Support ladder

Abstract

A ladder includes a first assembly and a second assembly, each including a pair of spaced apart ladder frames and a set of crosspieces coupled to and extending between the spaced apart ladder frames. A pair of brackets slidably receive a pair of spaced apart ladders. A pair of projections extends from the spaced apart ladders and is movable into a pair of slots defined by a pair of retainers coupled with another pair of spaced apart ladders. When the ladder is in a live ladder configuration at a non-zero angle between the first assembly and the second assembly, the protrusions are movable into the slots, such as by moving the pair of retainers from the locked position to the unlocked position when the ladder bed carrying the protrusions slides longitudinally relative to the pair of brackets. The ladder may also have struts and spaced crosspiece retainers that have a limited range of movement when stowed.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 579,764, filed August 30, 2023, the disclosure of which is incorporated herein by reference in its entirety. Background Technology

[0003] Typically, ladders are used to improve accessibility for users to elevated positions that would otherwise be inaccessible. Ladders come in many shapes and sizes, such as straight ladders, telescopic ladders, step ladders, and combination ladders that combine both. "Combination" ladders (sometimes also called articulated ladders) combine the advantages of multiple ladder designs into a single ladder and can be constructed by the user to mimic a variety of other ladders.

[0004] Straight ladders, telescopic ladders, or combination ladders (when constructed as straight or telescopic ladders) are traditionally positioned against a raised surface (such as the edge of a wall or roof) to support the ladder at a desired angle. The user then climbs the ladder to access the raised area, such as reaching the upper part of a wall or the roof. A pair of feet or pads (one attached to the bottom of each side rail) are typically used to engage with the ground, floor, or other generally level support surface.

[0005] Ladders and combination ladders (when constructed as ladders) are generally considered "self-supporting" because they include a first ladder frame assembly that includes rungs or crossbars connected to a second ladder frame assembly or other support structure. In a ladder construction, the first and second ladder frame assemblies are typically positioned at an acute angle relative to each other, such that multiple legs or support members (at least three, but typically four) support the ladder in a self-supporting position. Therefore, the ladder can be used "self-supporting" without needing to lean against a wall or other vertical support structure. A self-supporting or ladder construction may be referred to as a scaffolded ladder construction or an A-frame upright construction.

[0006] Some modular ladders can be converted from movable ladders to telescopic ladders by pivoting at the top hinge connecting the first and second ladder assemblies. Some ladders also have a rear ladder assembly configured to extend or retract parallel to the front ladder assembly, allowing the ladder to have a user-adjustable total length in either a straight or telescopic configuration. However, these modular ladders can be unstable or cumbersome to use because they require locking into place when reconstructed from a straight ladder configuration, especially when the user is unfamiliar with the ladder mechanism or for rapid operations. Summary of the Invention

[0007] One aspect of this disclosure relates to a ladder comprising: a first assembly including a first pair of spaced-apart ladder frames and a first set of runners coupled to and extending between the first pair of spaced-apart ladder frames; a second assembly including a second pair of spaced-apart ladder frames and a second set of runners coupled to and extending between the second pair of spaced-apart ladder frames; a pair of supports coupled to the second assembly and slidably receiving the first pair of spaced-apart ladder frames; a pair of protrusions extending from the first pair of spaced-apart ladder frames; and a pair of retainers movably coupled to the second pair of spaced-apart ladder frames and at least partially defining a pair of slots. The first pair of spaced-apart ladder frames are movable relative to the pair of supports between a first configuration and a second configuration. In the first configuration, the first pair of spaced-apart ladder frames and the second pair of spaced-apart ladder frames are positioned relative to each other at a non-zero angle, and the pair of protrusions are positioned outside the pair of slots. In the second configuration, the first pair of spaced-apart ladder frames and the second pair of spaced-apart ladder frames are positioned relative to each other at the non-zero angle, and the pair of protrusions are positioned within the pair of slots. The sliding movement of the first pair of spaced-apart ladder frames relative to the pair of supports can be configured to move the pair of retainers relative to the second pair of spaced-apart ladder frames.

[0008] In some embodiments, the pair of supports may be pivotable relative to the second component. The pair of protrusions may extend laterally from the first pair of spaced-apart ladder frames. The pair of retainers may be rotatably coupled to the second pair of spaced-apart ladder frames.

[0009] In some configurations, the ladder may further include a pair of biasing mechanisms that bias the movement of the pair of retainers relative to the second pair of spaced-apart ladder frames. In response to a force exerted on the pair of retainers by the pair of protrusions as the first pair of spaced-apart ladder frames move relative to the pair of supports from the first configuration to the second configuration, the pair of retainers may move against a pair of biasing forces exerted by the pair of biasing mechanisms. In some embodiments, at least one of the retainers includes a hook-like surface that defines a slot in the pair of grooves. The ladder may also include a cover portion configured to cover the distal surface of at least one of the retainers. The first pair of spaced-apart ladder frames can move from the first configuration to the second configuration while always maintaining the non-zero angle relative to the second pair of spaced-apart ladder frames.

[0010] Another aspect of this disclosure relates to a ladder comprising: a first component including: a first pair of spaced-apart ladder frames, a first set of runners extending between and connected to the first pair of spaced-apart ladder frames, and at least one pin member extending laterally from the first pair of spaced-apart ladder frames; a second component including: a second pair of spaced-apart ladder frames, a second set of runners extending between and connected to the second pair of spaced-apart ladder frames, and at least one retainer member connected to at least one of the second pair of spaced-apart ladder frames, the at least one retainer member being movable between an unlocked position relative to the at least one ladder frame and a locked position relative to the at least one ladder frame; and a hinge assembly rotatably connecting the first component to the second component. The first pair of spaced-apart ladder frames and the second pair of spaced-apart ladder frames are movable via the hinge assembly to an open configuration having an acute angle between the first pair of spaced-apart ladder frames and the second pair of spaced-apart ladder frames, wherein when in the open configuration and the at least one retainer member is in the locked position, longitudinal movement of the first component relative to the hinge assembly is prevented due to contact between the at least one pin member and the at least one retainer member, and wherein when in the open configuration and the at least one retainer member is in the unlocked position, the first component is movable longitudinally relative to the hinge assembly.

[0011] In some embodiments, the at least one retainer member at least partially defines a groove when in the locked position. The at least one pin member may include a rod extending between the top ends of the first pair of spaced-apart ladder frames. The second component may also include at least one biasing member configured to apply a force to the at least one retainer member, wherein the force biases the at least one retainer member toward the locked position. The at least one retainer member may move from the locked position to the unlocked position in response to a force applied by the at least one pin member to the distal surface of the at least one retainer member. When the first pair of spaced-apart ladder frames and the second pair of spaced-apart ladder frames are at the acute angle, the at least one retainer member may move from the locked position to the unlocked position by a force applied by the at least one pin member to the distal surface of the at least one retainer member. The first component may include a cover member configured to restrict user access to the distal surface of the at least one retainer member when the at least one pin member contacts the proximal surface of the at least one retainer member.

