AU2015101862B4

AU2015101862B4 - Height adjustable ladder

Info

Publication number: AU2015101862B4
Application number: AU2015101862A
Authority: AU
Inventors: Gavin Rundle; Ching Ting Wang
Original assignee: HARTMAN PACIFIC Pty Ltd
Current assignee: HARTMAN PACIFIC Pty Ltd
Priority date: 2015-05-12
Filing date: 2015-06-30
Publication date: 2017-10-12
Anticipated expiration: 2023-06-30
Also published as: GB201608335D0; AU2015101862A4; GB2540252A; AU2017100930B4; AU2017100930A4

Abstract

Some embodiments relate to a ladder extension and ladder assemblies including such ladder extensions. The ladder extension may be adapted to slidably receive a ladder and extend an operating height of the ladder. The ladder extension may comprise: first and second extension side rails; a first set of one or more rungs extending from the first extension side rail to the second extension side rail; a second set of one or more rungs extending from the first extension side rail to the second extension side rail; and a first securing mechanism to selectively secure a position of the ladder relative to the ladder extension and set the operating height; wherein a rung of the first set of rungs is aligned with and spaced apart from a corresponding rung of the second set of rungs to form an extension step having a gap between the rungs sized to receive a step of the ladder and allow passage of the ladder through the extension step to adjust the operating height of the ladder.

Description

"Height adjustable ladder"

Technical Field [0001] Embodiments generally relate to ladders, and in particular, to height adjustable ladders.

Background [0002] Existing extension ladders comprise two pairs of side rails, each pair of side rails having a set of steps. The two pairs of side rails are configured to slide alongside each other with the two sets of steps passing each other to extend the length of the ladder.

[0003] Some existing ladders have platforms and some platform ladders are height adjustable. However, the height adjustable platform ladders previously available are not or may not be compliant with the relevant Australian/New Zealand Standard AS/NZS 1892.1:1996.

[0004] It is desired to address or ameliorate one or more problems, disadvantages or drawbacks of prior height adjustable ladders, or to at least provide a useful alternative thereto.

[0005] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each claim of this application.

[0006] Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or Steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

Summary [0006A] According to the present invention, there is provided a ladder assembly comprising a platform ladder and a ladder extension adapted to slidably receive the platform ladder and to extend an operating height of the platform ladder, the ladder extension comprising: first and second extension side rails; a first set of one or more rungs extending from the first extension side rail to the second extension side rail; a second set of one or more rungs extending from the first extension side rail to the second extension side rail; and a first securing mechanism to selectively secure a position of the platform ladder relative to the ladder extension and set the operating height; wherein a rung of the first set of rungs is aligned with and spaced apart from a corresponding rung of the second set of rungs to form an extension step having a gap between the rungs sized to receive a step of the platform ladder and allow passage of the platform ladder through the extension step to adjust the operating height of the platform ladder.

[0007] Some embodiments relate to ladder extensions, while other embodiments relate to ladder assemblies comprising ladders with ladder extensions.

[0008] Some embodiments relate to a ladder extension adapted to slidably receive a ladder and extend an operating height of the ladder, the ladder extension comprising: first and second extension side rails; a first set of one or more rungs extending from the first extension side rail to the second extension side rail; a second set of one or more rungs extending from the first extension side rail to the second extension side rail; and a first securing mechanism to selectively secure a position of the ladder relative to the ladder extension and set the operating height; wherein a rung of the first set of rungs is aligned with and spaced apart from a corresponding rung of the second set of rungs to form an extension step having a gap between the rungs sized to receive a step of the ladder and allow passage of the ladder through the extension step to adjust the operating height of the ladder.

[0008a] Some embodiments relate to a ladder assembly comprising a ladder and a ladder extension adapted to extend an operating height of the ladder, the ladder extension comprising: first and second extension side rails; a first set of one or more rungs extending from the first extension side rail to the second extension side rail; a second set of one or more rungs extending from the first extension side rail to the second extension side rail; and a first securing mechanism to selectively secure a position of the ladder relative to the ladder extension and set the operating height; wherein a rung of the first set of rungs is aligned with and spaced apart from a corresponding rung of the second set of rungs to form an extension step having a gap between the rungs sized to receive a step of the ladder and allow passage of the ladder through the extension step to adjust the operating height of the ladder, the ladder comprising: first and second side rails; a set of ladder steps extending from the first side rail to the second side rail; a support structure having first and second support legs connected to each other by one or more braces or steps, the support structure being pivotally mounted to the first and second side rails to allow the ladder to be folded into a storage configuration, with the support legs alongside the side rails, and opened into an operating configuration, with the support legs extending away from the side rails to support the ladder assembly in a free-standing configuration; and a platform pivotally mounted to the ladder, the platform being moveable between a storage configuration alongside the first and second side rails, and an operating configuration in which the platform forms a topmost step of the ladder; wherein the first and second extension side rails of the ladder extension are slidably engageable with the first and second side rails of the ladder, and wherein the ladder extension can be positioned relative to the ladder such that one of the set of ladder steps is aligned with and disposed between the rungs of one of the extension steps of the ladder extension.

