Folding staircase

Abstract

A foldable staircase is (10) provided that is foldable between folded and operational conditions. The foldable staircase (10) has first and second spaced apart side structures (28, 30), and a plurality of steps (24) extending between the first and second side structures (28, 30) and hingedly connected to the first and second side structures (28, 30). The steps in the plurality of steps (24) are displaced vertically from each other in the operational condition of the foldable staircase (10). A landing (22) is provided at the top of the plurality of steps (24) which has a greater surface area than the steps of the plurality of steps (24) and the landing (22) is hingedly connected to the first and second side structures 28, 30. The second side structure (30) is moveable upwardly relative to the first side structure (28) to transition the foldable staircase (10) from the operational condition to the folded condition. The plurality of steps (24) and the landing (22) folding to a collapsed condition as the second side structure (30) is moved upwardly relative to the first side structure (28).

Description

FOLDING STAIRCASE Technical Field

[0001] The present invention relates to folding staircase that can be free-standing, or attached to a structure, such as a wall or partition, and that can be folded between operational and collapsed or folded conditions. The present invention has particular relevance for commercial or industrial applications, and so it will be convenient to describe the invention in relation to those applications. However, it should be understood that the invention can have wider application, such as to domestic uses. Background of Invention

[0002] The discussion of the background to the invention that follows is intended to facilitate an understanding of the invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any aspect of the discussion was part of the common general knowledge as at the priority date of the application.

[0003] Staircases are common throughout all sorts of domestic and commercial buildings. Folding staircases are much less common but do exist. Folding staircases tend to be installed where space is limited or where the staircase is rarely used. Australian patent application 2021209351 discloses a folding staircase which can attach to a wall and which can be folded into an operational condition for accessing an attic or loft in a house for example. The staircase can be folded into a collapsed position against a wall so that the staircase does not take up space in room or hall in which it is located.

[0004] The folding staircase of Australian patent application 2021209351 has steps connected to side rails with hinges, so that one side rail can be connected to a wall and the opposite side rail can be lifted to rotate the steps into a vertical position against the wall. The folding staircase also includes a folding handrail that also folds as the staircase is folded so as to reduce the overall space required for the staircase in the collapsed or folded condition.

[0005] The folding staircase of Australian patent application 2021209351 is intended for permanent installation, so that once the side rail is connected to a wall, it is not intended to be disconnected.

[0006] Folding staircases similar to that of Australian patent application 2021209351 can also be installed in commercial buildings a relatively permanent staircase is required but space is limited, or access to the upper level that the staircase provides is not required very often. However, in some industrial installations, the need for a staircase might only be temporary or there may be a need for a moveable staircase which can be shifted to different positions on site to provide access to different elevated areas. The folding staircase of Australian patent application 2021209351 Is not necessarily suitable for these types of applications.

[0007] The applicant has identified a need in the commercial or industrial space for a foldable staircase that can provide access to vertically spaced levels and that is foldable either to free up space when the staircase is not in use, or to prevent or reduce the likelihood of the staircase from becoming an obstruction to passage through the area where the staircase is installed. The development of the foldable staircase according to the present invention has been made specifically with the underground mining or tunnelling industries in mind. These industries often need to provide safe and robust access between different levels, with the access being required only temporarily rather than permanently. Moreover, underground sites often are very cramped with little room available for accommodating equipment or facilities, such as staircases. Summary of Invention

[0008] According to one embodiment of the present invention, a foldable staircase is provided that is foldable between folded and operational conditions, the foldable staircase comprising: a. first and second spaced apart side structures, b. a plurality of steps extending between the first and second side structures and hingedly connected to the first and second side structures, the steps in the plurality of steps being displaced vertically from each other in the operational condition of the foldable staircase,c. a landing at the top of the plurality of steps, the landing having a greater surface area than individual steps of the of steps and the landing being hingedly connected to the first and second side structures, d. the second side structure being moveable upwardly relative to the first side structure to transition the foldable staircase from the operational condition to the folded condition, the plurality of steps and the landing folding to a collapsed condition as the second side structure is moved upwardly relative to the first side structure.

