ladder

Abstract

Foldable and collapsible ladder. The ladder includes a first side rail and a second side rail that are spaced apart from one another by a plurality of rungs extending between the first and second side rails. The rungs are pivotally coupled to the first and second side rails. The ladder is foldable between a plurality of configurations, the ladder being rail-to-rail foldable.

Description

[0001] This application is a divisional application of Chinese invention patent application (application number: 2019800836071; invention title: ladder).

[0002] Cross-referencing of related patent applications

[0003] This application claims the following priorities: (1) U.S. Provisional Patent Application Serial No. 62 / 865,185, filed June 22, 2019; and (2) U.S. Non-Provisional Patent Application Serial No. 16 / 219,834, filed December 13, 2018, the entire contents of which are incorporated herein by reference. Background Technology

[0004] Traditional straight and stepped ladders have side railings and multiple rungs rigidly connected between them. Due to the large open space between the rungs and railings, these traditional ladders take up a significant amount of space. Transporting such ladders from one place to another is extremely difficult for those without large trucks, including transporting them from a physical store where they can be purchased to their home. Furthermore, traditional ladders are difficult, if not impossible, to access in older homes and buildings due to narrow staircases or other obstacles. Therefore, there is a need for a ladder that can be folded and collapsed to reduce its size for storage and transport without compromising its stability and usability. Summary of the Invention

[0005] In one aspect, the invention can be a ladder comprising: a first stair section including: a first side rail extending along a first axis; a second side rail extending along a second axis; a plurality of first rungs having a first end pivotally connected to the first side rail and a second end pivotally connected to the second side rail; a first handle on the first side rail; a second handle on the second side rail; the first stair section can be changed between the following states by folding the second side rail relative to the first side rail to cause pivoting about the first and second ends of the plurality of first rungs: (1) a ladder-loaded state, wherein the first handle and the second handle are axially offset from each other; (2) a rail-to-rail retracted state, wherein the first side rail and the second side rail are adjacent to each other and the first handle and the second handle are at least partially aligned with each other in the axial direction.

[0006] In another aspect, the present invention may be a ladder comprising: a first stair section including: a first side rail extending along a first axis; a second side rail extending along a second axis; a plurality of first rungs having a first end pivotally connected to the first side rail and a second end pivotally connected to the second side rail; a locking assembly being switchable between: (1) a locked state, wherein the first stair section is locked in a ladder-loaded state; (2) Unlocked state, wherein the second side railing is foldable relative to the first side railing so that the first stair section changes between a stair-loaded state and a railing-to-railing-retracted state; a user-operated actuator is located on the second side railing and operably coupled to a locking assembly to change the locking assembly from a locked state to an unlocked state when a force is applied to the user-operated actuator in an upward axial direction moving from the bottom end of the second side railing toward the top end of the second side railing; and wherein, when the locking assembly is in the unlocked state, a force continues to be applied to the user-operated actuator in the upward axial direction causing pivoting about the first and second ends of a plurality of first crossbars, thereby causing the second side railing to rise and fold toward the first side railing, thereby changing the first stair section from a stair-loaded state to a railing-to-railing-retracted state.

[0007] In another aspect, the invention can be a ladder comprising: a first stair section including: a first side rail extending along a first axis; a second side rail extending along a second axis; a plurality of first rungs having a first end pivotally connected to the first side rail and a second end pivotally connected to the second side rail; a locking assembly switchable between: (1) a locked state, wherein the first stair section is locked in a ladder-loaded state; (2) an unlocked state, wherein the second side rail is foldable relative to the first side rail such that the first stair section changes between a ladder-loaded state and a rail-to-rail-retracted state; a user-operated actuator switchable between the first and second states, the user-operated actuator being operatively connected to the locking assembly to change the locking assembly from the locked state to the unlocked state when changing from the first state to the second state; a first resilient element biasing the user-operated actuator to the first state; and a second resilient element biasing the locking assembly to the locked state.

[0008] In another aspect, the present invention can be a ladder comprising: a first stair section including: a first side rail extending along a first axis; a second side rail extending along a second axis; a plurality of first crossbars having a first end pivotally connected to the first side rail and a second end pivotally connected to the second side rail; a first locking assembly being changeable between: (1) a locked state, wherein the first stair section is locked in a ladder-loaded state; (2) an unlocked state, wherein the second side rail is foldable relative to the first side rail such that the first stair section changes between a ladder-loaded state and a rail-to-rail-retracted state; a first user-operated actuator located on the second side rail and operably connected to the first locking assembly to change the locking assembly from the locked state to the unlocked state; the second stair section including: a third side rail extending along a third axis; a fourth side rail extending along a fourth axis; a plurality of second crossbars extending between and connected to the third and fourth side rails; the second locking assembly being changeable between: (1) a locked state, wherein the second stair section is locked in a second ladder state; (2) Unlocked state, wherein the fourth side railing is foldable relative to the third side railing to change the second stair section between a ladder state and a railing-to-railing-retracted state; a second user-operated actuator is located on the second side railing and operably connected to a second locking assembly to change the second locking assembly from a locked state to an unlocked state; a pair of hinges pivotally connect the first and second stair sections to each other, and when both the first and second stair sections are in a loaded state, the hinges are adjustable and locked between a plurality of optional angle configurations, including at least one of the following: (i) a straight stair configuration, wherein the third axis of the third side railing is substantially coaxial with the first axis of the first side railing, and the fourth axis of the fourth side railing is substantially coaxial with the second axis of the second side railing; (ii) A stepped configuration in which a first acute angle is formed between the first axis of the first side railing and the third axis of the third side railing, and a second acute angle is formed between the second axis of the second side railing and the fourth axis of the fourth side railing; a folding configuration in which the first and third side railings extend adjacent to each other, and the second and fourth side railings extend adjacent to each other, such that the actuator operated by the first user and the actuator operated by the second user are at least partially aligned with each other in the axial direction.

[0009] In a further aspect, the present invention may be a ladder comprising: a first stair section including: a first side rail and a second side rail; a plurality of non-locking first rungs having a first end pivotally connected to the first side rail and a second end pivotally connected to the second side rail; at least one locking rung having a first end pivotally connected to the first side rail and a second end pivotally connected to the second side rail, the at least one locking rung including a track; a locking assembly comprising: a locking lever slidably coupled to the locking rung within the track; a locking member pivotally coupled to at least one of the locking rung and the second side rail; and a user-operated actuator operably coupled to the locking member such that the locking assembly changes between: (1) a locked state, wherein the locking lever is engaged by the locking member, thereby preventing the locking lever from sliding within the track of the locking rung; (2) In the unlocked state, the locking lever disengages from the locking member, allowing the locking lever to slide freely within the track of the locking crossbar; wherein, when the locking member is in the locked state, the first stair section remains in the stair-loaded state, wherein the first side railing and the second side railing are spaced apart by a first distance; and wherein, when the locking member is in the unlocked state, the first stair section can change from the stair-loaded state to the railing to the railing-retracted state, wherein the first side railing and the second side railing are spaced apart by a second distance, the second distance being less than the first distance.

[0010] In another aspect, the invention can be a ladder comprising: a first stair section including: a first side rail extending along a first axis; a second side rail extending along a second axis; a plurality of first rungs having a first end pivotally connected to the first side rail and a second end pivotally connected to the second side rail; a locking assembly switchable between: (1) a locked state, wherein the first stair section is locked in a ladder-loaded state; (2) an unlocked state, wherein the second side rail is foldable relative to the first side rail such that the first stair section changes between a ladder-loaded state and a rail-to-rail-retracted state; a user-operated actuator operably connected to the locking assembly to change the locking assembly from the locked state to the unlocked state; and the locking assembly including a mark indicating whether the locking assembly is in the locked or unlocked state.

