ladder

Abstract

A ladder includes a base section including a first base rail and a second base rail in spaced relation to the first base rail, a stretch section including a first stretch rail and a second stretch rail in spaced relation to the first stretch rail, a plurality of base rungs attached to and extending between the first base rail and the second base rail, a plurality of stretch rungs attached to and extending between the first stretch rail and the second stretch rail, and a lock assembly including a lock stretch portion coupled to at least one of the plurality of stretch rungs and a lock base portion attached to at least one of the plurality of base rungs, wherein the lock stretch portion and the lock base portion engage one another to prevent inadvertent unlocking and retraction of the base section or the stretch section relative to one another.

Description

[0001] Divisional application information

[0002] This application is a divisional application of the invention patent application filed on July 29, 2021, with application number 202110864970.6 and entitled "Segmentally Extendable Climbing Product, and Method of Using and Manufacturing the Climbing Product".

[0003] Cross-reference of related applications

[0004] These are U.S. Provisional Patent Application No. 63 / 058,805, filed July 30, 2020, and U.S. Provisional Patent Application No. 63 / 140,599, filed January 22, 2021, all of which are incorporated herein by reference. Technical Field

[0005] This invention relates to a climbing product having a retractable section locking assembly. (As used herein, references to "invention" or "the invention" refer to exemplary embodiments and not necessarily to every embodiment covered by the appended claims.) More specifically, this invention relates to a climbing product having a retractable section locking assembly, wherein the locking assembly includes a stretch lock portion attached to a stretch section of the climbing product, the stretch lock portion locking to a base section of the climbing product and easily unlocking from the base section by raising the stretch section relative to the base section. Background Technology

[0006] This paragraph is intended to introduce the reader to various aspects of the art that may relate to various aspects of the present invention. The following discussion is intended to provide information to facilitate a better understanding of the invention. Therefore, it should be understood that the statements in the following discussion should be interpreted in this light and not as an admission of prior art.

[0007] Current locking systems for retractable ladders and other devices with retractable sections require the user to perform a separate action to unlock the retractable section before moving it. Performing this separate action to unlock the retractable section can be cumbersome and introduces potential errors that could cause the retractable sections to move relative to each other in an undesirable manner, resulting in damage or injury. It would be desirable to eliminate the need to perform a separate action to unlock the retractable section before moving it.

[0008] Furthermore, the current locking systems on telescopic ladders are large and intrude on the user's workspace. There is a desire to reduce or eliminate the intrusion of the locking system into the user's workspace. Summary of the Invention

[0009] This invention relates to a climbing product whose sections are retractable. The climbing product includes a base section having a first base rail and a second base rail parallel and spaced apart from the first base rail, and a base crossbar attached to and between the first and second base rails. The climbing product includes a stretch section having a first stretch rail and a second stretch rail parallel and spaced apart from the first stretch rail, and a stretch crossbar attached to and between the first and second stretch rails. The stretch section is slidably engaged with the base section. The climbing product includes a locking assembly having a locking stretch portion directly attached to the stretch section. The locking stretch portion directly engages with the base section to lock the base section to the stretch section. The locking stretch portion disengages from the locking base portion by simply moving the stretch section relative to the base section to unlock the stretch section from the base section.

[0010] This invention relates to a method for using a climbing product 10, wherein a segment of the climbing product 10 is retractable. The method includes the following steps: sliding a retractable segment 20 of the climbing product 10 relative to a base segment 12 of the climbing product 10, the retractable segment 20 being slidably engaged with the base segment 12; locking the retractable segment 20 to the base segment 12; lifting the retractable segment 20 relative to the base segment 12 to unlock the retractable segment 20 from the base segment 12; and moving the retractable segment 20 downward relative to the base segment 12.

[0011] This invention relates to a method for manufacturing a climbing product 10, wherein a section of the climbing product 10 is retractable. The method includes the step of directly attaching a locking assembly 28 having a locking extension portion 30 to a crossbar of a retractable section 20 of the climbing product 10. There is also a step of sliding the retractable section 20 along a base section 12 of the climbing product 10, such that the retractable section 20 engages with the base section 12.

[0012] This invention relates to a climbing product whose sections are extendable. The climbing product includes a base section having a first base rail and a second base rail parallel and spaced apart from the first base rail, and a base crossbar attached to and between the first and second base rails. The climbing product includes a stretch section having a first stretch rail and a second stretch rail parallel and spaced apart from the first stretch rail, and a stretch crossbar attached to and between the first and second stretch rails. The stretch section is slidably engaged with the base section. The climbing product includes a locking assembly having a locking stretch portion directly attached to the stretch section. The locking stretch portion directly engages with the base section to lock the base section to the stretch section. The locking stretch portion has a locking bolt. By moving the locking bolt, the locking stretch portion disengages from the base section.

[0013] This invention relates to a method of using a ladder, wherein a section of the ladder is extendable. The method includes the step of moving the ladder to a desired position. The ladder includes a base section having a first base rail and a second base rail parallel to and spaced apart from the first base rail, and base runners attached to and between the first and second base rails. The ladder includes a stretch section having a first stretch rail and a second stretch rail parallel to and spaced apart from the first stretch rail, and stretch runners attached to and between the first and second stretch rails. The stretch section slidably engages with the base section, and the ladder includes a locking assembly having a locking stretch portion directly attached to the stretch section. The locking stretch portion directly engages with the base section to lock the base section to the stretch section. The locking stretch portion has a locking bolt. By moving the locking bolt, the locking stretch portion disengages from the base section. There is a step of moving the locking bolt so that the locking stretch portion disengages from the base section. There is a step of sliding the stretch section along the base section to extend the ladder to a desired length. There is a step of locking the stretching section to the base section when the locking portion is at the desired length.

[0014] This invention relates to a method for constructing a ladder, wherein a section of the ladder is extendable. The method includes the step of directly attaching a locking extension portion of a locking assembly to an extendable section of the ladder. The extendable section has a first extension rail and a second extension rail parallel to and spaced apart from the first extension rail, and an extension runner attached to and between the first and second extension rails. The extendable section is slidably engaged with a base section. The locking extension portion has a locking bolt. A step involves attaching a locking base portion of the locking assembly directly attached to the base section. The locking extension portion directly engages with the locking base portion to lock the extendable section to the base section. By moving the locking bolt, the locking extension portion disengages from the locking base portion. The base section has a first base rail and a second base rail parallel to and spaced apart from the first base rail, and a base runner attached to and between the first and second base rails. Attached Figure Description

[0015] Figure 1 Showing two sections of the extendable ladder.