[0008a] Some embodiments relate to a ladder assembly comprising a ladder and a ladder extension adapted to extend an operating height of the ladder, the ladder extension comprising: first and second extension side rails; a first set of one or more rungs extending from the first extension side rail to the second extension side rail; a second set of one or more rungs extending from the first extension side rail to the second extension side rail; a first securing mechanism to selectively secure a position of the ladder relative to the ladder extension and set the operating height; a straight portion near a first end of the ladder extension, the first extension side rail being parallel to the second extension side rail in the straight portion; and a tapered portion extending between the straight portion and a second end of the ladder extension, wherein the first and second extension side rails diverge from each other as they extend from the straight portion to the second end of the ladder extension, wherein a rung of the first set of rungs is aligned with and spaced apart from a corresponding rung of the second set of rungs to form an extension step having a gap between the rungs sized to receive a step of the ladder and allow passage of the ladder through the extension step to adjust the operating height of the ladder, and wherein a distance between the rungs of the extension step is greater than 75mm; the ladder comprising: first and second side rails; a set of ladder steps extending from the first side rail to the second side rail; a support structure having first and second support legs connected to each other by one or more braces, the support structure being pivotally mounted to the first and second side rails to allow the ladder to be folded into a storage configuration, with the support legs alongside the side rails, and opened into an operating configuration, with the support legs extending away from the side rails to support the ladder assembly in a freestanding configuration; a platform pivotally mounted to the ladder, the platform being moveable between a storage configuration alongside the first and second side rails, and an operating configuration in which the platform forms a topmost step of the ladder; and a safety rail extending from the first side rail to the second side rail at or near an end of the ladder distal to the ladder extension to restrict a user from falling forward from the platform and to provide a grab rail for the user to hold onto; wherein the first and second extension side rails of the ladder extension are slidably engageable with the first and second side rails of the ladder, and wherein the ladder extension can be positioned relative to the ladder such that one of the set of ladder steps is aligned with and disposed between the rungs of one of the extension steps of the ladder extension.

[0008a] Some embodiments relate to a ladder assembly comprising a ladder and a ladder extension adapted to extend an operating height of the ladder, the ladder extension comprising: first and second extension side rails; a first set of one or more rungs extending from the first extension side rail to the second extension side rail; a second set of one or more rungs extending from the first extension side rail to the second extension side rail; a first securing mechanism to selectively secure a position of the ladder relative to the ladder extension and set the operating height; a straight portion near a first end of the ladder extension, the first extension side rail being parallel to the second extension side rail in the straight portion; and a tapered portion extending between the straight portion and a second end of the ladder extension, wherein the first and second extension side rails diverge from each other as they extend from the straight portion to the second end of the ladder extension, wherein a rung of the first set of rungs is aligned with and spaced apart from a corresponding rung of the second set of rungs to form an extension step having a gap between the rungs sized to receive a step of the ladder and allow passage of the ladder through the extension step to adjust the operating height of the ladder, and wherein a distance between the rungs of the extension step is greater than 75mm; the ladder comprising: first and second side rails; a first set of ladder steps extending from the first side rail to the second side rail; third and fourth side rails; a second set of ladder steps extending from the third side rail to the fourth side rail, the third and fourth side rails being pivotally mounted to the first and second side rails to allow the ladder to be folded into a storage configuration, with the third and fourth side rails alongside the first and second side rails, and opened into an operating configuration, with the third and fourth side rails extending away from the first and second side rails to support the ladder assembly in a free-standing configuration; a platform pivotally mounted to the ladder, the platform being moveable between a storage configuration alongside the first and second side rails, and an operating configuration in which the platform forms a topmost step of the ladder; and a safety rail extending from the first side rail to the second side rail at or near an end of the ladder distal to the ladder extension to restrict a user from falling forward from the platform and to provide a grab rail for the user to hold onto; wherein the first and second extension side rails of the ladder extension are slidably engageable with the first and second side rails of the ladder, wherein the ladder extension can be positioned relative to the ladder such that one of the first set of ladder steps is aligned with and disposed between the rungs of one of the extension steps of the ladder extension.

[0009] The gap between the corresponding rungs forming the extension step means that less material may be required to form the extension step compared with an extension step of equivalent diameter formed of a single rung. The gap also allows the step of a ladder to be accommodated between the corresponding rungs of the extension step so that the ladder and ladder extension may be stored together in a more compact storage configuration compared to extension ladders with a ladder step and an extension step stored in a side-by-side storage configuration.

[0010] In some embodiments, one or more further rungs of the first set of rungs may each be respectively aligned with and spaced apart from corresponding rungs of the second set of rungs to form a set of extension steps, each extension step having a gap between the rungs sized to receive a step of the ladder and allow passage of the ladder through each extension step to adjust the operating height of the ladder.

[0011] A distance between the rungs of each or the extension step may be greater than 75mm, optionally greater than 50mm, optionally greater than 80mm, optionally greater than 90mm, optionally greater than 100mm. Each rung may have a load bearing capacity greater than 50kg, optionally greater than 70kg, optionally greater than 100kg, optionally greater than 150kg, optionally greater than 170kg. Each rung may include a tread surface having a width greater than 10mm, optionally greater than 15mm, optionally greater than 20mm, optionally greater than 25mm, optionally greater than 30mm, optionally greater than 40mm. The rungs may be disposed within a space between the first and second extension side rails.

[0012] A first end of the ladder extension may be narrower than a second end of the ladder extension. The ladder extension may include: a straight portion near the first end of the ladder extension, the first extension side rail being parallel to the second extension side rail in the straight portion; and a tapered portion extending between the straight portion and the second end, wherein the first and second extension side rails diverge from each other as they extend from the straight portion to the second end of the ladder extension. The ladder extension may further comprise a leveller disposed at or near an end of the first or second extension side rail.