[0009] The foldable staircase of the invention can include an end structure extending between the first and second side structures proximal an end of the landing remote from the plurality of steps. The end structure can form a safety barrier at the end of the landing remote from the plurality of steps when the foldable staircase is in the operational condition for the safety of personnel walking onto or off the landing. The end structure can be hingedly connected to the first and second side structures so as to facilitate folding of the end structure to a collapsed condition as the second side structure is moved upwardly relative to the first side structure.

[0010] The first side structure can include an opening aligned with the landing for passage of personnel to walk onto or off the landing when the foldable staircase is in the operational condition. If an end structure is provided, the opening in the first side structure can extend from or to the end structure.

[0011] The first side structure can form a safety barrier along the plurality of steps and the landing when the foldable staircase is in the operational condition for the safety of personnel walking onto or off the landing and walking up or down the plurality of steps. Likewise, the second side structure can also form a safety barrier along the plurality of steps and the landing when the foldable staircase is in the operational condition for the safety of personnel walking onto or off the landing and walking up or down the plurality of steps.

[0012] In another embodiment of the present invention, a foldable staircase is provided that is foldable between folded and operational conditions, the foldable staircase comprising: a. first and second spaced apart side structures,b. a plurality of steps extending between the first and second side structures and hingedly connected to the first and side structures, the steps in the plurality of steps being displaced vertically from each other in the operational condition of the foldable staircase, c. a landing at the top of the plurality of steps, the landing being hingedly connected to the first and second side structures, d. the first side structure including an opening aligned with the landing for passage of personnel to walk onto or off the landing when the foldable staircase is in the operational condition, e. the second side structure forming a safety barrier along the plurality of steps and the landing when the foldable staircase is in the operational condition for the safety of personnel walking onto or off the landing and walking up or down the plurality of steps, f. an end structure extending between first and second side structures proximal an end of the landing remote from the plurality of steps, the end structure forming a safety barrier at the end of the landing remote from the plurality of steps when the foldable staircase is in the operational condition for the safety of personnel walking onto or off the landing and the end structure being hingedly connected to the first and second side structures, g. the second side structure being moveable upwardly relative to the first side structure to transition the foldable staircase from the operational condition to the folded condition, each of the plurality of steps, the landing and the end structure folding to a collapsed condition as the second side structure is moved upwardly relative to the first side structure.

[0013] A foldable staircase according to either embodiment of the present invention can be self-supporting or free-standing so that it is not necessary for the staircase to be fixed to a wall or partition. For this, the first and second side structures can have base structures for resting on a ground or floor surface. Suitable base structures include feet, including non- slip feet, rollers, including rollers that incorporate braking devices, so that the foldable staircasecan be moved to a suitable position on the rollers and then retained in that position by applying the roller brakes. Alternatively, the structures can simply be bottom ends of the first and second side structures that are suitable to rest on a ground or floor surface. The bottom ends might be beams that extend from at or adjacent the front of the first and second side structures to at or adjacent the opposite ends.

[0014] The base structure can include an adjustment facility which allows the foldable staircase to be levelled on non- level surfaces, or to be raised or lowered to suit different height accessing requirements. A suitable adjustment facility can be provided by ground engaging feet that can be shortened or lengthened, such as by a threaded ground engaging member that threadably engages a threaded post, so that the position of the ground engaging member can be adjusted up or down by threading up or down along the post. Alternatively, telescopic posts can be employed and in a simple arrangement, two telescoping post sections can include openings through which a pin can be inserted to set the relative height positions of the post sections.

[0015] A foldable staircase that is self- supporting advantageously allows the staircase to be moved between different areas of a building or other installation without having to dismantle or disengage the staircase from connection with structural parts of the building or installation. A foldable staircase that is self- supporting can also have uses for temporary installations, such as for events or festivals. The staircase can be transported to site in the folded condition and expanded into the operational condition for use. Once the event is over, the staircase can be returned to the folded condition for convenient transport to the next event or for storage. For both storage and transport, the staircase takes less room than a staircase that is not foldable.