[0016] Figure 2 The demonstration shows two sections assembled together in a typical MT ladder configuration with a movable section positioned within a fixed section of rails.

[0017] Figure 3 Two embodiments of the lock assembly of the present invention are shown.

[0018] Figure 4 Show the flip lock in the position it returned to when it was free.

[0019] Figure 5 The flip lock deflects as the base crossbar and the stretch crossbar begin to pass each other.

[0020] Figure 6 The flip lock is shown when it enters the slot.

[0021] Figure 7 The flip lock is shown in the slot, which prevents the stretch bar from descending further.

[0022] Figure 8 The demonstration shows how raising and stretching the crossbar removes the flip lock from its engagement with the slot.

[0023] Figure 9 The flip lock is shown returning to its spring-biased position after it has disengaged from the base crossbar.

[0024] Figure 10 The flip lock deflects from the base crossbar to allow the stretch crossbar to descend freely.

[0025] Figure 11The lock and traction device are shown in their spring-biased position when there is no base crossbar.

[0026] Figure 12 The demonstration shows that when the stretching crossbar is raised, the lock is deflected by the base crossbar.

[0027] Figure 13 The display lock has detached from the base crossbar, and the traction device has been partially deflected by the base crossbar.

[0028] Figure 14 The demonstration shows that when the stretching crossbar has moved downwards and the traction device has disengaged from the base crossbar, the lock has engaged the base crossbar to prevent further downward movement.

[0029] Figure 15 The demonstration shows that the traction device is deflected by the base crossbar when the stretch crossbar is raised and the lock disengages from the base crossbar.

[0030] Figure 16 The demonstration shows that when the tension bar has been raised above the base bar, both the lock and the traction device are free and disengaged from the base bar.

[0031] Figure 17 The traction device is shown to be fitted into the lock's slot because the base crossbar deflects the traction device as the tension crossbar moves downward, thus allowing the tension crossbar to descend freely.

[0032] Figure 18 A lock assembly for use in the first embodiment is shown.

[0033] Figure 19 It is a cross-sectional side view showing the flip lock stop and frame stop, as well as the flip lock itself, when the flip lock is free and disengaged from any base crossbar.

[0034] Figure 20 This is a cross-sectional side view of the flip lock when it has been deflected upwards by the base crossbar.

[0035] Figure 21 This is a cross-sectional side view of the flip lock when it has been deflected downwards by the base crossbar.

[0036] Figure 22 A lock assembly for use in the second embodiment is shown.

[0037] Figure 23 It is a cross-sectional side view of the lock and frame stop and the lock stop and the traction device stop in the traction device when the lock and traction device are free and disengaged from any base crossbar.

[0038] Figure 24 It is a cross-sectional side view of the lock and traction device when it has been deflected upward by the base crossbar.

[0039] Figure 25It is a cross-sectional side view of the lock and traction device when it has been deflected downward by the base crossbar.

[0040] Figure 26 and 27 The ladder on display is called the NGMF (Next Generation Multiform) ladder.

[0041] Figure 28 This is a detailed view showing the inner crossbar, which has a flip lock that engages with one of the outer crossbars.

[0042] Figure 29 Only the inner and outer crossbars with flip locks are shown.

[0043] Figure 30 Only another view of the inner crossbar with the flip lock is shown.

[0044] Figure 31 Another view shows a typical outer crossbar with grooves for engagement of the flip lock.

[0045] Figure 32 The components of the invention are shown as seen when the inner crossbar is transparent.

[0046] Figure 33 exhibit Figure 32 A close-up of the image, which obscures some additional components. Key parts of the invention are the flip lock, the stop, and the bolt.

[0047] Figure 34 This demonstrates the relationship between the flip lock and the stop.

[0048] Figure 35 Showing a flip lock.

[0049] Figure 36 The conditions under which the bolt can engage the bolt locking groove in the flip lock are: the flip lock is horizontal and the stop is rotated relative to the flip lock to its extreme CCW position.

[0050] Figure 37 , 38 Figure 39 shows how the bolt (axis shown by the + symbol) is prevented from engaging the bolt locking groove (shown by the dashed line) whenever the stop is in its extreme CW position relative to the flip lock.

[0051] Figure 40 and 41 Demonstrate the function of the locking bar and bolt. When the right end of the locking bar is as follows: Figure 40 When the lever is oriented downwards, the bolt is positioned on its left side or in the engagement position with the locking groove. When the right end of the lever is... Figure 41 When the bolt is lifted, it moves to its right side or disengages from the locking groove.

[0052] Figure 42How does the contact between the demonstration block and the outer crossbar work? Figure 36 The stop block is positioned relative to the flip lock CCW as seen in the diagram.

[0053] Figure 43 The following describes the situation when the flip lock is not engaged in the groove in the outer crossbar: the stop prevents the bolt from engaging the flip lock, allowing the flip lock to move freely in the manner of the previously disclosed flip lock invention.

[0054] Figure 44 The arrangement of the lifting ropes between the base section and the tension section is shown.

[0055] Figure 45 Show the ladder in its fully extended, straight position from the non-climbing side.

[0056] Figure 46 The ladder is shown in its fully extended, straight-lined position from the climbing side.

[0057] Figures 47A to 47F Multiple views show the locking bar and locking bar handle in their proper positions on the crossbar.

[0058] Figure 48 It is a perspective view of the ladder, with the stretched section extending.

[0059] Figure 49 It is a perspective view of a flip lock having a stop and a flip lock spring that is biased in a suitable position in the flip lock and adjacent to the stop. Detailed Implementation

[0060] Referring now to the accompanying drawings, where similar element symbols in several views refer to similar or identical parts, and more specifically, referring to their... Figures 1 to 3The product showcases a climbing product with retractable sections. The climbing product includes a base section 12 having a first base rail 14 and a second base rail 16 parallel and spaced apart from the first base rail 14, and a base crossbar 18 attached to and between the first and second base rails 14 and 16. The climbing product includes a stretch section 20 having a first stretch rail 22 and a second stretch rail 24 parallel and spaced apart from the first stretch rail 22, and a stretch crossbar 26 attached to and between the first and second stretch rails 22 and 24. The stretch section 20 is slidably engaged with the base section 12. The climbing product includes a locking assembly 28 having a locking stretch portion 30 directly attached to the stretch section 20. The locking stretch portion 30 directly engages with the base section 12 to lock the base section 12 to the stretch section 20. The locking tension section 30 disengages from the locking base section 32 by simply moving the tension section 20 relative to the base section 12 to unlock the tension section 20 from the base section 12. The climbing product 10 may include, but is not limited to, MT ladders, inclined ladders, and work platforms.