[0013] Some embodiments relate to a ladder assembly comprising a ladder and a first ladder extension, the ladder being slidably engageable with the first ladder extension to adjust an operating height of the ladder assembly.

[0014] The ladder may comprise: first and second side rails; and a first set of ladder steps extending from the first side rail to the second side rail, wherein the first and second side rails are slidably engageable with the first and second extension side rails of the first ladder extension, and wherein the ladder can be positioned relative to the first ladder extension such that one of the first set of ladder steps is aligned with and r disposed between the rungs of one of the extension steps of the first ladder extension.

[0015] In some embodiments, the ladder may further comprise a support structure having first and second support legs connected to each other by one or more braces, the support structure being pivotally mounted to the first and second side rails to allow the ladder to be folded into a storage configuration, with the support legs alongside the side rails, and opened into an operating configuration, with the support legs extending away from the side rails to support the ladder assembly in a free-standing configuration.

[0016] The ladder assembly may further comprise a support extension adapted to slidably receive the support structure to extend an operating length of the support structure, the support extension comprising: first and second extension legs; a plurality of braces extending from the first extension leg to the second extension leg; and a support extension securing mechanism to selectively secure a position of the support extension relative to the support structure and set the operating length of the support structure. The support extension may further comprise a leveller disposed at or near an end of the first or second extension leg.

[0017] The ladder assembly may further comprise a platform pivotally mounted to the ladder between the first and second side rails and the support structure, the platform being moveable between a storage configuration alongside the first and second side rails, and an operating configuration in which the platform can carry a load.

[0018] In some embodiments, the ladder may further comprise third and fourth side rails and a second a second set of ladder steps extending from the third side rail to the fourth side rail, the third and fourth side rails being pivotally mounted to the first and second side rails to allow the ladder to be folded into a storage configuration, with the third and fourth side rails alongside the first and second side rails, and opened into an operating configuration, with the third and fourth side rails extending away from the first and second side rails to support the ladder assembly in a free-standing configuration.

[0019] The ladder assembly may further comprise a second ladder extension, wherein the third and fourth side rails are slidably engageable with the first and second extension side rails of the second ladder extension, and wherein the ladder can be positioned relative to the second ladder extension such that one of the second set of ladder steps is aligned with and disposed between the rungs of one of the extension steps of the second ladder extension.

[0020] The ladder assembly may further comprise a platform pivotally mounted to the ladder between the first, second, third and fourth side rails, the platform being moveable between a storage configuration alongside the first and second side rails, and an operating configuration in which the platform can carry a load.

[0021] The ladder assembly may further comprise a safety rail extending from the first side rail to the second side rail at or near an end of the ladder distal to the ladder extension.

Brief Description of Drawings [0022] Embodiments are described in further detail, by way of example, with reference to the accompanying drawings, in which: [0023] Figure 1A is a perspective view of a ladder assembly according to some embodiments in a disassembled state; [0024] Figure 1B is a perspective view of a ladder extension according to some embodiments; [0025] Figure 1C is a perspective view of the ladder assembly of Figure 1A in an assembled state; [0026] Figure 1D is a perspective view of the ladder extension with a leveller attached to an extension side rail of the ladder extension; [0027] Figure 2A is a perspective view of the ladder assembly of Figure 1A in a shortest operating configuration; [0028] Figure 2B is a perspective view of the ladder assembly of Figure 1A in an intermediate operating configuration; [0029] Figure 2C is a perspective view of the ladder assembly of Figure 1A in a tallest operating configuration; [0030] Figure 3A is a front view of the ladder assembly of Figure 1A in its shortest operating configuration; [0031] Figure 3B is a front view of the ladder assembly of Figure 1A in its intermediate operating configuration; [0032] Figure 3C is a front view of the ladder assembly of Figure 1A in its tallest operating configuration.

Description of Embodiments [0033] Embodiments generally relate to ladders, and in particular, to height adjustable ladders.

[0034] A ladder assembly 100 is shown in Figures 1A to 1C according to some embodiments. The ladder assembly 100 comprises a ladder 102; a ladder extension 130 slidably engaged with and moveable relative to the ladder 102 to extend an operating height of the ladder assembly 100 in use; and a securing mechanism 170 to secure a relative position of the ladder extension 130 relative to the ladder 102 to set a desired operating height of the ladder assembly 100.

[0035] The ladder 102 has a front or outer side 104 intended to be a climbing side in use; a back or inner side 106 opposite the front side 104; a first end 108 and a second end 110, the first end 108 being higher than the second end 110 in use. The ladder 102 comprises first and second elongate side rails 112 connected by a first set of one or more rungs or ladder steps 114 extending laterally between the first and second side rails 112. Each step 114 is adapted to support the weight of a user in use, and may be strong enough to support a load of about 50kg, optionally about 80kg, optionally about 100kg, optionally about 120kg, optionally about 150kg, optionally about 170kg, optionally about 200kg. Each step 114 has a horizontal depth in a direction from the front side 104 to the back side 106 which may be greater than about 75mm, optionally greater than 50mm, optionally greater than 100mm.

[0036] The steps 114 may be affixed to the side rails 112 by welding, cold forging, swaging, crimping, or with mechanical fasteners such as rivets, screws, nuts and bolts, or brackets, for example. The steps 114 may be arranged substantially in parallel to each other and substantially perpendicular to the first and second side rails 112. In some embodiments, the ladder 102 may comprise one or more braces 116 extending between one or more of the steps 114 and the side rails 112 to strengthen the join between one or more of the steps 114 and the side rails 112.

