by one skilled in the art to determine the rise and run of the complete stairway assembly, and to ensure uniform spacing and correct angling of the treads relative to the stringers. The present invention obviates such critical consideration of the angular disposition of the treads, whereby a builder's spirit level may be utilised to adjust and align each tread during assembly of the components and construction of the apparatus. 0 The term "step", "step extrusion" or "tread" as used herein refers to any member having a level upper surface, upon which the foot of a worker or other user may be securely placed, in the course of ascending or descending the apparatus. Generally, the adjustable access stairway comprises one or more treads. While the upper surface of the tread is typically 15 substantially planar, other types having non-planar upper surfaces are also contemplated as being useful. The term "leading edge" as used herein refers to the long edge of a stairway tread that is toward the toe of a user's foot, while the term "trailing edge" refers to the opposite long edge 20 that is toward the heel of a user's foot. It will be understood that where an access stairway is used for both ascending and descending (which is typical in service and maintenance installations), the leading edge and trailing edge terminology is by definition interchangeable. The term "elongate support member", "elongate step support extrusion" or "stringer" as used 25 herein refers to any member supporting a step, step extrusion or tread against the downward force of a worker or user standing thereon. The elongate support member, elongate step support extrusion or stringer may have an inner planar surface configured substantially normal to a step, step extrusion or tread. 30 In one embodiment, the apparatus comprises two stringers, with the opposite ends of each tread being fixed thereto by means of a pair of adjustable tread brackets. Identical sets of purpose designed special mating fasteners (preferably lockable and unlockable), comprising tee-head setscrews and serrated locknuts, locate into the elongate recesses of the tread lower fixing region, and extend through mating round holes in the tread bracket. 35 8 Given the benefit of the present invention, it will be apparent to one skilled in the art that several different means may be conceived as capable of facilitating alteration of the angle of the step extrusion relative to the elongate step support extrusion. For example, a hinge and pivot type arrangement capable of allowing movement of the tread relative to the stringer is 5 contemplated. A hinge type arrangement may be a tread bracket disposed directly under each end of the tread, and laterally up against the inner planar surface of each stringer. A pivot type arrangement may be a pair of standard fasteners, locating into the elongate recesses in the stringer, and extending respectively through the mating round hole and slotted hole in the tread bracket. It will be appreciated that these means of angular alteration 1o or adjustment do not adversely affect the ability of the stringer to support the tread. Other more complex means of angular alteration or adjustment, include an integral arcuate channel in the stringer profiled to receive mating edge projections of the tread. In such embodiments, the tread may have two integral projections toward both leading and trailing 15 edges respectively, extending laterally and locating into the arcuate channel in each parallel stringer. By virtue of this arrangement, the tread is capable of pivoting about the rotational axis lying between the leading and trailing edge projections. Preferably, the step extrusion is lockable in position at the desired angle with respect to the 20 elongate step support extrusion. Thus firstly, the step extrusion may be correctly attached and locked to the adjustable tread brackets by means of the special mating fasteners. The assembly may then be correctly positioned and angularly aligned to the elongate step support extrusions, levelled horizontally to the ground or bearing surface, tightened and then locked in the desired position by means of identical special mating fasteners to prevent 25 movement during use. Given the benefit of the present invention, the tread may be aligned, tightened and locked in position by any other method with which the skilled artisan is familiar. As one example, an alternative means whereby a set of locking pins, or standard hexagonal head bolts, nuts and 30 washers may be inserted laterally through the corresponding apertures in the adjustable access stairway modular components, and secured. Particularly where the adjustable access stairway is intended to be re-used at a second installation, it is preferred that the locking means between the step extrusion, adjustable 35 tread bracket and elongate step support extrusion, be readily and easily unlocked to allow for the further angular alteration and disposition of the tread relative to the stringer. The purpose designed special mating fasteners, comprising tee-head setscrews and serrated 9 locknuts, are ideally suited to the different rise over run parameters, or other requirements pertaining to a second or subsequent installation. As will be appreciated, the gradients (defined as rise over run) over which the apparatus is 5 operable is variable, and therefore the range within which the tread angle is alterable will vary accordingly. In accordance with stairway standards, the angle made by the latitudinal axis of the step extrusion relative to the longitudinal axis of the elongate step support extrusion, is alterable between a minimum of 25 degrees and a maximum of 45 degrees. 