[0061] like Figures 3 to 10 and Figures 18 to 21 As shown, the lock assembly 28 may include a lock base portion 32 directly attached to the base section 12. A lock extension portion 30 directly engages with the lock base portion 32 to lock the extension section 20 to the base section 12. The lock extension portion 30 disengages from the lock base portion 32 by simply moving the extension section 20 relative to the base section 12 to unlock the extension section 20 from the base section 12. The lock base portion 32 may include a slot 34 disposed in one of the base crossbars 18, and the lock extension portion 30 includes a flip lock 36 that fits into the slot 34 to lock the extension section 20 to the base section 12 such that the extension section 20 cannot move downward relative to the base section 12 when locked to the base section 12. The flip lock 36 is disposed in one of the extension crossbars 26. The flip lock 36 may include: a lever 38 fitted into a slot 34 to lock the tension section 20 to the base section 12; an anchor 40 from which the lever 38 extends; a flip shaft 42 extending through the anchor 40, the anchor 40 and the lever 38 rotating about the flip shaft 42; and a flip spring 44 biasing the lever 38 into a stable position, wherein the lever 38 extends substantially perpendicularly from the first tension rail 22 toward the first base rail 14.

[0062] The locking tension section 30 may include a lock 46 that directly engages with one of the base crossbars 18 to lock the tension section 20 to the base section 12, such that when the tension section 20 is locked to the base section 12, the tension section 20 cannot move downward relative to the base section 12. See Figures 11 to 17 and Figures 22 to 25The lock tensioning portion 30 disengages from the lock base portion 32 by simply moving the tensioning portion 20 relative to the base portion 12 to unlock the tensioning portion 20 from the base portion 12. The lock tensioning portion 30 may include a traction device 48 disposed adjacent to the lock 46, the traction device 48 engaging the lock 46 and holding the lock 46 in a position that does not obstruct the base crossbar 18 when the tensioning portion 20 moves downward relative to the base portion 12. The lock tensioning portion 30 may have: a lock shaft 50 extending through the lock 46, the lock 46 rotating about the lock shaft 50; and a traction device shaft 54 ​​extending through the traction device 48, the traction device 48 rotating about the traction device shaft 54. The lock 46 may have an anchor 40, a first arm 58 extending from the anchor 40, and a second arm 60 spaced apart from the first arm 58, wherein the first arm 58 is longer than the second arm 60, and wherein the second arm 60 extends from the anchor 40. The first arm 58, the second arm 60, and the anchor 40 together form a generally C-shape, defining a groove 62 between the first arm 58 and the second arm 60. The lock extension portion 30 may include a lock spring 64 that biases the lock 46 into a stable position in which the first arm 58 and the second arm 60 extend toward the first base rail 14. The lock extension portion 30 includes a traction spring 66 that biases the traction device 48 into a stable position in which the traction device 48 extends toward the first base rail 14.

[0063] This invention relates to a method for using a climbing product 10, wherein a segment of the climbing product 10 is retractable. The method includes the following steps: sliding a retractable segment 20 of the climbing product 10 relative to a base segment 12 of the climbing product 10, the retractable segment 20 being slidably engaged with the base segment 12; locking the retractable segment 20 to the base segment 12; lifting the retractable segment 20 relative to the base segment 12 to unlock the retractable segment 20 from the base segment 12; and moving the retractable segment 20 downward relative to the base segment 12.

[0064] This invention relates to a method for manufacturing a climbing product 10, wherein a section of the climbing product 10 is retractable. The method includes the step of directly attaching a locking assembly 28 having a locking extension portion 30 to a crossbar of a retractable section 20 of the climbing product 10. There is also a step of sliding the retractable section 20 along a base section 12 of the climbing product 10, such that the retractable section 20 engages with the base section 12.

[0065] In operation of the present invention, the locking assembly 28 allows the retractable section to be moved and locked without needing to reach the locking mechanism, for example, when extending and retracting the top section of the MT ladder in telescopic mode. Furthermore, the locking assembly 28 reduces or eliminates intrusion into the user's workspace by being primarily positioned in or below the rungs of the climbing product 10.

[0066] Figure 1 Show two sections of the extendable ladder. These sections can be an MT-type ladder or half of a straight extendable ladder. The fixed section (e.g., base section 12) rests on the ground, while the movable section (e.g., extension section 20) can be adjusted for different heights.

[0067] Figure 2 The demonstration shows two sections assembled together in a typical MT ladder configuration, with a movable section positioned within a track in a fixed section. The goal is for the movable section to lock into various positions relative to the fixed section when adjusted, ensuring alignment of the crossbars on the movable section with those on the fixed section, as shown.

[0068] The typical lock used on an MT ladder is called a J lock. Two J locks must be manually unlocked one at a time, the moving section moved to the desired position, and then the other J lock is manually locked one at a time. J locks are typically positioned at the top of the stationary section.

[0069] Figure 3 Two embodiments of the lock assembly 28 of the present invention are shown. Figure 3 The image shows an embodiment where crossbars are attached side-by-side to the moving section. In reality, only one embodiment would be installed at the center of the crossbars.

[0070] Figures 4 to 10 The operation of the first embodiment is demonstrated. Slots 34 are installed within the crossbars of each fixed (base) section. A flip lock 36 is attached to a crossbar of the movable section. Figure 4 Show the flip lock 36 in the position it returned to when it is free. Figure 5 The flip lock 36 deflects as the base crossbar and the stretch crossbar begin to pass each other. Figure 6 The flip lock 36 is shown when it enters slot 34. Figure 7 The flip lock 36 is shown in the wedge slot 34, which prevents the stretch crossbar from descending further. Figure 8 The lifting and stretching crossbars are used to remove the flip lock 36 from its engagement with the slot 34. Figure 9 The flip lock 36 is shown returning to its spring-biased position after it has disengaged from the base crossbar. Figure 10 The flip lock 36 is shown to deflect from the base crossbar to allow the stretch crossbar to descend freely.