[0037] In some embodiments, the first and second side rails 112 may include one or more securing apertures 118 sized to receive a securing pin 178 of the securing mechanism 170. In some embodiments, there may be a plurality of securing apertures 118 spaced along a length of the side rails 112 to define a plurality of relative securing positions between the ladder 102 and the ladder extension 130 corresponding to various operating heights of the ladder assembly 100.

[0038] The ladder extension 130 is shown in more detail 'in Figure IB. The ladder extension 130 comprises first and second extension side rails 132 having first ends 134 defining a first end 136 of the ladder extension 130, and second ends 138 defining a second end 140 of the ladder extension 130. The first end 136 of the ladder extension 130 is adapted to slidably receive the second end 110 of the ladder 102. The first and second side rails 112 may be adapted to fit between the first and second extension side rails 132.

[0039] In some embodiments, a lateral distance between the first and second extension side rails 132 may be greater at the second ends 138 than the first ends 134 and the second end 140 of the ladder extension 130 may be wider than the first end 136. The lateral distance between the first ends 134 of the extension side rails 132 may be greater than 290mm. The lateral distance between second ends 138 of the extension side rails 132 may be greater than the lateral distance between the first ends 134 by at least 12.5% of: the maximum total extended length of the ladder extension 130 combined with the side rails 112 of the ladder 102; or the distance between the first end 108 of the ladder 102 and the second end 140 of the ladder extension 130 when the ladder assembly 100 is extended to its maximum operating height.

[0040] In some embodiments, the extension side rails 132 may define a straight portion 142 at the first end 136. The distance between the extension side rails 132 may be constant along a length of the straight portion 142. The extension side rails 132 may further define an outwardly tapered portion 144 extending from the straight portion 142 towards the second end 140. The distance between the extension side rails 132 may increase along a length of the tapered portion 144 from the straight portion 142 towards the second end 140. The extension side rails 132 may diverge between the straight portion 142 and the second end 140.

[0041] In other embodiments, the extension side rails 132 may be parallel along their entire length, and a lateral base bar (not shown) may be attached to the second end 140 of the ladder extension 130 to extend the width of the second end 140 to be greater than the lateral distance between the extension side rails 132 by at least 12.5% of: the maximum total extended length of the ladder extension 130 combined with the side rails 112 of the ladder 102; or the distance between the first end 108 of the ladder 102 and the second end 140 of the ladder extension 130 when the ladder assembly 100 is extended to its maximum operating height.

[0042] Having the second end 140 wider than the first end 136 of the ladder extension increases a footprint of the ladder assembly 100 compared to embodiments with a narrower second end 140. Ladders 100 with a wider footprint are more stable (in the direction that the footprint is wider) and less likely to tip over or overbalance. A wider footprint may provide a ladder 100 which is safer for a user and make it less likely for the user to fall from or overbalance the ladder 100. This provides increased safety for increased operating heights of the ladder assembly 100.

[0043] The width of the second end 140 of the ladder extension 130 iti a lateral direction substantially parallel to the steps 114 may be greater than about 500mm, optionally greater than about 700mm, optionally greater than about 800mm, optionally greater than about 900mm, optionally greater than about lm.

[0044] In some embodiments, the ladder extension 130 may comprise feet 146 with gripping surfaces to increase traction between the ladder assembly 100 and the ground during use. Sloped gripping surfaces may be provided on the feet 146 such that in use, when the ladder extension 130 is inclined relative to the ground, the gripping surfaces are substantially horizontal thereby maximising contact between the feet 146 and the ground. The gripping surfaces may have a rough texture such as a series of grooves to further increase traction between the ladder assembly 100 and the ground. The increased traction may reduce the likelihood of the ladder assembly 100 slipping on the ground and further enhance the safety of the ladder assembly 100 for a user.

[0045] The first and second extension side rails 132 may each define channels 148 adapted to receive the first and second side rails 112 and restrict lateral movement of the ladder 102 with respect to the ladder extension 130. The channels 148 may extend from the first ends 134 of the extension side rails 132 along the length of the straight portion 142. In some embodiments, the channels 148 may be disposed on the first and second side rails 112 and the first and second extension side rails 132 may comprise tracks (not shown) to slidably engage the channels 148.

[0046] The ladder extension 130 comprises a first set of one or more vertically spaced rungs 150 extending between the first and second extension side rails 132 or an outer side of the side rails 132, and a second set of one or more vertically spaced rungs 152 extending between the first and second extension side rails 132 or an inner side of the side rails 132. At least one of the first set of rungs 150 is aligned with a respective at least one of the second set of rungs 152 so as to respectively form at least one pair of horizontally aligned rungs. Each pair of rungs defines one of a set of one or more extension steps 154 having a gap between the pair of rungs sized to receive one of the first set of steps 114 or the second end 110 of the ladder 102. For each pair of rungs 150,152 there is a distance between the rungs of each pair of rungs 150,152 which may be greater than about 50mm, optionally greater than about 75mm, optionally greater than about 80mm, optionally greater than about 100mm. The pairs of rungs 150, 152 may be positioned such that, when the ladder assembly 100 is in use, a top surface of each extension step 154 formed by each pair of rungs 150, 152 is substantially horizontal.

[0047] The gap formed between each pair of rungs 150,152 allows at least part of one of the ladder steps 114 to be received within each extension step 154 between the rungs 150,152 to form a composite step 204. When a ladder step 114 is received within an extension step 154, the total width of the composite step 204 is equal to a total width of the extension step 154. Therefore the ladder assembly 100 can be stored more compactly compared with extension ladders with equivalent step widths in which the r extension steps are stored alongside the ladder steps. The total width of the ladder step and extension step is greater than the sum of the widths of the ladder step and extension step, since there must be a gap between them.