[0012] Another aspect of this disclosure relates to a ladder comprising: a first assembly including: a first pair of spaced-apart ladder frames; a first set of runners extending between and connected to the first pair of spaced-apart ladder frames; and a second assembly including: a second pair of spaced-apart ladder frames; a second set of runners extending between and connected to the second pair of spaced-apart ladder frames; and at least one strut assembly including: a first strut member rotatably connected to a first ladder frame in the first pair of spaced-apart ladder frames; and a second strut member rotatably connected to a second ladder frame in the second pair of spaced-apart ladder frames, wherein the second strut member is rotatably connected to the first strut member between the first ladder frame and the second ladder frame. The at least one strut assembly is movable between an extended configuration and a retracted configuration, wherein when in the extended configuration, the at least one strut assembly keeps the first ladder and the second ladder separate; and wherein when in the retracted configuration, a portion of the at least one strut assembly prevents the first strut member or the second strut member from rotating beyond the volume envelope defined by the first and second assemblies together.

[0013] In some embodiments, a portion of the at least one strut assembly may include a bracket that limits the rotational range of the first strut member beyond the volume envelope. The portion of the at least one strut assembly may include an abutment member extending laterally from the first strut member between the outermost surfaces of the first and second ladder frames, wherein the abutment member is configured to engage at least one of the first and second ladder frames in response to rotation of the first strut member relative to the first ladder frame. The portion of the at least one strut assembly may include a stop surface on the first strut member, wherein the stop surface is configured to engage the second strut member when in the retracted configuration.

[0014] The above summary of the invention is not intended to describe every embodiment or every implementation of the invention. The following drawings and detailed description illustrate one or more preferred embodiments in more detail. Attached Figure Description

[0015] The accompanying drawings illustrate several exemplary embodiments and are part of the specification. Together with this specification, these drawings demonstrate and explain various principles of the present disclosure. A further understanding of the nature and advantages of the invention can be achieved by referring to the following drawings. In the drawings, similar parts or features may have the same reference numerals.

[0016] Figure 1 This is an isometric view of a ladder in a movable ladder configuration.

[0017] Figure 2 yes Figure 1 Front view of the ladder.

[0018] Figure 3 yes Figure 1 The ladder is in an isometric view of the retracted structure.

[0019] Figure 4 yes Figure 1 The ladder is in an isometric view of a straight ladder structure.

[0020] Figure 5 yes Figure 1 An isometric view of the top of the ladder.

[0021] Figure 6 yes Figure 1 The right-hand view of the top of the ladder.

[0022] Figure 7 yes Figure 1 The top right view of the ladder, with the hinge plate removed.

[0023] Figures 8 to 12 It shows when Figure 1 The top of the ladder moves from the self-supporting structure through a series of unlocked mechanisms, as seen from the right-hand view.

[0024] Figures 13 to 17 It shows when Figure 1 The top of the ladder moves to the right side view of the self-supporting structure via a series of locking movements of protrusions and retainers.

[0025] Figure 18 It shows Figure 1 An isometric view of the ladder at the strut assembly.

[0026] Figure 19 It shows Figure 1 The right-side center cross-section of the top end of the ladder.

[0027] Figure 20 It shows Figure 3 The right-side center cross-section of the top end of the ladder.

[0028] Figure 21 An isometric view of the lateral inner side of the front ladder frame and strut assembly of an exemplary ladder in the stowed state is shown.

[0029] Figure 22 An isometric view of the lateral inner side of the front ladder frame and strut assembly of an exemplary ladder in the stowed state is shown.

[0030] Figure 23It shows Figure 4 The right-side center cross-section of the top end of the ladder.

[0031] Figure 24 It is an isometric view of the top of a ladder with an alternative V-shaped bar.

[0032] Figure 25 yes Figure 24 The right-side view of the ladder.

[0033] While the embodiments described herein are susceptible to various modifications and alternatives, specific embodiments have been illustrated by way of example in the drawings and will be described in detail herein. However, the exemplary embodiments described herein are not intended to be limited to the particular forms disclosed. Rather, this disclosure covers all modifications, equivalents, and alternatives falling within the scope of the appended claims. Detailed Implementation

[0034] Combination ladders, such as those with support frames, can be difficult, unstable, and cumbersome to use. The rear component of the ladder can be configured to slide between an extended and retracted position relative to the front component, and in order to keep the rear component in place relative to the front component when the ladder is in a live or self-supporting configuration, it needs to be held in place by a retaining mechanism or locking component. The retainer of the retaining mechanism can receive one or more pins or protrusions extending laterally from the ladder frame of the rear component to prevent unwanted sliding of the rear component relative to the front component. However, holding the pins or protrusions in the retainer can be difficult for the user, especially during rapid operations. It is also difficult for the user to determine from a distance or at a glance whether the pins or protrusions are correctly locked in place. If the ladder is in a live configuration, the pins or protrusions may become misaligned when the user begins to apply load to the ladder, causing the rear ladder frame to slide unexpectedly and the ladder to collapse. Furthermore, it may be necessary to lift the ladder and move it to at least a partially retracted position before moving the pins or protrusions to the retaining position, which can lead to user fatigue and slow down their workflow.

[0035] Embodiments of this disclosure relate to combined ladders and similar ladders that can more safely and easily prevent unwanted slippage of the rear ladder frame assembly relative to the front ladder frame assembly. For example, the ladder may include a pair of protrusions extending (e.g., laterally) from the rear ladder frame and a pair of retainers movably coupled to the front ladder frame and at least partially defining a pair of slots. The pair of retainers can move between different configurations in response to sliding movement of the rear ladder frame within the pair of supports. See also Figures 13 to 17When a ladder is converted from a straight or telescopic ladder construction to a movable or self-supporting construction, a pair of protrusions can contact a pair of retainers, which can then be moved out of the path of movement of the protrusions and then moved to a position where the retainers hold the protrusions in place. The pair of retainers can be biased by a biasing mechanism (e.g., a spring) that pushes the pair of retainers toward the holding position after the protrusions have moved and disengaged from contact with the distal end or top surface of the retainers. See also Figure 7 In this way, the ladder can be unlocked from the movable ladder construction (where the protrusions are not held in place by the retainer, such as...). Figure 13 (As shown) Moves to the locked ladder construction (where the protrusion is held in place by the retainer, as shown) Figure 6 (As shown). Therefore, the user can switch from a straight ladder configuration to a locked movable ladder configuration without moving the front and rear components of the ladder to the retracted (or near-retracted) state. Furthermore, the movement of the retainer provides an audible and / or tactile click when it enters the locked position, helping the user confirm that the ladder is fully in the locked movable ladder configuration.

[0036] A cover plate or V-shaped bar may be provided to restrict or prevent tampering with the retainer when it is in the locked configuration, so that the protrusion cannot be unintentionally unlocked or released. The cover plate may also expose and make visible portions of the retainer, allowing the user to easily and visually determine whether the protrusion is locked in the proper position by the retainer.

[0037] In some exemplary embodiments, the ladder may further include one or more strut assemblies that help maintain the relative positions of the front and rear assemblies in the live ladder position (i.e., prevent the ladder frames from retracting towards each other). The strut assemblies can be unlocked and retracted to allow the front ladder frames to retract toward the rear ladder frames by pivoting at support brackets. When the strut assemblies are in their unlocked and retracted positions, their movement in the forward / backward (or vice versa) direction can be restricted by a portion of the strut assembly that contacts the rotating member of the strut assembly. This portion of the strut assembly may be a flange, protrusion, rivet, bar, pin, stop surface, or bracket that mechanically interferes with the movement of the rotating member of the strut assembly, or contacts the ladder frame, rungs, or other nearby ladder components in such a way as to restrict the range of motion of the strut assembly when it is in the retracted configuration. In this way, movement of the strut assemblies beyond a volume envelope defined by the first and second assemblies, such as the volume envelope between the front surface planes of a pair of front ladder frames and the rear surface planes of a pair of rear ladder frames.