[0016] A foldable staircase according to the present invention can also be fixed to a wall or partition or other form of support, such as by connecting the first side structure to a wall or partition or other form of support (the studs of a wall that is under construction for example). This can be by bolting the first side structure to the relevant support and the first side structure can include suitable connections for this. The first side structure can for example include brackets that include openings for bolts to be inserted through for boltingthe first side structure to the support. The brackets can be adjustable to allow the position of the first side structure in proximity to the support to be adjusted as required.

[0017] A foldable staircase according to the present invention can alternatively be fixed to a ground surface, for example a concrete or cement floor. For this, either or both of the first and second side structures can include openings for bolts to be inserted through for bolting to the ground surface, or, if the ground surface is an earth surface, then the openings could receive pegs or spikes that are driven into the ground surface.

[0018] It is thus the case that a foldable staircase according to the present invention can be self- supporting or free- standing, or can be fixed to a relevant support. Advantageously, a foldable staircase according to the present invention can be provided in a form that allows the staircase to be used either in a self- supporting or free- standing form, or in a form in which it is fixed to a relevant support. This provides the user or installer of the foldable staircase the option to adopt which ever installation form is appropriate.

[0019] The first and second side structures can take any suitable form. One or each of the first and second side structures can include a handrail. The handrail can have a section that extends along the plurality of steps and at the same or a similar angle to the angle of inclination of the plurality of steps. For the second side structure the handrail can have a second section that extends along the landing, generally parallel to the landing. The first and second side structures can also include other rail sections to provide safety to personnel walking up or down the plurality of steps, or onto or off the landing. Likewise, as previously discussed, the end structure can include rail sections for safety purposes.

[0020] The first and second side structures can be generally planar and extend generally parallel to each other. The end structure can extend generally perpendicular to the first and second side structures.

[0021] One or more of the first and second side structures and the end structure can be generally open structures formed from metal bar. Alternatively, one of more of the first and second side structures and the end structure can be formed generally solid, such as from metal sheet or timber sheet. Still further, one of more of the first and second side structures and the end structure can be formed partly solid and partly open.

[0022] A foldable staircase according to the present invention can be formed in a manner that the staircase naturally adopts operational condition once released from the folded condition. Accordingly, a foldable staircase according to the present invention can include a catch or the like to hold the staircase in the folded condition until such time as the staircase is ready for transition to the operational condition. The catch can then be released for the staircase to assume the operational condition.

[0023] Alternatively or additionally, a foldable staircase according to the present invention can be biased towards the folded condition and can include a mechanism that resists the bias in the operational condition. For example, a pneumatic strut may extend between the first side structure and another part of the staircase that is foldable relative to the first side structure, that pushes or pulls in a direction tending to fold the staircase. The strut can be fixed in place when the staircase is in the operational condition and can be released to allow the bias to shift the staircase towards the folded condition. Such a strut can extend between a part of the first side structure and a step of the plurality of steps, or the landing, or part of the end structure for example. In one form of the invention, a bar extends from the second side structure to the first side structure and is pivotally connected to both. The bar has a cantilever section that extends beyond the first side structure and the strut extends from the first side structure to the end of the cantilever section. The strut presses on the distal end of the cantilever section, tending to push that section down and thus tending to rotate the section of the bar between the first and second side structures upwardly. The bar thus tends to rotate the second side structure upwardly.

[0024] Still alternatively, a pulley arrangement, such as a weighted pulley arrangement, can be employed whereby movement between the folded and operational conditions is by operation of the pulley arrangement.

[0025] In some forms of the invention, the foldable staircase according to the present invention shifts between the folded and operational conditions with the use of a handle or lever that connects between the first side structure and the end structure or the landing. The lever is pivotally connected to the first side structure and the end structure or the landing and includes a slot so that one pivotal connection is fixed and the other is sliding. Rotation of the lever in one direction will raise the end structure, the second side structure,the plurality of steps and the landing relative to the first side structure to the folded condition, while rotation of the lever in the direction will lower the end structure, the second side structure, the plurality of steps and the landing relative to the first side structure to the operational condition.