[0071] The flip lock 36 is attached to a crossbar in the moving section. The flip lock 36 can pivot upwards or downwards, but is biased by spring force to return to its original position when free. Figure 4 The position seen in the diagram. Raising the moving section allows the lever 38 of the flip lock 36 to enter the slot 34. At this time, lowering the moving section causes the lever 38 of the flip lock 36 to wedge into the slot 34. Figures 5 to 7 Under these conditions, the size and shape of the slot 34 prevent the lever 38 from moving within the slot 34, thus preventing the moving section from moving downwards relative to the fixed section. To unlock the moving section, raise it until the flip lock 36 is above the crossbar of the fixed section. Figure 8 and 9 At this point, the moving section can be minimized as much as possible. Figure 10 It should be noted that as the lever 38 moves downward from above the fixed section crossbar, as the step moves downward past the fixed section crossbar, the fixed section crossbar causes the lever 38 to bulge upward, so the lever 38 slides past the slot 34 without entering it. Only when the lever 38 moves upward and disengages from the lower part of the fixed section crossbar and is forced back to its stable position by the reversing spring 44 can the lever 38 enter the slot 34, so that the lever 38 wedges into the slot 34 when it is now in the slot 34 and the moving section subsequently descends. The upper end of the lever 38 is inclined inward at the bottom to facilitate the removal of the lever 38 from the slot 34 when the moving section is raised. The shape of the slot 34 is generally flat along the top of the slot 34, so that when a downward force is applied to the rod 38, the rod 38 has virtually no place to move to come out of the slot 34, thus locking the fixed section and the moving section, while the rear of the slot 34 is more rounded to allow the upper end of the rod 38 to come out of the slot 34 when the moving section is raised.

[0072] Figures 11 to 17 The operation of a second embodiment of the lock assembly 28 is shown. Figure 11 The lock 46 and the traction device 48 are shown in their spring-biased positions when there is no base crossbar 18. Figure 12 The demonstration shows that when the stretching crossbar 26 is raised, the lock 46 is deflected by the base crossbar 18. Figure 13 The lock 46 has been disengaged from the base crossbar 18, and the traction device 48 has been partially deflected by the base crossbar 18. Figure 14 The lock 46 engages the base crossbar 18 to prevent further downward movement when the stretch crossbar 26 has moved downward and the traction device 48 has disengaged from the base crossbar 26. Figure 15 The traction device 48 is deflected by the base crossbar 18 when the stretch crossbar 26 is raised and the lock 46 disengages from the base crossbar 18. Figure 16 This demonstrates that when the stretching crossbar 26 has been raised above the base crossbar 18, both the lock 46 and the traction device 48 are free and disengaged from the base crossbar 18. Figure 17The traction device 48 is shown to be fitted into the slot 62 of the lock 46 because the base crossbar 18 has deflected the traction device 48 as the tension crossbar 26 moves downward, thus allowing the tension crossbar 26 to descend freely.

[0073] The lock 46 and traction device 48 of the locking assembly 28 are attached to a crossbar 26 of the moving section 20. Both the lock 46 and the traction device 48 are pivotable upwards and downwards, but are biased by spring force to return to their original position. Figure 11 The location seen in the text. Figures 12 to 14 The locking sequence is shown to be very similar to that of Example 1. The difference is that when the moving segment 20 is locked ( Figure 14 Lock 46 extends above the fixed section crossbar 18 via its first arm 58 and contacts the top flange 76 of the fixed section crossbar 18, while its second arm 60 contacts and presses against the web 70 of the fixed section crossbar 18, thus abutting against the top rear support of the fixed section crossbar 18. Therefore, this embodiment does not require a slot 34. Under these conditions, since lock 46 has nowhere to move relative to the downward force, it prevents the moving section 20 from moving downward relative to the fixed section 12. To unlock the moving section 20, the moving section 20 is raised until both lock 46 and traction device 48 are above the fixed section crossbar 18. Figure 16 Next, as the moving section 20 descends, the first traction arm 78 of the traction device 48 protrudes upward due to the fixed section crossbar 18 it has moved through, thereby causing the second traction arm 80 to engage with the slot 62 of the lock 46 (which is now free and disengaged from any fixed section crossbar 18), and retract the lock 46 so that the moving section 20 can descend as far as possible. Figure 17 Once the descent of the moving section 20 has stopped, the traction device 48 and the lock 46 will return to their stable positions under the action of the traction device spring 66 and the lock spring 64, respectively, provided that no fixed section crossbar 18 prevents them.

[0074] Figure 18 The lock assembly 28 of the first embodiment is shown. A frame 68 is riveted or screwed to the desired crossbar 26 of the moving section 20. A flip shaft 42 is mounted to the frame 68, and a flip lock 36 is mounted to the flip shaft 42. A flip spring 44 is positioned around the flip shaft 42, with its top and bottom ends extending outwards. Between the top and bottom ends of the flip spring 44 are a flip stop 73 extending from the flip lock 36 and a frame stop 72 extending from the frame 68. Figures 19 to 21 As shown, the flip stop 73 and the frame stop 72 bias their respective springs as they move.

[0075] Figure 19It is a cross-sectional side view showing the flip lock stop 74 and frame stop 72, as well as the flip lock 36, when the flip lock 36 is free and disengaged from any base crossbar 18. Figure 20 This is a cross-sectional side view of the flip lock 36 when it has been deflected upward by the base crossbar 18. The flip lock stop 74 has been pushed against the top of the flip lock spring 64, and the frame stop 72 has held the bottom of the flip lock spring 64 in place, thus causing a biasing force from the top of the spring against the flip lock stop 74. Figure 21 This is a cross-sectional side view of the flip lock 36 when it has been deflected downward by the base crossbar 18. The flip lock stop 74 has been pushed against the bottom of the flip lock spring 64, and the frame stop 72 has held the top of the flip lock spring 64 in place, thereby causing a biasing force from the bottom of the spring against the flip lock 36.

[0076] Figure 22 The lock assembly 28 of the second embodiment is shown. A frame 68 is riveted or screwed to the desired crossbar 26 of the moving section 20. A locking shaft 50 has a lock 46 mounted to the frame 68, and a traction device shaft 54 ​​has a traction device 48 mounted to the frame 68. A locking spring 64 is positioned around the locking shaft 50, and a traction device spring 66 is positioned around the traction device shaft 54. Between the top and bottom ends of the locking spring 64 are a locking stop 73 and a frame stop 72, and between the top and bottom ends of the traction device spring 66 are a traction device stop 75 and another frame stop 72.

[0077] like Figures 22 to 25 As shown, the frame stop 72, the locking stop 73, and the traction device stop 75 bias their respective springs as they move. Figure 23 It is a cross-sectional side view of the lock 46, the traction device 48, the frame stop 72, the lock stop 73, and the traction device stop 75 when the lock 46 and the traction device 48 are free and disengaged from any base crossbar 18.