[0011] In another aspect, the present invention can be a retractable ladder comprising: two or more left-side elongated longitudinal beams hingedly fixed at the midpoint of the retractable ladder; two or more right-side elongated longitudinal beams hingedly fixed at the midpoint of the retractable ladder; a plurality of rungs having left and right ends, each rung hingedly fixed to a longitudinal beam at each end; wherein the ladder is operable to retract along its longitudinal axis when folded at the hinged midpoint; and wherein the ladder is operable to retract along its transverse axis when the left longitudinal beams move longitudinally relative to the right longitudinal beams.

[0012] In a further aspect, the present invention may be a ladder comprising: a first stair section including: a first side rail extending along a first axis; a second side rail extending along a second axis; a plurality of first rungs having a first end pivotally connected to the first side rail and a second end pivotally connected to the second side rail; a first locking assembly being changeable between: (1) a locked state, wherein the first stair section is locked in a ladder-loaded state; (2) Unlocked state, wherein the second side railing is foldable relative to the first side railing so that the first stair section changes between a stair-loaded state and a railing-to-railing-retracted state; a first user-operated actuator is operatively connected to a first locking assembly to change the locking assembly from a locked state to an unlocked state; the second stair section includes: a third side railing extending along a third axis; a fourth side railing extending along a fourth axis; a plurality of second rungs extending between and connecting the third and fourth side railings, the second stair section changing between the following states by folding the fourth side railing toward the third side railing to cause pivoting about the first and second ends of the plurality of second rungs: (1) stair-loaded state; (2) The railing is in a retracted state, with the third and fourth side railings adjacent to each other; a pair of hinges pivotally connects the first and second stair sections, which can be adjusted and locked between several selectable angle configurations when both the first and second stair sections are under load. These selectable angle configurations include: a straight stair configuration, where the third axis of the third side railing is substantially coaxial with the first axis of the first side railing, and the fourth axis of the fourth side railing is substantially coaxial with the second axis of the second side railing; a stepped configuration, where a first acute angle is formed between the first axis of the first side railing and the third axis of the third side railing, and a second acute angle is formed between the second axis of the second side railing and the fourth axis of the fourth side railing; and a folding configuration, where the first and third side railings extend adjacent to each other, and the second and fourth side railings extend adjacent to each other.

[0013] In another aspect, the present invention can be a ladder comprising: a first stair section including: a first side rail extending along a first axis; a second side rail extending along a second axis; a plurality of first rungs having a first end and a second end pivotally connected to the first and second side rails via a pivotal connection assembly nested between the front and rear walls of the first and second side rails; each pivotal connection assembly including: an end cap member comprising: A crossbar receiving tube has a sidewall defining an inner surface of a receiving cavity, wherein a first end or a second end of one of the first crossbars is positioned in the receiving cavity, the receiving cavity extending along the axis of the crossbar; a first spacer tube and a second spacer tube extend from opposite sides of the outer surface of the crossbar receiving tube, both the first spacer tube and the second spacer tube extending along a pivot axis of the first end or the second end of one of the first crossbars; and a pivot pin extending along the pivot axis, the pivot pin having a first end connected to a first side rail and a second end connected to a second side rail, the pivot pin extending through the first spacer tube and the second spacer tube and the end of the first crossbar located within the receiving cavity.

[0014] Other applications of the invention will become apparent from the detailed description provided below. It should be understood that the detailed description and specific embodiments are intended to illustrate preferred embodiments of the invention. Attached Figure Description

[0015] Figure 1A A side perspective view of a fully retractable ladder with hinged rungs according to the present invention is shown.

[0016] Figure 1B A front perspective view of a fully retractable ladder with hinged rungs according to the present invention is shown.

[0017] Figure 1C A front perspective view of a fully retractable ladder with hinged rungs according to the present invention is shown.

[0018] Figure 1D A front perspective view of a fully retractable ladder with hinged rungs according to the present invention is shown.

[0019] Figure 2 A front perspective view of a fully retractable ladder with hinged rungs according to the present invention is shown.

[0020] Figure 3 A front perspective view of a fully retractable ladder with hinged rungs according to the present invention is shown.

[0021] Figure 4 A rear-partial perspective view of a fully retractable ladder with hinged rungs according to the present invention is shown.

[0022] Figure 5 A side perspective view of a fully retractable ladder with hinged rungs according to the present invention is shown.

[0023] Figure 6 A side perspective view of a fully retractable ladder with hinged rungs and a support tube according to the present invention is shown.

[0024] Figure 7 A front perspective view of a fully retractable ladder with hinged rungs according to the present invention is shown.

[0025] Figure 8 shows a side perspective view of an interlocking hinge for a foldable ladder according to the prior art.

[0026] Figure 9 This is a perspective view of a ladder according to an embodiment of the present invention, wherein the ladder is in an unfolded and unfolded configuration.

[0027] Figure 10 yes Figure 9 A 3D view of the ladder's unfolding and collapsing configuration;

[0028] Figure 11 yes Figure 9 A 3D diagram of the ladder's tiered configuration;

[0029] Figure 12 yes Figure 9 A 3D view of a ladder in both folded and unfolded configurations;

[0030] Figure 13 yes Figure 9 A 3D view of a ladder with folding and retracting configuration;

[0031] Figure 14 yes Figure 13 A side view of the ladder;

[0032] Figure 15 It is along Figure 14 A sectional view taken from line VII-VII;

[0033] Figure 16 It is along Figure 15 A sectional view taken from line VIII-VIII;

[0034] Figure 17 yes Figure 15 A close-up view of area IX, showing the actuator in its first state;

[0035] Figure 18 yes Figure 17 A close-up view showing the actuator in its second state;

[0036] Figure 19 yes Figure 15A close-up view of area X, showing the locking component in the locked state;

[0037] Figure 20 yes Figure 18 A close-up view showing the locking mechanism in the unlocked state;

[0038] Figure 21-23 yes Figure 20 A close-up view, showing sequentially from... Figure 12 The unshrink configuration was changed to Figure 13 The process of shrinking configuration;

[0039] Figure 24 yes Figure 9 Another perspective view of a folded and non-folded ladder;

[0040] Figure 25 yes Figure 24 A close-up view of area XVII, with the locking component in a locked state;

[0041] Figure 26 yes Figure 24 A close-up view of area XVII, with the locking mechanism in the unlocked state;

[0042] Figure 27A , 27B This is a perspective view of a ladder in a stepped configuration according to an alternative embodiment of the present invention;

[0043] Figure 28 This is a close-up view of the locking components as the ladder begins to change from a retracted state (towards the railing) to a loaded state.

[0044] Figure 29 This is a close-up view of the locking assembly when the locking part of the locking lever contacts the cam surface of the locking member to apply an opening force to the locking member, causing the locking member to pivot.

[0045] Figure 30 This is a close-up view of the locking assembly after it has passed the cam surface and the locking member has been biased back to the locked state; and

[0046] Figure 31 It is along Figure 12 The sectional view taken from the XXXI-XXXI views shows details of how the ends of the crossbars are pivotally connected to the first and second side rails. Detailed Implementation

[0047] The following description of preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or its use.

[0048] The description of illustrative embodiments of the invention is intended to be read in conjunction with the accompanying drawings, which are considered an integral part of the entire written description. Any references to directions or orientations in the description of embodiments of the invention disclosed herein are for ease of description only and are not intended to limit the scope of the invention in any way. Relative terms, such as “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “upward,” “downward,” “top,” and “bottom,” and their derivatives (e.g., “horizontally,” “downward,” “upward,” etc.), should be interpreted as referring to the direction described or shown in the figures discussed. These relative terms are for ease of description only and do not require the device to be constructed or operated in a particular orientation unless explicitly stated otherwise. Terms such as “attach,” “fix,” “connect,” “link,” “interconnect,” etc., refer to a relationship in which structures are directly or indirectly fixed or attached to each other via an intermediate structure, and both movable or rigid attachments or relationships, unless explicitly stated otherwise. Furthermore, the features and benefits of the invention are illustrated by reference to exemplary embodiments. Therefore, the invention should not be explicitly limited to such exemplary embodiments, which illustrate some possible non-limiting combinations of features that may exist alone or in other combinations of features; the scope of the invention is defined by the appended claims.