1o The upper non-slip surface across the width of the tread is typically substantially planar, in which case the angle thus made between the tread and the longitudinal axis of the stringer is clearly described. In circumstances where the upper face of the step extrusion is not substantially planar, a plane will nevertheless be ascertainable in order to describe the angle made with the longitudinal axis of the elongate step support extrusion. For example, the 15 plane may be described by reference to the plane of the sole of a user's foot, when placed in the most stable, convenient or safe manner possible. However, where the plane of the sole of a user's foot is curved when placed on the tread, the plane may be described by reference to a plane that connects the front edge of the sole to the heel of the user. 20 As discussed above, various means are proposed to allow for alteration of the step extrusion angle relative to the elongate step support extrusion. In a preferred embodiment the adjustable tread bracket is connected to the stringer by means of a first fastener disposed toward the leading edge of the tread, and a second fastener disposed toward the trailing edge of the tread respectively. These special mating fasteners may be tightened to lock the 25 tread securely in place, and loosened to release the tread readily and easily. In one particularly preferred embodiment, wherein both special mating fasteners are unlocked at the stringer interface, the first fastener acts as a pivot in its elongate recess thereby permitting the adjustable tread bracket to rotate about it, while the second fastener 30 slides freely in its elongate recess. By these means, loosening when altering the tread angle may be facilitated, at the same time constraining movement in a direction orthogonal to the axis of the elongate recess. Advantageously, the profiled cross-section of the step extrusion provides a lower fixing 35 region having two elongate recesses configured to receive special mating fasteners at each end. Correspondingly, the adjustable tread bracket may be substantially L-shaped, having a 10 first horizontal planar region with two round holes configured to receive these fasteners, thereby facilitating attachment and locking in position. Advantageously, the profiled cross-section of the elongate step support extrusion provides 5 inner and outer fixing regions in the symmetrical planar surfaces, each having two elongate recesses configured to receive special mating fasteners in any position. Correspondingly, the adjustable tread bracket may be substantially L-shaped, having a second vertical planar region with two apertures configured to receive these fasteners, thereby facilitating attachment, alignment and locking in position to the inner surface. Typically, one of the two 1o apertures comprises a round hole configured to receive a first fastener disposed toward the leading edge of the tread, while the other aperture comprises a slotted hole configured to receive a second fastener disposed toward the trailing edge of the tread respectively. Although substantially no free play in either fastener traversing the elongate recesses in the 15 stringer is allowed in the locked position, the second fastener may slide along its captive recess when altering the tread angle. By this means the leading edge of the step extrusion may be raised or lowered relative to the trailing edge, the fasteners however being held captive by virtue of the design of the two elongate recesses in the inner surface of the elongate step support extrusion. In a preferred embodiment, the clearance tolerances are 20 set to limit free play but allow the fasteners to slide easily along the elongate recesses. It is of significant advantage over the prior art that the present invention is able to be disposed at either shallow or steep angles, with the treads being capable of remaining substantially level, namely in a horizontal plane parallel to the ground or bearing surface. 25 While advantageous, a problem presents in so far as the upper end of the adjustable access stairway is required to connect to a service or maintenance platform at varying angles. For example, where the platform is at a higher elevation, the apparatus is inclined at a steep angle to the ground or bearing surface, and the angle of connection between the access 30 stairway and platform is smaller. Conversely, where the platform is at a lower elevation, the apparatus is inclined at a shallow angle to the ground or bearing surface, and the angle of connection between the access stairway and platform is greater. Typically, the connecting surface of the platform is a planar and vertical side edge. In a 35 preferred embodiment of the platform system, the profiled cross section of an elongate platform attachment extrusion provides inner and outer fixing regions in the symmetrical 11 planar surfaces, each having three elongate recesses configured to receive the purpose designed special mating fasteners, comprising tee-head setscrews and serrated locknuts. To overcome the problems associated with the prior art and the necessity for varying angles 5 of connection between an access stairway and a platform disposed at different elevations, the upper end of an elongate step support extrusion may be fitted with an adjustable upper connector plate, configured as a hinging means to engage with the elongate platform attachment extrusion, which in turn is securely fixed to a substantially planar and vertical side edge of the platform structure by means of special mating fasteners. 