[0026] The slot in the lever can have an offset, such as a return or dogleg at one end so that when the folded condition is reached, the sliding pivotal connection can be captured in the offset to resist unintentional return rotation of the lever or to lock the lever. The slot can be generally linear, or slightly curved to assist lever rotation. The offset can be a section that is lateral to the slot, such as generally perpendicular to a linear slot, or tangential to a curved slot. It is to be noted that the lever might not be used to fold or unfold the staircase, but rather personnel may lift other parts of the staircase, such as the second side structure to fold or unfold the staircase. The lever might simply be operational at each of the folded and operational conditions, to initiate movement from a locked position.

[0027] The lever can also assist to retain the foldable staircase in the operational condition by forming a strut between the first side structure and the end structure or landing, or the second side structure, to prevent folding of the staircase without firstly rotating the lever. Brief Description of Drawings

[0028] In order that the invention may be more fully understood, some embodiments will now be described with reference to the figures in which:

[0029] Figure 1 illustrates a foldable staircase according to one embodiment of the present invention.

[0030] Figure 2 is an end view of the foldable staircase of Figure 1.

[0031] Figure 3 is a side view of the foldable staircase of Figure 1.

[0032] Figure 4 is a view of the staircase of Figure 1 in isolation, taken from an underneath perspective.

[0033] Figure 5 is a detailed view of a section of Figure 4.

[0034] Figure 6 is a further end view of the foldable staircase of Figure 1.

[0035] Figure 7 is a detailed view of a section of Figure 6.

[0036] Figures 8 and 9 are end and detailed views showing the foldable staircase of Figure 1 slightly folded.

[0037] Figure 10 is an end view of the foldable staircase of Figure 1 folded further.

[0038] Figures 11 and 12 are end and detailed views showing the foldable staircase of Figure 1 almost fully folded.

[0039] Figures 13 and 14 are end and detailed views showing the foldable staircase of Figure 1 fully folded.

[0040] Figure 15 is a further end view showing the foldable staircase of Figure 1 fully folded. Detailed Description

[0041] Figure 1 illustrates a foldable staircase 10 according to one embodiment of the present invention. The staircase 10 is shown installed on a platform 12 that is resting on a base 14. The base 14 extends to a wall 16 that extends to a platform 18. The structure illustrated in Figure 1 to which the staircase 10 is assembled, is only intended to illustrate how the staircase 10 might be used to provide access between the platform 12 and the platform 18. Thus, personnel who wish to travel from the platform 18 to the platform 12 can enter the staircase 10 through the opening 20 and can walk onto the landing 22 and then travel down the plurality of steps 24. Personnel will exit the staircase 10 at the bottommost step 26 and onto the platform 12. Personnel can likewise move up the staircase 10 in the reverse manner.

[0042] In the illustrated embodiment of Figure 1, the staircase 10 is supported on platform surfaces with different heights. Accordingly, a first side structure 28 rests on a bottom end thereof on an upper section 32 of the platform 12, while a bottom end of the second side structure 30 rests on a lower section 34 of the platform 12. The platforms 12and 18 represent different working levels that need to be accessed by personnel, such as by tunnelling personnel working in an tunnelling operation.

[0043] The staircase 10 is foldable between the operational condition shown in Figure 1 to a folded or collapsed condition that will be described in relation to other figures. Folding of the staircase 10 results in the second side structure 30 being brought into close proximity with the first side structure 28 and with the steps of the plurality of steps 24 and the landing 22 being rotated to a generally vertical orientation compared to the generally horizontal orientation shown in Figure 1. The end structure 36 will also be shifted so that the generally horizontal cross members 38 of the end structure 38 will be rotated to a generally vertical orientation.

[0044] Folding of the staircase 10 as described above, will bring the second side structure 30 into a position overlying the upper section 32 of the platform 12. Thus, the entire staircase 10 will overlie the upper section 32 and so the lower section 34 will be available for operational needs, such as for travel of personnel and vehicles along with the platform 12. As will be appreciated from Figure 1, with the staircase 10 in the operational condition, a portion of the lower section 34 of the platform 12 is taken up by the staircase 10, but this might only be temporary, such as for ends of working shifts when personnel change, whereafter the staircase 10 can be returned to the folded condition.