[0078] Figure 24 This is a cross-sectional side view of lock 46 and traction device 48 when they have been deflected upward by base crossbar 18. Lock stop 73 has pushed against the top of lock spring 64, and frame stop 72 has held the bottom of lock spring 64 in place, thereby causing a biasing force against the top of lock spring 64 against lock stop 73. Similarly, traction device stop 75 has pushed against the top of traction device spring 66, and frame stop 72 has held the bottom of traction device spring 66 in place, thereby causing a biasing force against the top of traction device spring 66 against traction device stop 75.

[0079] Figure 25This is a cross-sectional side view of the lock 46 and the traction device 48 when they have been deflected downwards by the base crossbar 18. The locking stop 73 has abutted the bottom of the lock spring 64, and the frame stop 72 has held the top of the lock spring 64 in place, thereby causing a biasing force against the bottom of the lock spring 64 against the locking stop 73. Similarly, the traction device stop 75 has abutted the bottom of the traction device spring 66, and the frame stop 72 has held the top of the traction device spring 66 in place, thereby causing a biasing force against the bottom of the traction device spring 66 against the traction device stop 75.

[0080] Referring now to the accompanying drawings, where similar element symbols in several views refer to similar or identical parts, and more specifically, referring to their... Figures 26 to 33 The climbing product 10 is shown, and its sections are retractable. The climbing product 10 includes a base section 12 having a first base rail 14 and a second base rail 16 parallel and spaced apart from the first base rail 14, and a base crossbar 18 attached to and between the first and second base rails 14 and 16. The climbing product 10 includes a tension section 20 having a first tension rail 22 and a second tension rail 24 parallel and spaced apart from the first tension rail 22, and a tension crossbar 26 attached to and between the first and second tension rails 22 and 24. The tension section 20 is slidably engaged with the base section 12. The climbing product 10 includes a locking assembly 28 having a locking tension portion 30 directly attached to the tension section 20. The locking tension portion 30 directly engages with the base section 12 to lock the base section 12 and the tension section 20. The locking tension portion 30 has a locking bolt 39. By moving the locking bolt 39, the locking tension portion 30 disengages from the base portion.

[0081] Lock assembly 28 may include a lock base portion 32 directly attached to base section 12. Lock extension portion 30 directly engages with lock base portion 32 to lock extension section 20 to base section 12. Lock extension portion 30 disengages from lock base portion 32 by moving bolt 39. Lock base portion 32 may include a slot 34 disposed in one of base crossbars 18, and lock extension portion 30 includes a flip lock 36 that fits into slot 34 to lock extension section 20 to base section 12 such that when extension section 20 is locked to base section 12, extension section 20 cannot move downward relative to base section 12. Flip lock 36 is disposed in one of extension crossbars 26.

[0082] The flip lock 36 may include: a lever 38 fitted into a slot 34 to lock the tension section 20 to the base section 12; an anchor 40 from which the lever 38 extends; a flip shaft 42 extending through the anchor 40, the anchor 40 and the lever 38 rotating about the flip shaft 42; and a flip spring 44 biasing the lever 38 into a stable position, wherein the lever 38 extends substantially perpendicularly from the first tension rail 22 toward the first base rail 14. The flip lock 36 may have a locking recess 120 into which a bolt 39 moves. When the bolt 39 engages the recess, it prevents the flip lock 36 from rotating about its axis. The flip lock 36 may include a stop 122. When the stop 122 is in the first state and does not obstruct the engagement of the bolt 39 with the locking groove 120, the bolt 39 can engage the flip lock 36 to prevent the flip lock from rotating, and the stop 122 in the second state prevents the bolt 39 from engaging with the flip lock 36 and prevents the bolt 39 from engaging with the locking groove 120.

[0083] Lock assembly 28 may include a locking bar 112 that engages with a bolt 39 and a locking bar handle 116 directly connected to the locking bar 112. By directly pulling the locking bar handle 116, moving it from a downward position to an upward position, the locking bar handle 116 removes the bolt 39 from the locking recess 120. Lock assembly 28 may include a pulley 124 mounted to the locking bar 112 and a lifting rope 126 surrounding the pulley 124. By increasing the tension in the lifting rope 126, the locking bar 112 moves from its downward position to its upward position, which removes the bolt 39 from the locking recess 120.

[0084] This invention relates to a method of using a ladder, wherein sections of the ladder are extendable. The method includes the step of moving the ladder to a desired position. The ladder includes a base section 12 having a first base rail 14 and a second base rail 16 parallel to and spaced apart from the first base rail 14, and base runners 18 attached to and between the first and second base rails 14 and 16. The ladder includes a stretch section 20 having a first stretch rail 22 and a second stretch rail 24 parallel to and spaced apart from the first stretch rail 22, and stretch runners 26 attached to and between the first and second stretch rails 22 and 24. The stretch section 20 is slidably engaged with the base section 12, and the ladder includes a locking assembly 28 having a locking stretch portion 30 directly attached to the stretch section 20. The locking stretch portion 30 directly engages with the base section 12 to lock the base section 12 and the stretch section 20. The locking stretch portion 30 has a locking bolt 39. By moving the locking bolt 39, the locking extension portion 30 disengages from the base portion. There is a step of moving the locking bolt 39 to disengage the locking extension portion 30 from the base portion. There is a step of sliding the extension section 20 along the base section 12 to extend the ladder to the desired length. There is a step of locking the extension section 20 to the base section 12 when the locking portion is at the desired length.

[0085] This invention relates to a method for constructing a ladder, wherein a section of the ladder is retractable. The method includes the step of directly attaching a locking extension portion 30 of a locking assembly 28 to a retractable section 20 of the ladder. The retractable section 20 has a first extension rail 22 and a second extension rail 24 parallel to and spaced apart from the first extension rail 22, and extension rungs 26 attached to and between the first and second extension rails 22, 24. The retractable section 20 is slidably engaged with a base section 12. The locking extension portion 30 has a locking bolt 39. There is also the step of attaching a locking base portion 32 of the locking assembly 28, which is directly attached to the base section 12. The locking extension portion 30 directly engages with the locking base portion 32 to lock the retractable section 20 to the base section 12. By moving the locking bolt 39, the locking extension portion 30 disengages from the locking base portion 32. The base section 12 has a first base rail 14 and a second base rail 16 that is parallel to and spaced apart from the first base rail 14, and a base crossbar 18 attached to and between the first and second base rails 14 and 16.

[0086] This invention provides additional features and alternative embodiments of the locking assembly having the flip lock 36 described above. The invention prevents accidental unlocking of the retractable section lock by requiring a deliberate action from the user. For example, it is precisely what can be introduced into... Figures 26 to 35 Additional features of the device shown in 43 to 46 and described in this application (specifically, embodiment 1).