[0049] Figure 1A-1B A front perspective view of a fully retractable ladder with crossbars 1104 according to the present invention is shown.

[0050] Multiple crossbar components 1104a-b are hinged to two or more slender longitudinal beams 1102a-b. Each crossbar component 1104 includes a first terminal 1122a and a second terminal 1122b, which are hinged to the longitudinal beam 1102.

[0051] Each crossbar component 1104 includes an elongated shaft, tube, beam, rod, or extruded polymer or aluminum step or crossbar portion having a first end 1122a and a second end 1122b.

[0052] The longitudinal beam 1102 may also be provided with a hole 1142, which serves as a handle for the hand ladder 1100.

[0053] The ladder 1100 folds at a hinge 1800 fixed between adjacent longitudinal beams 1102. The hinge 1800 is known to those skilled in the art and is further described below in conjunction with FIG8.

[0054] Figure 1A The ladder 1100 is shown in a fully retracted configuration on both axes, while Figure 1BThe ladder 1100 is shown in a semi-retracted configuration on a single axis. When the ladder 1100 is in a fully retracted or semi-retracted configuration, the ladder 1100 is operable to fold along its transverse axis by moving the longitudinal beam 1102 along one side of the crossbeam member 1104 on opposite sides of the ladder 1100. The ladder 1100 is operable to retract along both the longitudinal and transverse axes in the semi-retracted or fully extended positions.

[0055] Figure 1C A front perspective view of a fully retractable ladder 1140 with hinged rungs according to the present invention is shown.

[0056] Shown in the open, semi-retracted position, ladder 1140 can also be folded open at hinge 1800 to be configured as follows: Figure 1D The fully extended position depicted in the text.

[0057] The ladder 1140 is provided with a latching mechanism 1144. The latching mechanism 1144 may include a simple hinge or a more complex hinge 1800 known to those skilled in the art, as further described below.

[0058] Figure 1D A front perspective view of a fully retractable ladder with hinged rungs according to the present invention is shown.

[0059] In its fully extended position, as shown, the ladder 1160 is operable to retract in its width direction or transverse axis by moving the longitudinal beam 1102 in the vertically opposite direction.

[0060] Figure 2 A front perspective view of a fully retractable ladder 1200 with hinged rungs according to the present invention is shown.

[0061] The crossbar member 1104 may be formed with ridges molded thereon or otherwise formed thereon to increase the track and stability for a user positioned on the crossbar member 1104. These ridges 1702 serve to provide a relatively non-slip surface on the pedal. Other non-slip surfaces may be provided alternatively, as will be apparent to those skilled in the art.

[0062] Figure 3 A front perspective view of a fully retractable ladder 1300 with hinged rungs according to the present invention is shown.

[0063] The crossbeam member 1104 is operable to pivot about its attachment point with the longitudinal beam 1102.

[0064] Figure 4 A rear partial perspective view of a fully retractable ladder 1400 with hinged rungs according to the present invention is shown.

[0065] In various embodiments, the ladder 1400 includes diagonal braces 1402 located below each rung member 1104. As shown, the diagonal braces 1402 are hingedly fixed to the longitudinal beam 1102 at a first end 1404. At a second end 1406, the diagonal braces 1402 are fixed to one of the pulleys or tracks in which the rung member 1104 and / or the second end 1406 travels. The second end 1406 may be fixed to a mounting bracket 1408 that travels within a traveling mechanism such as the pulley 1410 shown.

[0066] The diagonal brace 1402 is adapted to limit the movement of the crossbar member 1104 to which the diagonal brace 1402 is connected to to exceed 90 degrees. In the illustrated embodiment, when the crossbar member 1104 is oriented perpendicular to the longitudinal beam 1102 from a frontal view, the crossbar member 1104 is restricted to rotate axially in a clockwise direction about its left end.

[0067] The ladder 1400 may include multiple polymer legs 1412.

[0068] Figure 5 A side perspective view of a fully retractable ladder 1500 with hinged rungs according to the present invention is shown. The ladder 1500 is shown in a semi-retracted configuration.

[0069] Figure 6 A side perspective view of a fully retractable ladder with hinged rungs and a support tube 1600 according to the present invention is shown.

[0070] A fully retracted ladder 1100 can be inserted into tube 1602, which allows the ladder 1100 to be carried during transport without unfolding. Tube 1602 may be cylindrical and formed of polymer or metal alloy.

[0071] If needed, users can stack multiple fully retracted ladders 1100 one after another.

[0072] Figure 7 A front perspective view of a fully retractable ladder 1700 with hinged rungs according to the present invention is shown.

[0073] In various embodiments, the crossbar members 1104 are hingedly fixed to pivot less than 90 degrees to the vertical orientation of the longitudinal beam 1102, each crossbar member 1104 pivoting forward on a vertical (or longitudinal) axis at one end and pivoting backward on a vertical axis at the opposite vertical end.

[0074] Figure 8 shows a side perspective view of an interlocking hinge 1800 for a foldable ladder according to the prior art.

[0075] A known hinge 1800 for a folding ladder includes a first joint member integrally formed with a main plate, a second joint member integrally formed with a secondary plate, a locking device with a button, a connecting pin, a coil spring, a rectangular locking block, and a pressure locking control device for controlling the locking or unlocking of the locking device. The first and second joint members are joined together by a common axis of a central shaft that allows them to rotate. The secondary plate of the second joint member is inserted between a pair of parallel-spaced main plates of the first joint member. The main plates of the first joint member have a slot opening for inserting the locking device. A first convex arc-shaped stop is provided on the inner surface of the main plate. A second convex arc-shaped stop is formed on the rear surface of the secondary plate of the second joint member and mates with the first convex arc-shaped stop of the main plate. A plurality of pawls are formed around the periphery of the secondary plate. A pressure locking control device is mounted on one side of the slot opening of the main plate for resiliently actuating the device.

[0076] As shown in the figure, hinge 1800 can be integrated into ladder 1100, located between two longitudinal beams 1102. In various configurations, hinge 1800 is positioned at the midpoint between two longitudinal beams of equal length on ladder 1100.

[0077] Reference Figure 9 A ladder 100 according to an embodiment of the present invention is shown. The ladder 100 generally includes a first stair section 300 and a second stair section 400. A pair of locking hinges, including a first locking hinge 115 and a second locking hinge 125, pivotally connect the first and second stair sections 300, 400 to each other. As will be discussed in more detail below, when both the first and second stair sections 300, 400 are under load, the pair of hinges 115, 125 can be adjusted and locked between a plurality of selectable angle configurations. Selectable angle configurations include a straight ladder configuration (e.g.,...). Figure 9 As shown), tiered configuration (such as) Figure 11 (as shown) and folding configuration (as shown) Figure 12 (As shown). In some embodiments, the ladder 100 may be designed such that the selectable angle configurations include only the step configuration (e.g., Figure 11 (as shown) and folding configuration (as shown) Figure 12 (As shown). In other embodiments, ladder 100 may include only the first stair section 300, wherein the second stair section 400 and a pair of hinges 115, 125 are omitted.

[0078] The first stair section 300 typically includes a first side railing 110 extending along a first axis AA from a bottom end 111 to a top end 112 and a second side railing 120 extending along a second axis BB from a bottom end 121 to a second end 122. The first side railing 110 includes an inner surface 116 and an outer surface 117, and the second side railing 120 includes an inner surface 126. Figure 15 ) and outer surface 127.