[0048] The described ladder extension 130 allows the operating height of the ladder assembly 100 to be adjusted and allows for more compact storage of the ladder assembly 100 while still being strong enough and wide enough to support the weight of the user in a stable upright standing position.

[0049] In some embodiments, the ladder extension 130 may comprise three steps defined by three pairs of rungs 150,152 as shown in in Figures 1A to 1C. In other embodiments, the ladder extension 130 may comprise any suitable number of extension steps 154, such as one, two, four, five, six, or seven extension steps 154. In some embodiments, each of the first set of rungs 150 may be aligned with one of the second set of rungs 152. In other embodiments, the first and/or second set of rungs 150,152 may include one or more extra rungs 150,152 which do not form part of an extension step 154.

[0050] In some embodiments, each rung 150,152 may be adapted to carry a weight of a user independently of the other rung 150,152. The load capacity of each rung 150, 152 may be greater than about 50kg, optionally about 80kg, optionally about 100kg, optionally about 120kg, optionally about 150kg, optionally about 170kg, optionally about 200kg.

[0051 ] In some embodiments, the first and/or second sets of rungs 150,152 may extend across outer faces defined by the first and second extension side rails 132, or across but not within the space between the extension side rails 132. In some embodiments, the first and/or second sets of rungs 150,152 may extend between the first and second extension side rails 132 within the space between the extension side rails 132.

[0052] The rungs 150,152 may be affixed to the extension side rails 132 by welding, cold forging, swaging, crimping, or with mechanical fasteners such as rivets, screws or nuts and bolts, for example. In some embodiments, the ladder extension 130 may comprise one or more braces 156 extending between one or more of the rungs 150,152 and the extension side rails 132 to strengthen the join between one or more of the rungs 150,152 and the extension side rails 132.

[0053] The ladder extension 130 may further comprise a leveller 232 as shown in Figure ID to assist in levelling the ladder assembly 100 when used on uneven ground. A length of the leveller 232 may be adjustable to extend the length of the extension side rail 132 to which it is attached. The ladder extension 130 may include one leveller 232 on each extension side rail 132 at or near the second ends 138. The levellers 232 may be formed as part of the ladder extension 130, or may be retrofitted to a ladder extension 130. The extension side rails 132 may be adapted to receive an engagement means of the levellers 232 so that they can be attached to the side rails 132. For example, the extension side rails 132 may define apertures (not shown) sized to receive bolts to connect the levellers 232 to the extension side rails 132. As another example, a bracket or base unit (not shown) may be fixed to the extension side rails 132 at or near the second ends 138 and the leveller 232 may be mounted on the ladder extension 130 by engaging or connecting to the bracket.

[0054] In some embodiments, a ladder extension 130 as described may be manufactured separately and adapted to be retrofitted to an existing ladder. Such ladder extensions 130 may be sold separately to be used with certain ladders in the marketplace. In other embodiments, a ladder extension 130 and ladder 102 may be formed together or alongside each other to be sold as a complete ladder assembly 100 or kit forming the assembly 100.

[0055] In some embodiments, the first and second extension side rails 132 may define one or more securing apertures 158 sized to receive the securing pin 178 of the securing mechanism 170. The securing apertures 158 may be disposed near the first end 136, and may be disposed in the straight portion 142 of the ladder extension 130.

[0056] The securing mechanism 170 may comprise a catch, latch, clutch, ratchet, lock, brake or any other suitable mechanism which allows a user to activate the securing mechanism 170 to secure the ladder extension 130 in place with respect to the ladder 102 and release the securing mechanism 170 to allow relative movement between the ladder extension 130 and the ladder 102.

[0057] A securing mechanism 170 is shown in more detail in Figure 1C according to some embodiments. The securing mechanism 170 may comprise an axle 172, a handle 174 and a securing pin 178. The axle 172 may be mounted to the ladder extension 130 but free to move relative to the ladder extension 130 in an axial direction with respect to a longitudinal axis of the axle 172 extending away ffom'the ladder extension 130. In some embodiments, the axle 172 may also be free to rotate about its longitudinal axis relative to the ladder extension 130, The handle 174 may be fixedly attached to the axle 172. In some embodiments, the handle 174 may be pivotally mounted to the axle 172 and free to rotate about the longitudinal axis of the axle 172 relative to the axle 172 and the ladder extension 130, [0058] The securing pin 178 may extend from the handle 174 in parallel with the axle 172 back towards the ladder extension 130. The securing pin 178 may be adapted to pass through the securing apertures 118 and 158 when aligned and secure them in position relative to each other such that the ladder extension 130 is restricted from sliding along the length of the first and second side rails 112 by more than a few millimetres.

[0059] In some embodiments, the securing mechanism 170 may be spring loaded, as shown in Figure IB. The securing mechanism 170 may comprise a spring 180 disposed around the axle 172 to bias the securing mechanism 170 towards the ladder extension 130. The end ofthe axle 172 opposite the end connected to the handle 174 may comprise a stop in the form of a flanged or splayed portion 182 and a washer 184 to hold the spring 180 onto the axle 172. The axle 172 and spring 180 may be housed inside one of the rungs 150 and held in place with an end cap 186 affixed to the end of the rung 150. The axle 172 may extend through an aperture in the end cap 186 allowing the axle 172 to rotate about its longitudinal axis and move axially in and out of the rung 150. The end cap 186 may hold the spring 180 inside the rung 150 such that, when the axle 172 is drawn out from the rung 150, the spring 180 is compressed between the washer 184 and the end cap 186, and when the axle 172 is released, the spring 180 exerts a restoring force on the washer 184 to push the stop 182 away from the end cap 186.