[0045] Advantageously, as will be apparent from the discussion that follows, folding of the staircase 10 between the operational condition and the folded condition, is relatively easy and quick. Accordingly, the staircase 10 can be folded and expanded as required, for example in relation to the space requirements needed on the lower section 34 of the platform 12.

[0046] The staircase 10 as illustrated in Figure 1 is also shown connected to the wall 16 that extends between the base 14 and the platform 18. For this, the staircase 10 includes a bracket 40 at each end of the first side structure 28 (only one bracket 40 is visible in Figure 1 but both brackets can be seen in Figure 4) and the brackets 40 are bolted to the wall 16. This connection arrangement securely fixes the staircase 10 in place on the platform 12, although it is to be appreciated that this connection arrangement can be a releasable connection and is not essential to all deployments of the present invention. For example, a foldable staircaseaccording to the present invention can be self-supporting or free-standing so that fixing of the first side structure 28 to a wall or or other support is not necessary. Indeed, the staircase 10 will stand upright without further support, and fixing of the brackets 40 to the wall 16 is a choice that is available if the security of location of the staircase 10 is critical.

[0047] Figures 2 and 3 show the staircase 10 in the operational condition of Figure 1. Figure 2 is an end view of the installation of Figure 1, taken from the end of the staircase 10 at the bottommost step 26. Figure 3 is a side view of the installation of Figure 1, taken from the side of the staircase 10 of the second side structure 30. Figure 2 shows a lever in the form of a handle 62 that is used to fold and unfold the staircase 10 and to retain the staircase 10 in the folded condition and that will be described later herein in more detail in relation to Figures 6 to 14. Figure 3 shows a pneumatic strut 42 that assists in folding the staircase 10 from the operational condition to the folded condition by lifting some of the weight of the staircase 10 that is lifted relative to the first side structure 28.

[0048] It will be apparent from the figures, that the first and second side structures 28 and 30, and the end structure 36 form safety barriers for the safety of personnel walking up or down the plurality of steps 24, or onto or off the landing 22. Also, each of the first and second side structures 28 and 30 have handrails 44. The second side structure 30 and the end structure 36 form a right-angle safety barrier for the landing 22. Thus, personnel walking onto the landing 22 are protected from falling off the landing 22 by the barriers of the second side structure 30 and the end structure 36, while personnel walking up or down the plurality of steps 24 protected by the first and second side structures 28 and 30. The opening 20 can include a swinging door or gate to close the opening other than when personnel are entering or leaving the staircase 10, although as illustrated, no door or gate is provided.

[0049] The first and second side structures 28 and 30 each include stringers 46 and side plates 48. The stringers 46 are inclined at the same inclination as the plurality of steps 24 while the side plates 48 extend along the opposite sides of the landing 22. The stringers 46 and the side plates 48 connect to the posts 50, 51 and 52 of the second side structure 30and to posts 50, 51 and 64. The plurality of steps 24 hingedly connect at each end with the stringers 46. The landing 22 hingedly connects at each side with the side plates 48. This enables the plurality of steps 24 and the landing 22 to each fold upwardly to a folded orclosed position as shown in Figures 13 and 15 (to be described later herein) when the second side structure 30 is lifted. The stringers 46 the side plates 48 remain in the orientation illustrated in Figure 1 during this movement to the folded or closed position of Figures 13 and 15, as does the second side structure 30.

[0050] Figure 4 is a view of the staircase 10 of Figure 1 in isolation, taken from an underneath perspective. Figure 4 shows some of the hinge connections made between the plurality of steps 24 and the stringers 46, and between the landing 22 and the side plates 48. The hinge connections shown in Figure 4 are circled and identified by the letter H, while Figure 5 is an enlarged view of a portion of Figure 4 marked by the broken lines A in Figure 4, showing two of the hinge connections between the bottommost step 26 and the bottom end of the stringer 46 of the first side structure 28. With reference to Figure 5, the hinge connections of the staircase 10 are relatively simple and for each step of the plurality of steps 24 the hinge connection comprises a pair of inwardly extending plates 54 welded to an inwardly facing surface 56 of the stringer 46, with the plates 54 having a bolt opening to accept bolts 58. The bolts also extend through an opening in a lip 60 of the step 26. The same arrangement is made at the opposite end of the step 26 to the other stringer 46 as well as to each of the other steps of the plurality of steps 24. The step 26 can thus rotate about the bolts 58 at each end of the step 26 as can the other steps in the same manner. Likewise, the same type of hinge arrangement is applied to the landing 22 in its connection with the side plates 48. Thus, each of the hinge connections shown in Figure 4 and circled and identified by the letter H, have the same construction as described in Figure 5. In Figure 4, a hinge is shown positioned generally centrally of the landing 22 interfacing with the side plate 48. Two further hinges will be provided at the opposite ends of the landing 22 in connection with each of the side plates 48, but those hinges are not visible in Figure 4.