[0079] The first stair section 300 also includes a plurality of first crossbars (including first unlocked crossbars 130 and first locked crossbars 140) extending between the first and second side rails 110, 120. Each of the plurality of first unlocked crossbars 130 includes a first end 131 and a second end 132 (e.g., Figure 15 As shown, a first end 131 is pivotally connected to the first side rail 110 along or adjacent to the inner surface 116 of the first side rail 110, and a second end 132 is pivotally connected to the second side rail 120 along or adjacent to the inner surface 126 of the second side rail 120. The first end 131 of the first unlocked crossbar 130 includes a hole through which a pin / rod connected to the first front wall 102 and the first rear wall 103 of the first side rail 110 extends to allow the first unlocked crossbar 130 to pivot relative to the first side rail 110. Similarly, the second end 132 of the first unlocked crossbar 130 includes a hole through which a pin / rod connected to the second front wall 105 and the second rear wall (not visible) of the second side rail 120 extends to allow the first unlocked crossbar 130 to pivot relative to the second side rail 120. The first non-locking crossbar 130 can pivot freely relative to the first and second side rails 110 and 120, so that the first stair section 300 can be in the stair-loaded state (e.g., Figure 9 , 11 (as shown in Figure 12) and the railing to the retracted state (as shown in Figure 12) Figure 10 and 13 The variation between (as shown) will be described in more detail below.

[0080] More specifically, now also refer to Figure 12 and 31 The first and second ends 131, 132 of the first unlocked crossbar 130 are pivotally connected to the first and second side rails 110, 120 via a pivoting connection assembly, which typically includes an end cap member 750. While the pivotable connection is described below with respect to the first end 131 of one of the first unlocked crossbars 130 being pivotally connected to the first side rail 110, it should be understood that the second end 132 of the first unlocked crossbar 130 is pivotally connected to the second side rail 120 in the same manner. Furthermore, the second crossbar 430 of the second stair section 400 is also pivotally connected to the third and fourth side rails 410, 420 in the same manner.

[0081] like Figure 31As shown, end cap component 750 is nested between portions of the first front wall 102 and the first rear wall 103 of the first and second side rails 110, 120 extending from the inner wall 212. End cap component 750 includes a crossbar receiving tube 751 having sidewalls, and an inner surface 752 defining a receiving cavity 753 in which a first end 131 of a first non-locking crossbar 130 is positioned. The receiving cavity 753 extends along the crossbar axis RR. End cap component 750 also includes first and second spacer tubes 755, 756 extending from opposite sides of the outer surface 752 of the crossbar receiving tube 751. Both first and second spacer tubes 755, 756 extend along a pivot axis PP, on which the first end 131 of the first non-locking crossbar 130 pivots when the first stair section 300 changes between a stair-loaded state and a railing-to-railing-retracted state.

[0082] A pivot pin 760 is provided, extending along the pivot axis PP and having a first end connected to a first front wall 102 of the first side rail 110 and a second end connected to a first rear wall 103 of the first side rail 110. It can be seen that the pivot pin 760 extends through the first and second spacer tubes 755, 756, through the first end 131 of the first unlocked crossbar 130 located in the receiving cavity 753, and through holes in the first front wall 102 and the first rear wall 103 of the first side rail 110. The outer diameters of the first and second spacer tubes 755, 756 are larger than the holes in the first front wall 102 and the first rear wall 103 of the first side rail 110 through which the pin 760 extends. Therefore, the first and second spacer tubes 755, 756 maintain the first unlocked crossbar 130 in a properly spaced relationship with the first front wall 102 and the first rear wall 103 of the first side rail 110. Finally, the crossbar receiving tube 751 has a closed end wall to prevent the first unlocked crossbar 130 from sliding within the end cap component 750.

[0083] See again Figure 9 Similar to the first staircase 300, the second staircase 400 typically includes a third side railing 410 extending from the bottom 411 to the top 412 along the third axis FF and a fourth side railing 420 extending from the bottom 421 to the top 422 along the fourth axis GG. Figure 9 As shown, in a straight ladder configuration, the third axis FF of the third side railing 410 is substantially coaxial with the first axis AA of the first side railing 110, and the fourth axis GG of the fourth side railing 420 is substantially coaxial with the second axis BB of the second side railing 120. In a stepped configuration, as... Figure 11As shown, a first acute angle Q1 is formed between the first axis AA of the first side rail 110 and the third axis FF of the third side rail 410, and a second acute angle Q2 is formed between the second axis BB of the second side rail 120 and the fourth axis GG of the fourth side rail 420. When in a folded configuration, as... Figure 12 As shown, the first and third side rails 110 and 410 extend adjacent to each other, and the second and fourth side rails 120 and 420 extend adjacent to each other. Furthermore, in some embodiments, when in the folded state, the first and third axes AA and FF are substantially parallel to each other, and the second and fourth axes BB and GG are substantially parallel to each other, as shown in Figure 12.

[0084] The third side railing 410 includes an inner surface 413 and an outer surface 414, and the fourth side railing 420 includes an inner surface (not visible) and an outer surface 424. The second stair section 400 also includes a plurality of transverse members, which in this exemplary embodiment are a plurality of second crossbars 430, which are non-locking crossbars (as described below; in other embodiments, for example...). Figure 27A In the embodiment shown in -B, the plurality of second crossbars 430 may include locking crossbars 435. In other embodiments where it is not desired that the second stair section be a load-bearing stair section, the transverse members may take the form of retractable and / or pivotally connected to the third and fourth side rails 410, 420.

[0085] A plurality of second crossbars 430 are pivotally connected to the third and fourth side rails 410 and 420 in the same manner as the first unlocked crossbars 130 are connected to the first and second side rails 110 and 120. Thus, although not shown in detail in the figures, each of the plurality of second crossbars 430 includes a first end and a second end, the first end being pivotally connected to the third side rail 410 along or adjacent to the inner surface 413 of the third side rail 410, and the second end being pivotally connected to the fourth side rail 420 along or adjacent to the inner surface of the second side rail 420. Therefore, in the exemplary embodiment, each of the second crossbars 430 is freely pivotable relative to the third and fourth side rails 410 and 420 to facilitate the second stair section 400 in a stair-loaded state (e.g., Figure 9 , 11 (as shown in Figure 12) and the railing to the retracted state (as shown in Figure 12) Figure 10 and 13 The values ​​shown in the image can be changed between the two, as will be described in more detail below.

[0086] As described above, the first and second locking hinges 115, 125 are adjustable and lockable between a plurality of selectable angle configurations. When rotated to one of the selectable angle configurations (e.g., a straight ladder structure, a stepped structure, and a folding structure), the first and second locking hinges 115, 125 will automatically be locked due to an elastic element (e.g., a coil spring), biasing the first and second locking hinges 115, 125 into a mechanical interlock. The first and second locking hinges 115, 125 will remain locked until the user applies a force to the hinge actuator, which will overcome the bias of the elastic element and release the mechanical interlock. Once the mechanical interlock is released, the first and second ladder segments 300, 400 can rotate relative to each other about a rotation axis CC transverse to the first, second, third, and fourth axes AA, BB, FF, and GG. Therefore, the ladder 100 can be changed and locked between selectable angle configurations.

[0087] The first and second locking hinges 115, 125 can be the hinges shown and described above with respect to FIG8. Furthermore, examples of suitable hinges for the first and second locking hinges 115, 125 are described in U.S. Patent Nos. 7,364,017, 7,264,082, 6,220,389, 7,047,597, 6,886,117, and 4,182,431, the entire contents of which are incorporated herein by reference.

[0088] Now see also Figure 9 , 15 31, the first side railing 110 includes a first enclosed passage 101 and a first open passage 201. The first side railing 110 includes a first outer wall 211 having an outer surface 117, a first inner wall 212 having an inner surface 126, a first front wall 102, and a first rear wall 103. The first enclosed passage 101 includes a closed cross-sectional profile formed by the first outer wall 211, the first inner wall 212, the first front wall 102, and the first rear wall 103. The first open passage 201 includes a U-shaped open cross-sectional profile formed by the first inner wall 212, a portion of the first front wall 102 extending inward beyond the first inner wall 212, and a portion of the first rear wall 103 extending inward beyond the first inner wall 212.