0 A similar problem presents in so far as the lower end of the adjustable access stairway is required to rest on the ground or bearing surface at various angles, depending on whether the service or maintenance platform is at a higher or lower elevation. To further overcome this problem, the lower end of an elongate step support extrusion may be fitted with an 15 adjustable lower base plate by means of special mating fasteners, and configured as a hinging means to rest in a horizontal plane at ground or other pre-determined level, and be securely fixed to a bearing surface or structure by means of standard anchor bolts. Given the benefit of the present invention, it will be apparent to one skilled in the art that 20 other contrivances may be conceived as capable of facilitating both the upper and the lower hinging means, that ensure correct engagement, alignment and secure connection of the stairway to the platform, and allow the stairway to rest firmly and squarely on the ground. The present invention may additionally include any of the auxiliary features normally 25 associated with similar contrivances of the prior art, including a protective handrailing system. In this particular embodiment, the apparatus may provide for a series of stanchions to extend vertically from and be securely affixed to each parallel stringer, thereby providing a rigid means of support for attaching the handrail and kneerail extrusions and fittings, to facilitate a worker or other user ascending or descending the adjustable access stairway. 30 When the angle of an adjustable access stairway is altered to accommodate different elevations or heights of a service or maintenance platform, the angle between the stanchions and handrailings and the longitudinal axis of the two parallel stringers correspondingly changes. The design of the present invention embodies means for 35 accommodating such angular alterations, whereby a stanchion may be unlocked, re-aligned and locked again in the required position, and the handrailings adjusted accordingly. 12 Adjustment of a stanchion to accommodate varying angles, is facilitated by virtue of the two elongate recesses in the outer planar surface of an elongate step support extrusion, configured to receive the special mating fasteners. The lower end of a stanchion is provided with one round hole and one slotted hole, and configured to receive these fasteners. The 5 mating profile of a handrail extrusion slides against the upper end of a stanchion, while the mating profile of a kneerail extrusion slides against the centre portion respectively. Die-cast adjustable elbows are also provided, the various handrailing system components being assembled using standard plated TEKscrews. These features facilitate adapting the auxiliary protective handrailing system to accommodate the required angular alterations. 0 Although constituting a novel step over the prior art, the protective handrailing system described herein, and which may be included as an auxiliary feature to the present invention, does not form part of the adjustable access stairway Specification, but is fully described a in Certified Australian Innovation Patent 2008100068, the contents of which is herein 15 incorporated by reference The features of the austenitic stainless steel special mating fasteners constitute a significant advantage and further novel step over the prior art, by virtue of their adaptation throughout for assembling all modular components of the present invention. The M10 x 25 mm long 20 purpose designed tee-head setscrew facilitates easy insertion, twisting and locking in position into the elongate recesses of all three extrusions. After assembly of all four adjustable pressings, the standard M10 flanged serrated hexagon head locknuts are then readily tightened onto the threaded shanks of the setscrews, and after alignment tightened up and locked in position by frictional engagement of the mating component surfaces. 25 The present invention is amenable to incorporation into a system typically having a combination of an adjustable access stairway and a service or maintenance platform having an adjustable height. Such an arrangement will find enhanced use in a multitude of industrial and commercial environments. Accordingly in a further aspect, the apparatus provides a 30 system of novel concept and design, for facilitating the safe ascent and/or descent of a worker or other user to and from a first level to a second level, by means of an adjustable access stairway described herein and interconnected to a service or maintenance platform having an adjustable height. 35 By way of an example of the system, the apparatus is configured with an integral platform to form a step bridge or part thereof. Typically, a step bridge comprises a central structure and an elevated adjustable service or maintenance platform, with an adjustable access stairway 13 at either end. The central structure may comprise four vertical support columns and a superstructure attached by means of standard structural fasteners, to facilitate raising and lowering of the horizontal platform surface. 5 In some embodiments of a typical step bridge, where a protective handrailing system is affixed, the superstructure may be attached to the support columns by some hinging means or other contrivance, to facilitate alteration of the platform surface to the desired level. Each component of the protective handrailing system may then be adjusted to accommodate the desired angular dispositions of the two adjustable access stairways. 