[0038] Furthermore, in some examples, the ladder may include a pair of rung support members extending from the front assembly toward the rear assembly. The rung support members may be retainers including a hook-shaped or U-shaped top surface configured to receive the lower surface of the rungs of the rear assembly when the rear assembly is in the straight ladder position or the retracted position. A crossbar in the retainer prevents the rear assembly from retracting by sliding relative to the front assembly. The rungs of the rear assembly can be removed from the rung support members to adjust the overall length of the straight ladder, and then the rung support members can support different rungs. The rung support members may be spaced apart to allow the user's hands to move between the rung support members as they adjust the position of the rear ladder frame and the rungs. Therefore, the user can move their hand across the rung support members while grasping one of the rungs of the rear assembly without rotating the rear assembly.

[0039] This specification provides examples and does not limit the scope, applicability, or construction set forth in the claims. Therefore, it will be understood that changes may be made to the function and arrangement of the elements discussed without departing from the spirit and scope of this disclosure, and various embodiments may appropriately omit, substitute, or add other processes or components. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Moreover, features described with respect to certain embodiments may be combined in other embodiments.

[0040] Figures 1 to 4 A combined ladder 100 is shown in various configurations. The combined ladder 100 may include a rear assembly 102 and a front assembly 104. The rear assembly 102 may alternatively be referred to as a first assembly, a first ladder frame assembly, or a front ladder frame assembly, and the front assembly 104 may also be referred to as a second assembly, a second ladder frame assembly, or a rear ladder frame assembly. The rear assembly 102 may include a pair of spaced-apart ladder frames (i.e., rear ladder frames 106) and a set of rear runners (e.g., rear runners 108) directly coupled to the rear ladder frames 106 and extending between the rear ladder frames. The front assembly 104 may include a second pair of spaced-apart ladder frames (i.e., front ladder frames 110) and a set of front runners (e.g., front runners 112) directly coupled to the front ladder frames 110 and extending between the front ladder frames. Each of the front assembly 104 and the rear assembly 102 may include one or more legs 114, 116 for supporting the ladder 100 when it is in a live ladder configuration (e.g., as shown in the image). Figures 1 to 2 (As shown). A pair of strut assemblies 118 may extend between the front assembly 104 and the rear assembly 102 to help hold the ladder 100 in the ladder configuration, such as by maintaining an acute angle between the front ladder frame 106 and the rear ladder frame 110 (e.g., Figure 6 (Angle X in the middle). See also Figure 18 Figure 19 And its relevant description in this article.

[0041] As used herein, the "front" or "forward" direction refers to the direction when ladder 100 is in the retracted configuration (e.g., Figure 3 When the vertical center plane of the ladder 100, which is parallel to the front ladder frame 110 and the rear ladder frame 106, is away from the ladder 100, (e.g., Figure 20 The direction of plane K in the ladder. The "back" or "rearward" direction is the opposite of the "front" direction; the "lateral" direction is the left or right direction perpendicular to the front and back directions; the "outer lateral" direction is the left or right direction perpendicular to the front and back directions and also away from the center of the ladder (i.e., between the front crossbeams 110 or the rear crossbeams 106); the "far end" direction is the direction away from the volume center of the ladder (e.g., facing upward at the top of the ladder); and the "near end" direction is the direction towards the volume center of the ladder (e.g., facing downward at the top of the ladder).

[0042] Features referred to as “substantially parallel” in this article are considered to be offset by an angle of less than 5 degrees relative to each other, unless they are referred to as “parallel”, in which case these features will be offset by an angle of less than 1 degree relative to each other.

[0043] As used herein, components can be “connected” to each other by being held together directly or indirectly (i.e., via intermediate components). “Directly connected” components are attached directly to each other (i.e., without intermediate components). “Slidingly connected” components can be held together while also sliding relative to each other, such as by contact with each other’s surfaces, or by being connected via intermediate components but translatable relative to each other. Components can be “attached,” “joined,” or “mounted” to each other by being connected, but cannot move relative to each other.

[0044] The rear ladder 106 can be configured to be substantially parallel to each other along its entire length. In this way, the rear ladder 106 can slide along most of its entire length through a pair of sliding support brackets 121 (described below) without getting stuck in the sliding support brackets 121. Figure 2 As shown, the front ladder 110 may have an upper end (near the hinge plate 120) spaced at an interval equal to that of the rear ladder 106, and may have a lower end (near the legs 114) that flares out or bends to a greater distance than the upper end. The increased width of the lower end of the front ladder 110 can improve the stability of the ladder 100 by providing a wider support span. The central portion of the front ladder 110 (e.g., between the second front crossbar 112 from the top and the second front crossbar 112 from the bottom) may include a bend that makes the lower end of the front ladder 110 wider than its upper end.

[0045] Ladder frames 106, 110 can be made of rigid metal (e.g., aluminum), wood, or composite materials (e.g., fiberglass) to provide rigidity. Rear rung 108 and front rung 112 can comprise similar materials and can provide a set of spaced-apart footholds for a user climbing ladder 100. In some embodiments, one or more rungs 108, 112 can be replaced by cross braces or other horizontal supports extending between ladder frames 106, 110 that are not intended to be used as rungs or footholds. When ladder 100 is in the stowed position, rungs 108, 112 can be positioned entirely between and within the front and rear surfaces of their respective ladder frames 106, 110 in a manner that minimizes the overall volume envelope of ladder 100 (e.g., as shown in the image). Figure 3 As shown, and in combination Figure 20 (Further detailed description).

[0046] A pair of hinge plates 120 can be positioned at the top of the front ladder frame 110. The pair of hinge plates 120 are pivotally connected to a pair of sliding support brackets 121, which are coupled to the rear assembly 102. The sliding support brackets 121 are slidably coupled to and receive a pair of rear ladder frames 106. Each sliding support bracket 121 may include an upper bracket 128, a ladder frame guard 122, and a lower bracket 124. The pivot axis of the hinge plates 120 and the upper bracket 128 can be extended by a pair of pivoting connectors 129 (e.g., ...). Figures 5 to 6 (As shown). Therefore, the rear assembly 102 can rotate relative to the front assembly 104 about the axis of rotation of the pivoting connection 129 extending through each side of the ladder 100. The maximum spread angle of assemblies 102, 104 (e.g., the maximum pivot angle X when the ladder 100 is in a movable ladder configuration) can be limited by the strut assembly 118, since the strut assembly 118 is directly coupled to the front ladder frame 110 and the lower support 124. In some examples, the strut assembly 118 may be omitted from the ladder 100, and as described below, the protrusion 132 at the hinge plate 120, the retainer 130, and other upper components can hold the ladder 100 in the movable ladder configuration when the protrusion 132 is in its locked position in the slot 134.

[0047] The rear component 102 can also pivot around the pivot connector 129 to the retracted configuration (e.g.) Figure 3 As shown), the retractable configuration is also referred to as an approximately and substantially parallel component configuration, a fully retracted straight ladder configuration, or a fully overlapping ladder configuration. When in or near the retractable configuration, the rear ladder 106 can be moved upward relative to the plate 120 to an extended position (e.g., Figure 4 (As shown), the extended position is also called an extended position or a straight ladder construction. See also Figures 11 to 12 .