[0087] This invention prevents the ladder section from extending unintentionally, which increases user safety and convenience.

[0088] Figure 26 and 27 This ladder is described as an NGMF (Next Generation Multiform) ladder. This ladder can be folded and unfolded like a step ladder, and can also be configured as a straight ladder like an MT ladder. Like the MT ladder, the NGMF has outer sections attached to its front and rear inner sections. These outer sections can extend relative to the inner sections to increase the ladder's height. The NGMF shown uses a conventional J-lock on its front section. The rear section uses a flip lock 36, which is installed within the lowest rung of the rear inner section.

[0089] Figure 28 This is a detailed view showing the inner crossbar with a flip lock 36 that engages with one of the outer crossbars. Also shown is the lifting rope 126, whose function will be described below. A hole 161 is present in the top surface of the tension crossbar 26, through which the rope 126 extends and wraps around the pulley 124.

[0090] Figure 29 Only the inner and outer crossbars with flip lock 36 are shown.

[0091] Figure 30 Only another view of the inner crossbar with flip lock 36 is shown.

[0092] Figure 31 Another view shows a typical outer crossbar with grooves for engaging the flip lock 36. These grooves are identical regardless of the length of a particular outer crossbar.

[0093] Figure 32 The components of the invention are shown with the inner crossbar transparent. It is important to note that the locking lever pivot 114 and the crank pivot 110 are fixed to the inner crossbar. The locking lever pivot 114 and the crank pivot 110 are rotatable about their respective pivots.

[0094] Figure 33 exhibit Figure 32 A close-up of the image, which obscures some additional components. The key parts of the invention are the flip lock 36, the stop 122, and the bolt 39. The essence of the invention is that the bolt 39 can engage the flip lock 36 under certain conditions to prevent its rotation, and under other conditions, the stop 122 prevents the bolt 39 from engaging the flip lock 36.

[0095] Figure 34 This illustrates the relationship between the flip lock 36 and the stop 122. The stop 122 is pivotally fixed to the flip lock 36. The stop 122 is rotatable relative to the flip lock 36 at the CCW and CW positions. Figure 37 , 38As seen in 39, stop 122 is spring-biased to its extreme CW position.

[0096] Figure 35 Showing a flip lock 36. The flip lock 36 has a locking groove 120 into which a bolt 39 can enter. When the bolt 39 engages this groove, it prevents the flip lock 36 from rotating about its axis.

[0097] Figure 36 The conditions under which the bolt 39 can engage the bolt 39 locking groove 120 in the flip lock 36 are: the flip lock 36 is horizontal and the stop 122 is rotated relative to the flip lock 36 to its extreme CCW position.

[0098] Figure 37 , 38 Figure 39 shows how the stop 122 prevents the bolt 39 (axis shown by the + symbol) from engaging the bolt 39 locking groove 120 (shown by the dashed line) whenever the stop 122 is in its extreme CW position relative to the flip lock 36.

[0099] Figure 40 and 41 Demonstrate the function of locking bar 112 and bolt 39. When the right end of locking bar 112 is as follows... Figure 40 When the bolt is in the downward position, the bolt 39 is in its left side or in the engagement position with the locking groove 120. (This assumes that the stop 122 does not prevent the bolt 39 from entering the bolt 39 locking groove 120 in the flip lock 36.)

[0100] When the right end of the rod is as Figure 41 During the lifting process, the bolt 39 moves to its right side or disengages from the locking groove 120. The bolt 39 is moved by the action of the stud 118 on the locking rod 112, which causes the crank 108 to rotate.

[0101] The locking lever 112 is moved from its downward position to its upward position by the user directly pulling the locking lever handle 116, which is directly connected to the locking lever 112, or by increasing the tension in the lifting rope 126 surrounding the pulley 124 mounted on the right end of the locking lever 112.

[0102] Figure 42 How does the contact between the display block 122 and the outer crossbar work? Figure 36 As seen, the stop block 122 is positioned relative to the flip lock 36CCW. Therefore, Figure 42 The only case in which the stop 122 allows the bolt 39 to prevent the flip lock 36 from rotating is when the flip lock 36 is fully engaged with the groove in the outer crossbar and allows the locking lever 112 to move to its downward position.

[0103] Figure 43The situation is illustrated whenever the flip lock 36 is not engaged in the groove in the outer crossbar: the stop 122 prevents the bolt 39 from engaging the flip lock 36, so the flip lock 36 can move freely in the manner previously disclosed in the invention of the flip lock 36.

[0104] like Figure 32 , 33 As shown in 40 and 41, when the lifting rope 126 wound on pulley 124 is tightened to raise the stretching section 20 relative to the base section 12, or when the locking lever handle 116 is raised, the locking lever 112 rotates upward about the locking lever pivot 114. As the locking lever 112 moves upward, the stud 118 pushes against the crank 108, as shown in 40 and 41. Figure 40 As shown in the diagram, this causes crank 108 to pivot about crank pivot 110, and pulls the bolt 39 directly connected to crank 108 out of locking groove 120 and completely withdraws it from flip lock 36, as... Figure 41 As shown in the diagram. With the bolt 39 fully withdrawn from the flip lock 36, the flip lock 36 can rotate freely about the flip lock axis 106. When the rope 126 is released or the lever handle 116 is loosened, the lever pivot 114 moves downward about the lever pivot 114, causing the stud 118 to move away from the crank 108 and causing the crank 108 to rotate clockwise about the crank pivot 110. This causes the bolt 39 to move forward in an attempt to re-enter the locking groove 120. If the stop 122 blocks the locking groove 120, then the stop 122 prevents the bolt 39 from entering the locking groove 120 and re-engaging with the flip lock 36 to lock the flip lock 36 in place.

[0105] When the tension section 20 is locked to the base section 12, the flip lock 36 positions its lever 38 in the slot 34 of the desired base crossbar with respect to the height of the tension section 20 relative to the base section 12. In this case, the bolt 39 is positioned in the locking recess 120, thereby preventing the flip lock 36 from rotating. Figure 36 and 42 As shown in the diagram, this prevents the flip lock 36 from coming out of the locking groove 120, and thus prevents the stretch section 20 from moving relative to the base section 12.