0 In a further aspect of the present invention, a kit of components may be provided comprising one or more step extrusions (treads), two elongate step support extrusions (stringers), two or more adjustable tread brackets, and a set of special mating fasteners, whereby the treads are disposed between the stringers, and configured such that the angle made by the 15 latitudinal axis of the treads to the longitudinal axis of the stringers is alterable. The kit may further comprise instructions for assembling the various modular components to construct an adjustable access stairway, as described herein. In yet a further aspect of the present invention, a kit of components may be provided 20 comprising the apparatus as described herein, in conjunction with one elongate platform attachment extrusion, two adjustable upper connector plates, two adjustable lower base plates and a set of special mating fasteners and standard anchor bolts, whereby the components are interconnected to a platform system having an adjustable height. The kit may further comprise instructions for assembling the various components to construct an 25 adjustable access stairway onto a service or maintenance platform, as described herein. PREFERRED EMBODIMENTS OF THE INVENTION The present invention will now be further described by way of the following non-limiting 30 preferred embodiments, cross-referenced to the annotated drawings Fig.1 to Fig. 7. Reference is made to Fig. 1, showing a perspective cut-away arrangement in Fig. 1 A of an adjustable access stairway 1, interconnected at an angular disposition to a typical elevated service or maintenance platform 2 of varying height, whereby the ascent or descent of, and 35 traversing by a worker or other user is facilitated. 14 The annotated side elevations show the modular system components assembled by means of identical sets of purpose designed special mating fasteners, comprising tee-head setscrews and serrated locknuts, and configured such that the elongate step support extrusion (stringer) is disposed at the typical angles of 35 degrees (Fig. 1 B) or 45 degrees 5 (Fig. 1 C) to a horizontal plane of the ground or bearing surface. In the first preferred embodiment of an adjustable access stairway 1, each step extrusion or tread 10 is provided with and fixed to two adjustable tread brackets 40, which are then assembled to two elongate step support extrusions or stringers 20, aligned and adjusted to 1o the desired angle, each set of special mating fasteners 16 and 24 being then tightened and locked in position. In the second preferred embodiment of an elevated service or maintenance platform 2, an elongate platform attachment extrusion 30 is securely fixed to the typically planar and 15 vertical edge surface of the platform structure by means of special mating fasteners 37. One end of each stringer 20 is fitted with an adjustable upper connector plate 50, configured as a hinging means to engage with the elongate platform attachment extrusion 30. The opposite end of each stringer 20 is fitted with an adjustable lower base plate 60, configured 20 as a hinging means to rest on a horizontal plane at ground or other predetermined level, and be securely fixed to a bearing surface or structure by means of standard anchor bolts 64. The two side elevations show the seven components of an adjustable access stairway in conjunction with a platform system, assembled and configured such that the stringers 20 are 25 disposed at the typical angles of 35 degrees in Fig. 1B or 45 degrees in Fig. 1C to the horizontal, each set of special mating fasteners 16 and 24 and 37, as well as captive fasteners 55, being then tightened and locked in position. It will be noted that the treads 10 remain substantially level and horizontal throughout the 30 whole angular range, thereby allowing a worker or other user to ascend or descend safely. Reference is made to Fig. 2, showing perspective views in their preferred embodiments, of the three modular extruded components of an adjustable access stairway 1, interconnected with a service or maintenance platform 2 having an adjustable height. 35 The three high grade mill finish aluminium alloy extrusions, constituting high strength light weight low maintenance aesthetic modular components, each having unique cross-sectional 15 profiles with wider inner and narrower outer slots, to accommodate the respective profile tee head and threaded shank of a purpose designed setscrew, are annotated as follows: A step extrusion (tread) 10 in Fig. 2A, having an upper non-slip level surface 11, fold 5 over leading and trailing edges 12 and 13, a lower fixing region 14 with two elongate recesses 15 configured to receive sets of special mating fasteners 16 at each end. An elongate step support extrusion (stringer) 20 in Fig. 2B, having inner and outer symmetrical planar surfaces 21 and 22, each with two elongate recesses 23 configured to 1o receive sets of special mating fasteners 24, as required along the entire surface lengths. An elongate platform attachment extrusion 30 in Fig. 2C, having upper and lower flanges 31 and 32, inner and outer symmetrical planar surfaces 33 and 34, each with three elongate recesses 35 (upper and lower) and 36 (intermediate) providing attachment, and configured 15 to receive sets of special mating fasteners 37, as required along the entire surface lengths. Reference is made to Fig. 3, showing perspective views in their preferred embodiments, of the four modular pressed or die-cast components of an adjustable access stairway 1, interconnected with a service or maintenance platform 2 having an adjustable height. 