[0051] Figure 6 is an end view of the foldable staircase 10 of Figure 1 but with the platform 12 removed and taken from the opposite end of the staircase 10 to that of Figure 2. Figure 6 shows that the staircase 10 can be installed with the bottom end of the second side structure 30 resting on the upper surface of the base 14 and the brackets 40 fixed to the facing surface of the wall 16.

[0052] Figure 6 shows the staircase 10 in the operational condition and also shows a locking handle or arm 62 shown connected the post 64 of the first side structure 28 and a cross member 38a of the end structure 36. The end 66 of the locking handle 62 that is connected to the cross member 38a is permanently and rotatably connected to the cross member 38a by a bolt 67. Accordingly, the end 66 is fixed to the cross member 38a at the bolt 67 but can rotate relative to the cross member 38a about the bolt as the staircase 10 is folded or unfolded between the operational and folded conditions.

[0053] The handle 62 is also connected to the post 64 of the first side structure 28 by a bolt connection, but that connection is by a bolt 70 being located within an elongate slot 68 in the handle 62. The slot 68 and the bolts 67 and 70 are shown in more detail in Figure 7, which shows the top section of the staircase 10 of Figure 6 in which the handle 62 is located.

[0054] The staircase 10 can be shifted from the operational condition shown in Figures 6 and 7 by rotating the handle 62 in a clockwise direction as shown in Figures 8 and 9. Figure 9 clearly shows that the bolt 70 that connects the handle 62 to the post 64 has 13oved within the slot 68 from one end of the slot 68 as shown in Figure 7, to a position towards the opposite end of the slot 68. Also shown in Figures 8 and 9 is the lifted position of the second side structure 30 relative to the first side structure 28 away from the upper surface of the base 14 and the angled or inclined orientations of the plurality of steps 24, 26 and the landing 22. It can also be seen in Figures 8 and 9 that the cross members 38 of the end structure 36 have also inclined.

[0055] Figure 10 shows further movement of the staircase 10 towards the folded condition, in which the handle 62 is rotated further clockwise.

[0056] Figures 11 and 12 show still further movement of the staircase 10 towards the folded condition. In Figure 12, the bolt 70 is close to the end of the slot 68 that is proximate the handle end 66. In Figure 12, the staircase 10 is just about in the folded condition, but not quite.

[0057] Figures 13 and 14 show the staircase 10 in the folded condition. In that condition, the handle 62 is almost vertical and the second side structure 30 is close to and generally parallel to the first side structure 28. This final position of the second side structure30 is shown in Figure 15, which returns the platform 12 into the figure and thus shows that the entire staircase 10 is folded to a is overlying the upper section 32 of the platform 12.

[0058] A unique feature of the slot 68 of the handle 62 is that it includes a main linear section 72 and offset sections 73 and 74 at each end of the linear section 72. This is best seen in Figures 9 and 12, in which in Figure 9, the linear section 72 is shown generally horizontal and the offset sections 73 and 74 extend upwardly or generally vertically from each end of the linear section 72. The offset sections 73 and 74 are intended to house or accommodate the bolt 70 when the staircase 10 is in the folded condition or the operational condition respectively. Thus, in Figure 7, the bolt 70 is housed in the section 74, while in Figure 14, the bolt 70 is housed in the section 73.