[0089] Similarly, the second side railing 120 includes a second enclosed passage 104 and a second open passage 202. The second side railing 120 includes a first outer wall 211 having an outer surface 127, a first inner wall 212 having an inner surface 126, a second front wall 105, and a second rear wall (not visible). The second enclosed passage 104 includes a closed cross-sectional profile formed by the second outer wall 221, the second inner wall 222, the second front wall 105, and the second rear wall. The second open passage 202 includes a U-shaped open cross-sectional profile formed by the second inner wall 222, a portion of the second front wall 105 extending inward beyond the second inner wall 222, and a portion of the second rear wall extending inward beyond the second inner wall 222.

[0090] As can be understood from the above discussion, the first and second side rails 110 and 120 have the same construction and the same cross-sectional profile, and in some embodiments, are portions of the same extruded railing. Furthermore, although not discussed in detail herein to avoid redundancy, the third side rail 410 and the fourth side rail 420 also have the same construction and the same transverse cross-sectional profile as the first and second side rails 110 and 120, and therefore also include the open and closed passages as described above.

[0091] Now refer to Figure 12 and 13 When in folded configuration, both the first and second stair sections 300 and 400 can be in stair-loaded condition. Figure 12 ) and the railing to the retracted state ( Figure 13 The first stair section 300 changes from a stair-loaded state to a railing-to-railing-retracted state by folding the second side railing 120 relative to the first side railing 110 to cause pivoting about the first and second ends 131, 132 of a plurality of first unlocked crossbars 130 and first locked crossbars 140. When the first stair section 300 is in the stair-loaded state, the first and second side railings 110, 120 are substantially parallel and spaced apart from each other by a first distance, and the plurality of first unlocked crossbars 130 and first locked crossbars 140 are substantially perpendicular to the first and second side railings 110, 120 (and the first and second axes AA, BB). When the first stair section 300 is in the railing-to-railing-retracted state, the first and second side railings 110, 120 are substantially parallel and spaced apart from each other by a second distance, and the plurality of first unlocked crossbars 130 and first locked crossbars 140 are inclined relative to the first and second side railings 110, 120 (and the first and second axes AA, BB). The first distance is greater than the second distance.

[0092] Similarly, by folding the second side railing 120 relative to the first side railing 110 to cause pivoting about the first end 431 and the second end 431 (not visible) of the plurality of second crossbars 430, the second stair section 400 also changes from a stair-loaded state to a railing-to-railing-retracted state. When the second stair section 400 is in the stair-loaded state, the third and fourth side railings 410, 420 are substantially parallel to each other and spaced apart by a first distance, and the plurality of second crossbars 430 are substantially perpendicular to the third and fourth side railings 410, 420 (and the third and fourth axes FF, GG). When the second stair section 400 is in the railing-to-railing-retracted state, the third and fourth side railings 410, 420 are substantially parallel to each other and spaced apart by a second distance, and the plurality of second crossbars 430 are inclined relative to the third and fourth side railings 410, 420 (and the third and fourth axes FF, GG). The first distance is greater than the second distance.

[0093] Because the first stair section 300 and the second stair section 400 are connected together by a pair of hinges 115 and 125 (and specifically, the second side rail 120 is connected to the fourth side rail 420 by hinge 125), the second and fourth side rails 120 and 420 move as a unit. Therefore, the first and second stair sections 300 and 400 change simultaneously in a consistent manner between their stair-loaded state and their railing-to-railing-retracted state. Additionally, during the transition of the first stair section 300 from the stair-loaded state to the railing-to-railing-retracted state, the first side rail 110, the second side rail 120, and the plurality of first unlocked crossbars 130 and first locked crossbars 140 maintain a first parallelogram linkage. Similarly, during the transition of the second stair section 400 from the stair-loaded state to the railing-to-railing-retracted state, the third side rail 410, the fourth side rail 420, and the plurality of second crossbars 430 maintain a second parallelogram linkage.

[0094] As will be described in more detail below, the first stair section 300 also includes a user-operated actuator 160 and a locking assembly 190. The user-operated actuator 160 is operatively coupled to the locking assembly 190 to change the locking assembly 190 from a locked state to an unlocked state when an actuating force is applied to the user-operated actuator 160 in an upward axial direction (moving from the bottom end 121 of the second side rail 120 toward the top end 122 of the second side rail 120). When the locking assembly 190 is in the locked state, the first stair section 300 (and the second stair section 400) is locked in its stair-loaded state and cannot be changed to its rail-to-rail retracted configuration. When the locking assembly 190 is in the unlocked state, the second side rail 120 can be folded relative to the first side rail 110 such that the first stair section 300 can change between its stair-loaded state and its rail-to-rail retracted state (as with the second stair section 400).

[0095] When the first and second stair sections 300 and 400 are in the stair load-bearing state (e.g.) Figure 9 , 11 As shown in Figures 1 and 12, each of the first non-locking rung 130, the first locking rung 140, and the second rung 430 is configured to support the weight of the user of the ladder 100. Furthermore, each of the first non-locking rung 130, the first locking rung 140, and the second rung 430 may have a textured upper surface for slip resistance during user use.

[0096] See also Figure 12-14 The first stair section 300 also includes a first handle 118 on the first side railing 110 and a second handle 119 on the second side railing 120. The first and second handles 118 and 119 are located on the first and second side railings 110 and 120, respectively, such that when the first stair section 300 is in a stair-loaded state, the first and second handles 118 and 119 are axially offset from each other (e.g., ...). Figure 12 (As shown in Figure 14). It can be seen that the first handle 118 is located at a first distance 111 from the bottom end of the first side railing 110, and the second handle 119 is located at a second distance 121 from the bottom end of the second side railing 120. The first distance is greater than the second distance.

[0097] When the first stair section 300 transforms into a railing or retracted railing, the first and second handles 118 and 119 are at least partially aligned with each other in the axial direction. Most preferably, as shown in the image... Figure 13 As shown, when the first stair section 300 changes to the railing-to-railing retracted state, the first and second handles 118, 119 are fully aligned with each other in the axial direction. By aligning the first and second handles 118, 119 at least partially as described above, the user can grip and transport the ladder 100 with one hand (when both the first and second stair sections 300, 400 are in the railing-to-railing configuration).

[0098] The first and second side rails 110 and 120 each include front surfaces 240A and 240B having inner edges 241A and 241B and outer edges 242A and 242B, respectively. A first handle 118 is positioned on the front surface of the first side rail 110 near the inner edge 241A of the front surface 240A. A second handle 119 is positioned on the front surface 240B of the second side rail 120 near the inner edge 241B of the front surface 240B. This arrangement further enhances the user's ability to carry the ladder 100 in the rail-to-rail retracted state with one hand. Furthermore, this positioning of the first and second handles 118 and 119 holds the first and second ladder sections 300 and 400 in the rail-to-rail retracted state when the first and second handles are gripped.

[0099] In an exemplary embodiment, each of the first and second handles 118, 119 includes a strap component. In other embodiments, the first and second handles 118, 119 may be in the form of flexible or rigid structures, protrusions, cutouts, or other gripping structures.

[0100] Simultaneously refer to Figure 9 and Figure 15-16 The first stair section 300 also includes at least one locking crossbar 140 having a first end 141 pivotally connected to the first side rail 110 and a second end 142 connected to the second side rail 120. Figure 15 In some embodiments, the second end 142 may be pivotally connected to the second side rail 120, although this may not be necessary in all embodiments. The connection of the first locking rung 140 to the first and second side rails 110, 120 may be achieved in the same manner as the connection of the first unlocked rung 130 to the first and second side rails 110, 120 described above (using a hole / pin structure). In an exemplary embodiment, there is only one first locking rung 140, but the invention is not limited to all embodiments, and the ladder 100 may include more than one first locking rung 140 on the first and / or second stair sections 300, 400 as needed. In an exemplary embodiment, the first locking rung 140 is the lowermost rung of the first stair section 300, but the invention is not limited to all embodiments, and the first locking rung 140 may be located at other positions along the ladder 100. The first locking rung 140 is also configured to support the weight of the user when the first stair section 300 is in a ladder-loaded state.