20 The four high tensile polished austenitic stainless steel pressings (alternatively high pressure aluminium/magnesium die castings), constituting heavy duty modular components, and each configured as novel hinging, connecting and adjusting means, are annotated as follows: 25 An adjustable tread bracket 40 in Fig. 3A, comprising a horizontal leg 41 having two round holes 43, to receive sets of special mating fasteners 16, for fixing to the two elongate recesses 15 in the lower fixing region 14 of a tread 10; and a vertical leg 42 disposed at right angles to the horizontal leg 41, having one round hole 44 and one slotted hole 45, to receive sets of special mating fasteners 24, for fixing and positioning respectively to the two elongate 30 recesses 23 in the inner planar surface 21 of a stringer 20. An adjustable upper connector plate 50 in Fig. 3B, comprising two parts 51 and 52 pre assembled together with captive fasteners 55, and having one round hole 53 for fixing and one slotted hole 54 for positioning; the major part 51 having two round holes 56 to receive 35 sets of special mating fasteners 24, for fixing to the two elongate recesses 23 in the upper end of the outer planar surface 22 of a stringer 20; and the minor part 52 having two slotted apertures 57, to receive sets of special mating fasteners 37 for fixing to the upper and lower 16 elongate recesses 35 in the outer symmetrical planar surface 34 of an elongate platform attachment extrusion 30. An adjustable lower base plate 60 in Fig. 3C, comprising a horizontal leg 61 having two 5 round holes 63, to receive standard anchor bolts 64 for holding-down to a bearing surface or structure; and a vertical leg 62 disposed at right angles to horizontal leg 61, having one round hole 65 and two slotted holes 66, to receive sets of special mating fasteners 24 for fixing and positioning respectively to the two elongate recesses 23 in the lower end of the outer planar surface 22 of a stringer 20. 0 Reference is made to Fig. 4, showing cut-away portions and cross-sectional views of an adjustable access stairway 1, in a first aspect of the present invention, whereby a tread 10 is shown mounted on an adjustable tread bracket 40, which is in turn assembled to the inner symmetrical planar surface 21 of a stringer 20. 15 Lateral view Fig. 4A shows a stringer 20 disposed at a steep maximum horizontal angle of 45 degrees to the ground or other predetermined level, to access a service or maintenance platform 2 of greater height. Lateral view Fig. 4C shows a stringer 20 disposed at a correspondingly shallow minimum horizontal angle of 25 degrees, to access a service or 20 maintenance platform 2 of lesser height. Cross-sectional views Fig. 4B and Fig. 4D show the disposition of the three modular components when assembled, and the various sets of special mating fasteners provided for fixing and positioning, tightening and locking in position. The two elongate recesses 15 of a 25 tread 10, and the two elongate recesses 23 of a stringer 20, have unique cross-sectional profiles with wider inner and narrower outer slots, to accommodate the respective profile tee head and threaded shank of a purpose designed setscrew. The clearances are such as to provide a tight sliding fit to the setscrews, being sized to limit free play but allow them to slide easily along the elongate recesses. 30 The heads of setscrews 16 slide into the two elongate recesses 15 in the lower fixing region 14 of a tread 10, and the threaded shanks of the setscrews locate and protrude through the two round holes 43 in the horizontal leg 41 of an adjustable tread bracket 40. The mating serrated locknuts are then tightened onto the threaded shanks and, after adjusting and 35 aligning the tread and adjustable tread bracket, are locked in position. 17 The heads of setscrews 24 slide into the two elongate recesses 23 on the inner planar surface 21 of a stringer 10, and the threaded shanks of the setscrews locate and protrude through one round hole 44 and one slotted hole 45 in the vertical leg 42 of an adjustable tread bracket 40. The angular disposition of the tread 10 and adjustable tread bracket 40 5 assembly is then altered accordingly, by pivoting the trailing edge 13 relative to the leading edge 12, the head of setscrew 24 sliding along the elongate recess 23 and the shank being guided in an arc through the slotted hole 45. The mating serrated locknuts are then tightened onto the threaded shanks, and after adjusting and aligning the tread and adjustable tread bracket assembly at the desired angle, are locked in position on a stringer 20. 0 The methods described above for mounting and assembly, fixing and positioning, adjusting and aligning, tightening and locking in position of a single set of the above three modular components, apply equally to any configuration of an adjustable access stairway 1 of the present invention, comprised of multiple treads 10, left and right adjustable tread brackets 15 40, and left and right stringers 20. The special mating fasteners 16 and 24 used throughout for assembly are identical, thereby constituting a significant advantage over the prior art. Reference is made to Fig. 5, showing cut-away portions and cross-sectional views of an adjustable access stairway 1 in conjunction with a service or maintenance platform 2, in a 20 second aspect of the present invention, whereby the assembly depicted in Fig. 4 and described above, is shown interconnected at varying angles to the outer symmetrical planar surface 34 of an elongate platform attachment extrusion 30. Perspective view Fig. 5A shows an adjustable upper connector plate 50, disposed between 25 the upper end of an access stairway stringer 20 and an elongate platform attachment extrusion 30, which in turn is securely fixed to a platform structure (not shown), by means of special mating fasteners provided in the three elongate recesses 35 (upper and lower) and 36 (intermediate), in the inner planar surface 33. 