[0106] When it is desired to reposition the tension section 20 relative to the base section 12, the lifting rope 126 is pulled, or the handle is raised, to disengage the bolt 39 from the locking groove 120 and allow the flip lock 36 to rotate freely, as explained above. The tension section 20 is then raised relative to the base section 12, causing the lever 38 of the flip lock 36 to disengage from the slot 34. This is possible because the bottom front surface of the lever 38 is curved, and when the tension section 20 is raised, it causes the lever 38 of the flip lock 36 to move along with the tension section 20 and slide unobstructed out of the slot 34. Because the flip lock 36 is now disengaged from the slot 34, the tension section 20 can continue to be raised unobstructed. Once the stop 122 attached to the flip lock 36 disengages from the base crossbar, the flip lock 36 engages, the nose 137 of the stop 122 no longer shifts due to the base crossbar, and the stop 122 is spring-biased back to its stable position by the flip lock spring, causing the stop 122 to rotate clockwise about the stop pivot 102 above the locking groove 120, preventing the bolt 39 from sliding into the locking groove 120. Figure 43 As shown, this is because the bolt axis 104 of the bolt 39 aligned with the locking groove is blocked by the stop 122. It should be noted that the bolt 39 can only engage and move into the locking groove 120 when the nose 137 of the stop 122 is deflected by the base crossbar and rotated counterclockwise about the pivot stop 102. In all other positions, the flip-locking spring biases the stop 122 to a position that prevents the bolt 39 from sliding into the locking groove 120.

[0107] Even when the tension rope 126 is tightened or the handle is pulled up and the bolt 39 has been withdrawn from the locking groove 120, the flip lock 36 inserted in the slot 34 prevents the tension section 20 from moving directly downwards. This is because the top surface of the lever 38 is flat, so when the tension section 20 moves downwards, the top surface of the lever 38 hits the top of the slot 34 and has nowhere to go, as explained above regarding the first embodiment of the flip lock 36. In this situation, the flip lock 36 cannot slide out of the slot 34. Therefore, the flip lock 36 can only be withdrawn from the slot 34 when the tension section 20 is raised upwards, and the bolt 39 has been withdrawn.

[0108] Once the stretching section 20 has been raised and the flip lock 36 has disengaged from the base crossbar, the stretching section 20 can move downwards. As the stretching section 20 moves downwards, the flip lock 36 and the nose 137 strike the top of the base crossbar and deflect upwards, as... Figure 38 As shown in the diagram. It should be noted that stop 122 pivots forward CW about stop 122 pivot axis, and the flip lock shaft moves to the rightmost position of stop slot 139 because nose 137 is no longer deflected by the base crossbar. As the stretching section 20 continues to move downward, lever 38 of flip lock 36 slides through slot 34 of base crossbar and continues to move downward until it disengages from base crossbar, where flip lock 36 and stop 122 will return to their original positions. Figure 37 The location shown in the middle.

[0109] When the stretching section 20 is raised, the lever 38 of the flip lock 36 and the nose 137 of the stop block 122 will strike the bottom of the bottom crossbar as it deflects downward, as... Figure 39 As the stretching section 20 continues to move upward, the rod 38 and nose 137 will move through the slot 34 of the base crossbar and continue upward until the flip lock 36 and stop 122 disengage from the base crossbar, after which it will return to its original position. Figure 37 The position shown in the diagram. Only one stretch crossbar 26 has a flip lock 36 and a stop 122 arrangement, but at least some (if not all) base crossbars 18 will have slots 34, such that the stretch section 20 can be positioned at a desired height relative to the base section 12 by fitting the flip lock 36 into the desired slot 34.

[0110] For the flip lock 36 to be repositioned in the slot 34 of another base crossbar, this can only occur when the stretch section 20 moves upward relative to the base section 12. Instead of the flip lock 36 passing through the slot 34, as the stretch section 20 moves upward, as explained above, the stretch crossbar 26 with the flip lock 36 is substantially adjacent to the base crossbar, preventing the stretch section 20 from moving further upward. At this point, the top surface of the flip lock 36 will be slightly inserted into the slot 34, where the flip lock 36 and the support are substantially as Figure 39 The positioning is demonstrated in the diagram. When the top of the flip lock 36 strikes the top surface of the slot 34, a clicking or contact sound can be heard to remind the user that the flip lock 36 is correctly positioned. Next, the stretch section 20 moves slightly downward, causing the lever 38 of the flip lock 36 to slide fully into the slot 34, and the nose 137 of the stop 122 is deflected downward by the base crossbar and is in position. Figure 36 The location shown in the text. As explained above, Figure 36 The configuration aligns the opening of the stop 122 with the locking recess 120, causing the bolt 39 to slide into the locking recess 120 and engage with the flip lock 36 to lock the flip lock 36 in place with the slot 34 of the base crossbar.

[0111] Figure 44The arrangement of the lifting rope 126 between the base section 12 and the tension section 20 is shown. The first end 152 of the rope 126 is attached to the top of the outer / base section 12 of the rear section 142. From there, the rope 126 extends downward along the base rail of the rear section 142, passing over a pulley 124 on the locking bar 112. From there, the rope 126 extends along the base rail and the tension rail above the base rail to the hinge 148, where it is positioned to reach the front section 140. At the front section 140, the rope extends downward along the tension rail of the front section 140 to the base rail below the tension rail of the front section 140, where the second end 154 of the rope 126 is attached to the lowest tension crossbar 26 on the inner / tension section 20 of the front section 140.

[0112] Figure 45 Show the ladder in its fully extended, straight position from the non-climbing side.

[0113] Figure 46 The ladder is shown in its fully extended, straight-lined position from the climbing side.

[0114] Figures 47A to 47F Multiple views are shown of the locking bar 112 and locking bar handle 116 in their proper positions on the tension crossbar 26. The locking bar 112 and locking bar handle 116 are mounted on the exterior of the rear wall of the tension crossbar 26. However, the pulley 124 on the locking bar 112 intrudes into the interior of the tension crossbar 26. Figure 47A This is a perspective view of the top of the stretch crossbar 26 and the locking assembly 28. Figure 47B This is a right-side view of the stretch crossbar 26 and the locking assembly 28. Figure 47C This is a rear / right view of the stretch crossbar 26 and the locking assembly 28. Figure 47D This is a top view of the stretch crossbar 26 and the locking assembly 28. Figure 47E This is a front view, inverted view, of the stretch crossbar 26 and the locking assembly 28. Figure 47F This is a left-side view of the tension bar 26 and the locking assembly 28. As can be seen from these figures, the locking assembly 28 is essentially fitted within and protected by the tension bar 26. The flip lock 36 and handle 116 of the locking assembly 28 are essentially the only components extending beyond the tension bar 26.

[0115] Figure 48 It is a perspective view of the ladder, with the stretched section extending. Figure 49 It is a perspective view of a flip lock 36 having a stop 122 and a flip lock spring 145 that biases the stop 122 in a suitable position in the flip lock 36 and adjacent to the stop 122.