[0048] In its retracted or extended position, the ladder 100 can be supported in an elevated state by resting against a vertical support surface, a rod, or a similar raising structure. The ladder 100 may include a V-shaped bar 126 or similar support structure or abutment member having an angled outer surface and a spaced surface geometry, said angled outer surface and spaced surface geometry being configured such that the upper end of the ladder frame 106 rests against a planar wall, an interior angle (e.g., two vertical support structures forming a 90-degree interior angle, e.g., a wall), an exterior angle (e.g., two vertical support structures forming a 90-degree exterior angle), a rod, a rectangular column, a post, or a similar structure. In some examples, the V-shaped bar 126 may be replaced by a straight bar or a crossbar (e.g., 108), or it may be omitted. Figure 5 As shown, the V-shaped rod 126 can adopt an M-shaped profile, wherein the very end of the V-shaped rod 126 (at the cover plate portion 150) is laterally outward positioned outside the rear ladder frame 106.

[0049] like Figures 5 to 6 As shown, a pair of plates 120 can be installed on the top of the front ladder 110. Figure 5 An isometric view of the front of ladder 100 is shown, and Figure 6 The right-side view of the ladder is shown. Figure 7 A right-side view is shown after removing panel 120. Panel 120 can wrap around the top of the front ladder frame 110 to protect the ends of the ladder frame. Therefore, panel 120 can include multiple wall portions 120-1, 120-2, 120-3 facing different directions and wrapping around the ladder frame 110. For example, as Figure 5 As shown, the front wall portion 120-1 can be positioned facing forward and away from the front side of the front ladder frame 110, the outer wall portion 120-2 can be positioned laterally outward from the front ladder frame 110, and the top wall or inner wall portion 120-3 can be positioned upward and / or laterally inward from the ladder frame 110. The plate 120 may also each have a rearwardly projecting portion 120-4, which extends rearward relative to the rear surface of the ladder frame 110 (i.e., the surface facing the rear ladder frame 106). The wall portions 120-1, 120-2, 120-3 and the rearwardly projecting portion 120-4 (which may be part of the wall portion 120-2) may be portions of a single piece of material (e.g., stamped steel or aluminum), which are bent into a final shape covering multiple sides of the front ladder frame 110 and surrounding other components (such as the retainer 130 and the biasing member 144). See below. Figures 6 to 7 And its related descriptions.

[0050] A pair of hinge plates 120 may at least partially cover and surround a pair of retainers 130, said pair of retainers being movably coupled to one or more portions of the plates 120 or the ladder frame 110. The pair of retainers 130 may at least partially define a pair of slots 134 (see...). Figure 6 The pair of slots are configured to each receive one of a pair of protrusions 132 extending from the rear ladder 106. The retainer 130 may be referred to as a retainer member, a protruding retainer hook, a door hook, or a pivotable latch. The slot 134 may also be defined at least partially by one or more portions of the plate 120, such as the outer wall portion 120-2 and the rearwardly projecting portion 120-4. Figures 5 to 6 As shown, when the ladder 100 is in the movable ladder configuration, each protrusion 132 can be positioned at the innermost end of its corresponding slot 134. When the ladder 100 is in the movable ladder configuration, the ladder frames 106, 110 can form a non-zero acute angle X between the plane defined by the rearward-facing side of the front ladder frame 110 and the plane defined by the forward-facing side of the rear ladder frame 106 (or the plane defined by the front side of the sliding support bracket 121) (see...). Figure 6 Furthermore, all the legs of the ladder 100 (e.g., 114, 116) can be supported by a common plane or one or more horizontal planes when in a live ladder configuration.

[0051] like Figures 3 to 5 As shown, protrusion 132 may include a pin, bar, or other protruding member extending laterally from the outer surface of the rear ladder frame 106. In some embodiments, such as Figures 1 to 5 As shown, the protrusion 132 may be the end portion of a rod or bar 133 located between and connected to the rear ladder frames 106. The bar 133 may reinforce the ends of the rear ladder frames 106 and provide additional rigidity to the ladder 100. The bar 133 may also be connected to a V-shaped bar 126 to increase the rigidity and load-bearing capacity of the V-shaped bar 126. In some embodiments, the protrusion 132 may include a flange, pin, or stud (e.g., a rivet) extending laterally from the rear ladder frames 106. In this case, the bar 133 between the ladder frames 106 may be omitted.

[0052] With the protrusion 132 positioned in the groove 134, the rear ladder frame 106 is prevented from being in at least one direction D within the sliding support bracket 121 (see...). Figures 6 to 7 Sliding on the surface of the retainer 130, the direction of which points towards the proximal surface 136 of the retainer 130 and is parallel or substantially parallel to the longitudinal axis of the rear ladder 106 (e.g., Figure 13 (156 in the text). Because the protrusion 132 contacts the proximal surface 136, the retainer 130 can mechanically block and interfere with any movement of the protrusion 132 in the D direction. The proximal surface 136 may be referred to as the lower surface, inner surface, or hook-shaped surface of the retainer 130. The proximal surface 136 may be substantially straight, or it may be hook-shaped or curved around the protrusion 132 to support the protrusion 132 from multiple sides when in the locked position. For example, as Figure 7As shown, retainer 130 may have an inverted J-shaped or L-shaped profile, its pivot end 138 being substantially straight and its retainer ends (including surfaces 136 and 146) extending or curving away from pivot end 138 at an angle. Each proximal surface 136 may form an angle of less than 90 degrees with a fully vertical axis (e.g., the direction of gravity) extending through the proximal surface 136, such as an angle of about 87 degrees or about 88 degrees relative to the vertical axis, to help prevent retainer 130 from accidentally moving into the space between hinge plate 120 and front ladder 110. Pivot end 138 may be pivotally coupled directly to plate 120 (e.g., in protrusions 120-4, as shown). Figure 6 (See pivot connector 140 in the diagram). In some embodiments, the proximal surface 136 of the retainer 130 may have an L-shaped or C-shaped profile, each profile determining a different path for the protrusion 132 to retract from the slot 134 when appropriate. (See below...) Figures 8 to 11 Additional details are provided regarding the retraction of protrusion 132 from slot 134.

[0053] A pair of retainer support members 142 can be directly connected to the lateral outer side of the front ladder frame 110 between the ladder frame 110 and the plate 120. See also Figure 7 A pair of retainer support members 142 may each be coupled to an end of one of a pair of retainer biasing members 144. The retainer biasing members 144 may also each be coupled to a single retainer of a pair of retainers 130. The biasing member 144 may include a spring or other biasing structure configured to apply a biasing force to the retainer 130 in such a way that it drives the retainer about the pivoting connection 140 toward… Figures 6 to 7 Rotation to the indicated position. In some embodiments, the biasing member 144 may include a compression spring, a tension spring, a leaf spring, a torsion spring, a helical spring, a gas spring, similar structures, and combinations thereof. The biasing member 144 may be positioned at other locations on the ladder 100, such as at or around the pivoting connection 140. In some cases, a force applied to the upper surface or distal surface 146 of the retainer 130 may overcome the biasing force and allow the retainer 130 to rotate in the opposite direction about the pivoting connection 140, as will be described in further detail below. Retraction rotation of the retainer 130 (e.g., retraction behind the plate 120) may be limited by contact between the structure of the pivot end 138 and the retainer support member 142. The tab 162 in the plate 120 may limit the extension rotation of the retainer 130.