30 Cross-sectional views Fig. 5B and Fig. 5C show the disposition of the two parts 51 and 52 of an adjustable upper connector plate 50 when assembled, and the various sets of special mating fasteners provided for fixing and positioning, tightening and locking in position. The extruded profiles of the two elongate recesses 23 of a stringer 20, and the three elongate recesses 35 and 36 of an elongate platform attachment extrusion 30, have unique cross 35 sectional profiles with wider inner and narrower outer slots, to accommodate the respective profile tee-head and threaded shank of a purpose designed setscrew. The clearances are 18 such as to provide a tight sliding fit to the setscrews, being sized to limit free play but allow them to slide easily along the elongate recesses. The heads of setscrews 24 slide into the two elongate recesses 23 in the outer planar 5 surface 22 of a stringer 20, and the threaded shanks of the setscrews locate and protrude through the two round holes 56 in the major part 51 of an adjustable upper connector plate 50. The heads of setscrews 37 slide into the upper and lower elongate recesses 35 in the outer planar surface 34 of an elongate platform attachment extrusion 30, and the threaded shanks of the setscrews locate and protrude through the two slotted apertures 57 of the 1o minor part 52 of an adjustable upper connector plate 50. The angular disposition of the adjustable upper connector plate 50 is then altered relative to the elongate platform attachment extrusion 30, pivoting the minor part 52 about the major part 51, by means of the captive setscrews 55 locating in the round hole 53 and sliding 15 through the slotted hole 54. All mating serrated locknuts are then tightened onto the threaded shanks of setscrews 24 and 37, and after adjusting and aligning the adjustable upper connector plate, are locked in position together with captive setscrews 55. Perspective view Fig. 5D shows an adjustable lower base plate 60, disposed between the 20 lower end of an access stairway stringer 20 and a bearing surface or structure (not shown). Cross-sectional view Fig. 5E shows the disposition of an adjustable lower base plate 60 when assembled, and the set of special mating fasteners provided for fixing and positioning, tightening and locking in position. 25 The two elongate recesses 23 in the outer planar surface 22 of a stringer 20, have unique cross-sectional profiles with wider inner and narrower outer slots, to accommodate the respective profile tee-head and threaded shank of a purpose designed setscrew. The clearances are such as to provide a tight sliding fit to the setscrews, being sized to limit free play but allow them to slide easily along the elongate recesses. 30 The heads of setscrews 24 slide into the two elongate recesses 23 of a stringer 20, and the threaded shanks of the setscrews locate and protrude through the round hole 65 and one of the slotted holes 66 in the vertical leg 62 of an adjustable lower base plate 60. The threaded shanks of standard anchor bolts 64 (not shown), for holding-down to a bearing surface or 35 structure, locate and protrude through the two round holes 63 in the horizontal leg 61. 19 The angular disposition of an adjustable lower base plate 60 is then altered relative to the lower end of a stringer 20, pivoting the vertical leg 62 by means of setscrews 24 locating in the round hole 65 and sliding through one of the slotted holes 66. All mating serrated locknuts are then tightened onto the threaded shanks of setscrews 24 and anchor bolts 64, 5 and after adjusting and aligning the adjustable lower base plate, are locked in position. The methods described above for mounting and assembly, fixing and positioning, adjusting and aligning, tightening and locking in position of a single set of the above four modular components, apply equally to any configuration of an adjustable access stairway 1 of the 1o present invention, in conjunction with a service or maintenance platform 2, comprised of an elongate platform attachment extrusion 30, left and right adjustable upper connector plates 50, left and right adjustable lower base plates 60, and left and right stringers 20. The special mating fasteners 24 are identical to those used throughout the present invention for assembly of all components, thereby constituting a significant advantage over the prior art. 15 Reference is made to Fig. 6, showing a perspective general arrangement comprising a central structure 80 with an elevated service or maintenance platform 2, and two adjustable access stairways 1 disposed at each end and fitted with auxiliary protective handrailings 90, according to an example of the present invention. All the modular components as well as the 20 stanchions, are assembled by means of identical sets of purpose designed special mating fasteners, comprising tee-head setscrews and serrated locknuts to connect and secure the system and structure. A stanchion 91 is depicted as extending vertically from and securely affixed to the outer 25 symmetrical planar surface 22 of a parallel stringer 20, whereby a rigid means of support is provided for attaching a handrail extrusion 92 and a kneerail extrusion 93, to facilitate a worker or other user safely ascending a first adjustable access stairway 1, and descending a second adjustable access stairway 1. 