[0101] The first locking crossbar 140 has a different cross-sectional shape than the first unlocked crossbar 130. Specifically, the first locking crossbar 140 includes an upper surface 143, a lower surface 144, and a track 145 formed in the lower surface 144, having an opening in the lower surface 144. The track 145 is essentially a channel formed in the first locking crossbar 140. The track 145 is configured to slidably receive a portion of the locking lever 150 such that when the first stair section 300 changes between a stair-loaded state and a railing-to-railing-retracted state, the locking lever 150 can slide relative to the first locking crossbar 140 within the track 145.

[0102] Now refer to Figure 9 and 15 The first stair section 300 includes a locking assembly 190, which typically includes a locking lever 150, a locking member 170, and a resilient element 275. Figure 19For example, the elastic element 275 of a torsion spring is operatively coupled to the locking member 170, as will be described in more detail below regarding the function of the locking assembly 190. A user-operated actuator 160 is operatively coupled to the locking assembly 190 to enable the locking assembly 190 to be released from the locked state when an actuating force is applied to the user-operated actuator 160 (see [link to relevant documentation]). Figure 19 Change to unlocked state (see) Figure 20 In an exemplary embodiment, actuator 160 is operatively coupled to locking assembly 190 via link 180. In an exemplary embodiment, link 180 is a rigid rod, but can take various forms, such as a flexible cable, bar, or connector. In an exemplary embodiment, link 180 is located within the second enclosed passage 104 of the second side rail 120, such that link 180 is not exposed to the user, but is positioned internally and invisible during normal use and operation of ladder 1100.

[0103] Now for reference Figure 15 and 17 -20, will describe the use of actuator 160 to change locking assembly 190 from a locked state (where the first stair section 300 is locked in the stair-loaded state) to an unlocked state (where the first stair section 300 can change from the stair-loaded state to the railing to the railing retracted state).

[0104] from Figure 17 and 19 Initially, the first section of the ladder (300) is in a load-bearing state (e.g., Figure 12 (As shown). When in this state, the locking component 190 is in a locked state (as shown). Figure 19 (as shown) and actuator 160 is in the first state (as shown) Figure 17 (As shown). The actuator 160 includes a slide trigger 161 and an elastic element 162 in the form of a coil spring 162. The slide trigger 161 is nested within a recess 165 in the outer surface 127 of the second side rail 120. It can be seen that the slide trigger 161 is connected to the link 180, and both the slide trigger 161 and the link 180 are disposed within the second closed channel 104.

[0105] The elastic element 162 is arranged such that the actuator 160 is biased to a first state. When the actuator 160 is in the first state, the locking member 170 is also in a locked state, as described below. In an exemplary embodiment, the elastic element 162 is a compression coil spring. However, the invention is not limited to all embodiments; the elastic element 162 may be a flexible member formed of rubber or the like, or it may be a different type of spring.

[0106] The trigger 161 is located within the housing 163 of the actuator 160 and can move upwards to actuate it, such as... Figure 17As indicated by the arrow in the diagram. The travel distance of the trigger 161 used for actuation can be relatively small, such as 0.1 to 3 inches, or more specifically 0.1 to 2 inches, or more specifically 0.1 to 1 inch.

[0107] Locking member 170 is pivotally mounted to the second side rail 120. The position of the illustrated locking member 170 (and locking lever 150) corresponds to the actuator 160 in the first state. As described above, link 180 is operably connected at one end to locking member 170 and at the other end 182 to the slide trigger 161 of actuator 160. Therefore, if link 180 moves upward in the direction of the arrow due to actuation of actuator 160 from the first state to the second state, locking member 170 will pivot about pivot axis DD, as indicated by the arc arrow.

[0108] The locking member 170 includes a first portion 176 located within the second closed channel 104 and a second portion 177 projecting from the second inner wall 222. It can be seen that the locking member 170 extends through an opening 175 in the second inner wall 222 of the second side rail 120, such that the second portion 177 is located within the second open channel 202 of the second side rail 120. A link 180 is connected to the first portion 175 of the locking member 170. The second portion 177 of the locking member 170 includes a receptacle-like engagement feature 172 that engages the locking member 155 of the locking lever 150. Due to the engagement between the engagement feature 172 and the locking member 155 of the locking lever 150, the locking lever 150 is locked in place and cannot slide relative to the first locking crossbar 140. If the locking member 155 is not engaged by the engagement feature 172, the locking lever 150 will be able to slide freely relative to the first locking crossbar 140.

[0109] The elastic element 275 is a torsion spring that engages with the edges of the locking member 170 and the first locking crossbar 140, biasing the locking member 170 to... Figure 19 The locking state is shown. The locking member 170 includes an elongated slot 171, and the second end 181 of the link 180 is connected to the locking member 170 within the elongated slot 171.

[0110] Actuator 160 is operatively coupled to link 180 such that upward axial movement of trigger 161 (away from the bottom end 121 of the second side rail 120) also causes upward axial movement of link 180.

[0111] Now for reference Figure 18 and 20Actuator 160 is illustrated as moved to the second state and locking member 170 is illustrated as having pivoted to the unlocked state. To change actuator 160 from the first state to the second state, the user engages trigger 161 and pulls trigger 161 upward, thereby generating an axially upward actuating force on trigger 161 toward the first and second locking hinges 115, 125 (i.e., away from the first end 121 of the second side rail 120). In doing so, resilient element 162 is compressed, and trigger 161 moves axially upward within housing 163. Because trigger 161 is operatively coupled to link 180, link 180 also moves axially upward, thereby overcoming the bias of resilient element 275 and releasing locking member 170 from the locked state. Figure 19 The linkage 80 pivots about axis DD to the unlocked state (Figure 20). During this movement, the second end 181 of the linkage 80 engages the end wall 178 of the elongated slot 171, thereby causing the locking member 170 to pivot about axis DD as the actuator 160 moves from the first state to the second state.

[0112] In order to release the locking component 190 from the locked state ( Figure 19 Change to unlocked state Figure 20 The force applied to the user-operated actuator 160 in the upward axial direction must overcome the biasing forces of both elastic elements 162 and 275. When the user releases the trigger 161, the trigger 161 will automatically... Figure 18 The second state change to Figure 17 The first state. This is because elastic elements 162 and 275 are biased to return to their normal state.

[0113] Now for reference Figure 21-23 Once the locking assembly 190 (through the rotation of the locking member 170) reaches the unlocked state, force continues to be applied to the first user-operated actuator 160 in the upward axial direction, causing the second side railing 120 to rise relative to and fold towards the first side railing 110. As a result, the first stair section 300 can be lowered from the ladder-loaded state ( Figure 12 Change to the railing retracted state. Figure 13 As mentioned earlier, due to their connection, the second stair section 400 will also be transferred from the stair-bearing state ( Figure 12 ) Change to the railing retracted state ( Figure 13 ).