[0060] In use, to adjust the height of the ladder assembly TOO, the securing mechanism 170 may be pulled away from the ladder extension 130 to retract the securing pin 178 from the securing apertures 118,158 allowing the ladder extension 130 to be moved to a new position relative to the ladder 102. Once the ladder extension 130 has been moved to align the securing aperture 158 ofthe ladder extension 130 with the securing aperture 118 of the ladder 102, the securing mechanism 170 may be moved to insert the securing pin 178 into the securing apertures 118,158 and restrict further movement of the ladder extension 130 with respect to the ladder 102.

[0061] In embodiments where the securing mechanism 170 is free to rotate relative to the ladder extension 130 in the retracted state, the handle 174 may be rotated to move the securing pin 178 away from the securing aperture 158 and then released to allow the securing pin 178 to rest against one of the extension side rails 132. This allows the user to move the ladder extension 130 relative to the ladder 102 without having to hold the securing mechanism 170 in the retracted state.

[0062] The first and second side rails 112 may define a plurality of securing apertures 118 arranged with similar spacing to that of the steps 114. Bach securing aperture 118 can be selectively secured to the securing apertures 158 of the ladder extension 130 using the securing pin 178 to hold the ladder 102 in respective securing positions relative to the ladder extension 130. Each securing position may correspond to an operating configuration of the ladder assembly 100 in which one or more of the steps 114 is aligned with one of the extension steps 154 to form a composite step 204. The spacing of the securing apertures 118 may be arranged such that moving the ladder extension 130 so that the securing aperture 158 aligns with a successive securing aperture 118 of the ladder 102 changes the operating height of the ladder assembly 100 by the distance between successive steps 114.

[0063] The relative positions of the securing apertures 118,158 and steps 114,154 may be arranged such that when a securing aperture 158 of the ladder extension 130 is aligned with a securing aperture 118 of the ladder 102 in a;'securing position (and can receive the securing pin 178), at least one of the steps 114 of the ladder 102 is aligned with one of the extension steps 154 of the ladder extension 130 at a similar distance from the second end 140 of the ladder extension 130 to form at least one composite step 204. In some securing positions in some embodiments, one or more of the steps 114 of the ladder may be disposed in the spaces between pairs of rungs 150,152 that form each extension step 154, such that the ladder steps 114 are aligned with the extension steps 154 to form composite steps 204. In some embodiments, the ladder 102 may include further securing apertures 118 corresponding to one or more securing positions in which the steps 114 of the ladder 102 are not aligned with the extension steps 154 of the ladder extension 130, and may be positioned at a higher level than the extension steps 154 so as to further extend the operating height of the ladder assembly 100 in use.

[0064] In some embodiments, the ladder 102 may further comprise a support structure 120 pivotally connected to the first and second side rails 112. The support structure may comprise first and second support legs 122 and one or more braces 124 connecting the first and second support legs 122 to each other. The support structure 120 is moveable from a storage configuration, with the first and second support legs 122 positioned alongside the first and second side rails 112, to a support configuration, with the first and second support legs 122 inclined with respect to the first and second side rails 112, such that in use, the support structure 120 can be used to support the ladder 102 in a free-standing upright orientation. This type of ladder 102 may be referred to as a free-standing ladder, a self-supporting ladder, an “A-frame” ladder or a single-sided step ladder, for example.

[0065] In some embodiments, the ladder assembly 100 may further comprise a support extension 160 slidably engaged with the first and second support legs 122 to extend an operating length of the support structure 120. The support extension 160 may engage the first and second support legs 122 in a similar way as described in relation to the engagement between the ladder extension 130 and the first and second side rails 112, and a similar securing mechanism 170 may secure a relative position between the second ladder extension 160 and the first and second extension side rails 122 to set the operating length.

[0066] The support extension 160 may comprise first and second extension legs 162 and two or more braces 164 connecting the first and second extension legs 162 to each other. The support extension 160 may comprise feet 166 with gripping surfaces to increase traction between the ladder assembly 100 and the ground during use. Sloped gripping surfaces may be provided on the feet 166 such that in use, when the support structure 120 is inclined relative to the ground, the gripping surfaces are substantially horizontal thereby maximising contact between the feet 166 and the ground. The gripping surfaces may have a rough texture such as a series of grooves to further increase traction between the ladder assembly 100 and the ground. Levellers 232 may be attached to one or both of the extension legs 162 as described in relation to the extension side rails 132.

[0067] The support extension 160 may include one or more securing apertures 168 and the support structure 120 may include one or more securing apertures 128. The securing apertures 128,168 may be sized to receive a securing pin 178 of the securing mechanism 170 to secure the position of the second ladder extension 160 relative to the support structure 120 in a similar way to the securing apertures 118,158 described in relation to the ladder 102 and ladder extension 130.