[0059] Entry of the bolt 70 into either of the offset sections 73 or 74 tends to lock the handle 62 in the operational condition of Figure 7, or the folded condition of Figures 14 and 15. In order to rotate the handle 62 from either of these positions, effort must be applied to dislodge the bolt 70 from the offset section within which it is accommodated, before the handle 62 can be rotated more generally to fold or unfold the staircase 10. This locking feature is most advantageous for retaining the staircase 10 in the folded condition, as the staircase 10 will tend to maintain the operational condition simply by the weight of the unfolded components resisting being lifted upwardly. Nevertheless, the locking feature in the operational condition tends to resist movement of the second side structure 30 relative to the first side structure 28 and thus it tends to stiffen the staircase 10 in the operational condition. This is particularly useful in the illustrated form of the staircase 10 which employees a pneumatic strut 42, which operates to lift the second side structure 30 relative to the first side structure 28 in order to assist folding movement of the staircase 10. Thus, there is always a load acting on the second side structure 30 tending to lift it, and so the locking feature of the handle 62 resists that load.

[0060] The present invention advantageously provides a staircase that can be used in a variety of locations, either as a permanent structure that can be folded and opened, or as a removable or temporary structure that can provide staircase access for a predeterminedperiod of time. The staircase is simple and easy to operate and in the folded condition is suitable for compact transport and storage.

[0061] Where any or all of the terms "comprise", "comprises", "comprised" or "comprising" are used in this specification (including the claims) they are to be interpreted as specifying the presence of the stated features, integers, steps or components, but not precluding the presence of one or more other features, integers, steps or components.

[0062] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is understood that the invention includes all such variations and modifications which fall within the spirit and scope of the present invention.

Claims

The claims defining the invention are as follows:

1. A foldable staircase that is foldable between folded and operational conditions, the foldable staircase comprising: a. first and second spaced apart side structures, b. a plurality of steps extending between the first and second side structures and hingedly connected to the first and second side structures, the steps in the plurality of steps being displaced vertically from each other in the operational condition of the foldable staircase, c. a landing at the top of the plurality of steps, the landing having a greater surface area than the steps of the plurality of steps and the landing being hingedly connected to the first and second side structures, d. the second side structure being moveable upwardly relative to the first side structure to transition the foldable staircase from the operational condition to the folded condition, the plurality of steps and the landing folding to a collapsed condition as the second side structure is moved upwardly relative to the first side structure.

2. A foldable staircase according to claim 1, including an end structure extending between first and second side structures proximal an end of the landing remote from the plurality of steps.

3. A foldable staircase according to claim 2, the end structure being hingedly connected to the first and second side structures.

4. A foldable staircase according to any one of claims 1 to 3, the first side structure including an opening aligned with the landing for passage of personnel to walk onto or off the landing when the foldable staircase is in the operational condition.

5. A foldable staircase according to claim 4, the opening in the first side structure extending from or to the end structure.

6. A foldable staircase according to any one of claims 1 to 5, the first side structure forming a safety barrier along the of steps and the landing when the foldable staircase is in the operational condition for the safety of personnel walking onto or off the landing and walking up or down the plurality of steps.

7. A foldable staircase according to any one of claims 1 to 6, the second side structure forming a safety barrier along the plurality of steps and the landing when the foldable staircase is in the operational condition for the safety of personnel walking onto or off the landing and walking up or down the plurality of steps.

8. A foldable staircase according to any one of claims 1 to 7, the foldable staircase being self-supporting or free-standing.

9. A foldable staircase according to any one of claims 1 to 8, the first and second side structures having base structures for resting on a ground or floor surface.

10. A foldable staircase according to claim 9, the base structures including feet, including non- slip feet, or rollers, including rollers that incorporate braking devices.

11. A foldable staircase according to claim 9, the base structures being bottom ends of the first and second side structures that are suitable to rest on a ground or floor surface, such as beams that extend from at or adjacent the front of the first and second side structures to at or adjacent the opposite ends of the first and second side structures.

12. A foldable staircase according to any one of claims 9 to 11, the base structure including an adjustment facility which allows the foldable staircase to be levelled on non- level surfaces, or to be raised or lowered to suit different height accessing requirements.

13. A foldable staircase according to claim 12, the adjustment facility comprising ground engaging feet that can be shortened or lengthened, such as by a threaded ground engaging member that threadably engages a threaded post, so that the position of the ground engaging member can be adjusted up or down by threading up or down along the post.