[0114] When the user raises the second side railing 120 relative to the first side railing 110 (and folds the second side railing 120 toward the first side railing 110), the locking lever 150 slides within the track 145 of the first locking crossbar 140 in a direction away from the locking member 170. During this movement, the second side railing 120 moves toward the first side railing 110 by pivoting both the first unlocking crossbar 130 and the first locking crossbar 140 about their respective pivot axes. Figure 21 As shown, when the second side rail 120 is raised relative to the first side rail 110, the second end 152 of the locking lever 150 slides within the track 145 of the first locking crossbar 140 in a direction away from the locking member 170 and also away from the second side rail 120, and toward the first side rail 110. Once the locking member 155 of the locking lever 150 has moved out of alignment with the engagement feature 172, the user can release the actuator 160. Because the locking member 155 of the locking lever 150 has moved away from the engagement feature 172, the release actuator 160 will not lock the locking assembly 190. Figure 22 and 23 This illustrates the continuous sliding movement of the second end 152 of the locking lever 150 within the track 145 of the first locking crossbar 140 as the second side rail 120 continues to move toward the first side rail 110. The second end 152 of the locking lever 150 moves further and further away from the locking member 170 and the second side rail 120 to facilitate the retraction of the ladder 100. Because each of the first unlocked crossbars 130 is freely pivotally coupled to the first and second side rails 110, 120, once the locking member 190 changes to the unlocked state, it is impossible to prevent the user from retracting the ladder 100 as described herein.

[0115] It should be understood that ladder 100 does not automatically change to its folded state. Instead, as described herein, a user action is required to move the second side rail 120 toward the first side rail 110. This is because locking lever 150 has a moment of inertia that holds locking lever 150 in the locked position (where it can be engaged with locking member 170). The user must take action to remove locking lever 150 from the locked position, which is to lift / pivot the second side rail 120 toward the first side rail. As seen in the figures and described herein, the same upward actuation motion that occurs for actuating actuator 160 also facilitates rail-to-rail retraction of ladder 100.

[0116] Now for reference Figures 28-30 This will describe the process by which the locking component 190 enters a locked state when the first stair section 300 changes from a retracted state (to a stair-loaded state) to a stair-supported state. (Refer to...) Figure 28When the first stair section 300 changes from a retracted state to a loaded state, the second side railing 120 is lowered and folded away from the first side railing 110. As a result, the second end 152 of the locking lever 150 begins to slide towards the second side railing 120 within the track 145 of the first locking crossbar 140, as indicated by the movement arrow. Figure 29 As shown, this sliding continues unimpeded until the locking member 155 of the locking lever 150 contacts the cam surface 179 of the locking member 170. As the second side rail 120 continues to descend and fold relative to the first side rail 110, the locking member 155 applies an opening force to the cam surface 179 of the locking member 170, thereby overcoming the bias of the resilient element 275 and causing the locking member 170 to pivot about axis DD. However, since the second end 181 of the link 180 can slide freely within the elongated slot 171, the locking member 170 pivots from the locked state to the unlocked state while the actuator 160 is held in the first state. In other words, the opening force must overcome only the bias of the resilient element 275 (not the combined bias of both resilient elements 275 and 162) to change the locking assembly 190 from the locked state to the unlocked state. This differs from the actuating force applied to the actuator 160, which must overcome the combined bias of both resilient elements 275 and 162 to change the locking assembly 190 from the locked state to the unlocked state.

[0117] The locking member 155 continues to travel along the cam surface 179 (and rotates the locking member 170) until the locking member 155 is aligned with the engagement feature 172. Once this occurs, the bias of the resilient element 275 causes the locking member 170 to rotate back to the locked state, thereby forcing the locking member 155 to engage with the engagement feature 172, as... Figure 30 As shown.

[0118] Generally, the locking lever 150 extends from a first end 151, pivotally connected to the first side rail 110, to a second end 152, slidably connected within a track 145 of the first locking crossbar 140. When the ladder 100 is in a ladder-loaded state (e.g.) Figure 9 As shown, the locking lever 150 extends obliquely relative to the first and second axes AA, BB (and therefore also relative to the first and second side rails 110, 120). As described above, the locking lever 150 includes a locking member 155 that slides within the track 145 and engages the locking member 170 to lock the ladder 100 in the ladder-loaded state. In an exemplary embodiment, the locking member 155 is a lever nested within a channel of the track 145 located on opposite sidewalls, such that the locking lever 150 remains connected to the first locking rung 140 regardless of the specific position of the locking member 155 relative to the first locking rung 140. Therefore, whether the ladder 100 is in the ladder-loaded state or the railing-to-railing-retracted state ( Figure 10 The locking lever 150 remains slidably connected to the first locking crossbar 140.

[0119] exist Figure 9 In this configuration, ladder 100 is in a straight ladder arrangement. In this arrangement, the first and second side rails 110 and 120 are spaced apart by a first distance D1. In this straight ladder arrangement, ladder 100 is prepared for use as a regular ladder. Ladder 100 in this configuration is very stable to use.

[0120] As described above, actuator 160 is operatively coupled to locking member 170. In an exemplary embodiment, actuator 160 is operatively coupled to locking member 170 via a link 180 extending along first side rail 110, but other structural arrangements for such coupling are possible in alternative embodiments. Actuator 160 can change between a first state and a second state; for the first state, refer to... Figure 9 and Figure 15 The locking member 170 is connected to the locking lever 150, so that the locking assembly 190 is in a locked state; for the second state, refer to the description below. Figure 19 The locking member 170 separates from the locking lever 150, thereby placing the locking assembly 190 in an unlocked state. In an exemplary embodiment, the actuator 160 includes a trigger 161, and pulling the trigger 161 upward in a direction opposite to gravity (or, in an exemplary embodiment, in a direction toward the second locking hinge 125) causes the actuator 160 to transition from a first state to a second state. In other words, the actuator 160 is actuated by pulling the trigger 161 in a direction away from the first end 121 of the second side rail 120 (and also away from the first locking crossbar 140 and away from the locking lever 150).

[0121] In an exemplary embodiment, the actuator 160 is located on the upper region of the first portion 123 of the second side rail 120, adjacent to the second locking hinge 125. Therefore, if the first portion 123 of the second side rail 120 is divided into three parts, the actuator 160 will be located at the upper third of the first portion 123 of the second side rail 120. Furthermore, in an exemplary embodiment, the actuator 160 is located on the outer surface 127 of the second side rail 120. This positioning of the actuator 160 makes actuation very easy, allowing the ladder 100 to change between an open and retracted state. However, the requirement to pull the trigger 161 upwards away from the first locking rung 140 makes it unlikely that the trigger 161 will be accidentally actuated, which is a safety feature.

[0122] Reference Figure 10 As mentioned above, ladder 100 can be directly accessed from... Figure 9The illustrated straight ladder configuration is changed to a retracted railing state. Specifically, by actuating actuator 160, locking lever 150 can be disengaged from locking member 170, allowing the first side railing 110 and the second side railing 120 to move closer to each other. During this process, as the second side railing 120 moves toward the first side railing 110, the first unlocked crossbar 130 and the first locked crossbar 140 pivot relative to the first and second side railings 110, 120. In the retracted state, the first and second side railings 110, 120 are spaced apart by a second distance D2 less than a first distance D1, and in some embodiments, this distance may be zero. Furthermore, in the retracted state, the second side railing 120 is longitudinally raised relative to the first side railing 110, causing the bottom ends 111, 121 of the first and second side railings 110, 120 to offset each other, and the top ends 112, 122 of the first and second side railings 110, 120 to offset each other, as shown below. Figure 10 As shown.

[0123] Figure 11 The illustration shows a ladder 100 in a staircase configuration. Specifically, first and second locking hinges 115, 125 can be actuated to allow the first and second stair sections 300, 400 to fold about the axis of rotation CC. As shown in several figures, ladder 100 includes feet 199 connected to the bottom ends of the first, second, third, and fourth side rails 110, 120, 410, 420. To meet ANSI standard requirements for staircases, ladder 100 has a minimum flare for the required rail length. For example, for each side rail foot, ladder 100 has a flare of at least 1.25 inches. Therefore, feet 199 are designed to increase the bottom width of the first and second stair sections 300, 400 to meet staircase safety standards.