[0068] In some embodiments, the support structure 120 may be replaced with third and fourth side rails pivotally connected to the first and second side rails 112 as described in relation to the support structure 120. The third and fourth side rails may be connected to each other by a second set of ladder steps that are similar to the first set of ladder steps 114. This type of ladder 102 may be referred to as a free-standing ladder, a self-supporting ladder, a double-sided "A-frame” ladder or a double-sided step ladder, for example. f [0069] The support extension 160 may be replaced with a second ladder extension 130 and engage with the third and fourth side rails as described in relation to the ladder extension 130 and first and second side rails 112, [0070] In some embodiments, the ladder assembly 100 may further comprise a platform 190 pivotally mounted to the ladder 102 and moveable between a storage configuration alongside the first and second side rails 112 and a use or operating configuration as shown in Figures 1A and 1C, wherein the platform 190 extends between the first and second side rails 112 and the first and second support legs 122 (or third and fourth side rails). This provides a work platform for the user to stand on t and/or place tools or other items on. A ladder assembly 100 including a work platform 190 as described may be referred to as a platform ladder, platform step ladder, or podium ladder, for example.

[0071] The platform 190 may have a body formed of or comprising moulded plastic and defining an upper surface 192. A first end of the platform 190 may be pivotally mounted to the first and second side rails 112 and a second? end of the platform 190 may be free to move between the storage and operating configurations. In the operating configuration, the second end may rest on a brace 126 extending between the support legs 122. The platform 190 may include an upright back wall 194 to act as a kick plate to allow a user to detect the second end of the platform 190 with their feet and not step past the second end of the platform 190. The back wall 190 may define an aperture 196 to allow a part of the back wall 190 to be used as a handle to assist the user in folding the ladder assembly 100 into Hie storage configuration.

[0072] In some embodiments, the ladder assembly 100 may further comprise a safety rail 198 extending between the first and second side rails 112 at or near the first end 108. This may provide an added level of safety to the ladder assembly 100 by restricting the user from falling forward from the platform 190 or providing a grab rail for the user to hold onto to stop themselves falling backwards from the platform 190.

[0073] Each of the described components may be formed of any suitable material such as any one or more of: metals, metal alloys, steel, aluminium, aluminium alloys, plastics, polymers, resins, or fibreglass, for example. The side rails 112, extension side rails 132, support legs 122, extension legs 162, rungs 150,152, ladder steps 114 and braces 124, 156, 164 may be formed of a light metal such as Aluminium, for example, or may be formed of a non-conductive material such as fibre glass, for example, to reduce the chance of the user receiving an electric shock while working. The feet 146, 166 may be formed of a relatively soft material such as rubber, or an elastomer, to allow a small degree of deformation and increase traction with the ground or other surface on which the ladder assembly 100 is placed.

[0074] Figure 1C show the ladder assembly 100 in an assembled state. In this exemplary embodiment, the ladder 102 comprises three ladder steps 114 with six corresponding securing apertures 118 (three on each side rail 112). The ladder extension 130 includes a pair of securing apertures 158 disposed in the straight section 142, the first set of rungs 150 includes three rungs 150 and the second set of rungs 152 includes three rungs 152. The three ladder steps 114 are equally spaced from each other with similar spacing to the three extension steps 154 formed by the pairs of rungs 150, 152.

[0075] Figures 2A to 2C show the ladder assembly 100 set at three different operating heights corresponding to the three pairs of securing apertures 118. (Figures 2A to 2C show the configurations from a perspective view and Figures 3A to 3C show the configurations from a front view of the ladder assembly 100). The lowest ladder step 114 may be referred to as the bottom ladder step 114a, the next step up may be referred to as the intermediate ladder step 114b and the uppermost step may be referred to as the top ladder step 114c. The lowest extension step 154 may be referred to as the bottom extension step 154a, the next step up may be referred to as the intermediate extension step 154b and the uppermost step may be referred to as the top extension step 154c.

[0076] Figures 2A and 3 A show the ladder assembly 100 at its shortest operating height with each of the three ladder steps 114 accommodated in respective gaps between the rungs 150,152 of each extension step 154. The bottom ladder step 114a is aligned with the bottom extension step 154a, the intermediate ladder step 114b is aligned with the intermediate extension step 154b and the top ladder step 114c is aligned with the top extension step 154c. The ladder steps 114 and extension steps 154 cooperate to provide three useable steps, including three composite steps 204.

[0077] Figures 2B and 3B show the ladder assembly 100 at an intermediate operating height with the lower two ladder steps 114 accommodated in respective gaps between the rungs 150, 152 of the upper two extension steps 154. The bottom ladder step 114a is aligned with the intermediate extension step 154b, the intermediate ladder step 114b is aligned with the top extension step 154c, the top ladder step 114c is disposed above the extension steps 154 and the bottom extension step 154a disposed below the ladder steps 114. The ladder steps 114 and extension steps 154 cooperate to provide four useable steps, including two composite steps 204, one extension step 154 lower than the composite steps 204 and one ladder step 114 higher than the composite steps 204.

[0078] Figures 2C and 3C show the ladder assembly 100 at its tallest operating height with the lowest ladder step 114 accommodated in the gap between the rungs 150,152 of the uppermost extension step 154. The bottom ladder step 114a is aligned with the top extension step 154c, the intermediate and top ladder steps 114b, 114c are disposed above the extension steps 154 and the bottom and intermediate extension steps 154a, 154b are disposed below the ladder steps 114, The ladder steps 114 and extension steps 154 cooperate to provide five useable steps, including one composite step 204, two extension steps 154 lower than the composite step 204 and two ladder steps 114 higher than the composite step 204..