30 The lower end of a stanchion 91 is provided with a round hole 94 and a slotted hole 95, configured to receive the special mating fasteners. The heads of setscrews 24 slide into the two elongate recesses 23 in the outer planar surface 22 of a stringer 20, and the threaded shanks of the setscrews locate and protrude through the two apertures. 35 Each stanchion 91 is altered relative to the angular disposition of a stringer 20, by means of setscrews 24 locating in the round hole 94 and pivoting in the slotted hole 95. The mating serrated locknuts are then tightened onto the threaded shanks of setscrews 24, and after 20 adjusting and aligning the stanchions, are locked to maintain their vertical position irrespective of the angular disposition of the two adjustable access stairways 1. The upper end of a stanchion 91 locates and slides within the mating profile of a handrail 5 extrusion 92, while the centre portion locates with the mating profile of a kneerail extrusion 93. Adjustable elbows 97 and 98 are provided where angular transitions are required at respective junctures of the handrails and kneerails. It should be noted that these components of a protective handrailing system 90, are all assembled using standard plated TEKscrews 96. 0 By these means, each component of the protective handrailing systems may be adjusted to accommodate the desired angular dispositions of the two adjustable access stairways of a typical step bridge. The protective handrailing system described herein, and which may be included as an auxiliary feature to the present invention, does not form part of thepresent 15 invention, but is fully described a in Certified Australian Innovation Patent 2008100068, the contents of which is herein incorporated by reference. Reference is made to Fig. 7, showing details of a purpose designed tee-head setscrew and standard flanged serrated hexagon locknut, adapted for utilisation throughout the present 20 invention for assembly of all the modular components. Perspective, plan and bottom views, and side elevations are depicted in Fig. 7A, the annotations being referenced to the special mating fastener sets common for all three respective extrusions namely, 16 to a tread, 24 to a stringer, and 37 to a platform attachment, in conjunction with the four metal pressings. 25 The typical diagrams in Fig. 7B depicting the typical insertion, twisting and locking in position into an elongate recess of an elongate platform attachment extrusion 30, serve to illustrate the design features of the tee-head setscrew. By virtue of being preferably lockable and unlockable, unlocking for angular alteration or disassembly is also facilitated. 30 Utilisation of identical special mating fasteners for assembly of all the modular components of the present invention, represents both a novel step and a significant advantage over the prior art. Given the benefit of the present invention, it will be apparent to one skilled in the art that standard hexagonal head bolts, hexagonal nuts and lock washers may be substituted for the special mating fasteners, as a temporary or contingency measure if necessitated. 35 It should be appreciated that in the foregoing Detailed Description of exemplary embodiments of the present invention, various features of the invention are sometimes 21 grouped together in a single embodiment or configuration, form or description thereof, for purposes of streamlining the disclosure and aiding in the understanding of one or more of the various inventive steps and novel aspects. This method of disclosure however, is not to be interpreted as reflecting any intention, either explicit or implicit, that the present invention 5 requires more features than are expressly recited in each claim. Rather as the following claims reflect, these inventive steps and novel aspects lie in less than all the features of a single foregoing disclosed embodiment. Thus the Claims following the Detailed Description of the Invention are hereby expressly incorporated into this Detailed 10 Description, with each claim standing on its own as a separate and distinct embodiment of the present invention. Moreover while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are 15 meant to be within the scope of the present invention, and form different embodiments as would be understood by those skilled in the art. By way of example, in the following Claims any of the claimed embodiments and features can be used in any combination. Furthermore in the foregoing Detailed Description of the Invention, numerous specific details 20 are set forth. However, it is understood that embodiments or features of the present invention may be practised without these specific details. In other instances, ancillary systems and structures etc. have not been shown in detail, nor have commonly known methods and techniques been described, in order not to obscure an understanding of the present invention. 25 Thus while there have been described what are believed to be the preferred embodiments of the present invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit thereof, and it is intended to claim all such changes and modifications as falling within the scope of the 30 present invention. For example, components and functionality may be added to or deleted from diagrams, operations may be interchanged among functional blocks, and steps may be added to or deleted from methods described within the scope of the present invention. 35 22