[0124] Reference Figure 24-26 Another feature of the ladder 100 will be described below. In an exemplary embodiment, the locking lever 150 includes a hole 156 through which a portion of the locking member 170 is exposed. More specifically, the portion of the locking member 170 exposed through the hole 156 includes a marking. Figure 25 The first mark 157a is shown as visible through the hole 156 when the locking assembly 190 is in the locked state. Figure 18A second mark 157b is shown, visible through hole 156, when the locking assembly 190 is in the unlocked state. In an exemplary embodiment, the first mark 157a is an image of a padlock in the locked state, and the second mark 157b is an image of a padlock in the unlocked state. Of course, the invention is not limited to these specific marks. In other embodiments, the first mark 157a may be a first color (i.e., red), and the second mark 157b may be a second color different from the first color (i.e., green). The first and second marks 157a, 157b are intended to indicate to the user whether the locking assembly 190 is in the locked or unlocked state, so that the user knows whether the ladder can be retracted and / or used safely in a conventional manner.

[0125] The ladder 100 may have various different sizes, including but not limited to five feet, seven feet, nine feet, eleven feet, etc., measured from the bottom 111, 121 of the first and second side rails 110, 120 to the top 112, 122 of the first and second side rails 110, 120. In some embodiments, the ladder 100 may be less than five feet or greater than eleven feet. In some embodiments, the ladder 100 may be the same as described herein, regardless of its length.

[0126] Brief Reference Figure 27A -B, According to an alternative embodiment, ladder 100B is shown, wherein the length of ladder 100B is greater than the length of ladder 100. Ladder 100B is structurally and functionally identical to ladder 100, except that it includes two locking components 390B and two actuators 160B. The locking components 390B and actuators 160B are structurally and functionally identical to the locking components 190 and actuators 160 of ladder 100 described above. Therefore, detailed descriptions of these and other elements of ladder 100B will be omitted, and it will be understood that the above discussion regarding ladder 100 applies to ladder 300B (unless otherwise stated below).

[0127] exist Figure 27A In the diagram, ladder 100B is shown as a stepped configuration, while... Figure 27B In the diagram, ladder 100B is shown in a folded configuration. It can be seen that both the first section 300B and the second section 400B include their own locking assembly 190B and actuator 160B. The locking assembly 190B and actuator 160B on the second section 400B operate on the third and fourth side rails 410B and 420B in the same manner as discussed above with respect to the first and second side rails 110 and 120 of ladder 100.

[0128] The first actuator of actuator 160B is located on the second side rail 120B, while the second actuator of actuator 160B is located on the fourth side rail 420B. Actuators 160B are positioned on the second and fourth side rails 120B and 420B such that when ladder 100B is changed to a folding configuration (… Figure 27B The actuators 160B are at least partially aligned with each other in the axial direction. In an exemplary embodiment, the actuators 160B are fully aligned with each other. The first actuator of the actuators 160B is located on the outer surface of the second side rail 120B, while the second actuator of the actuators 160B is located on the outer surface of the fourth side rail 420B. In the folded configuration, the first and second actuators of the actuators 160B are adjacent to each other.

[0129] Although the actuator 360 for the two locking components 390 is shown as located in Figure 27A -B. On the same side of ladder 300, in other embodiments, they may be positioned on opposite sides of ladder 300. Increasing the number of locking components 390 increases the stability of ladder 300 to accommodate increases in ladder 300 length.

[0130] As used throughout, "range" is used as a shorthand to describe each value within the range. Any value within the range can be chosen as an endpoint of the range. Furthermore, all references cited herein are incorporated herein by reference in their entirety. In the event of any conflict between definitions in this disclosure and definitions in cited references, this disclosure shall prevail.

[0131] While the present invention has been described with reference to specific examples including the currently preferred mode of implementing the invention, those skilled in the art will understand that various variations and arrangements of the above-described systems and techniques exist. It should be understood that other embodiments can be utilized and structural and functional modifications can be made without departing from the scope of the invention. Therefore, the spirit and scope of the invention should be broadly interpreted as set forth in the appended claims.

Claims

1. A ladder, comprising: The first stage includes: The first side railing extending along the first axis; The second side railing extending along the second axis; A plurality of first crossbars have a first end and a second end, the first end being pivotally connected to the first side rail and the second end being pivotally connected to the second side rail; A locking assembly includes a locking member comprising an elongated slot, the locking assembly being capable of changing between: (1) a locked state, wherein the first stair section is locked in a stair-loaded state; and (2) an unlocked state, wherein the second side rail is foldable relative to the first side rail such that the first stair section changes between the stair-loaded state and the rail to a rail-retracted state. A user-operated actuator capable of changing between a first state and a second state, the user-operated actuator being operably connected to the locking member via a linkage to change the locking assembly from the locked state to the unlocked state when changing from the first state to the second state, the end of the linkage being operably engaged in an elongated slot of the locking member; A first elastic element biases the user-operated actuator to the first state; and A second elastic element is operatively coupled to the locking member to bias the locking assembly into the locked state; The opening force applied directly to the locking member causes the locking member to pivot, while the end of the connecting rod slides freely within the elongated slot, changing the locking assembly from the locked state to the unlocked state. The opening force must overcome only the biasing force of the second elastic element to change the locking assembly from the locked state to the unlocked state. The user-operated actuator changes from the first state to the second state such that the end of the linkage engages the end wall of the elongated slot to pivot the locking member and change the locking assembly from the locked state to the unlocked state.

2. The ladder of claim 1, wherein the force applied to the user-operated actuator must overcome the biasing forces of both the first and second elastic elements to change the locking assembly from the locked state to the unlocked state using the user-operated actuator.

3. The ladder of claim 1, wherein the opening force is applied to the locking member by a locking member of a locking lever, the locking lever having a first end and a second end, the first end being pivotally connected to the second side rail, and the second end being slidably connected to one of the plurality of first rungs; wherein, When the first stair section changes from the railing to the railing folded state to the stair load state, the second end of the locking lever slides along one of the plurality of first crossbars, thereby the locking component contacts the locking member and applies the opening force, thereby allowing the locking component to enter the engagement feature of the locking member, which engages with the locking component in the locked state.

4. The ladder according to claim 3, wherein when the locking member enters the engagement feature of the locking member, the second elastic element biases the locking assembly into the locked state, in which the engagement feature closes and engages the locking member.

5. The ladder according to any one of claims 1 to 4, further comprising a second ladder section, The second section includes: The third side railing extending along the third axis; The fourth side railing extending along the fourth axis; and Multiple second crossbars, each having a first end and a second end, the first end being pivotally connected to a third side rail and the second end being pivotally connected to a fourth side rail; By folding the fourth side railing toward the third side railing to cause pivoting around the first and second ends of the plurality of second crossbars, the second stair section can change between: (1) a stair-loaded state; (2) a railing-to-railing-retracted state, wherein the third side railing and the fourth side railing are adjacent to each other; and The first and second stair sections are pivotally connected to each other via a pair of hinges. When the first and second stair sections are under load, the pair of hinges can be adjusted and locked between multiple optional angle configurations, including: (1) a straight stair configuration, wherein the third axis of the third side railing is substantially coaxial with the first axis of the first side railing, and the fourth axis of the fourth side railing is substantially coaxial with the second axis of the second side railing; (2) a stepped stair configuration, wherein the first axis of the first side railing and the third axis of the third side railing form a first acute angle, and the second axis of the second side railing and the fourth axis of the fourth side railing form a second acute angle; (3) a folding configuration, wherein the first and third side railings extend adjacent to each other, and the second and fourth side railings extend adjacent to each other.

6. The ladder according to claim 5, wherein, When the locking component is in the locked state, the second stair section is prohibited from changing from the stair-loaded state to the railing-retracted state because the first stair section and the second stair section are connected by the pair of hinges.

7. The ladder according to claim 1, wherein, When the actuator is held in the first state, an opening force is applied to the locking component, which can change from the locked state to the unlocked state.

8. The ladder according to claim 7, wherein, When the locking component of the locking lever slides along one of the plurality of first crossbars toward the second side rail, the opening force is applied to the cam surface of the locking member of the locking assembly through the locking component.

Images