[0079] As discussed above, in some embodiments, the ladder 102 may include further securing apertures 118 allowing the ladder 102 to be set at a higher operating height relative to the ladder extension 130 with all of the ladder steps 114 disposed higher than all of the extension steps 154. In some embodiments, the ladder 102 may include further ladder steps 114 and/or the ladder extension 130 may include further extension steps 154.

[0080] The ladder assembly 100 can be adjusted between the three operating configurations described by disengaging the securing mechanisms 170; sliding the ladder extension 130 relative to the ladder 102; and then reengaging the securing mechanisms 170 to set the operating height of the ladder assembly 100. The support extension 160 may also be repositioned in a similar way to adjust the operating length of the support structure 120, The support extension 160 may be adjusted to make the platform 190 substantially horizontal when the feet 146, 166 are placed on the ground. In some cases, the ladder assembly 100 may be used on uneven ground, or a flight of stairs, for example, and the operating length of the support'structure 120 may be adjusted to make the platform 190 substantially horizontal, taking into account the height difference of the positions of the feet 146, 166 on different steps.

[0081 ] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A ladder assembly comprising a platform ladder and a ladder extension adapted to slidably receive the platform ladder and to extend an operating height of the platform ladder, the ladder extension comprising: first and second extension side rails; a first set of one or more rungs extending from the first extension side rail to the second extension side rail; a second set of one or more rungs extending from the first extension side rail to the second extension side rail; and a first securing mechanism to selectively secure a position of the platform ladder relative to the ladder extension and set the operating height; wherein a rung of the first set of rungs is aligned with and spaced apart from a corresponding rung of the second set of rungs to form an extension step having a gap between the rungs sized to receive a step of the platform ladder and allow passage of the platform ladder through the extension step to adjust the operating height of the platform ladder.
2. A ladder assembly according to claim 1, wherein the platform ladder comprises: first and second side rails; a first set of ladder steps extending from the first side rail to the second side rail, wherein the first and second side rails are slidably engageable with the first and second extension side rails of the ladder extension, and wherein the platform ladder can be positioned relative to the first ladder extension such that one of the first set of ladder steps is aligned with and disposed between the rungs of the extension step of the ladder extension; a support structure having first and second support legs connected to each other by one or more braces, the support structure being pivotally mounted to the first and second side rails to allow the platfonn ladder to be folded into a storage configuration, with the support legs alongside the side rails, and opened into an operating configuration, with the support legs extending away from the side rails to support the ladder assembly in a free-standing configuration; and a platform pivotally mounted to the platform ladder, the platform being moveable between a storage configuration alongside the first and second side rails, and an operating configuration in which the platform extends between the first and second side rails and the first and second support legs; and wherein the ladder assembly further comprises a support extension adapted to slidably receive the support structure of the platform ladder to extend an operating length of the support structure, the support extension comprising: first and second extension legs; a plurality of braces extending from the first extension leg to the second extension leg; and a support extension securing mechanism to selectively secure a position of the support extension relative to the support structure of the platform ladder and set the operating length of the support structure.
3. A ladder assembly according to claim 1, wherein the platform ladder comprises: first and second side rails; a first set of ladder steps extending from the first side rail to the second side rail, wherein the first and second side rails are slidably engageable with the first and second extension side rails of the ladder extension, and wherein the platform ladder can be positioned relative to the first ladder extension such that one of the first set of ladder steps is aligned with and disposed between the rungs of the extension step of the ladder extension; third and fourth side rails; a second set of ladder steps extending from the third side rail to the fourth side rail, the third and fourth side rails being pivotally mounted to the first and second side rails to allow the platform ladder to be folded into a storage configuration, with the third and fourth side rails alongside the first and second side rails, and opened into an operating configuration, with the third and fourth side rails extending away from the first and second side rails to support the ladder assembly in a free-standing configuration, a platform pivotally mounted to the platform ladder, the platform being moveable between a storage configuration alongside the first and second side rails, and an operating configuration in which the platform extends between the first and second side rails and the third and fourth side rails; and wherein the ladder assembly further comprises a second ladder extension adapted to slidably receive the platform ladder and to extend an operating height of the platform ladder, the second ladder extension comprising: first and second extension side rails; a first set of one or more rungs extending from the first extension side rail to the second extension side rail; a second set of one or more rungs extending from the first extension side rail to the second extension side rail; and a first securing mechanism to selectively secure a position of the platform ladder relative to the second ladder extension and set the operating height; wherein a rung of the first set of rungs is aligned with and spaced apart from a corresponding rung of the second set of rungs to form an extension step having a gap between the rungs sized to receive a step of the platform ladder and allow passage of the platform ladder through the extension step to adjust the operating height of the platform ladder; and wherein the third and fourth side rails of the platform ladder are slidably engageable with the first and second extension side rails of the second ladder extension, and wherein the platform ladder can be positioned relative to the second ladder extension such that one of the second set of ladder steps is aligned with and disposed between rungs of the extension step of the second ladder extension.
4. A ladder assembly according to any one of the preceding claims, wherein the width between the extension side rails at a bottom end of the ladder extension is configured to be greater than the lateral distance between the extension side rails at a top end of the ladder extension by at least 12.5% of: the maximum total extended length of the ladder extension combined with side rails of the platform ladder; or the distance between a top end of the platform ladder and the bottom end of the ladder extension when the platform ladder combined with the ladder extension is extended to a maximum operating height.
5. A ladder assembly according to any one of claims 2 to 4, wherein the platform ladder further comprises a safety rail extending from the first side rail to the second side rail at or near an end of the platform ladder distal to the ladder extension.