Claims (20)

1. Apparatus for facilitating the conveyance of a user from a first level to a second level, the apparatus comprising: 5 a step having an upper face configured to receive a foot of a user, and an elongate step support member wherein the step is connected to the elongate step support member such that the angle made by the step upper face with the longitudinal axis of the elongate step support member is alterable. -0

2. The apparatus of claim 1 wherein the step is a stairway tread and the elongate step support member is a stairway stringer.

3. The apparatus of claim 1 or claim 2 wherein the step is lockable (and optionally .5 unlockable) in position with respect to the elongate step support member.

4. The apparatus of any one of claims 1 to 3 wherein the angle made by the step upper face with the longitudinal axis of the elongate step support member is alterable between about 25 degrees and about 45 degrees. -O

5. The apparatus of any one of claims 1 to 4 wherein the step is connected indirectly to the elongate step support member.

6. The apparatus of claim 5 comprising an adjustable step support bracket disposed 25 between the step and the elongate support member, the bracket configured to indirectly connect the step to the elongate support member.

7. The apparatus of any one of claims 1 to 6 wherein the step or the step support bracket comprises a fixing region having one or more apertures, each aperture configured to 30 receive a fastener.

8. The apparatus of claim 7 wherein the fixing region is connected to the elongate step support member via a first fastener disposed toward the leading edge of the step, and a second fastener disposed toward the trailing edge of the step respectively. 35 23

9. The apparatus of claim 7 or 8 wherein one of the one or more apertures is an elongate slot.

10. The apparatus of any one of claims 7 to 9 comprising two apertures, wherein the first 5 aperture is an elongate slot, and the second aperture is a hole.

11. The apparatus of claim 9 or claim 10 wherein the elongate slot is configured to accept a fastener such that substantially no free play in the fastener traversing the slot is permitted, while the fastener is permitted to slide along the slot when the stair is not locked. -0

12. The apparatus of any one of claims 7 to 11 wherein the hole is configured to accept a T-head fastener.

13. The apparatus of any one of claims 1 to 12 wherein an end of the elongate step .5 support member is fitted with a hinged fixing region, the hinged fixing region configured to engage with a substantially vertical surface.

14. The apparatus of claim 13 wherein the hinged fixing region is a hinged plate configured to engage with a substantially vertical surface. -0

15. The apparatus of claim 14 wherein the hinged plate is configured to rest horizontally on the ground.

16. A system for facilitating the conveyance and support of a user, the system 25 comprising the apparatus of any one of claims 1 to 15, and a platform having an adjustable height, wherein the apparatus and/or platform are interconnected such that, in use, a user is able to ascend or descend the apparatus to or from the platform.

17. The system of claim 16 comprising hinging means interconnecting an end of the 30 elongate step support member and the platform.

18. The system of claim 16 or claim 17 wherein the apparatus and/or platform are configured to form a step bridge or a part thereof. 35

19. A kit of parts comprising two elongate step support members, steps configured to be disposed between the two elongate step support members, the elongate step support 24 members and/or the steps configured such that the angle of the upper surfaces of the steps with the longitudinal axes of the two elongate support members are alterable.

20. A kit of parts comprising the apparatus of any one of claims 1 to 15, and a platform 5 having an adjustable height. DATED: 31 March 2015 BY: CHURCHILL ATTORNEYS .0 Patent Attorneys for: SAYFA R&D PTY LTD -5 25