[0054] When in such a situation Figures 6 to 7In the locked position shown, the distal surface 146 of the protrusion 132 can be at least partially covered (from above) by the cover portion 150 of the V-shaped bar 126. The cover portion 150 can be positioned laterally outside the rear ladder 106 and vertically overlaps the retainer 130 at the distal surface 146. Therefore, since the cover portion 150 is located directly above the distal surface 146, the user's access to the distal surface 146 (e.g., via their fingers or tools) is restricted or prevented. Figures 24 to 25 A ladder 200 is shown, having a V-shaped bar 226 configured to fully overlap and cover a set of retainers 230 to further limit or prevent accidental actuation of the retainers 230. All other components of the ladder 200 may be similar to those of the ladder 100, and the ladder 100 may perform the functions of the ladder 200. To facilitate the full overlap of the retainers 230, the V-shaped bar 226 may have a cover portion 250 extending over the entire distal surface 246 when the ladder frame is configured in an upright position. Thus, each retainer 230 may have a horizontal width H (see [reference needed]). Figure 25 When the ladder frame is in an upright, angled configuration and the protrusion 232 is held by the retainer 230, the entire or substantially all of the width H is located below the cover portion 250. The overhang of the cover portions 150, 250 relative to the retainers 130, 230 can advantageously prevent the retainers 130, 230 from accidentally or unintentionally unlocking and the protrusions 132, 232 from being released, which would otherwise allow the rear ladder frames 106, 206 to slide in the sliding support brackets 121, 221 under improper operating conditions (e.g., when a user is standing on the ladders 100, 200).

[0055] Figure 6 and Figures 8 to 17 Various possible positions of the protrusion 132 and the retainer 130 relative to each other are shown. The protrusion 132 from... Figure 6 Lock position to Figure 11 The movement of the unlocked position can be referred to as the unlocking movement of the rear ladder 106. The protrusion 132 (and retainer 130) from... Figure 13 Unlock location to Figure 17 Location (and then to) Figure 6 The movement of the locked position can be referred to as the locking movement of the rear ladder 106.

[0056] The unlocking and movement of the rear ladder 106 can be accomplished as follows. For example... Figure 6 As shown, initially, protrusion 132 can be positioned against the proximal surface 136 of retainer 130. V-shaped rod 126 can be offset by a length L relative to upper bracket 128. A longitudinally downward force (e.g., in the opposite direction to D) is applied to rear ladder 106, or a longitudinally upward force (e.g., along D) is applied to front ladder 110. Figure 13The upward-pointing axis 157 (while the rear ladder 106 remains substantially stationary) allows the rear ladder 106 (and protrusion 132) to slide downward relative to the sliding support bracket 121, as shown. Figure 8 As shown. Therefore, the length L can be derived from its original length (such as...) Figure 6 (as shown) reduced to a reduced length (e.g.) Figure 8 As shown, L'). Therefore, when the protrusion 132 begins to separate from the contact with the retainer 130, the rear ladder 106 can slide downward in the longitudinal direction.

[0057] like Figure 8 As shown, by contacting the distal end or substantially upward-facing surface 152 of plate 120, further longitudinal downward movement of protrusion 132 and rear ladder 106 relative to plate 120 can be prevented. Therefore, in order to further withdraw from slot 134, protrusion 132 rotates about the axis of pivot connector 129 as rear ladder 106 continues to decrease in length L until it reaches... Figure 9 The position shown indicates that the length L reaches zero or is substantially zero. Protrusion 132 can be drawn from... Figure 9 The position continues to rotate about the pivoting connector 129 (e.g., along the curved arrow 153) until it passes the proximal surface 136 of the retainer 130, as... Figures 10 to 11 As shown. Therefore, protrusion 132 can slide longitudinally as it rotates about the axis of rotation (via 129) of the rear ladder 106. Once reached Figure 11 Once the position is reached, the rear component 102 can be unlocked vertically and slide within the sliding support bracket 121 to the user-selected extension position, such as... Figure 3 , Figure 4 and Figure 12 As indicated.

[0058] from Figure 4 The extension position (or Figure 3 and Figure 12 (Regarding the location), the user may wish to separate components 102 and 104 to achieve a movable ladder structure (e.g., as...). Figures 1 to 2 and Figure 6 (As shown). Therefore, protrusion 132 may need to be via Figures 13 to 17 The locking action shown is secured in place by retainer 130. The user can conveniently convert the ladder into a movable ladder configuration by pre-opening the angle between components 102 and 104 without allowing protrusion 132 to be positioned within slot 134, for example, as... Figure 13 The starting position is shown. From Figure 13As shown in the extended and non-parallel ladder rack position, the user can lock the strut assembly 118 in its fully extended and locked position, thereby orienting the ladder racks 106, 110 and the support bracket 121 while maintaining a non-zero angle X between the front assembly 104 and the rear assembly 102 when fully open. In some cases, the strut assembly 118 is partially extended, and the assemblies 102, 104 are oriented at an angle less than X but greater than zero, such as at an angle between 10 and 30 degrees. When fully open (i.e., at angle X), the forward-facing side of the protrusion 132 can be aligned with a plane 155 extending through a pair of top guide surfaces 154 and longitudinally aligned with the distal surface 146 of the retainer 130 (i.e., aligned with the distal surface 146 along an axis 158 parallel to the longitudinal axis 156 of the rear ladder rack 106).

[0059] Therefore, when the user moves the rear ladder 106 longitudinally to lock the protrusion 132 in the retainer 130 (i.e., slides the rear ladder 106 along the longitudinal axis 156 in a manner that reduces the length L between the V-shaped rod 126 and the upper bracket 128), the protrusion 132 can contact the distal surface 146, such as Figure 14 As shown. Because the shape and angle of plate 120 at the top guide surface 154 are such that the distance between the plate 120 and the front surface of the rear ladder 106 is equal to or greater than the distance between the protrusion 132 and the front surface of the ladder 106, the protrusion 132 can contact the distal end face 146 without contacting plate 120. In other words, the top guide surface 154 can be angled relative to the longitudinal axis 160 of the front ladder 110 at angle X' (e.g., ...). Figure 13 As shown), the angle is greater than or equal to the angle X between the rear component 102 and the front component 104. Therefore, when the protrusion 132 from Figure 13 When the raised position shown is lowered, the protrusion will not get stuck or press against the plate 120 or the front ladder 110.

[0060] Once the protrusion 132 contacts the distal surface 146 of the retainer 130, the continued downward movement of the rear ladder 106 can cause the protrusion 132 to apply a force F to the distal surface 146, such as... Figure 14 As indicated. When a sufficient force F is applied to the protrusion 132, the protrusion 132 can apply a torque or moment to the retainer 130 to overcome the biasing force applied by the biasing member 144, thereby causing the retainer 130 to rotate in the forward direction about the pivoting connection 140, as indicated. Figure 15 The position (the protrusion 132 rotates to the rear of the hinge plate 120) to Figure 16 The position (protrusion 132 or even further rotated) to Figure 17The progression of the position (protrusion 132 fully retracted behind plate 120) is shown. Therefore, rotation of retainer 130 can be described as retraction or withdrawal of retainer 130 away from protrusion 132 and / or into the space between front ladder 110 and hinge plate 120. The surface curvature of distal surface 146 can be shaped such that when retainer 130 moves from its extended position ( Figure 14 Move to its essentially fully retracted position. Figure 16 When the force F is applied by the protrusion 132 at a substantially single angle (relative to the vertical direction), it can help ensure smooth operation of the locking mechanism and the retainer 130 and gradually increase the force required to move the retainer 130 (because the lever arm to the pivoting connection 140 gradually decreases) in order to prevent accidental unlocking of the retainer 130.