[0116] Ladder 10 may be a standard extended ladder having a tension section 20 and a base section 12. Alternatively, ladder 10 may be a multipurpose ladder having a front section 140 and a rear section 142, such as... Figure 26 and 27 The image shows a configuration of unelongated treads, or as shown in the image. Figure 48 The image shows an extended staircase configuration, or as shown in the image. Figure 45 and 46 The image shows an extended ladder in its unextended configuration. As a multi-purpose ladder, the front section may have a J-lock 144 for locking the extension section 20 and the base section 12 together to a desired length, and the rear section 142 has a locking assembly 28 described herein for locking the extension section 20 and the base section 12 of the rear section 142 to a desired length. Alternatively, if desired, the front section 140 may use the locking assembly 28 to lock the extension section 20 and the base section 12 together instead of having the J-lock 144.

[0117] As a multi-purpose ladder 10, the front section 140 also has a base section 12 having a first base rail 14 and a second base rail 16, wherein a base crossbar 18 is attached to and disposed between the first base rail 14 and the second base rail 16, as described above regarding the base section 12 and the tension section 20. The front section 140 also has a tension section 20 having a first tension rail 22 and a second tension rail 24, wherein a tension crossbar 26 is attached to and disposed between the first tension rail 22 and the second tension rail 24, as described above regarding the base section 12 and the tension section 20. The base crossbar 18 is attached to the outer flanges of the first and second base rails, and the tension crossbar 26 is attached to the inner side of the web of the first and second tension rails to avoid interfering with the movement of the tension section 20 relative to the base section 12.

[0118] The first and second extension rails of the front section are attached to the top of the ladder 146 by rivets or fasteners. A hinge 148 is attached to the first and second extension rails of the front section adjacent to the top of the ladder 146 by rivets or fasteners. The top of the extension rail of the rear section 142 is attached to the hinge 148. The hinge 148 allows the rear section 142 to rotate relative to the front section 140. Figure 20 and 21 As shown, the rear section 142 has been rotated approximately 180° relative to the front section 142, forming an extended ladder position. In the extended ladder position, the first extension rail 22 and the second extension rail 24 of the rear section 142 are fitted into the channel 150 in the top 146 of the ladder to allow the rear section 142 to be aligned with the front section 140, although slightly offset due to the rear section extension rails being attached to the hinge 148.

[0119] Although the invention has been described in detail in the foregoing embodiments for illustrative purposes, it should be understood that such details are merely for the purposes described, and that those skilled in the art may make variations therein without departing from the spirit and scope of the invention, unless as described in the following claims.

Claims

1. A ladder comprising: The base section includes a first base rail and a second base rail, wherein the second base rail is spaced apart from the first base rail. The stretching section includes a first stretching rail and a second stretching rail, wherein the second stretching rail is spaced apart from the first stretching rail. Multiple base crossbars are attached to the first base rail and the second base rail and extend between the first base rail and the second base rail; Multiple tension crossbars are attached to the first tension rail and the second tension rail and extend between the first tension rail and the second tension rail. as well as A locking assembly comprising a locking tension portion coupled to at least one of the plurality of tension crossbars and a locking base portion attached to at least one of the plurality of base crossbars. The locking stretching portion includes a lock that directly engages one of the plurality of base crossbars to lock the stretching section to the base section such that when the stretching section is locked to the base section, the stretching section cannot move downward relative to the base section. and The lock tensioning portion includes a traction device, wherein the tensioning crossbar moves downward, causing the base crossbar to deflect the traction device, thereby fitting the traction device into the slot of the lock and allowing the tensioning crossbar to descend freely.

2. The ladder of claim 1, wherein the stretch section and the base section are locked to each other by engaging the lock of at least one of the plurality of base rungs.

3. The ladder of claim 2, wherein the plurality of base rungs includes a top flange configured to contact at least the lock or the traction device.

4. The ladder of claim 1, wherein the plurality of base rungs includes a web to at least prevent the lock or the traction device from extending into the plurality of base rungs.

5. The ladder of claim 1, wherein the lock comprises a first arm and a second arm, the first arm and the second arm being spaced apart from each other by a slot and configured to contact at least one of the plurality of base rungs.

6. The ladder of claim 1, wherein the lock is coupled to at least one of the plurality of stretch rungs via a shaft.

7. The ladder according to claim 1, wherein the traction device is coupled to at least one of the plurality of tension rungs via a traction device shaft.

8. The ladder according to claim 1, wherein the traction device comprises a first traction device arm and a second traction device arm.

9. The ladder of claim 1, wherein the lock includes a lock spring to bias the lock, and the traction device includes a traction device spring to bias the traction device.

10. The ladder of claim 1, wherein the lock and the traction device are coupled together and coupled to at least one of the plurality of tension rungs via a frame.

11. A ladder comprising: The base section includes a first base rail and a second base rail, wherein the second base rail is spaced apart from the first base rail. The stretching section includes a first stretching rail and a second stretching rail, wherein the second stretching rail is spaced apart from the first stretching rail. Multiple base crossbars are attached to the first base rail and the second base rail and extend between the first base rail and the second base rail; Multiple tension crossbars are attached to the first tension rail and the second tension rail and extend between the first tension rail and the second tension rail. as well as The locking mechanism includes a locking tension portion coupled to at least one of the plurality of tension crossbars and a locking base portion coupled to at least one of the plurality of base crossbars. The lock extension portion includes a lock coupled to at least one of the plurality of extension crossbars and a traction device, the traction device being sized to engage at least a portion of the lock, and The traction device is positioned adjacent to the lock, and when the stretching section moves downward relative to the base section, the traction device engages the lock and holds the lock in a position that does not obstruct the base crossbar.

12. The ladder of claim 11, wherein the lock and the traction device are coupled together and coupled to at least one of the plurality of tension rungs via a frame.

13. The ladder of claim 11, wherein the traction device further comprises a traction device spring for biasing the traction device.

14. The ladder of claim 11, wherein the lock further comprises a locking spring to bias the lock.

15. The ladder of claim 11, wherein the lock comprises a first arm and a second arm spaced apart by a slot.

16. The ladder according to claim 15, wherein the traction device comprises a first traction device arm and a second traction device arm.

17. The ladder of claim 16, wherein the second traction arm is configured to engage the slot of the lock to allow movement between the stretch section and the base section.

18. The ladder of claim 11, wherein the plurality of base rungs includes a web to at least prevent the lock or the traction device from extending into the plurality of base rungs.

19. The ladder of claim 11, wherein the plurality of base rungs include a top flange configured to contact at least the lock or the traction device.

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