14. A foldable staircase according to claim 12, the adjustment facility comprising, telescopic posts comprising two post sections that comprise openings through into which a pin can be inserted to set the relative height positions of the post sections.

15. A foldable staircase according to any one of claims 1 to 14, the first side structure including connections for fixing to a wall or partition or other form of support.

16. A foldable staircase according to claim 14, the first side structure including brackets that include openings for bolts to be inserted through for bolting the first side structure to a wall or partition or other form of support.

17. A foldable staircase according to claim 16, the brackets being adjustable to allow the position of the first side structure in proximity to the wall or partition or other form of support to be adjusted.

18. A foldable staircase according to any one of claims 1 to 17, the first and second side structures including a handrail.

19. A foldable staircase according to any one of claims 1 to 18, the first and second side structures being generally planar and extending generally parallel to each other and the end structure extending generally perpendicular to the first and second side structures.

20. A foldable staircase according to any one of claims 1 to 19, including a catch like to hold the staircase in the folded condition until such time as the staircase is ready for transition to the operational condition, the catch being releasable for the staircase to assume the operational condition.

21. A foldable staircase according to any one of claims 1 to 20, including a bias towards the folded condition and a mechanism that resists the bias in the operational condition.

22. A foldable staircase according to claim 21, the bias being provided by a pneumatic strut extending between the first side structure and another part of the staircase thatis foldable relative to the first side structure, that pushes or pulls in a direction tending to fold the staircase.

23. A foldable staircase according to any one of claims 1 to 22, including a handle or lever that connects between the first side structure and the end structure or the landing to assist shifting of the foldable staircase between the folded and operational conditions.

24. A foldable staircase according to claim 23, the lever being pivotally connected to the first side structure and the end structure or the landing and includes a slot so that one pivotal connection is fixed and the other is sliding and whereby rotation of the lever in one direction will raise the end structure, the second side structure, the plurality of steps and the landing relative to the first side structure to the folded condition, while rotation of the lever in the opposite direction will lower the end structure, the second side structure, the plurality of steps and the landing relative to the first side structure to the operational condition.

25. A foldable staircase according to claim 24, the slot in the lever having an offset at one end so that when the folded condition is reached, the sliding pivotal connection can be captured in the offset to resist unintentional return rotation of the lever or to lock the lever.

26. A foldable staircase according to claim 25, the slot being generally linear, or slightly curved.

27. A foldable staircase according to claim 25 or 26, the offset being lateral to the slot, such as generally perpendicular to a linear slot, or tangential to a curved slot.

28. A foldable staircase according to any one of claims 23 to 27, the lever assisting to retain the foldable staircase in the operational condition by forming a strut between the first side structure and the end structure or landing, or the second side structure, to prevent folding of the staircase without firstly rotating the lever.

29. A foldable staircase is provided that is foldable between folded and operational conditions, the foldable staircase comprising:a. first and second spaced apart side structures, b. a plurality of steps extending between the first and second side structures and hingedly connected to the first and second side structures, the steps in the plurality of steps being displaced vertically from each other in the operational condition of the foldable staircase, c. a landing at the top of the plurality of steps, the landing being hingedly connected to the first and second side structures, d. the first side structure including an opening aligned with the landing for passage of personnel to walk onto or off the landing when the foldable staircase is in the operational condition, e. the second side structure forming a safety barrier along the plurality of steps and the landing when the foldable staircase is in the operational condition for the safety of personnel walking onto or off the landing and walking up or down the plurality of steps, f. an end structure extending between first and second side structures proximal an end of the landing remote from the plurality of steps, the end structure forming a safety barrier at the end of the landing remote from the plurality of steps when the foldable staircase is in the operational condition for the safety of personnel walking onto or off the landing and the end structure being hingedly connected to the first and second side structures, g. the second side structure being moveable upwardly relative to the first side structure to transition the foldable staircase from the operational condition to the folded condition, each of the plurality of steps, the landing and the end structure folding to a collapsed condition as the second side structure is moved upwardly relative to the first side structure.

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