[0061] like Figure 17 As shown, once the protrusion 132 passes the tip of the retainer 130 (i.e., the distal surface 146 of the retainer bends to the tip portion of the proximal surface 136), the force F applied by the protrusion 132 may no longer be applied to the retainer 130. Therefore, in response to the protrusion 132 passing the tip and reaching... Figure 17 As shown, the biasing member 144 can rotate the retainer 130 about the pivoting connector 140 by means of its biasing force. Figure 6 The position is shown. In this way, even if the rear ladder 106 is in an angular orientation (e.g., angle X) during its descent, the protrusion 132 will return to its locked position during its longitudinal descent by moving the retainer 130 out of its path. A set of stop surfaces (e.g., stop surfaces on the curved tab 162 of the hinge plate 120) can limit the retainer 130 from moving into its locked position. Figure 6 The indicated position represents the amount of backward movement, thereby reforming groove 134. See also... Figures 5 to 6 .

[0062] The bias return of retainer 130 can cause retainer 130 to snap or engage back to its locked position (e.g., when from...). Figure 17 Move the position to Figure 6 (When in position). This latch or engagement can provide the user with auditory and tactile / vibrational feedback to help the user recognize that the ladder 100 is now properly locked in its ladder configuration and that if he or she begins to apply a load to the ladder (e.g., the user steps on a rung), the protrusion 132 will not slide further upward. Furthermore, the retainer 130 is visible to the user when viewed from the lateral side of the ladder 100 at its top, so the user can easily visually inspect the relative position of the retainer 130 and the protrusion 132, thus identifying whether the ladder 100 is locked in its ladder configuration by observing whether the retainer 130 is above the protrusion 132 (i.e., whether the protrusion 132 engages with the proximal surface 136).

[0063] In some examples, it can be done by following relative to Figures 6 to 11 The reverse process of the numbering action locks the rear component 102 relative to the front component 104. Figure 6 The location of the movable ladder. For example, the rear component 102 can be accessed from... Figure 11 Move the position to Figure 10 The position, then move to the location. Figure 9 Move to the position, then move to the position. Figure 8 The position was finally moved to. Figures 6 to 7 Therefore, the ladder 100 does not need to be an open, A-frame, or movable ladder construction from the outset, and the protrusion 132 can eventually achieve a locking configuration. If the user chooses to do so, the protrusion 132 can rotate to its locked position in the slot 134 without contacting the distal surface 146, and the retainer 130 will not move substantially (or in some cases, not at all).

[0064] Now for reference Figures 1 to 6 , Figure 19 and Figure 20 The rear ladder 106 can slide within the sliding support bracket 121. The sliding support bracket 121 may be referred to as a hinge assembly, bracket assembly, guard, ladder guide, or part of the hinge assembly. The upper bracket 128 and the lower bracket 124 may each comprise a rigid, durable, and tough material, such as steel, aluminum, or magnesium. The rigid and tough materials used in the upper bracket 128 and the lower bracket 124 can contribute to the durable attachment (or integration) of the lower bracket 124 to the strut assembly 118 and can contribute to the durable attachment of the upper bracket 128 to the hinge plate 120.

[0065] The guard 122 of the sliding support bracket 121 may comprise a durable and strong material, such as, for example, metal, plastic, or composite material (e.g., aluminum, polyvinyl chloride (PVC), or fiberglass). The guard 122 may advantageously be made of fiberglass, plastic, or other lightweight composite materials to reduce the overall weight of the ladder 100, or to provide an electrically insulating / non-conductive material for the user's hands to grip the ladder 100. The guard 122 may connect the lower bracket 124 to the upper bracket 128 in such a way that the brackets 124, 128 are aligned along the longitudinal axis of the rear ladder frame 106. This helps prevent the ladder frame 106 from jamming or twisting as it slides past the sliding support bracket 121. The guard 122 may also advantageously have a smooth outer surface, which can serve as a side handle for the user climbing the rear assembly 102. In other words, the user can initially grasp the rear ladder frame 106 when stepping onto the ladder 100, and after reaching a certain point during his or her ascent, his or her hands can switch to gripping the guard 122. The outer profile of the guard 122 may be similar to that of the rear ladder 106 (e.g., essentially a rounded rectangle) so that when climbing, the user's hands can easily and comfortably shift from gripping the ladder 106 to gripping the guard 122.

[0066] The upper support 128, the lower support 124, and the cover 122 may all have a C-shaped cross-sectional profile, which allows the rear crossbar 108 to slide between the C-shaped openings 164. See, for example... Figure 5 and Figure 18 Therefore, the rear crossbar 108 may not contact the sliding support bracket 121 and can slide through the opening 164 as needed when the rear assembly 102 extends or retracts. The lower bracket 124 may contact the foot 116 to prevent the rear assembly 102 from sliding to a position where it is completely removed from the sliding support bracket 121 when the rear assembly 102 moves upward. Figures 9 to 11 As shown, the upper bracket 128 can contact the V-shaped rod 126 (or protrusion 132) to prevent the rear component 102 from being completely removed as it slides down through the sliding support bracket 121.

[0067] Figure 18A strut assembly 118 in an unfolded and locked configuration is shown. Each of the strut assemblies 118 may include a first strut member 170 (e.g., a rear strut member) directly pivotally coupled to a rear support 172 (or a rear support portion of a lower support 124), which is coupled to a rear ladder frame 106 (or lower support 124). Each of the strut assemblies 118 may also include a second strut member 174 (e.g., a front strut member) directly pivotally coupled to a front support 176, which is coupled to a front ladder frame 110 or a front crossbar 112. The first strut 170 and the second strut 174 may be rotatably coupled to each other between the front ladder frame 110 and the rear ladder frame 106. A strut connecting bracket 178 may be directly coupled to the strut members 170, 174 as a connection point, which, when in the unfolded / locked configuration, also restricts the inner ends of the strut members 170, 174 from rotating downwards, thus placing them in a locked position. Figure 19 The right-side center cross-section shows a basically horizontal position.

[0068] like Figure 18 As shown, the strut assembly 118 may have a first strut member 170 and a second strut member 174, both located on the respective laterally inner sides of the rear ladder frame 106 and the front ladder frame 110. The rear support 172 and the front support 176 may also be positioned on the laterally inner sides of the rear ladder frame 106 and the front ladder frame 110. In some embodiments, supports 172, 176 may be pivotally connected to strut members 170, 174 via vertical side plate portions 173, which are positioned laterally inside the ends of strut members 170, 174. The horizontal cross-sectional profiles of supports 172, 176 may each define an L-shape, with struts 170, 174 directly connected to the L-shaped side plate portions 173. Supports 172 and 176 may also include corresponding stop portions 180 and 182, which serve as other sections of the L-shape and are positioned further rearward (in the case of portion 180) or forward (in the case of portion 182) relative to their directly connected struts 170 and 174. See also Figures 18 to 19 As explained in more detail below, when the ladder 100 is retracted, the stop portions 180 and 182 can prevent the struts 170 and 174 from rotating.

[0069] Such as at least Figure 3 and Figure 20As shown, when the strut assembly 118 is folded into its stowed configuration, strut members 170 and 174 can pivot at supports 172 and 176 and at connecting support 178. In its final position, the strut assembly 118 can be entirely located between a front plane 110-F defined by the front of the front ladder frame 110 and a rear plane 106-R defined by the rear of the rear ladder frame 106. In some embodiments, when the ladder 100 is in its fully stowed position, the strut assembly can be entirely located between a front plane 102-F defined by the foremost front face of the front assembly 104 and a rear plane 104-R defined by the rearmost rear face of the rear assembly 102.

[0070] Furthermore, the stop portions 180, 182 of the strut assembly 118 can mechanically interfere with and thereby prevent the strut members 170, 174 from rotating beyond the aforementioned defined front and rear planes in the forward or rearward direction. In this way, when the ladder 100 is in the retracted position, the extender assembly can be prevented from rotating beyond the volume envelope defined by the first component 102 and the second component 104 (e.g., between planes 110-F / 106-R or 102-F / 104-R). Additionally, in some embodiments, the rear stop portion 180 can prevent the first strut member 170 from rotating into the volume envelope defined between the front and rear surfaces of the guard 122 or the rear ladder frame 106. These stop portions and range-limiting features for the strut assembly 118 help to minimize and avoid damage to the strut assembly 118 and ensure that the profile of the ladder 100 is minimized for ease of storage, transport, and handling.

[0071] Figure 21 An isometric detailed view of an alternative example of the transverse inner side of the front ladder frame 110 is shown, with the first strut member 170 and the second strut member 174 in the retracted position. In this example, strut members 170 and 174 each include thickened portions 184 and 186, which are configured to fit within the strut connecting bracket 178 when in the retracted configuration. The thickened portions 184 and 186 may also be referred to as protrusions or widened sections of the strut members 170 and 174. The thickened portions 184 and 186 may be configured to engage the inner surface of a groove 185 within the strut connecting bracket 178. In this way, rotation of the strut members 170 and 174 relative to the strut connecting bracket 178 is substantially prevented when in the retracted position because the thickened portions 184 and 186 mechanically interfere with and engage with the inner stop surface of the strut connecting bracket 178 in the longitudinal direction of the groove 185. Therefore, in some examples of ladder 100, thickened portions 184, 186 can be implemented to prevent strut assembly 118 from moving outside the volume envelope of the front and rear planes of ladder 100, as described in detail above.

[0072] Figure 22An isometric detail view of another alternative example of the lateral inward side of the front ladder frame 110 is shown, with the first strut member 170 and the second strut member 174 in a retracted position. In this example, strut members 170 and 174 each include a protrusion 188 configured to mechanically interfere with supports 124, 172, 176, guard 122, or ladder frames 106 and 110 when the strut assembly 118 is in the retracted configuration. In various examples, the protrusion 188 may extend laterally inward, outward, or in both lateral directions from the strut members 170 and 174 to engage with different nearby components and features of the ladder 100. The protrusion 188 may include abutment members, studs, fasteners (e.g., rivets), flanges, tabs, protrusions, similar features, and combinations thereof. In some cases, the protrusion 188 may engage the top surface of the rear support 172 or the front support 176 in such a way that it prevents the corresponding connecting struts 170 and 174 from rotating beyond a predetermined angle. The maximum displacement of strut members 170 and 174 in the retracted state can be limited by the position of protrusion 188 engaging with supports 172 and 176 when or after the ladder 100 is closed. In some examples, protrusion 188 can limit their angular displacement in a way that prevents strut assemblies 118 from moving outside the volume envelope of the front and rear planes of the ladder 100, as described in detail above.

[0073] Now for reference Figure 3 , Figure 4 , Figure 20 and Figure 23 Because the rear rung 108 is placed within a set of rung retainers 190 extending from the front assembly 104, the rear assembly 102 of the ladder 100 can be held in the folded position relative to the front assembly 104. See also Figure 18 , Figure 19 and Figure 22 The crossbar retainer 190 may alternatively be referred to as a crossbar hook, crossbar support member, ladder retainer, or rear assembly retainer hook. The crossbar retainer 190 may be attached to the front crossbar 112 and / or the front ladder frame 110 of the front assembly 104. In some examples, the crossbar retainer 190 may include a top step surface 192 (see [link to documentation]). Figure 22 The top step surface is ribbed or textured to provide traction and grip for a user standing on the crossbar 112 to which the crossbar retainer 190 is attached. With the rear crossbar 108 located in the rear recess of the crossbar retainer 190, rotation of the rear assembly 102 about the pivot connector 129 beyond the width of the top recess of the crossbar retainer 190 can be prevented (even if rotation occurs, it is extremely limited).

[0074] The rear assembly 102 can slide longitudinally between different positions, wherein different rear rungs 108 at different longitudinal positions on the rear ladder frame 106 can be selectively positioned within the rung retainer 190. For different rungs 108, the overall adjustable length of the ladder 100 (from the front support 114 to the V-bar 126) can be varied. Therefore, the rung retainer 190 can hold the ladder 100 in a folded configuration or a straight ladder configuration, depending on which rear rung 108 the rung retainer 190 holds in the appropriate position. Figure 20 In the example shown, the second rung 108 from the top is held in place, and the ladder 100 is in a retracted configuration, with the rear component 102 retracted. Figure 23 In the example shown, the bottom crossbar 108 is held by the crossbar retainer 190, and the ladder is in an extended straight ladder configuration, in which the rear component 102 extends.

[0075] like Figures 18 to 20 and Figure 23 As shown, the crossbar retainer 190 may include a J-shaped or U-shaped side profile that can support the bottom surface of the rear crossbar 108. In some examples, the rear crossbar 108 may include a rounded bottom surface, and the crossbar retainer 190 may have a flared top recess (i.e., the top of the recess is wider than the width below the top) to help guide the crossbar 108 into the crossbar retainer 190. Furthermore, the rounded bottom surface of the rear crossbar 108 can improve the ergonomic comfort of the user by placing their hands under the crossbar 108 to grip and lift the rear assembly 102.

[0076] At least as Figure 18 As shown, the crossbar retainer 190 can be implemented as a set of two separate crossbar retainer hooks spaced apart from each other at opposite ends of the crossbar 112 of the front assembly 104. The spacing between the individual crossbar retainers 190 allows the user's hand to move between the crossbar hooks when gripping the rear crossbar 108 and sliding the rear assembly 102 longitudinally upward or downward. Thus, the user's hand and fingers can pass between the crossbar retainers 190 as the rear assembly 102 is moved, thereby preventing the hand from being pinched or otherwise squeezed by the crossbar retainers 190 and the crossbar 108, which would occur if the crossbar retainer 190 included a hook that extends substantially across the entire lateral length of the front crossbar 112.

[0077] In various examples, the rung retainer 190 can be positioned to extend from the second rung 112 from the top of the front component 104. This positioning ensures a minimum overlap length G between the front and rear rungs when the ladder 100 is in a straight ladder configuration, such as... Figure 23As shown. The length G is defined as the length from the bottom of the rear ladder 106 to the top of the front ladder 110 when the rear ladder 106 is in its maximum extended position and the crossbar 108 is held by the crossbar retainer 190.

[0078] The rear assembly 102 cannot be installed to the crossbar retainer 190 with an overlap length less than the minimum overlap length G because the bottom crossbar 108 of the rear assembly 102 is installed to the crossbar retainer 190, and no lower portion of the rear assembly 102 can be installed to the crossbar retainer 190. Therefore, the minimum overlap length G can be constructed at least in part based on the following factors: the distance between the pivot connection point 129 and the crossbar retainer 190 (i.e., the two contact areas of the front assembly 104 and the rear assembly 102), the additional ladder overlap distance on the rear ladder 106 extending downwards from the bottom crossbar 108 to the support leg 116 (if present), and the additional ladder overlap distance extending upwards from the pivot connection 129 to the top of the upper support 128 (if present). The minimum overlap length G can be selected to ensure that the ladder 100 is in the position of the maximum possible extended straight ladder (i.e., Figure 23 Stability and limited bending during ladder construction. In some examples, the minimum overlap length G can be designed based on the characteristics of ladder 100 to meet safety or construction standards, such as its maximum possible length (from ladder legs 114 to V-shaped bars 126 in a straight ladder construction), the materials used in ladder 100, the width of rungs 108 / 112 or legs 114, similar characteristics, or combinations thereof.

[0079] This document describes various inventions with reference to certain specific embodiments and examples. However, those skilled in the art will recognize that many variations are possible without departing from the scope and spirit of the invention disclosed herein, as the inventions set forth in the following claims are intended to cover all variations and modifications of the disclosed invention without departing from its spirit. The terms "comprising" and "having" as used in the specification and claims shall have the same meaning as the term "including".

Claims

1. A ladder comprising: A first component, the first component including a first pair of spaced-apart ladders and a first set of crossbars connected to the first pair of spaced-apart ladders and extending between the first pair of spaced-apart ladders; The second component includes a second pair of spaced-apart ladders and a second set of crossbars connected to and extending between the second pair of spaced-apart ladders. A pair of supports, the pair of supports being connected to the second component and slidably receiving the first pair of spaced-apart ladders; A pair of protrusions extending from the first pair of spaced-apart ladder frames; as well as A pair of retainers, the pair of retainers being movably connected to the second pair of spaced-apart ladders and at least partially defining a pair of slots; The first pair of spaced-apart ladders are movable relative to the pair of supports between the first and second configurations; When in the first configuration, the first pair of spaced-apart ladders and the second pair of spaced-apart ladders are positioned relative to each other at a non-zero angle, and the pair of protrusions are positioned outside the pair of slots. In the second configuration, the first pair of spaced-apart ladder frames and the second pair of spaced-apart ladder frames are positioned relative to each other at the non-zero angle, and the pair of protrusions are positioned within the pair of slots; and The sliding movement of the first pair of spaced-apart ladders relative to the pair of supports is configured to move the pair of retainers relative to the second pair of spaced-apart ladders.

2. The ladder of claim 1, wherein the pair of supports are pivotable relative to the second component.

3. The ladder according to claim 1, wherein the pair of protrusions extend laterally from the first pair of spaced-apart ladder frames.

4. The ladder according to claim 1, wherein the pair of retainers are rotatably connected to the second pair of spaced-apart ladder frames.

5. The ladder of claim 1, further comprising a pair of biasing mechanisms that bias the movement of the pair of retainers relative to the second pair of spaced-apart ladder frames.

6. The ladder of claim 5, wherein the pair of retainers moves against a pair of biasing forces applied by the pair of protrusions as the first pair of spaced-apart ladder frames move relative to the pair of supports from the first configuration to the second configuration.

7. The ladder of claim 1, wherein at least one of the pair of retainers includes a hook-shaped surface that defines a slot in the pair of slots.

8. The ladder of claim 1, further comprising a cover configured to cover the distal surface of at least one of the pair of retainers.

9. The ladder of claim 1, wherein the first pair of spaced-apart ladder frames are movable from the first configuration to the second configuration while always maintaining the non-zero angle relative to the second pair of spaced-apart ladder frames.

10. A ladder comprising: The first component includes: The first pair of spaced-out ladder racks, Extending between the first pair of spaced-apart ladder frames and connecting to the first set of crossbeams of the first pair of spaced-apart ladder frames, and At least one pin member extending laterally from the first pair of spaced-apart ladder frames; The second component includes: The second pair of spaced-out ladder racks, Extending between the second pair of spaced-apart ladder frames and connecting to the second set of crossbeams of the second pair of spaced-apart ladder frames, and At least one retainer member connected to at least one of the second pair of spaced-apart ladder frames, the at least one retainer member being movable between an unlocked position relative to the at least one ladder frame and a locked position relative to the at least one ladder frame; and A hinge assembly that rotatably connects the first component and the second component; The first pair of spaced-apart ladders and the second pair of spaced-apart ladders can be moved via the hinge assembly to an acute-angle unfolding configuration between the first pair of spaced-apart ladders and the second pair of spaced-apart ladders. When the assembly is in the unfolded configuration and the at least one retainer member is in the locked position, longitudinal movement of the first component relative to the hinge assembly is prevented due to the contact between the at least one pin member and the at least one retainer member; and When the first component is in the unfolded configuration and the at least one retainer component is in the unlocked position, the first component is capable of longitudinal movement relative to the hinge component.

11. The ladder of claim 10, wherein the at least one retainer member at least partially defines the groove when in the locked position.

12. The ladder of claim 10, wherein the at least one pin member comprises a rod extending between the top ends of the first pair of spaced-apart ladder frames.

13. The ladder of claim 10, wherein the second component further comprises at least one biasing member configured to apply a force to the at least one retainer member, the force causing the at least one retainer member to bias toward the locked position.

14. The ladder of claim 10, wherein the at least one retainer member is capable of moving from the locked position to the unlocked position in response to a force applied by the at least one pin member to the distal surface of the at least one retainer member.

15. The ladder of claim 14, wherein when the first pair of spaced-apart ladder frames and the second pair of spaced-apart ladder frames are at the acute angle, the at least one retainer member is movable from the locked position to the unlocked position by a force applied by the at least one pin member to the distal surface of the at least one retainer member.

16. The ladder of claim 10, wherein the first component includes a cover plate member configured to restrict a user's access to the distal surface of the at least one retainer member when the at least one pin member is in contact with the proximal surface of the at least one retainer member.

17. A ladder comprising: The first component includes: The first pair of spaced-out ladder racks; A first set of crossbars extends between and connects to the first pair of spaced-apart ladder frames; and The second component includes: The second pair of spaced-out ladder racks; The second set of crossbars extends between and connects to the second pair of spaced-apart ladder frames; and At least one strut assembly, the at least one strut assembly comprising: A first strut member, the first strut being rotatably connected to a first ladder frame in the first pair of spaced-apart ladder frames; and The second strut member is rotatably connected to the second ladder frame in the second pair of spaced-apart ladder frames, and the second strut member is rotatably connected to the first strut member between the first ladder frame and the second ladder frame; The at least one strut assembly is movable between the extended configuration and the retracted configuration; When in the extended configuration, the at least one strut assembly keeps the first ladder frame and the second ladder frame separate; and When in the retracted configuration, a portion of the at least one strut assembly prevents the first strut member or the second strut member from rotating beyond the volume envelope defined by the first and second assemblies.

18. The ladder of claim 17, wherein the portion of the at least one strut assembly includes a bracket that limits the rotational range of the first strut member beyond the envelope.

19. The ladder of claim 17, wherein the portion of the at least one strut assembly includes an abutment member extending laterally from the first strut member between the outermost surfaces of the first and second ladder frames, the abutment member being configured to engage at least one of the first and second ladder frames in response to rotation of the first strut member relative to the first ladder frame.

20. The ladder of claim 17, wherein the portion of the at least one strut assembly includes a stop surface on the first strut member, the stop surface being configured to engage the second strut member when in the retracted configuration.

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